Articles de revues : « Basalt plains »

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Sinclair, Steve, Geordie Scott‐Walker, Khorloo Batpurev, John W. Morgan, Karl Just et Damien Cook. « The forgotten annual forbs of Victoria’s basalt plains grassland ». Ecological Management & ; Restoration 22, n^o 2 (mai 2021) : 126–33. http://dx.doi.org/10.1111/emr.12480.

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Gibson-Roy, Paul, John Delpratt et Greg Moore. « Restoring Western (Basalt) Plains grassland. 2. Field emergence, establishment and recruitment following direct seeding ». Ecological Management & ; Restoration 8, n^o 2 (août 2007) : 123–32. http://dx.doi.org/10.1111/j.1442-8903.2007.00349.x.

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Young, Cyanne, Hervé Fritz, Erica AH Smithwick et Jan A. Venter. « Patch-scale selection patterns of grazing herbivores in the central basalt plains of Kruger National Park ». African Journal of Range & ; Forage Science 37, n^o 3 (29 juin 2020) : 199–213. http://dx.doi.org/10.2989/10220119.2020.1733084.

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Kutt, A. S., G. Coulson et J. Wainer. « Diet of the Striped Legless LizardDelma impar(Squamata : pygopodidae) in a western (basalt) plains grassland, Victoria ». Australian Zoologist 30, n^o 4 (avril 1998) : 412–18. http://dx.doi.org/10.7882/az.1998.007.

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Young, Cyanne, Hervé Fritz, Erica A. H. Smithwick et Jan A. Venter. « The landscape-scale drivers of herbivore assemblage distribution on the central basalt plains of Kruger National Park ». Journal of Tropical Ecology 36, n^o 1 (23 décembre 2019) : 13–28. http://dx.doi.org/10.1017/s0266467419000312.

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AbstractThe distribution and abundance of herbivores in African savannas are constrained by interactions between abiotic and biotic factors. At the species-level, herbivores face trade-offs among foraging requirements, vegetation structure and the availability of surface water that change over spatial and temporal scales. Characterizing herbivore requirements is necessary for the management of the environment in which they occur, as conservation management interventions such as fencing and artificial water provision consequently have effects on how herbivores address these trade-offs. We tested the effects of environmental attributes on the probability of presence of herbivore functional types at different distances to water in the Satara section of Kruger National Park over the period of a year. Hypotheses about species’ relative distribution and abundance were developed through a literature review of forage and water availability constraints on feeding preference and body size of herbivore. We expected strong seasonal relationships between vegetation biomass and quality, and biomass of water-dependent herbivores with increasing distance to water. Our analyses of herbivore distribution across the region confirmed broad-scale descriptions of interactions between forage requirements and water availability across a set of species which differ in functional traits.

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Hausrath, Elisabeth M., Alexis K. Navarre-Sitchler, Peter B. Sak, Carl I. Steefel et Susan L. Brantley. « Basalt weathering rates on Earth and the duration of liquid water on the plains of Gusev Crater, Mars ». Geology 36, n^o 1 (2008) : 67. http://dx.doi.org/10.1130/g24238a.1.

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Yen, Alan L., et Amanda J. Kobelt. « The composition and seasonal changes in the beetle (Coleoptera) fauna of the western Victorian basalt plains native grasslands ». Proceedings of the Royal Society of Victoria 121, n^o 2 (2009) : 228. http://dx.doi.org/10.1071/rs09228.

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The western Victorian basalt plains native grasslands are recognised as one of the most endangered plant communities in Australia. Since European settlement, they have been cleared, grazed, and fragmented and are now found as small scattered remnants. No general invertebrate surveys were undertaken in these grasslands until the 1990s, and this paper reports on the beetles associated with 12 native grassland sites that were sampled seasonally between 1992 and 1993. A total of 114 beetle morphospecies from 26 families were collected, dominated by members of four families (Carabidae, Staphylinidae, Scarabaeidae and Tenebrionidae). The beetle fauna comprised a small number of widespread species and over 63% of species were found at only one or two sites. In terms of relative abundances, a small number of beetle species dominated the fauna; the 10 most common species comprised nearly 64% of the total number of individuals collected.

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Morris, R. V., G. Klingelhöfer, C. Schröder, D. S. Rodionov, A. Yen, D. W. Ming, P. A. de Souza et al. « Mössbauer mineralogy of rock, soil, and dust at Gusev crater, Mars : Spirit's journey through weakly altered olivine basalt on the plains and pervasively altered basalt in the Columbia Hills ». Journal of Geophysical Research : Planets 111, E2 (février 2006) : n/a. http://dx.doi.org/10.1029/2005je002584.

