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1
DeMott, Laura M., and Christopher A. Scholz. "Lacustrine carbonate tufa facies of Winnemucca Dry Lake Basin, Nevada, U.S.A." Journal of Sedimentary Research 90, no. 12 (December 31, 2020): 1804–28. http://dx.doi.org/10.2110/jsr.2020.004.
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ABSTRACT Lacustrine carbonate tufa deposits are common in present-day lakes and dry pans of the western United States, and large-scale deposits (> 100 m high) are found throughout the subbasins of Pleistocene Lake Lahontan. This study presents a depositional model for very well exposed tufa in Winnemucca Dry Lake, a subbasin of Lake Lahontan, that incorporates new observations of tufa growth over length scales of 10–4–102 m. Tufa depositional facies are defined on the basis of outcrop morphology and texture. Deposits were mapped using satellite imagery and field observations. Tufa facies and volumes were quantified for seven tufa exposures across the basin using digital outcrop and elevation models from aerial images acquired from a small uncrewed aerial system (sUAS). Tufa thin sections were examined using transmitted-light petrography and scanning electron microscopy and combined with measurements of porosity and permeability to define small-scale facies characteristics. Both porosity and permeability are highly variable across textures; average values for both (ϕ = 29%, k = 5.5 D) indicate that all tufa types may exhibit excellent reservoir properties. The age and distribution of these facies across the basin are directly linked to hydroclimate and variations in lake level. The most important controls on tufa distribution at the basin scale are basin hydrology and pathways of groundwater inflow. Groundwater flow into the basin is largely concentrated along the western flexural margin along the contact between volcanic and volcaniclastic bedrock and alluvial sediments, rather than concentrated along the border fault margin, in contrast to other models which predict strong fault control of tufa occurrence. Microbially influenced tufa textures and morphologies are the most volumetrically significant tufas in the basin, composing between 77% and 100% of tufa volume at individual exposures; these are inferred to form during times when lake waters were warmer and levels higher, while physico-chemical processes dominate during early tufa formation, and generally in colder waters and under conditions of lower lake level. Deposition of tufas is a result of combined physical, chemical, and biological factors that are directly related to the basin geology and hydroclimate; however, the importance of each controlling factor is highly variable both spatially and temporally, complicating the development of effective and predictive depositional models. This case study describes tufa deposition intrinsically linked to basinal hydroclimatic histories, and understanding these relationships may assist in predicting volumes, physical properties, and stacking patterns of petroleum reservoir facies in lacustrine basins.
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Isabel, Sandra, Éric Leblanc, Maurice Boissinot, Dominique K. Boudreau, Myrian Grondin, François J. Picard, Eric A. Martel, et al. "Divergence among Genes Encoding the Elongation Factor Tu of Yersinia Species." Journal of Bacteriology 190, no. 22 (September 12, 2008): 7548–58. http://dx.doi.org/10.1128/jb.01067-08.
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ABSTRACT Elongation factor Tu (EF-Tu), encoded by tuf genes, carries aminoacyl-tRNA to the ribosome during protein synthesis. Duplicated tuf genes (tufA and tufB), which are commonly found in enterobacterial species, usually coevolve via gene conversion and are very similar to one another. However, sequence analysis of tuf genes in our laboratory has revealed highly divergent copies in 72 strains spanning the genus Yersinia (representing 12 Yersinia species). The levels of intragenomic divergence between tufA and tufB sequences ranged from 8.3 to 16.2% for the genus Yersinia, which is significantly greater than the 0.0 to 3.6% divergence observed for other enterobacterial genera. We further explored tuf gene evolution in Yersinia and other Enterobacteriaceae by performing directed sequencing and phylogenetic analyses. Phylogenetic trees constructed using concatenated tufA and tufB sequences revealed a monophyletic genus Yersinia in the family Enterobacteriaceae. Moreover, Yersinia strains form clades within the genus that mostly correlate with their phenotypic and genetic classifications. These genetic analyses revealed an unusual divergence between Yersinia tufA and tufB sequences, a feature unique among sequenced Enterobacteriaceae and indicative of a genus-wide loss of gene conversion. Furthermore, they provided valuable phylogenetic information for possible reclassification and identification of Yersinia species.
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Drysdale, Russell, and John Head. "Geomorphology, Stratigraphy and 14C-Chronology of Ancient Tufas at Louie Creek, Northwest Queensland, Australia." Géographie physique et Quaternaire 48, no. 3 (November 23, 2007): 285–95. http://dx.doi.org/10.7202/033009ar.
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ABSTRACT Louie Creek is a karst spring-fed stream situated in the seasonally humid tropics of northwest Queensland, Australia. It rises as a series of small exsurgences along the eastern edge of the Barkly Tableland. As it enters the lowlands of the Carpentaria plain, the creek deposits tufa which produces a series of cascades. This modern tufa extends discontinuously for about 1.5 km. A series of ancient tufas, in places lying adjacent to sites of modern deposition, extends discontinously for about 8 km downstream. At least two ancient tufa units are preserved at one location, Little lndarri site. The older unit comprises a sequence of well-preserved barrages with an orientation transverse to present-day stream flow. In places, erosion has reduced these barrages to their calcrete substrate. The older tufa is overlain in places by sediment which has become cemented to form a second calcrete unit. This sediment is in turn succeeded by the younger ancient tufa. Subsequent river incision has removed part of the sediment from the older unit and exposed several contact points between the ancient tufa and calcrete units. Radiocarbon dating of the Little lndarri site tufas, as well as other ancient Louie Creek units, yielded apparent ages ranging from ~ 30 to ~ 14 ka BP, suggesting that conditions were sufficiently wet during the period immediately preceding and throughout the Last Glacial Maximum for tufa depostion to occur. However, ancient tufa formation occurred during a phase of net river aggradation. There is geomorphic evidence that such aggradation was a result of an increased sediment supply to the fluvial system, most likely in response to conditions drier than present. Results from studies elsewhere in the region support such a Late Pleistocene trend. Incision of Louie Creek, which postdates the youngest of the dated ancient tufas, is most likely to have resulted from a shift to wetter conditions during the early Holocene,
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Pazdur, Anna. "The Relations Between Carbon Isotope Composition and Apparent Age of Freshwater Tufaceous Sediments." Radiocarbon 30, no. 1 (1988): 7–18. http://dx.doi.org/10.1017/s0033822200043915.
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This paper presents a synthetic approach to 14C dating of calcareous tufa, based on statistical analysis of correlations betwen lithologic type of tufaceous sediment, carbon isotope composition, and apparent age. Experimental data on several profiles from southern Poland and the United Kingdom reveal either constant or systematically changing values of apparent age. Constant value of apparent age in a profile can be attributed to calcareous muds precipitated from stagnant or low-energy water, and to tufas precipitated from turbulent water (oncoids, stromatolites, moss travertines) which are characterized by lack of significant correlation between δ13C and 14C age of tufa carbonate. It was found that the relation between the apparent age of tufaceous sediment and δ13C value of tufa carbonate depends on lithologic type of tufa. Phenomenological equations describing the dependence of apparent age upon δ13C are given, and applied to estimate true ages of tufas from Gliczarów (southern Poland) and Folkestone (United Kingdom).
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Pazdur, Anna, and Mieczysław F. Pazdur. "Further Investigations on 14C Dating of Calcareous Tufa." Radiocarbon 32, no. 1 (1990): 17–22. http://dx.doi.org/10.1017/s0033822200039916.
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Systematic studies on 14C dating of tufa profiles in southern Poland have resulted in developing a simple phenomenological model which enables us to estimate the reservoir correction factor of 14C dates of individual carbonate samples. We made further studies to test model assumptions and to verify relationships between the value of reservoir correction factor TR and 13C content of tufa carbonate. Two new study sites, Rudawa and Szklarka, are close to previously studied sites. Four tufa samples with associated organic fraction from ca 2000m asl in South America (Peruvian Andes) were measured to test the possible application of the developed model to tufas in different geochemical and climatic environments. Finally, a series of calcareous tufa samples from the Villers-devant-Orval profile (Belgium) were dated, although no direct comparison with organic matter dates is available for this profile.
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Pazdur, Anna, and Mieczysław F. Pazdur. "14C Dating of Calcareous Tufa from Different Environments." Radiocarbon 28, no. 2A (1986): 534–38. http://dx.doi.org/10.1017/s0033822200007682.