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Sarker, Md Nuruddin. « Gravel Deposits Of Dauki-Piyain River Bed And Surrounding Flood Plains : A Case Study ». Journal of the Asiatic Society of Bangladesh, Science 41, n^o 2 (30 décembre 2015) : 225–32. http://dx.doi.org/10.3329/jasbs.v41i2.46206.

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The Dauki-Piyain river is the major source of gravels in Jaflong area which is located on the alluvial plain south of the Khasi-Jainta Hills. Jaflong gravels comprise quartzite, granite, gneiss, amphibolite, basalt, sandstone and conglomerate. The gravels are mostly fresh and hard and can be used as good construction materials. The deposition of gravels is controlled by the frequency and intensity of water-flow in the Dauki-Piyain river forming the Jaflong quarry. The Dauki river is constantly changing its course. Controlling the river course and keeping its tract clear from debris will make the replenishment of the gravel deposit steady. The main economic activities of the local people are mostly dependent on the gravel and sand extraction business from Jaflong quarry. It is found that about 30,00,000 cubic meters of gravel from 200 hectares areas are extracted per year from the Dauki-Piyain river of Jaflong. The average revenue collected by the Government of the People’s Republic of Bangladesh from this location stands at approximately 30.00 million taka per year. Asiat. Soc. Bangladesh, Sci. 41(2): 225-232, December 2015

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Bryant, David, Matthew J. Bruce et Steve J. Sinclair. « Observations of responses to re-introducing fire in a Basalt Plains grassland after the removal of grazing : Implications for restoration ». Ecological Management & ; Restoration 18, n^o 3 (19 juin 2017) : 239–45. http://dx.doi.org/10.1111/emr.12268.

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Gibson-Roy, Paul, John Delpratt et Greg Moore. « Restoring the Victorian Western (Basalt) Plains grassland. 1. Laboratory trials of viability and germination, and the implications for direct seeding ». Ecological Management & ; Restoration 8, n^o 2 (août 2007) : 114–22. http://dx.doi.org/10.1111/j.1442-8903.2007.00348.x.

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Raiber, Matthias, John A. Webb et Darren A. Bennetts. « Strontium isotopes as tracers to delineate aquifer interactions and the influence of rainfall in the basalt plains of southeastern Australia ». Journal of Hydrology 367, n^o 3-4 (avril 2009) : 188–99. http://dx.doi.org/10.1016/j.jhydrol.2008.12.020.

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Acworth, R. Ian, et Wendy A. Timms. « Hydrogeological investigation of mud-mound springs developed over a weathered basalt aquifer on the Liverpool Plains, New South Wales, Australia ». Hydrogeology Journal 11, n^o 6 (1 décembre 2003) : 659–72. http://dx.doi.org/10.1007/s10040-003-0278-0.

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Sutherland, F. L., R. R. Coenraads, A. Abduriyim, S. Meffre, P. W. O. Hoskin, G. Giuliani, R. Beattie, R. Wuhrer et G. B. Sutherland. « Corundum (sapphire) and zircon relationships, Lava Plains gem fields, NE Australia : Integrated mineralogy, geochemistry, age determination, genesis and geographical typing ». Mineralogical Magazine 79, n^o 3 (juin 2015) : 545–81. http://dx.doi.org/10.1180/minmag.2015.079.3.04.

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AbstractGem minerals at Lava Plains, northeast Queensland, offer further insights into mantle-crustal gemformation under young basalt fields. Combined mineralogy, U-Pb age determination, oxygen isotope and petrological data on megacrysts and meta-aluminosilicate xenoliths establish a geochemical evolution in sapphire, zircon formation between 5 to 2 Ma. Sapphire megacrysts with magmatic signatures (Fe/Mg ∼100–1000, Ga/Mg 3–18) grew with ∼3 Ma micro-zircons of both mantle (δ18O 4.5–5.6%) and crustal (δ18O 9.5–10.1‰) affinities. Zircon megacrysts (3±1 Ma) show mantle and crustal characteristics, but most grew at crustal temperatures (600–800°C). Xenolith studies suggest hydrous silicate melts and fluids initiated from amphibolized mantle infiltrated into kyanite+sapphire granulitic crust (800°C, 0.7 GPa). This metasomatized the sapphire (Fe/Mg ∼50–120, Ga/Mg ∼3–11), left relict metastable sillimanite-corundum-quartz and produced minerals enriched in high field strength, large ion lithophile and rare earth elements. The gem suite suggests a syenitic parentage before its basaltic transport. Geographical trace-element typing of the sapphire megacrysts against other eastern Australian sapphires suggests a phonolitic involvement.