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14C dates of carbonate and organic matter fractions are compared with a series of calcareous tufa samples from selected sites representing different geochemical environments and associated with different bedrocks. Results obtained in this study indicate values of apparent age ranging from 940 ± 110 yr for calcareous tufas associated with Pleistocene sediments to 2000 ± 110 yr and even ca 4000 yr for tufas from sites associated with Jurassic or Cretaceous limestone. It was found also that within each of the investigated sites the value of apparent age does not change significantly with the age of the tufa layer.
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Szabo, Barney J., Charles A. Bush, and Larry V. Benson. "Uranium-Series Dating of Carbonate (Tufa) Deposits Associated with Quaternary Fluctuations of Pyramid Lake, Nevada." Quaternary Research 45, no. 3 (May 1996): 271–81. http://dx.doi.org/10.1006/qres.1996.0028.
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AbstractUranium-series dating of dense tufa deposited in a small cave, at former lake margins, and in large tufa mounds clarifies the timing of lake-level variation during the past 400,000 yr in the Pyramid Lake basin. A moderate-sized lake occasionally overflowed the Emerson Pass sill at elevation of ∼1207 m between ca. 400,000 and 170,000 and from ca. 60,000 to 20,000 yr B.P., as shown by 230Th/234U ages of the cave samples, 230Th-excess ages of tubular tufas, and average isochron-plot ages of shoreline-deposited tufas. (By comparison, modern Pyramid Lake is ∼50 m below this sill). There is a lack of tufa record during the intervening period from ca. 170,000 to 60,000 yr B.P. After ca. 20,000 yr, Pyramid Lake underwent abrupt changes in level and, based on previous 14C ages, reached its highest elevation (ca 1335 m) at ca. 14,000 yr B.P. The youngest uranium-series ages are comparable with previously reported 14C ages.
8
Pazdur, Anna, Mieczysław F. Pazdur, and Joachim Szulc. "Radiocarbon Dating of Holocene Calcareous Tufa in Southern Poland." Radiocarbon 30, no. 2 (1988): 133–52. http://dx.doi.org/10.1017/s0033822200044076.
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Calcareous tufa from five sites in southern Poland, representing several most typical conditions of tufa sedimentation, were chosen for 14C, 13C, and 18O measurements. These tufas were deposited in a high-energy turbulent stream (the Racławka site), in streams with moderate but variable flow (Rzerzuśnia and Trzebienice), and in semilimnic conditions (Sieradowice site). Sediments of the Gliczarów site represent spring travertines. In all but the latter site, direct comparison of 14C dates of carbonate and organic fractions was possible, leading to an estimate of initial apparent age of carbonate sediments. Clear correlation was found between the value of initial apparent age of tufas and the hydrodynamic conditions of sedimentation. Corresponding values range from ca 3900 yr (Racławka) to 910 yr for semilimnic sediments (Sieradowice). Intermediate, almost identical values, equal to 2460 ± 200 yr and 2100 ± 160 yr, were obtained for tufas from Rzerzuśnia and Trzebienice, respectively. Detailed sedimentologic classification of tufaceous deposits is presented and some primary and secondary factors affecting the accuracy of radiocarbon dates of various types of tufas are also discussed.
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Barešić, Jadranka, Sanja Faivre, Andreja Sironić, Damir Borković, Ivanka Lovrenčić Mikelić, Russel N. Drysdale, and Ines Krajcar Bronić. "The Potential of Tufa as a Tool for Paleoenvironmental Research—A Study of Tufa from the Zrmanja River Canyon, Croatia." Geosciences 11, no. 9 (September 7, 2021): 376. http://dx.doi.org/10.3390/geosciences11090376.
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Tufa is a fresh-water surface calcium carbonate deposit precipitated at or near ambient temperature, and commonly contains the remains of macro- and microphytes. Many Holocene tufas are found along the Zrmanja River, Dalmatian karst, Croatia. In this work we present radiocarbon dating results of older tufa that was found for the first time at the Zrmanja River near the Village of Sanaderi. Tufa outcrops were observed at different levels, between the river bed and up to 26 m above its present level. Radiocarbon dating of the carbonate fraction revealed ages from modern, at the river bed, up to 40 kBP ~20 m above its present level. These ages fit well with the hypothesis that the Zrmanja River had a previous surface connection with the Krka River, and changed its flow direction toward the Novigrad Sea approximately 40 kBP (Marine Isotope Stage 3). Radiocarbon AMS dating of tufa organic residue yielded a maximum conventional age of 17 kBP for the highest outcrop position indicating probable penetration of younger organic material to hollow tufa structures, as confirmed by radiocarbon analyses of humin extracted from the samples. Stable carbon isotope composition (δ13C) of the carbonate fraction of (−10.4 ± 0.6)‰ and (−9.7 ± 0.8)‰ for the Holocene and the older samples, respectively, indicate the autochthonous origin of the carbonate. The δ13C values of (−30.5 ± 0.3)‰ and (−29.6 ± 0.6)‰ for organic residue, having ages <500 BP and >5000 BP, respectively, suggest a unique carbon source for photosynthesis, mainly atmospheric CO2, with an indication of the Suess effect in δ13C during last centuries. The oxygen isotopic composition (δ18O) agrees well with deposition of tufa samples in two stages, the Holocene (−8.02 ± 0.72‰) and “old” (mainly MIS 3 and the beginning of MIS 2) (−6.89 ± 0.34‰), suggesting a ~4 °C lower temperature in MIS 3 compared to the current one.
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He, Jinchen, Jiayuan Lin, and Yanhao Xu. "Modeling the Relationships between the Height and Spectrum of Submerged Tufa Barrage Using UAV-Derived Geometric Bathymetry and Digital Orthoimages." Sensors 21, no. 21 (October 21, 2021): 6987. http://dx.doi.org/10.3390/s21216987.
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Tufa barrages play an important role in fluviatile tufa ecosystems and sedimentary records. Quantifying the height of tufa barrage is significant for understanding the evolution and development of the Holocene tufa barrage systems. However, for submerged tufa barrages, there is no low-cost non-contact method to retrieve barrage height. Generally, it is difficult to recognize small tufa barrages by means of remotely sensed satellite data, but the combination of unmanned aerial vehicles (UAV) and Structure-from-Motion (SfM) photogrammetry makes it possible. In this study, we used a fixed-wing UAV and a consumer-grade camera to acquire images of the submerged tufa barrage in Lying Dragon Lake, Jiuzhaigou National Nature Reserve, China, and estimated the height of the tufa barrage through UAV-based photogrammetric bathymetry. On this foundation, the relationship between barrage height and its spectrum was established through band ratio analysis using UAV-derived geometric bathymetry and digital orthoimages, which provided an alternative strategy to characterize the height of submerged tufa barrages. However, the spectral characteristics of submerged tufa barrages will oscillate with changes in the environmental conditions. In future research, we will consider using a dedicated aquatic multispectral camera to improve the experimentation.
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Bonny, Sandy, and Brian Jones. "Relict tufa at Miette Hot Springs, Jasper National Park, Alberta, Canada." Canadian Journal of Earth Sciences 40, no. 11 (November 1, 2003): 1459–81. http://dx.doi.org/10.1139/e03-050.
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At the Miette Hot Springs site, relict tufa stretches for nearly 500 m along the west side of Sulphur Creek valley and rises up to 30 m above the valley floor. The tufa, composed of low-Mg calcite, precipitated from waters discharged from a line of perched springs.14C dating of bone material embedded in the tufa indicates that tufa precipitation took place between ~4500 and 2500 years BP under cool and moist climatic conditions. The spring biota was dominated by filamentous microbes (mainly Phormidium and Oscillatoria), with fewer diatoms (including Cymbella), testate protozoans (including Quadrulella), ostracodes (including Darwinula, Heterocypris, Cadonia, and Cyclocypris), and various bryophytes. The ecological preferences of these microbes indicate that the spring water had near-neutral pH, was Ca, HCO3, and H2SSO4rich, and emerged at 5065 °C. Landslides disrupted the west wall of Sulphur Creek valley during and after tufa growth. The relict tufa is divided into six morphotypes that reflect variations in water flow down the steep and rugged flow path. Domal tufa is located around the spring vents, roll-over tufa developed where water flowed over sharp lips or structural barricades, vertical tufa formed where calcite was precipitate from water flowing down steep to vertical inclines, flat-banded tufa reflects precipitation on a gentle slope, and wedge-shaped tufa formed where more rapid downslope calcite precipitation caused a progressive decrease in slope. The tufa contains stromatolitic facies (including streamer, porous laminar, dense laminar) and nonstromatolitic facies (bedded, crenulated) that reflect variations in the biology, water temperature, and style of flow of different parts of the spring flow path.