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Raiber, M., J. A. Webb, D. I. Cendón, P. A. White et G. E. Jacobsen. « Environmental isotopes meet 3D geological modelling : Conceptualising recharge and structurally-controlled aquifer connectivity in the basalt plains of south-western Victoria, Australia ». Journal of Hydrology 527 (août 2015) : 262–80. http://dx.doi.org/10.1016/j.jhydrol.2015.04.053.

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Williams, B., J. Walker et J. Anderson. « Spatial variability of regolith leaching and salinity in relation to Whole Farm Planning ». Australian Journal of Experimental Agriculture 46, n^o 10 (2006) : 1271. http://dx.doi.org/10.1071/ea04110.

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An electromagnetic induction (EM31) survey was carried out on a 700-ha property in the western basalt plains of Victoria. The apparent electrical conductivity (ECa) was interpreted in terms of the inferred salt content and, hence, the degree of leaching or recharge through the upper 5 m of the regolith. The focus of the survey was to determine the spatial variability of ECa across a landscape of low relief which included salt lakes. The area mapped is subject to regional groundwater discharge. All parts of the property exhibited hydrological ‘sinks’ and ‘trenches’ of relatively low ECa values, interpreted as areas of preferential recharge or leaching through the regolith. They ranged in size from 200 to 500 m in diameter and/or length and were not related to relief. This apparent hydrological ‘holeyness’ of the upper regolith suggests local recharge into the regional groundwater system. This finding has important implications for Whole Farm Planning and Environmental Management Strategies as local recharge can be reduced by manipulating ground cover and land-use practices. Both the mean and standard deviation of ECa values across the property provide a rational basis for planning land management practices. The location of hydrological ‘holes’ can be built in as significant layers in Whole Farm Plans to minimise water entering the water table and/or salt lakes.

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Pritchard, Chad J., David R. Gaylord, Drew B. Adams, Shawna Ernst et Michael Hermanson. « Role of Quaternary glacial-outburst megaflood paleochannel deposits in a basalt-dominated aquifer system in the West Plains area of eastern Washington, USA ». Hydrogeology Journal 28, n^o 3 (13 janvier 2020) : 921–39. http://dx.doi.org/10.1007/s10040-019-02100-1.

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Wearne, L. J., et J. W. Morgan. « Floristic composition and variability of subalpine grasslands in the Mt Hotham region, north-eastern Victoria ». Australian Journal of Botany 49, n^o 6 (2001) : 721. http://dx.doi.org/10.1071/bt01025.

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Subalpine grasslands in the Mt Hotham area, Victoria, are a common feature of cold-air drainage valleys at elevations of 1260–1660 m. Here, the pooling of cold air prevents trees from establishing and results in a distinct grassland community, composed of tussock grasses and a wide variety of intertussock species. Despite their common occurrence in the region, such grasslands have yet to be fully described. This study focused on identifying the floristic composition of subalpine grasslands across 51 sites in the vicinity of Mt Cope, Dinner Plain and Mt Hotham. The vegetation was sampled from 172, 20-m2 quadrats which were analysed by multivariate ordination techniques. Environmental variables were quantified (i.e. soil depth, pH, aspect, slope, biomass, grazing intensity, altitude). Analysis revealed that the grassland sites varied greatly in their composition and richness. There was a gradual rather than abrupt change in species composition across grassland sites, thought to be related to both the geographic proximity of the sites and environmental factors such as geology. The following five grassland types were identified from the entire data set and defined primarily by the dominant species: Poa hiemata, Poa costiniana, Poa sieberiana, Poa labillardierei and Themeda triandra. Vector-fitting revealed significant correlations between the location of the quadrats in ordination space and altitude, biomass, pH and soil depth. Both increasing altitude and biomass were associated with the P. costiniana grasslands and some of the P. hiemata grasslands. The P. hiemata grasslands were widely distibuted across altitudes and geology (i.e. basalt and metamorphic). The lower-altitude grasslands (P. labillardierei, P. sieberiana, T. triandra) were associated with increasing pH and increasing soil depth. These grasslands were of limited extent and usually occupied small areas within larger grasslands dominated by P. hiemata or P. costiniana. The floristic composition of the Hotham grasslands (1260–1630 m a.s.l.), when compared with previously published data from the higher-elevation subalpine grasslands of both the Dargo High Plains (1450–1680 m a.s.l.) and Bogong High Plains (>1700 m a.s.l.), showed that there was no distinct differentiation between grasslands of these areas. However, there was a suggestion of gradual floristic change across this geographic range. This study highlights the need for ongoing conservation of grasslands in the Hotham area, particularly those at lower altitudes (1260–1450 m a.s.l.), which represent the upper limits of many temperate grassland species.