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Megerle, Heidi Elisabeth. "Calcerous Tufa as Invaluable Geotopes Endangered by (Over-)Tourism: A Case Study in the UNESCO Global Geopark Swabian Alb, Germany." Geosciences 11, no. 5 (May 2, 2021): 198. http://dx.doi.org/10.3390/geosciences11050198.
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Calcerous tufa and sinter are among the most impressive natural spectacles in karst landscapes whose scientific and aesthetic value is universally recognized. Being visually often very appealing they attract numerous visitors. At the same time tufa landforms are extremely vulnerable and can be seriously damaged even by minor interference. The challenge is, therefore, to protect the calcerous tufa heritage, to communicate its values, and to enhance it with the help of adequate geotourism offers. Tufa geotopes are an essential part of the geological heritage of the UNESCO Global Geopark Swabian Alb in Southwest Germany. Unfortunately tufa landforms, especially tufa cascades, suffer serious impairments by (over-)tourism, particularly during the Corona pandemic. The article explores where best to strike the balance between valorization and protection, as well as how to ensure that growth in tourism is compatible with nature preservation, especially in the case of the extremely vulnerable tufa geotopes.
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Dabkowski, J., J. Andrews, P. Antoine, and A. Marca-Bell. "Stable isotope record of Eemian seasonal temperature from MIS 5e tufa stromatolite; Somme Basin, Northern France." Climate of the Past Discussions 9, no. 2 (March 27, 2013): 1657–74. http://dx.doi.org/10.5194/cpd-9-1657-2013.
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Abstract. In many modern to sub-fossil deposits tufa formations, very well crystallised deposits called stromatolites are preserved. These are often strongly laminated deposits, the laminae linked to seasonal climatic and environmental variations. Where found in fossil tufas such deposits have huge potential as high resolution archives of Pleistocene climate. One of the first investigations of this type has been performed on a 2.5 cm-radius stromatolite from the Eemian sequence of Caours (Somme Basin, Northern France), where precise observations in thin section have been combined with intra-lamina δ18O and δ13C analyses. Independent interpretations of petrographical and geochemical data are strongly coherent and demonstrate a clear seasonal signal. Moreover, as δ18O is temperature dependent, we have quantified likely maximum water temperature variations between summer and winter at Caours. A small mismatch between the δ18O derived temperature values and the typical modern range is observed, which may reflect a real difference between modern and Eemian temperature seasonality. This study supports previous investigations performed on a laminated tufa from central Greece and clearly confirms the potential of tufa stromatolites as records of seasonal climatic information and for the quantification of riverine water temperature variations.
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Doran, Taylor Louise, Andy I. R. Herries, Philip J. Hopley, Hank Sombroek, John Hellstrom, Ed Hodge, and Brian F. Kuhn. "Assessing the paleoenvironmental potential of Pliocene to Holocene tufa deposits along the Ghaap Plateau escarpment (South Africa) using stable isotopes." Quaternary Research 84, no. 1 (July 2015): 133–43. http://dx.doi.org/10.1016/j.yqres.2015.04.008.
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The tufa deposits of the Ghaap Plateau escarpment provide a rich, yet minimally explored, geological archive of climate and environmental history coincident with hominin evolution in South Africa. This study examines the sedimentary and geochemical records of ancient and modern tufas from Buxton-Norlim Limeworks, Groot Kloof, and Gorrokop, to assess the potential of these sediments for providing reliable chronologies of high-resolution, paleoenvironmental information. Chronometric dating demonstrates that tufa formation has occurred from at least the terminal Pliocene through to the modern day. The stable isotope records show a trend toward higher, more variable δ18O and δ13C values with decreasing age from the end of the Pliocene onwards. The long-term increase in δ18O values corresponds to increasingly arid conditions, while increasing δ13C values reflect the changing proportion of C3/C4 vegetation in the local environment. Analysis of the Thabaseek Tufa, in particular, provides valuable evidence for reconstructing the depositional and chronological context of the enigmatic Taung Child (Australopithecus africanus). Collectively, the results of the present study demonstrate the potential of these deposits for developing high-precision records of climate change and ultimately, for understanding the causal processes relating climate and hominin evolution.
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Srdoč, Dušan, Nada Horvatinčić, Bogomil Obelić, Ines Krajcar-Bronić, and Peg O'Malley. "The Effects of Contamination of Calcareous Sediments on their Radiocarbon Ages." Radiocarbon 28, no. 2A (1986): 510–14. http://dx.doi.org/10.1017/s0033822200007657.
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Two principal reasons for the inherent uncertainty in 14C dating of calcareous sediments such as tufa or those of lacustrine origin are the unknown initial 14C activity (Ao) of the sediment, mainly affecting younger (Holocene) samples, and contamination of older sediments with recent carbonate, causing 14C ages to be excessively young. To assess the contamination effect, samples of old tufa from the Riss/Würm interglacial were examined. These sediments contain essentially no 14C except that contributed by surface contamination. Tufa samples were crushed and grains ranging in size from <1 mm, 1 to 2mm, up to 4 to 5mm were separated for analysis; 2M HCl was then used to dissolve the samples in successive steps. 14C measurements indicated that each subsequent soluble fraction obtained from porous tufa gave a successively older age, indicating that the surface of the sample was contaminated by younger carbonates. No consistent effect of grain size on the 14C age was observed. Compact tufa proved to be less subject to contamination. 14C ages obtained on this material were also too young, yet older than the age obtained from porous tufa samples.14C ages of interglacial tufa were cross-checked with the 230Th/234U dating method, using samples of very clean calcite which overlies the tufa blocks. Inferred 230Th/234U ages of the interglacial tufa (which had yielded 14C dates ranging from 25,000 to 37,000 yr) coincided with the last interglacial (Riss/Würm, Stage 5). Samples of Holocene tufa, in which contributions of recent 14C from surface contamination would pose less of a problem, yielded 14C and 230Th/234U dates which were in excellent agreement.
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Lv, Congcong, Xueqin Zhao, Yaoxi Jiang, Heyan Zhu, Hongmin Zhang, Fudong Wang, Qiongfang Li, and Keli Hou. "Insights into Alpine-Karst-Type Tufa Deposits in Geological Environmental Records: A Case Study of the Calcareous Tufa Profile of the Jiuzhaigou Natural Reserve on the Eastern Margin of the Tibetan Plateau." Minerals 13, no. 1 (January 13, 2023): 120. http://dx.doi.org/10.3390/min13010120.
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To study the geological environmental records of alpine-karst-type tufa deposits in the eastern margin of the Tibetan Plateau, the calcareous tufa profile exposed by the “8.8” Jiuzhaigou earthquake was taken as the research object and combined with a field geological investigation. Further, the petrography, sedimentology, chronology, and elemental geochemistry of the calcareous tufa were studied and analyzed. The results show the following. (1) The Sparkling Lake calcareous tufa profile was deposited under the background of a warm and humid climate during the Holocene. The growth pattern follows a bottom-to-top deposition. (2) At 750 ± 30–300 ± 30 aB.P., the calcareous tufa layers were gray-black as a whole, and the changes in mineral composition and elemental geochemistry indicate a fluctuating upward trend for temperature and precipitation during this period. (3) The formation of two sets of black peat layers in the upper part of the tufa calcareous profile is due to the synergistic action of multiple factors caused by strong tectonic activity. In conclusion, the deposition mechanism of the calcareous tufa in Jiuzhaigou was controlled by paleoclimate hydrology and glaciation for a long time, while strong tectonic activity over a short period of time considerably changed the color, structure, element content, and mineral composition of the calcareous tufa.
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Petrovic, Aleksandar, and Dragana Nikolic. "Geomorphologic study of tufa on the locality Bigreni stream (Donja Bela Reka)." Glasnik Srpskog geografskog drustva 89, no. 4 (2009): 61–73. http://dx.doi.org/10.2298/gsgd0904061p.
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The tufa accumulations in the valley of Bigreni stream are morphogenetically complex. The great importance for the occurrence of tufa, as in majority of other accumulations in Eastern Serbia, has the vicinity of the karst spring. The presence of cascades in the gorge of Bigreni stream enabled primary formation of waterfall tufa. After partitioning the gorge, the phase of the barrier tufa accumulation began. The erosive phase is currently present and therefore, once unique accumulation has been divided into several smaller accumulations. The possibility for protection because of the vicinity of the protected capped spring and the beauty of tufa waterfalls indicate the potential for tourist exploitation of this locality.
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Horvatinčić, Nada, Romana Čalić, and Mebus A. Geyh. "Interglacial Growth of Tufa in Croatia." Quaternary Research 53, no. 2 (March 2000): 185–95. http://dx.doi.org/10.1006/qres.1999.2094.