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Winarti, Winarti, et Hill Gendoet Hartono. « Identifikasi Batuan Gunung Api Purba di Pegunungan Selatan Yogyakarta Bagian Barat Berdasarkan Pengukuran Geolistrik ». EKSPLORIUM 36, n^o 1 (30 mai 2015) : 57. http://dx.doi.org/10.17146/eksplorium.2015.36.1.2771.

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Daerah penelitian berada di perbatasan antara Dataran Yogyakarta dengan Pegunungan Selatan Yogyakarta bagian barat. Secara morfologi dan litologi yang tersingkap, indikasi gunung api purba yang dibuktikan dengan keterdapatan batuan gunung api seperti lava, breksi, dan tuf. Tujuan dari penelitian ini adalah identifikasi adanya batuan gunung api purba di bawah permuaan sepanjang Berbah-Imogiri berdasarkan data geolistrik. Metode yang digunakan adalah melakukan pengukuran geolistrik di empat lokasi secara mapping dengan konfigurasi dipole-dipole. Panjang bentangan untuk setiap lintasan 500 meter. Hasil pengukuran geolistrik menunjukkan pada lintasan 1 di Sumber Kulon-Kalitirto, Kecamatan Berbah,diinterpretasi adanya batuan gunung api berupa lava basal dan tuf. Lintasan 2 di Pilang-Srimulyo, Kecamatan Piyungan, diinterpretasi berupa breksi skoria. Lintasan 3 di Ngeblak-Bawuran, Kecamatan Pleret, diinterpretasi adanya tuf dan lava. Lintasan 4 di Guyangan-Wonolelo, Kecamatan Pleret diinterpretasi berupa tuf dan lava. Batuan gunung api secara umum terbaca mempunyai nilai tahanan jenis yang tinggi, yaitu >300 Ωm. Adanya kandungan air atau mineralisasi cenderung menurunkan nilai tahan jenis batuan gunung api tersebut. The study area is located between western part of Yogyakarta plains and Southern Mountains. The morphology and lithology along the Berbah-Imogiri show the existence of an ancient volcano. This is proven by outcrop of volcanic rock like lava, breccia and tuff. The aim of this study is to identify the existence of ancient volcanic rocks along Berbah-Imogiri based on geoelectrical data. The method used to perform measurements at four locations geoelectrical mapping with dipole-dipole configuration a long stretch of track for every 500 meters. Geoelectrical measurement results showed on track 1 in Source Kulon-Kalitirto, District Berbah, interpretedas volcanic rocks such as basalt lava and tuff. Tracks 2 in Pilang-Srimulyo, District Piyungan, iterpreted as volcanic rocks of scoria breccia. Tracks 3 in Ngeblak-Bawuran, District Pleret, interpreted as lava and tuff. And track 4 on Guyangan-Wonolelo, District Pleret interpreted as form of tuff and lava. Volcanic rocks are generally having a high resistivity value > 300 Ωm. The content of water or mineralization tends to reduce the resistivity value of resistant volcanic rock.

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Ellis, Murray V., Susan G. Rhind, Martin Smith et Daniel Lunney. « Changes in the distribution of reports of the koala (Phascolarctos cinereus) after 16 years of local conservation initiatives at Gunnedah, north-west New South Wales, Australia ». Pacific Conservation Biology 23, n^o 1 (2017) : 63. http://dx.doi.org/10.1071/pc16004.