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AbstractTufa samples from the Krka River area in Croatia were dated by 14C and 230Th/234U methods. The study area is situated in the karst region of the southern Dinarides. 14C ages of 40 tufa samples collected at the waterfalls coincide with the early Holocene interglaciation, up to 6000 14C yr B.P. Comparison of conventional 14C dates of Holocene tufa and those of speleothems in the Dinaric Karst shows that speleothem formation started several thousand years earlier than tufa growth. Samples of old tufa deposits from the Krka River (17) and Plitvice Lakes (12) area and speleothem samples from caves in Dinaric Karst (5) yield 34 230Th/234U dates, most of which cluster around interglacial marine δ18O stage 5 (21). Eight of 13 older dates belong to interglacial stages 7 and 9; only 5 dates fall within stage 6 and 8 glaciations. 230Th/234U dates of speleothems and tufa samples from central Europe have indicated that these were formed preferentially during warm and humid interglacial and interstadial periods, and it appears that this is true of southern Croatia as well. Stable isotope (δ13C, δ18O) analyses of 40 tufa samples from the Krka River area were compared with stable isotope analyses of tufa from the Plitvice Lakes area. The δ13C values for both locations are similar and range from −10 to −6‰, indicating similar conditions of tufa formation. A systematic difference between the δ18O values of tufa in these two areas reflects the regional distribution of the oxygen composition of precipitation.
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Rübekeil, Ludwig. "Tufa und Armilausini." Beiträge zur Geschichte der deutschen Sprache und Literatur 142, no. 2 (May 26, 2020): 185–213. http://dx.doi.org/10.1515/bgsl-2020-0013.
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AbstractThis article investigates the origin and history of two names dating from late Antiquity or the migration period. The first is the personal name Tufa, the second is the tribal name Armilausini. The two names can be traced back to a corresponding Germanic loan word in the Latin military language, tufa and armilausia, respectively, both of which are continued in the military language of the Eastern Roman and Byzantine Empire. The names are based on the appellative nouns. Both the appellatives and, even more so, the names turn out to be characteristic products of the multilingual background of the Roman military, as they show several signs of linguistic interference such as lexical reanalysis / folk etymology, morphological remodelling and semantic specialization.
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Sancho, Carlos, Concha Arenas, Marta Vázquez-Urbez, Gonzalo Pardo, María Victoria Lozano, José Luis Peña-Monné, John Hellstrom, et al. "Climatic implications of the Quaternary fluvial tufa record in the NE Iberian Peninsula over the last 500 ka." Quaternary Research 84, no. 3 (November 2015): 398–414. http://dx.doi.org/10.1016/j.yqres.2015.08.003.
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The drainage area of the Iberian Ranges (NE Spain) houses one of the most extensive Quaternary fluvial tufaceous records in Europe. In this study, tufa deposits in the Añamaza, Mesa, Piedra and Ebrón river valleys were mapped, stratigraphically described and chronologically referenced from U/Th disequilibrium series, amino acid racemization and radiocarbon methods. Tufa deposits accumulated in cascades, barrage-cascades and related damming areas developed in stepped fluvial systems. The maximum frequency of tufa deposition was identified at 120 ka (Marine Oxygen Isotope Stage [MIS] 5e), 102 ka (MIS 5c), 85 ka (~ MIS 5a) and 7 ka (MIS 1), probably under warmer and wetter conditions than today. Additional phases of tufa deposition appear at ~ 353 ka (~ end of MIS 11), 258–180 ka (MIS 7) and 171–154 ka (MIS 6). Although most tufa deposition episodes are clearly correlated with interstadial periods, the occurrence of tufa deposits during the penultimate glaciation (MIS 6) is remarkable, indicating that the onset of this stage was climatically favourable in the Iberian Peninsula. Biostatic conditions and the dynamics of karstic systems regulating tufa deposition seem to be sensitive to the precipitation regime, controlled by shifts in the position of North Atlantic atmospheric belts, and summer insolation, regulated by orbital forcing.
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Šiljeg, Ante, Ivan Marić, Neven Cukrov, Fran Domazetović, and Vlatko Roland. "A Multiscale Framework for Sustainable Management of Tufa-Forming Watercourses: A Case Study of National Park “Krka”, Croatia." Water 12, no. 11 (November 4, 2020): 3096. http://dx.doi.org/10.3390/w12113096.
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Tufa sedimentary systems are sensitive fluvial landscapes subject to various external disturbances. Tufa landscape degradation reflected in negative hydrological changes and a decrease in the intensity of the tufa formation process have been detected in National Park Krka (Croatia). The main causes were recognized in the uncontrolled spread of invasive vegetation (Ailanthus altissima) and increased anthropogenic influence. Therefore, the Park administration launched the project, Management and Maintenance of Macro-Vegetation at Skradinski Buk (SB)—Development of a Multicriteria Model for Sustainable Management. The methodological framework was divided into three scales of research. The macro-scale research comprised a set of activities aimed at selecting the most suitable test surface within a wider area of the Skradinski Buk (SB) waterfall. The meso-scale research involved mapping the reference and final state of the vegetation and hydrological network after the removal of invasive vegetation and mitigation of negative anthropogenic impact. At the micro-scale, a monitoring system was established to track the quality of the tufa sedimentary system. Special emphasis was placed on the measurement of tufa formation dynamics (TFD) on limestone plates using a new methodological approach based on structure from motion (SfM) photogrammetry. Implementation of the proposed multiscale framework resulted in reactivation of tufa-forming watercourses, prevention of invasive vegetation regeneration and achievement of sustainable conditions for the tufa formation process. In reactivated watercourses, the average tufa growth rate was 4.267 mm a−1 (n = 18). Potential users of this framework include local authorities and administrators of protected areas.
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Intan, Fadhlan Syuaib. "GEOLOGI DAN SUMBER BAHAN BATUAN SITUS CANDI SIRIH, KABUPATEN SUKOHARJO, PROVINSI JAWA TENGAH." JURNAL WALENNAE 19, no. 1 (June 25, 2021): 33–46. http://dx.doi.org/10.24832/wln.v19i1.436.
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Candi Sirih merupakan tinggalan budaya dari masa Hindu-Buddha, yang masih cukup lengkap yang terbuat dari batuan tufa, sehingga dianggap sebagai candi yang tidak umum di Pulau Jawa karena menggunakan batuan yang bukan andesit. Hal inilah yang menjadi pokok permasalahan pada penelitian ini, yang mencakup bahan batuan candi dan kondisi geologi secara umum. Maksud dan tujuan penelitian ini adalah pemetaan geologi untuk mengetahui gambaran keadaan lingkungan alam yang mencakup morfologi, litologi, struktur geologi, dan menentukan lokasi pengambilan sumber bahan batuan untuk pembangunan candi. Metode penelitian diawali dengan kajian pustaka, survei, dan dilanjutkan dengan analisis petrologi, dan interpretasi data. Hasil pengamatan lingkungan memberikan informasi tentang bentang alam yang termasuk pada satuan morfologi dataran, dan satuan morfologi bergelombang lemah. Pola pengeringan permukaan dendritik, radial, dan rektangular, stadia sungai dewasa-tua, dan sungai periodik/permanen. Batuan penyusun adalah aluvial, dan satuan batuan tufa serta struktur geologi berupa sesar normal. Penentuan lokasi bahan batuan tufa (kasar. halus, berlapis) dan serpih untuk pembangungan Candi Sirih berasal dari lingkungan sekitarnya dalam radius 3,5 kilometer bujursangkar. Sirih Temple is a cultural heritage from the Hindu-Buddhist era, which is still quite complete, made of tufa rock, so it is considered an unusual temple in Java because it uses non-andesite rocks. This is the main problem in this study, which includes the material of the temple rock and geological conditions in general. The purpose and objective of this research is geological mapping to determine the description of the state of the natural environment which includes morphology, lithology, geological structure, and determining the location of the source of rock material for the construction of the temple. The research method begins with a literature review, survey, and is followed by petrological analysis and data interpretation. The results of environmental observations provide information about the landscape that is included in the morphological units of the plains, and the weak wavy morphological units. Drying patterns of dendritic, radial, and rectangular surfaces, mature-old river stage, and periodic/permanent river. The constituent rocks are alluvial, and the tuff rock units and the geological structure are normal faults. The location of the tuff (coarse, fine, layered) and shale materials for the Sirih Temple construction came from the surrounding environment in a radius of 3.5 square kilometers.