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In the early 1990s the koala became the mascot for a revegetation program to control salinity on agricultural land around Gunnedah in New South Wales, and a snapshot of the koala’s distribution in the shire was collected at that time, mainly via a mail survey. After the success of tree plantings in the 1990s, the koala population of the Liverpool Plains became a focus of increasing local conservation efforts, as well as research to explain koala population dynamics. This included a repeat mail survey conducted in 2006, which enabled the comparison of the reported distributions to be undertaken. These two citizen science surveys had different response rates but both produced extensive datasets. By 2006, koalas were reported from a wider extent than in 1990, particularly to the north and east of the town, and in more developed agricultural areas, but with highest densities in areas with more than 25% wooded vegetation. In 1990, koalas were reported mostly from locations that were surrounded by more than 40% wooded vegetation with the core of the distribution being on the basalt hills south of the town of Gunnedah. Koalas were also reported with increased relative frequency in the town, and this formed the core of the reported sightings at that time. There were still no reports from many of the vegetated hilly margins of the shire. The observed changes in the pattern of reporting reflects the actual distribution of koalas intersected with the likelihood of observation and the willingness of people to report koalas, and also identify the areas that may be under-sampled to determine the true habitat breath of koalas in the area.

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Doyle, RB, et FM Habraken. « The distribution of sodic soils in Tasmania ». Soil Research 31, n^o 6 (1993) : 931. http://dx.doi.org/10.1071/sr9930931.

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It is estimated that sodic soils (ESP>6) occupy at least 23% of Tasmania's land area based on the present limited soil data set. Sodic soils are mostly restricted to lower rainfall areas (<800 mm/y) of eastern Tasmania, occurring primarily in the Launceston Tertiary Basin, the Derwent, Coal, Jordan and Huon River Valleys and on Flinders Island. In Tasmania, sodic soils have formed predominantly from Triassic and Permian mudstones and sandstones, Tertiary clays and unconsolidated Quaternary deposits. However, profiles with sodic features have also developed above granite, Jurassic dolerite and Tertiary basalt. Sodic soils most commonly occur on lowland plains, river terraces and in valley floors. In Tasmania, sodic soils are characterized morphologically by: (i) abrupt separation of a sandy, bleached A2 horizon from a moderately sodic (ESP 6-15) clay subsoil; (ii) coarse prismatic, columnar and/or angular blocky pedality in the subsoil, which may exhibit vertic properties; (iii) hardsetting sandy A2 horizons in some profile classes; (iv) fine sandy crack infills and clay-organic coatings on ped faces in the upper B2 horizon; and (v) thick, sticky and greasy fine clay argillans on ped faces, and clay infills in cracks and other voids in the lower B2 horizon that contribute to reduced porosity and permeability. Sodic soils in Tasmania have traditionally been utilized for pasture production with occasional cultivation for fodder crops and pasture renewal. Under a pastoral system, few sodicity problems have been recognized as such. However, in the last 10 years there has been increased cropping, particularly for poppies and more recently potatoes. Soil structure decline and drainage problems have become key factors limiting production. Management problems are mainly due to poor internal and external drainage, with poor structure in the A2 horizons which liquefy in winter and often set hard in summer. Salinity in associated drainage depressions is a problem gaining increasing recognition.

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Indrastomo, Frederikus Dian, I. Gde Sukadana, Asep Saepuloh, Agus Handoyo Harsolumakso et Dhatu Kamajati. « Interpretasi Vulkanostratigrafi Daerah Mamuju Berdasarkan Analisis Citra Landsat-8 ». EKSPLORIUM 36, n^o 2 (30 novembre 2015) : 71. http://dx.doi.org/10.17146/eksplorium.2015.36.2.2772.

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Daerah Mamuju dan sekitarnya umumnya disusun oleh batuan gunung api. Batuan sedimen vulkanoklastik dan batugamping berada di atas batuan gunung api. Aktivitas gunung api membentuk beberapa morfologi unik seperti kawah, kubah lava, dan jalur hembusan piroklastika sebagai produknya. Produk tersebut diidentifikasi berdasarkan karakter bentuk-bentuk melingkar di citra Landsat-8. Hasil koreksi geometrik dan atmosferik, interpretasi visual pada citra Landsat-8 dilakukan untuk mengidentifikasi struktur, geomorfologi, dan kondisi geologi daerah tersebut. Struktur geologi regional menunjukkan kecenderungan arah tenggara – baratlaut yang mempengaruhi pembentukan gunung api Adang. Geomorfologi daerah tersebut diklasifikasikan menjadi 16 satuan geomorfologi berdasarkan aspek genetisnya, yaitu punggungan blok sesar Sumare, punggungan kuesta Mamuju, kawah erupsi Adang, kawah erupsi Labuhan Ranau, kawah erupsi Sumare, kerucut gunung api Ampalas, kubah lava Adang, bukit intrusi Labuhan Ranau, punggungan aliran piroklastik Adang, punggungan aliran piroklastik Sumare, perbukitan sisa gunung api Adang, perbukitan sisa gunung api Malunda, perbukitan sisa gunung api Talaya, perbukitan karst Tapalang, dan dataran aluvial Mamuju, dataran teras terumbu Karampuang. Berdasarkan hasil interpretasi citra Landsat-8 dan konfirmasi lapangan, geologi daerah Mamuju dibagi menjadi batuan gunung api dan batuan sedimen. Batuan gunung api terbagi menjadi dua kelompok, yaitu Kompleks Talaya dan Kompleks Mamuju. Kompleks Talaya terdiri atas batuan gunung api Mambi, Malunda, dan Kalukku berkomposisi andesit, sementara Kompleks Mamuju terdiri atas batuan gunung api Botteng, Ahu, Tapalang, Adang, Ampalas, Sumare, dan Labuhan Ranau berkomposisi andesit sampai basal leusit. Vulkanostratigrafi daerah ini disusun berdasarkan analisis struktur, geomorfologi, dan distribusi litologi. Vulkanostratigrafi daerah Mamuju diklasifikasikan ke dalam Khuluk Talaya dan Khuluk Adang. Khuluk Talaya terdiri atas Gumuk Mambi, Gumuk Malunda, dan Gumuk Kalukku. Khuluk Mamuju terdiri atas Gumuk Botteng, Gumuk Ahu, Gumuk Tapalang, Gumuk Adang, Gumuk Ampalas, Gumuk Sumare, dan Gumuk Labuhan Ranau. Mamuju and its surrounding area are constructed mainly by volcanic rocks. Volcanoclastic sedimentary rocks and limestones are laid above the volcanic rocks. Volcanic activities create some unique morphologies such as craters, lava domes, and pyroclastic flow paths as their volcanic products. These products are identified from their circular features characters on Landsat-8 imagery. After geometric and atmospheric corrections had been done, a visual interpretation on Landsat-8 imagery was conducted to identify structure, geomorphology, and geological condition of the area. Regional geological structures show trend to southeast – northwest direction which is affects the formation of Adang volcano. Geomorphology of the area are classified into 16 geomorphology units based on their genetic aspects, i.e Sumare fault block ridge, Mamuju cuesta ridge, Adang eruption crater, Labuhan Ranau eruption crater, Sumare eruption crater, Ampalas volcanic cone, Adang lava dome, Labuhan Ranau intrusion hill, Adang pyroclastic flow ridge, Sumare pyroclastic flow ridge, Adang volcanic remnant hills, Malunda volcanic remnant hills, Talaya volcanic remnant hills, Tapalang karst hills, Mamuju alluvium plains, and Karampuang reef terrace plains. Based on the Landsat-8 imagery interpretation result and field confirmation, the geology of Mamuju area is divided into volcanic rocks and sedimentary rocks. There are two groups of volcanic rocks; Talaya complex and Mamuju complex. The Talaya complex consists of Mambi, Malunda, and Kalukku volcanic rocks with andesitic composition, while Mamuju complex consist of Botteng, Ahu, Tapalang, Adang, Ampalas, Sumare, danLabuhanRanau volcanic rocks with andesite to leucitic basalt composition. The volcanostratigraphy of Mamuju area was constructed based on its structure, geomorphology and lithology distribution analysis. Volcanostratigraphy of Mamuju area is classified into Khuluk Talaya and Khuluk Mamuju. The Khuluk Talaya consists of Gumuk Mambi, Gumuk Malunda, and Gumuk Kalukku, while Khuluk Mamuju consists of Gumuk Botteng, Gumuk Ahu, Gumuk Tapalang, Gumuk Adang, Gumuk Ampalas, Gumuk Sumare, and Gumuk Labuhan Ranau.

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Nelson, Faye E., René W. Barendregt et Mike Villeneuve. « Stratigraphy of the Fort Selkirk Volcanogenic Complex in central Yukon and its paleoclimatic significance : Ar/Ar and paleomagnetic data ». Canadian Journal of Earth Sciences 46, n^o 5 (mai 2009) : 381–401. http://dx.doi.org/10.1139/e09-025.