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Pazdur, Anna, Mieczyslaw F. Pazdur, Leszek Starkel, and Joachim Szulc. "Stable Isotopes of Holocene Calcareous Tufa in Southern Poland as Paleoclimatic Indicators." Quaternary Research 30, no. 2 (September 1988): 177–89. http://dx.doi.org/10.1016/0033-5894(88)90022-1.
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The isotopic composition of oxygen in freshwater calcareous tufa seems to be a sensitive indicator of past climatic changes. Results of measurements of δc18O and δc13C in tufa samples dated with the 14C method are used to reconstruct Holocene climatic changes in southern Poland. Values of δc18O obtained on tufa samples from four sites (Raclawka, Rzerzuŝnia, Trzebienice, Sieradowice) representing different hydrodynamic conditions of tufa sedimentation seem to form a selfconsistent series. These values, with some simplifying assumptions concerning the course of tufa sedimentation, were therefore used to estimate mean annual temperatures in the interval ca. 9500-2000 yr B.P. When the resulting curve of thermal changes in southern Poland is compared with changes of deposition and erosion of tuffaceous sediments and with results of other methods of reconstruction of paleoclimate in central Europe, a reasonable agreement among the different specific methods is seen.
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Hughes, Diarmaid. "Mutant forms of tufA and tufB independently suppress nonsense mutations." Journal of Molecular Biology 197, no. 4 (October 1987): 611–15. http://dx.doi.org/10.1016/0022-2836(87)90467-0.
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Pavlović, Gordana, Jožica Zupanič, Esad Prohić, and Darko Tibljaš. "Impressions of the Biota Associated With Waterfalls and Cascades from a Holocene Tufa in the Zrmanja River Canyon, Croatia." Geologia Croatica 55, no. 1 (2002): 25–37. http://dx.doi.org/10.4154/gc.2002.03.
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The following types of calcified deposits characterize Holocene waterfall tufas in the Zrmanja river: mossy deposits, algally laminatedcrusts and algally coated grains. Petrological examination revealed,that abundant organic remains belonging to mosses and algae provide supporting material, over which tufa accretion takes place, leavingwell-defined impressions of the biota. Postgenetic features likemeniscus, isopachous and drusy mosaic calcite spar cementation, aswell as aggradational neomorphism are only rarely present.
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von der Meden, Jessica, Robyn Pickering, Benjamin J. Schoville, Helen Green, Rieneke Weij, John Hellstrom, Alan Greig, Jon Woodhead, Wendy Khumalo, and Jayne Wilkins. "Tufas indicate prolonged periods of water availability linked to human occupation in the southern Kalahari." PLOS ONE 17, no. 7 (July 20, 2022): e0270104. http://dx.doi.org/10.1371/journal.pone.0270104.
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Detailed, well-dated palaeoclimate and archaeological records are critical for understanding the impact of environmental change on human evolution. Ga-Mohana Hill, in the southern Kalahari, South Africa, preserves a Pleistocene archaeological sequence. Relict tufas at the site are evidence of past flowing streams, waterfalls, and shallow pools. Here, we use laser ablation screening to target material suitable for uranium-thorium dating. We obtained 33 ages covering the last 110 thousand years (ka) and identify five tufa formation episodes at 114–100 ka, 73–48 ka, 44–32 ka, 15–6 ka, and ~3 ka. Three tufa episodes are coincident with the archaeological units at Ga-Mohana Hill dating to ~105 ka, ~31 ka, and ~15 ka. Based on our data and the coincidence of dated layers from other local records, we argue that in the southern Kalahari, from ~240 ka to ~71 ka wet phases and human occupation are coupled, but by ~20 ka during the Last Glacial Maximum (LGM), they are decoupled.
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Sugihara, S., K. Kurisaki, I. Morinaga, N. Momoshima, and K. Yoshimura. "The extraction of past environmental information using 137Cs and some elements in terrestrial carbonate deposits." Proceedings in Radiochemistry 1, no. 1 (September 1, 2011): 415–19. http://dx.doi.org/10.1524/rcpr.2011.0075.
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AbstractTerrestrial carbonate deposits with a banded layer structure can be good tools for the extraction of past environmental information on global and local scales. The absolute age dating is most important for the reconstruction of an environmental chronicle. The terrestrial carbonate deposits(tufa) was collected at Hirao-dai Plateau in Fukuoka, Japan. Tufa has wide banded layers in which the growth rates are about a few mm a year. The activity of 137Cs that was a global or local fallout radionuclide was measured in each layer of the tufa sample. The absolute age was determined by the numbering of a banded layer and 137Cs activity profiles. The trace of the atomic bombing at Nagasaki was detected. The growth rate of the tufa is related to the environment of the year. The variations of a depositional condition of tufa sample were checked by some metal concentrations determined by neutron activation analysis. The relationship between the variation of environmental condition and the historical event at Hirao-dai was discussed using these metal concentration profiles.
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FORD, TREVOR D. "Tufa: a freshwater limestone." Geology Today 5, no. 2 (March 1989): 60–63. http://dx.doi.org/10.1111/j.1365-2451.1989.tb00619.x.
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Pedley, H. M. "The Flandrian (Quaternary) Caerwys Tufa, North Wales: an ancient barrage tufa deposit." Proceedings of the Yorkshire Geological Society 46, no. 2 (June 1987): 141–52. http://dx.doi.org/10.1144/pygs.46.2.141.
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Dabkowski, Julie, Quentin Wackenheim, Christophe Falguères, Denis Fiorillo, Olivier Tombret, Nicole Limondin-Lozouet, Larbi Boudad, and Jean-François Berger. "Timing and intensity of humid interglacial and interstadial periods from the Eemian in the southwestern Mediterranean region: new chronological and stable isotope data from Aït Said ou Idder (Middle Atlas) and comparison with other regional tufa deposits (Morocco and southern Spain)." E&G Quaternary Science Journal 71, no. 1 (March 14, 2022): 45–58. http://dx.doi.org/10.5194/egqsj-71-45-2022.
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Abstract. In the last few decades, multidisciplinary research on calcareous tufas as palaeoenvironmental and palaeoclimatic records has intensively grown, which has provided an increasing number of well-documented sites. Consequently, inter-site comparisons and regional- to continental-scale reviews have developed, discussing the link between tufa distribution and climate or providing diachronic comparisons of climatic and environmental conditions prevailing during Quaternary interglacials (and interstadials). This paper proposes such a review for the southeastern Mediterranean area, including new dating and isotopic data from Aït Said ou Idder (northern Morocco) to be compared with available regional data, in order to discuss the intensity of some humid periods of the last 125 kyr. According to several radiocarbon and U–Th dates, three chronological phases are indeed identified at Aït Said ou Idder: the Holocene, the Dansgaard–Oeschger (D–O) interstadial 8 and the Marine Isotopic Stage (MIS) 5e. Similarly, other tufa deposits from both Morocco and southern Spain (mostly Andalusia) appear to have preferentially developed during interglacial or interstadial periods, marked by maximal developments of the Mediterranean forest as reported in the palynological records from regional marine cores. Furthermore, isotopic data (δ18O and δ13C) from Aït Said ou Idder (and from other southeastern Mediterranean tufa deposits where available) suggest no significant difference in terms of temperature or air mass circulation between the Holocene, D–O 8 and MIS 5e. In terms of humidity conditions, no evidence of strong aridity is recorded even if D–O 8 appears drier than both interglacials. Conditions seems slightly wetter during the Holocene than during MIS 5e, but δ13C values at Aït Said ou Idder could also reflect strong differences in the seasonality of these interglacials. We demonstrate that calcareous tufa deposits have promising potential for discussing, in both space and time, the climate variability in the southeastern Mediterranean area, but new investigations, including dating and stable isotopes, are required to accurately feed such discussions.
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Radišić, Maja, Josip Rubinić, Igor Ružić, and Andrijana Brozinčević. "Hydrological System of the Plitvice Lakes—Trends and Changes in Water Levels, Inflows, and Losses." Hydrology 8, no. 4 (November 26, 2021): 174. http://dx.doi.org/10.3390/hydrology8040174.