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Brunhes, Matuyama, Kaena, and Mammoth age basaltic lava flows (Tertiary–Quaternary Selkirk Volcanics) were sampled in west-central Yukon. The mean characteristic remanent magnetization (ChRM) direction of the flows sampled in this and previous studies has a declination of 348.7° and an inclination of 70.8° (n = 42, k = 99.6, α95 = 2.2°) (all on lower hemisphere). The time range represented in this study (ca. 3.25 to ca. 0.004 Ma) is great enough to have confidently averaged secular variation. Sediment associated with the basalt has a mean declination of 7.6° and inclination of 78.8° (n = 5, k = 5.6, α95 = 35.7°). A new 40Ar–39Ar date on the reversely magnetized basal basalts at Ne Ch’e Ddhäwa places the eruption in the Mammoth subchron of the Gauss Normal Chron. The newly dated basal basalt at Ne Ch’e Ddhäwa precedes the initial continental glaciation in Yukon and is older than the Fort Selkirk vent (Lower Mushroom), which was previously thought to be the oldest eruption at Fort Selkirk Volcanic Complex (FSVC). This basal flow at Mushroom is dated at 1.82 ± 0.03 Ma and the uppermost flow is reproducibly dated at 1.36 ± 0.04 Ma. Till on the flanks of a subglacial volcanic mound called Ne Ch’e Ddhäwa (informal) is older than previously thought; its reverse magnetization indicates an Early Pleistocene age rather than the Reid glaciation, which falls during the Brunhes Normal Chron. The paleomagnetism of Tertiary–Quaternary Selkirk Volcanics outcrops outside the FSVC was studied for the first time. The ChRM direction of basalt at the northern edge of the northern Cordillera volcanic province agrees with FSVC directions, suggesting that this flow reflects the same period of volcanism. This suggests that an Eocene K–Ar date, previously thought to be unreliable, may well be correct.

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Law, Bradley S., Mark Chidel et Trent Penman. « Do young eucalypt plantations benefit bats in an intensive agricultural landscape ? » Wildlife Research 38, n^o 3 (2011) : 173. http://dx.doi.org/10.1071/wr10204.

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Context Environmental benefits of timber plantations have been a major selling point for land use change from previously cleared farmland, but data concerning the response of biodiversity are scarce. Aims We investigated the use of young (4–11 years old) timber plantations by bats in comparison with other vegetation classes in a highly cleared and productive agricultural landscape in north-west New South Wales (NSW), Australia. Methods Initially, we recorded activity in paddocks before plantation establishment, and then four to six years after establishment. We compared activity within young eucalypt plantations with surrounding paddocks and remnant woodland. We also radio-tracked four different bat species to investigate how roosting and foraging was apportioned into different habitats. Key results The ultrasonic survey of bats found that the young plantations were typically used by 7–8 species and activity averaged 87 passes per night. Activity within plantations was similar to treeless paddocks, and approximately six times less than in small remnants. The very high activity levels and feeding buzzes in small remnants was significantly related to rich, basalt soil (which was used as a proxy for invertebrate biomass) on agricultural plains. Total activity and species richness was correlated positively with the number of remnant trees on the site, but neither plantation area nor shape influenced bat activity. Plantations were not used preferentially by radio-tracked bats at night compared with their availability in the local landscape (13–14% bat use, 17% available). No bat roosts were located within the plantations. Most bat roosts were in tree hollows, which were absent in the plantations. Decorticating bark was abundant in eucalypt plantations, but only Nyctophilus geoffroyi was observed beneath bark and only in remnant trees outside of plantations. Conclusions Young eucalypt plantations have limited value for bats, and this is comparable to previous studies on more environmentally focussed plantings. Implications The value of plantations for bats would be improved by retaining remnant trees, both in the surrounding landscape and within plantations. We also recommend varying tree densities to increase the diversity of animal species using plantations.

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Hooper, P. R., B. A. Gillespie et M. E. Ross. « The Eckler Mountain basalts and associated flows, Columbia River Basalt Group ». Canadian Journal of Earth Sciences 32, n^o 4 (1 avril 1995) : 410–23. http://dx.doi.org/10.1139/e95-035.