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The Plitvice Lakes National Park is inscribed on UNESCO’s World Heritage List. The lake system is composed of 16 cascading lakes of different sizes separated by tufa barriers, which are the park’s key phenomenon. The lakes are characterized by highly diverse trends of the characteristic hydrological indicators—mean annual water levels, discharges, and tufa barrier growth. The analyses carried out in this paper identified that in the period before the early 1990s, Kozjak Lake had a trend of decreasing discharges, together with a trend of increasing water levels and growing tufa barriers. In contrast to this, in the period after 2001, a trend of increasing discharges was recorded, as well as a trend of decreasing water levels and decreasing tufa barriers. A potential cause of the barriers decreasing in size were the extremely high discharges during the last decade, which resulted in increased erosion of the tufa barriers. Losses of water due to the sinking from the lake system as well as the upper Korana course were confirmed, and it was identified that during the analyzed period the losses had not changed significantly. It was determined that the losses of water from Kozjak Lake occurred during low-water periods; however, they depended not only on the quantity of water flowing through the lakes but also on the hydrological conditions underground. The analyses carried out and the methodological procedures used in the analyzed area of the Plitvice Lakes are useful examples for the performance of analyses at similar lakes in karst formed by tufa deposition processes.
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Roche, Adeline, Emmanuelle Vennin, Irina Bundeleva, Anthony Bouton, Dahédrey Payandi-Rolland, Philippe Amiotte-Suchet, Eric C. Gaucher, Hélène Courvoisier, and Pieter T. Visscher. "The Role of the Substrate on the Mineralization Potential of Microbial Mats in A Modern Freshwater River (Paris Basin, France)." Minerals 9, no. 6 (June 13, 2019): 359. http://dx.doi.org/10.3390/min9060359.
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The relationship between environmental conditions and the development, mineralization and preservation of modern tufa microbialites was investigated in a 1.1 km long freshwater stream in Villiers-le-Bâcle, a tributary of Mérantaise river. Detailed mapping of the tufa microbialite distribution combined with sedimentological, petrographical and mineralogical analyses were coupled with chemical measurements. Six organosedimentary structures were identified; their distribution appears heterogeneous along the stream and responds to physicochemical conditions of water and specific biological components (e.g., microorganism, exopolymeric substance). Two of the organosedimentary structures show evidence of mineralization and only one is lithified. Based on field observations and in-situ deployment of mineralization markers (bricks), three zones with increasing mineralization intensities are defined, ranging from no mineralization to thick mineralized crusts forming riverine tufa. Both biotic and abiotic processes were proposed for the tufa microbialite formation. We explained changes in mineralization intensities by the specific physicochemical conditions (e.g., calcite saturation index (SIcalc) and partial pressure of CO2 (pCO2) and a closed proximity of the cyanobacterial biofilm and carbonates precipitates. The physical and chemical composition of substrate impact development of microbial communities, mineralization potential of tufa microbialite. Even though the physicochemical and biological conditions were optimal for mineral precipitation, the potential of lithification depended on the presence of a suitable (physical and chemical) substrate.
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Dražina, Tvrtko, Maria Špoljar, Biserka Primc, and Ivan Habdija. "Distribution of rotifers and other meiofauna in the bryophytes and hyporheic zone of a karst hydrosystem – an example of a nested community." Marine and Freshwater Research 68, no. 1 (2017): 43. http://dx.doi.org/10.1071/mf14291.
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The meiofauna assemblages inhabiting the bryophyte-covered tufa barriers were investigated in the barrage system of Plitvice Lakes (Croatia). The main aims of the present study were: (1) to analyse the structure of the rotifer community and other meiofaunal communities in the bryophytes and the hyporheic tufa zone; and (2) to determine the influence of food sources on the meiofauna. Our results indicate that meiofauna were a constant and abundant component in bryophytes and tufa. Of the nine identified groups (Catenulida, Gastrotricha, Nematoda, Rotifera, Hydrachnidia, Oligochaeta, Copepoda, Tardigrada and Chironomidae (Diptera)), rotifers (50%) and nematodes (40%) were most abundant. Rotifers were the most diverse meiofaunal group and reached their highest numbers within the bryophytes. Also, the highest amount of ultrafine particulate organic matter, as a potential food source for rotifers, was recorded in this layer. Nematodes were the dominant meiofaunal group in deeper tufa layers. They are an omnivorous trophic group and different food sources (such as phytal remains or other meiofauna) were available in tufa layers. Meiofaunal assemblages were significantly nested and their composition was under the influence of community established in surface bryophyte mats. Information on these often overlooked faunal groups is essential for estimates of overall abundance, species richness and productivity in freshwater ecosystems.
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Sutasoma, Muwardi, Anjar Pranggawan Azhari, and Meidi Arisalwadi. "IDENTIFIKASI AIR TANAH DENGAN METODE GEOLISTRIK RESISTIVITAS KONFIGURASI SCHLUMBERGER DI CANDI DASA PROVINSI BALI." KONSTAN - JURNAL FISIKA DAN PENDIDIKAN FISIKA 3, no. 2 (December 11, 2018): 58–65. http://dx.doi.org/10.20414/konstan.v3i2.8.
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Pengukuran resistivitas secara sounding telah dilakukan di daerah Candi Dasa (CD), Provinsi Bali. Tujuan penelitian ini adalah mengidentifikasi sumber air tanah baru. Untuk menentukan posisi aquifer air tanah bawah permukaan maka dilakukan pengambilan data sounding di dua titik yaitu CD 1 dan CD 2. Metode yang digunakan adalah metode geolistrik resistivitas Konfigurasi Schlumberger dengan panjang lintasan CD 1 dan CD 2 adalah 150 m dengan spasi 1 m. Pemrosesan data dengan menggunakan software IP2Win dan Progress 3 untuk memungkinkan penggambaran distribusi resistivitas batuan dalam 1 D. Hasil interpretasi menunjukkan bahwa struktur batuan bawah permukaan terdiri dari batuan soil, tuff, lava dan sandy tufa. Hasil interpretasi menunjukkan bahwa lapisan batuan yang terdapat terbentuk karena aktifitas vulkanik yang berasal dari aktifitas Gunung Agung yang berada di Kabupaten Karang Asem. Batuan seperti lava dan tuff adalah batuan yang memiliki porositas yang kecil karena memiliki ukuran butiran yang halus dan kecil, memiliki permeabilitas yang rendah sehingga menyebabkan susah untuk menyimpan dan dan mengalirkan air. Lapisan batuan ini diperkirakan berfungsi sebagai lapisan impermeable dan selanjutnya berfungsi untuk menahan air yang mengalir secara horizontal. Selanjutnya, lapisan batuan sandy tufan yang memiliki porositas dan permeabilitas yang besar karena memiliki butiran batuan yang besar bertugas untuk menyimpan dan mengalirkan air.
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Pentecost, Allan, P. M. Thorpe, D. D. Harkness, and T. C. Lord. "Some Radiocarbon Dates for Tufas of the Craven District of Yorkshire." Radiocarbon 32, no. 1 (1990): 93–97. http://dx.doi.org/10.1017/s0033822200040005.
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14C dates of relict tufa deposits at Gordale indicated a Subboreal age when the carbonate age was corrected with empirical bedrock dilution factors ‘q’ of 0.79 or 0.85. Estimates of ‘apparent age,’ based on extrapolated δ13C values were about twice those obtained with q, and the 1σ error was large. The δ13C values of tufa samples were not correlated with carbonate age and were close to −10. Application of q values in this district requires caution as they appear to be site-specific. We recommend that wherever possible, levels of 13C and 14C are measured in the associated tufa-depositing water, and an empirical dilution factor employed.
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Du, Jie, Xue Qiao, Meng Zhang, Baofeng Di, and Ya Tang. "Wetlands in the Jiuzhaigou World Natural Heritage site of south-west China: classification and recent changes." Marine and Freshwater Research 69, no. 5 (2018): 677. http://dx.doi.org/10.1071/mf17118.
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To understand the effects of tourism and climate change on wetlands, a study was performed at Jiuzhaigou, a destination receiving >5 million people per year. There are 21 types of wetlands in region, covering an area of 265.1ha, with 42.8% on tufa. Wetland areas declined by 16.1% from 1983 to 1999 (autumn) and by 31.2% from 1983 to 2002 (summer) and increased by 31.8% from 1999 to 2011 (autumn) and by 60% from 2002 to 2014 (summer). Wetland changes included dissolving tufa, a reduced tufa deposit rate, collapse of tufa mats, increases in water nutrients and algae, and marshland development. Mean annual air temperature increased from 1977. Annual precipitation varied from 430 to 810mm between 1951 and 2015, exhibiting an increasing trend from 2005 onwards. The number of both heavy rain and storm events increased from 2005. The number of tourists grew slowly from 1984 to 1997, but increased quickly from 360000 in 1998 to 5.1 million in 2015. Commercial logging between 1966 and 1978 and debris flows are probably the key factors contributing to increased lake sedimentation and marshland development. Rapid tourism development with intensive bus movement and regional air pollution likely caused changes in water chemistry, which, in turn, caused tufa changes and wetland degradation. Reducing tourist numbers is likely to be effective in reducing effects on wetlands and conserving them, but research is needed to determine appropriate tourist numbers.
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Buchardt, Bjørn, Paul Seaman, Gabrielle Stockmann, Marie Vous, Uffe Wilken, Lene Düwel, Aase Kristiansen, et al. "Submarine columns of ikaite tufa." Nature 390, no. 6656 (November 1997): 129–30. http://dx.doi.org/10.1038/36474.
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Ke, Danbing, Maurice Boissinot, Ann Huletsky, François J. Picard, Johanne Frenette, Marc Ouellette, Paul H. Roy, and Michel G. Bergeron. "Evidence for Horizontal Gene Transfer in Evolution of Elongation Factor Tu in Enterococci." Journal of Bacteriology 182, no. 24 (December 15, 2000): 6913–20. http://dx.doi.org/10.1128/jb.182.24.6913-6920.2000.
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ABSTRACT The elongation factor Tu, encoded by tuf genes, is a GTP binding protein that plays a central role in protein synthesis. One to three tuf genes per genome are present, depending on the bacterial species. Most low-G+C-content gram-positive bacteria carry only one tuf gene. We have designed degenerate PCR primers derived from consensus sequences of the tuf gene to amplify partial tuf sequences from 17 enterococcal species and other phylogenetically related species. The amplified DNA fragments were sequenced either by direct sequencing or by sequencing cloned inserts containing putative amplicons. Two different tufgenes (tufA and tufB) were found in 11 enterococcal species, including Enterococcus avium,Enterococcus casseliflavus, Enterococcus dispar, Enterococcus durans, Enterococcus faecium, Enterococcus gallinarum, Enterococcus hirae, Enterococcus malodoratus, Enterococcus mundtii, Enterococcus pseudoavium, andEnterococcus raffinosus. For the other six enterococcal species (Enterococcus cecorum, Enterococcus columbae, Enterococcus faecalis, Enterococcus sulfureus, Enterococcus saccharolyticus, andEnterococcus solitarius), only the tufA gene was present. Based on 16S rRNA gene sequence analysis, the 11 species having two tuf genes all have a common ancestor, while the six species having only one copy diverged from the enterococcal lineage before that common ancestor. The presence of one or two copies of thetuf gene in enterococci was confirmed by Southern hybridization. Phylogenetic analysis of tuf sequences demonstrated that the enterococcal tufA gene branches with the Bacillus, Listeria, andStaphylococcus genera, while the enterococcaltufB gene clusters with the generaStreptococcus and Lactococcus. Primary structure analysis showed that four amino acid residues encoded within the sequenced regions are conserved and unique to the enterococcaltufB genes and the tuf genes of streptococci and Lactococcus lactis. The data suggest that an ancestral streptococcus or a streptococcus-related species may have horizontally transferred a tuf gene to the common ancestor of the 11 enterococcal species which now carry two tuf genes.
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Gruszczyński, Tomasz, Jerzy Małecki, Anastasiia Romanova, and Maciej Ziułkiewicz. "Reconstruction of Thermal Conditions in the Subboreal Inferred from Isotopic Studies of Groundwater and Calcareous Tufa from the Spring Mire Cupola in Wardzyń (Central Poland)." Water 11, no. 9 (September 19, 2019): 1945. http://dx.doi.org/10.3390/w11091945.
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Studies with application of stable isotopes of oxygen and carbon have been performed on calcareous tufa, groundwater and dissolved inorganic carbon (DIC) from the spring mire cupola in Wardzyń. This study was focused on the verification of the a priori hypothesis that the analysed calcareous tufa is a chemical deposit and on the attempt to supplement an earlier scenario of environmental changes in the Subboreal with oscillations of water temperature. The constructed model of chemical and isotope balance, and δ13C determinations in DIC, allowed for calculating ratios of stable isotopes of carbon in particular speciations and in gaseous CO2. The obtained results coupled with δ13C values in calcite indicate that this mineral precipitated from the solution chemically (without the contribution of living organisms). Additionally, it was possible to reconstruct the temperature range at which the calcareous tufa was formed. The reconstructed scenario of changes in the thermal conditions was refined based on δ18O determinations in groundwater and calcite. Accordingly, the oldest calcareous tufa, with an age of about 5500 cal years BP, was formed in cool climate conditions (with average annual temperatures by about 3 °C lower than presently). The formation of younger series of the calcareous tufa took place between 4400–2900 cal years BP and represents a much warmer period with two distinct cooler episodes at 3900 and 3000 cal years BP, respectively. The course of the obtained temperature curves correlates well with the GISP2 curve and curves obtained for other sites in Northern, and Central Europe.
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Tufano, Lucio. "Calzabigi e Metastasio: Napoli, Parigi, Vienna e ritorno." Palinsesti 9788879169363 (September 2020): 71–90. http://dx.doi.org/10.7359/936-2020-tufa.
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Mičetić Stanković, Vlatka, Manfred A. Jäch, Marija Ivković, Igor Stanković, Petar Kružić, and Mladen Kučinić. "Spatio-temporal distribution and species traits of water beetles along an oligotrophic hydrosystem: a case study." Annales de Limnologie - International Journal of Limnology 55 (2019): 22. http://dx.doi.org/10.1051/limn/2019019.
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This study presents the first comprehensive investigation of population aspects and ecological traits of water beetles in oligotrophic hydrosystems with tufa formation in southeastern Europe. Diverse lotic habitats (springs, rivers and tufa barriers) were investigated monthly for one year in Plitvice Lakes National Park in Croatia. Elmidae were the most diverse and abundant family, followed by Scirtidae and Hydraenidae. The ecological traits of water beetles were primarily defined by nutrients and water depth. Elmis bosnica Zaitzev, 1908, about which little has been published, was found to be bryophilous and to prefer low water temperatures. Biogeographical analysis revealed the dominance of typical southeastern and Mediterranean species. Species population dynamics could be attributed to differences in flow permanence, current velocity and canopy coverage. Both current velocity and water depth significantly influenced the occurrence of larval stages, while abundance of adults correlated with water depth. Our results highlight tufa barriers as preferred habitats for species of the genus Riolus and the family Scirtidae. The results of this study, many of which are the first to be reported for water beetles, provide a basis for further investigations of these animals and their ecology in oligotrophic hydrosystems with tufa. In particular, our study demonstrates the potential of Elmidae as water quality indicators, which should be considered in future conservation and protection management efforts.
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Tobias, Phillip V., John C. Vogel, H. Dieter Oschadleus, Timothy C. Partridge, and Jeffrey K. McKee. "New Isotopic and Sedimentological Measurements of the Thabaseek Deposits (South Africa) and the Dating of the Taung Hominid." Quaternary Research 40, no. 3 (November 1993): 360–67. http://dx.doi.org/10.1006/qres.1993.1089.
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AbstractEarlier attempts to date the Taung hominid type specimen of Australopithecus africanus Dart yielded conflicting results. Recent faunal studies pointed to an age of 2.3 myr. Radioisotopic results suggested 1.0 myr. New uranium studies reveal that the Thabaseek (the oldest Taung tufa) was not a closed system and that younger uranium entered the tufa after initial deposition, producing an apparent isotopic age younger than the age of deposition. The Thabaseek isotopic dates provide only a terminus ad quem and this technique is therefore not applicable to the older Taung tufas. Delson's dating (2.3 myr) of cercopithecoids from Hrdlicka's pinnacle ca. 50 m from the hominid site provides the best available approximation to the age of the hominid. In our new Taung excavation, stratigraphic analysis indicates that the hominid may somewhat predate most identified fauna. Sedimentologically the hominid matrix proves to be of fluvial deposition, and hence closely resembles one Hrdlicka deposit, both samples differing appreciably from all other Taung samples which bespeak eolian deposition. Thus, the conditions under which the hominid-bearing stratum was deposited were virtually identical to those pertaining to one of the Hrdlicka deposits. The newest results show that Taung was not the youngest South African australopithecine site and eliminate the discrepancy between the relative ages of the Taung A. africanus africanus and the Sterkfontein A. africanus transvaalensis.
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Barbour, George B. "The Origin of the Niangtzekuan Tufa." Bulletin of the Geological Society of China 9, no. 3 (May 29, 2009): 213–22. http://dx.doi.org/10.1111/j.1755-6724.1930.mp9003005.x.
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GUO, XUAN, and HENRY S. CHAFETZ. "Large tufa mounds, Searles Lake, California." Sedimentology 59, no. 5 (February 15, 2012): 1509–35. http://dx.doi.org/10.1111/j.1365-3091.2011.01315.x.
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Kepčija, Renata Matoničkin, Ivan Habdija, Biserka Primc-Habdija, and Marko Miliša. "Simuliid silk pads enhance tufa deposition." Archiv für Hydrobiologie 166, no. 3 (July 1, 2006): 387–409. http://dx.doi.org/10.1127/0003-9136/2006/0166-0387.
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Keevil, Claire E., Mike Rogerson, Daniel R. Parsons, Ramon Mercedes-Martín, Alexander T. Brasier, John J. G. Reijmer, and Anna Matthews. "The geomorphological distribution of subaqueous tufa columns in a hypersaline lake: Mono Lake, U.S.A." Journal of Sedimentary Research 92, no. 6 (June 21, 2022): 530–45. http://dx.doi.org/10.2110/jsr.2021.034.
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Abstract Understanding the flow of carbon through hyperalkaline lakes is a key means of understanding their biogeochemistry, sedimentology, and their paleoenvironmental and paleoclimatic records. Furthermore, understanding how mineral precipitation is regulated in these lakes can provide insights into how their sequestration of carbon can be managed. We report geophysical surveys of Mono Lake, California, USA, which show unanticipated geomorphological control on the recent/contemporary formation of lacustrine carbonate formations (“tufa”). Acquired shallow-penetration seismic data show a fault zone below the lake floor, but despite the regional evidence for geothermal waters rising up these fractures, we find no evidence for tufa precipitation at the surface exposure of this structure, either in the seismic data or in the swath bathymetry. However, we do find sub-lacustrine tufa columns in these data elsewhere, which is the first time these have been reported directly. We find and report on a strong link between column location and meteoric Ca supply to the lake, with the latter sourced either through surface runoff or groundwater. For example, a region close to a creek inlet has more frequent and larger tufa bodies, which grow at a wider depth range than another region far from an inlet but close to the fault. This demonstrates the importance of meteoric water ingress in regulating carbonate mineral formation in these basins, and raises the possibility that management of water within the catchment could be a means to enhance carbon capture in natural and artificial hyperalkaline lakes.
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Cantwell, Marie M., Mary A. T. Flynn, and Michael J. Gibney. "Acute postprandial effect of hydrogenated fish oil, palm oil and lard on plasma cholesterol, triacylglycerol and non-esterified fatty acid metabolism in normocholesterolaemic males." British Journal of Nutrition 95, no. 4 (April 2006): 787–94. http://dx.doi.org/10.1079/bjn20051723.
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The majority of research has focused on the association betweentransunsaturated fatty acids (TUFA) from hydrogenated vegetable oils and heart disease even though TUFA are also produced from hydrogenated fish oil. We compared the acute effect of three solid fats on postprandial cholesterol, triacylglycerol (TAG) and NEFA concentrations in normocholesterolaemic males. Eight healthy male volunteers consumed each of the three 40g fat meals (partially hydrogenated fish oil (PHFO), palm oil and lard) in random order and blood samples were drawn at 2, 4, 6 and 8h thereafter for lipid analysis. The postprandial response in plasma TAG, TAG-rich lipoprotein-TAG (TRL-TAG), total cholesterol and plasma NEFA, measured as the area under the postprandial curve, was not significantly different between the three meals (p>0·05), which varied in MUFA, PUFA and TUFA content. There was no marked elevation of longer-chain fatty acids (C20–22,cisortransisomers) into the TRL-TAG fraction following the PHFO meal even though they provided 40% of the total fatty acids in the PHFO meal. The postprandial TRL-TAG response to PHFO was expected to be higher, as it is higher in TUFA, lower in PUFA and similar in saturated fatty acid composition compared with the lard and palm oil test meals. The absence of a higher postprandial response following ingestion of PHFO could be as a result of reduced absorption and increased oxidation of long-chain fatty acids (bothcisandtransisomers)
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Bourel, Benjamin, Jean-David Moreau, Vincent Trincal, and Anne-Véronique Walter-Simonnet. "Fossiliferous Holocene tufa of Mende (Lozère, southern France): implication for the Atlantic vegetation of the Causses Basin." Bulletin de la Société Géologique de France 187, no. 4-5 (2016): 225–35. http://dx.doi.org/10.2113/gssgfbull.187.4-5.225.
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AbstractTufas bearing plant macroremains are uncommon in the Causses Basin (southern France). Here, we report a new fossiliferous tufa deposits at Mende, in Lozère. This palaeontological site is the first Quaternary tufa from the northern part of the Causses Basin that yields such an abundance of plant macroremains. The radiocarbon dating shows that these Holocene deposits are related to the Atlantic period. Geomorphology and mineralogy show that the plant-bearing deposit is a calcareous tufa only composed by calcite, deposited near to an outlet of cool water, linked to the karstic hydrological system of the Causse de Mende. The flora exposed in this article is dominated by angiosperms. Leaves and reproductive structures were assigned to Acer platanoides, Corylus sp., Hedera sp., Salix cf. cinerea, and Tilia cordata. This new palaeobotanical data complements our scarcely knowledge of the Atlantic floras from the Causses Basin. During the Atlantic period, and in the northern part of the basin, whereas Pinus-dominated forests and oak groves were probably well-developed, valleys were locally inhabited by diversified wet angiosperm-dominated forests.
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Horvatinčć, Nada, Dušan Srdoč, J. A. N. Šilar, and Hana Tvrdíková. "Comparison of the 14C activity of groundwater and recent Tufa from Karst areas in Yugoslavia and Czechoslovakia." Radiocarbon 31, no. 03 (1989): 884–92. http://dx.doi.org/10.1017/s0033822200012509.
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14C activity of dissolved inorganic carbon (DIC) in water and in recent tufa samples in several karst areas of Yugoslavia and Czechoslovakia was measured. Groundwater from 11 karst springs were measured for their isotopic content (14C, 3H, 13C), chemical composition (HCO3 −, Ca2+, Mg2+) and physico-chemical properties (temperature, pH). Seasonal variations of the 14C activity of DIC in two karst springs in Plitvice Lakes area, Yugoslavia, were measured systematically from 1979 – 1987.14C activity of recent tufa samples from several locations downstream were also measured. The activity of DIC in karst spring water in both countries ranged from 63–87 pMC, which is attributed to differences in geologic structure of the recharge area, topsoil thickness and composition. Grouping of 14C activities of DIC ca (82±4)% is evident. Tritium activity at all the springs indicated short mean residence time (1–10 yr). Concentration of HCO3 −, Ca2+ and Mg2+ in spring water varied with geomorphology. 14C activity of streamwater and recent tufa increased downstream from karst springs due to the exchange between atmospheric CO2 and DIC.
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Darmawan, Muhamad, Neviaty Putri Zamani, Hari Eko Irianto, and Hawis H. Madduppa. "Molecular characterization of Caulerpa racemosa (Caulerpales, Chlorophyta) from Indonesia based on the Plastid tufA Gene." Squalen Bulletin of Marine and Fisheries Postharvest and Biotechnology 16, no. 1 (December 13, 2021): 1–9. http://dx.doi.org/10.15578/squalen.588.
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The green seaweed Caulerpa racemosa is a seaweed of high prospect that is being given emphasis by the Indonesian government. However, C. racemosa in Indonesia may include multiple species level-entity exhibiting morphological overlap and require molecular analysis for species identification. Molecular documentation of species richness of indigenous populations of C. racemosa is essential to underpin cultivar development and conservation of the species to avoid overharvesting. The present study aimed to determine the genetic diversity of C. racemosa and document the haplotype network of the specimens from four different locations (Bintan Island, Jepara, Takalar and Osi Island) using the chloroplast tufA gene. Twenty individuals from four areas were collected and amplified with the chloroplast-encoded gene tufA for species identification against publicly available data. The identification of C. racemosa based on the tufA gene showed that the species found in four locations were C. cylindracea (previously C. racemosa var. cylindracea), C. macra (previously C. racemosa var. macra), C. racemosa, and C. oligophylla (previously C. racemosa var. lamourouxii). This study records the existence of C. cylindracea in Takalar and Jepara, Indonesia for the first time. The most diverse C. racemosa species was in Osi Island, where the exploitation of this seaweed is very low. In contrast, the lowest number of C. racemosa varieties were found in Takalar, where exploitation is very high. There were only minor light variations of Caulerpa species in the tufA gene in four different sites with only four haplotypes found, and each haplotype corresponded to another species.