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Recent mapping of flows of the Columbia River Basalt Group between Lewiston and Pomeroy, southeast Washington, places the chemically distinctive Shumaker Creek flow as a new member between the Frenchman Springs and Roza members of the Wanapum Basalt. This leaves the Eckler Mountain Formation composed of only the Robinette Mountain and Dodge chemical types, with the Lookingglass flow forming the base of the overlying Wanapum Basalt. One Robinette Mountain flow and five separate flows of Dodge composition are recognized and traced across the Blue Mountains Anticline of southeast Washington and northeast Oregon. The aerial distribution of the flows is used to constrain the onset of deformation in the Blue Mountains area between the Hite and Limekiln faults. A series of open east–west folds formed during late Wanapum and Saddle Mountains time, cut by northeast-trending faults with left-lateral strain. Chemical variations between Eckler Mountain, Grande Ronde, and Wanapum Basalt flows require different source components. But between the Eckler Mountain flows the variation of most chemical parameters is consistent with fractional crystallization in the crust and can be modeled for major and trace elements. An exception is the behaviour of Cr and Zr/Y between the Robinette Mountain and Dodge flows, which suggests variable partial melting or possibly olivine accumulation.

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Mathews, W. H. « Neogene Chilcotin basalts in south-central British Columbia : geology, ages, and geomorphic history ». Canadian Journal of Earth Sciences 26, n^o 5 (1 mai 1989) : 969–82. http://dx.doi.org/10.1139/e89-078.

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An extensive but generally thin mantle of basalt flows, the Chilcotin Group, covers much of the Interior Plateau of south-central British Columbia. It provides material for dating and for reconstructing the original form of the paleosurface on which it was deposited. K–Ar whole-rock dates demonstrate that several ages of basalt are represented, from Early Miocene (or even Late Oligocene?) to Early Pleistocene, with particularly abundant eruptions about 14–16, 9–6, and 1–3 Ma ago.Basalts of Middle Miocene and later ages, if not the Early Miocene relics as well, clearly rest on land surfaces of low local relief. In places the low-relief surfaces had been incised to depths of 100–200 m and the valleys backfilled with mid-or late Cenozoic sediments prior to burial by the basalts. The low-relief surfaces throughout the area are believed to have been developed close to a common base level, and regional differences in their present elevation are thus largely a product of post-basalt deformation. This is recorded by Miocene or later uplift of the southern Coast Mountains and gentle flexing in parts of the Interior Plateau.Major stream incision to depths of up to 1000 m following uplift provides a convenient, but not infallible, means of distinguishing Chilcotin basalts from mid-Pleistocene and younger "valley basalts."The Chilcotin Group is, for the most part, a small-scale counterpart of the roughly contemporaneous Columbia River basalt group of Washington and Oregon.

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MOGHAZI, ABDEL-KADER M. « Geochemistry of a Tertiary continental basalt suite, Red Sea coastal plain, Egypt : petrogenesis and characteristics of the mantle source region ». Geological Magazine 140, n^o 1 (janvier 2003) : 11–24. http://dx.doi.org/10.1017/s0016756802006994.

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Major and trace element data on Tertiary continental basalt flows from the Shalatein area, Red Sea coastal plain of Egypt, have been presented and used to obtain more information about their source region and the processes involved in their generation. The rocks are mainly alkali olivine basalt with MgO and Mg no. in the range of 9.8–5 wt % and 65–46, respectively. They display wide variations in incompatible element concentrations, particularly LREE, Zr, Nb, K, Y, Ba and Sr. There is no evidence of significant crustal contamination or a lithospheric mantle signature in these rocks. Normalized trace element patterns and diagnostic elemental ratios are very similar to those of modern ocean-island basalts (OIB) a feature which suggests that the mantle source region was the asthenosphere. Comparison with the different types of OIB indicates that the basalts may be derived from a high U/Pb (HIMU) source with slightly elevated K and Ba contents. The basalts show general trends of increasing incompatible elements (K2O, Nb, Y, Sr and Yb), and decreasing contents of compatible elements (Cr, Ni, Sc and Ca) with decreasing Mg no. Furthermore, TiO2, P2O5, LREE and Th define maxima at about Mg no.=56, suggesting late fractionation of Fe–Ti oxides and apatite. Although these variations are consistent with fractional crystallization processes, the wide variations in LREE contents and the incompatible trace element ratios Ce/Y (1.2–3.8), Zr/Nb (2.3–7.1) and Nb/Y (0.6–4) in the least fractionated samples (Mg no. > 56) suggest that fractional crystallization involving the observed phenocryst assemblage (olivine and clinopyroxene) cannot fully explain such compositional variations. Modelling of the mafic rocks (Mg no. > 56) using REE suggests varying degrees of partial melting of an enriched mantle source region in the garnet stability field. Partial melting is attributed to plume-related mantle upwelling beneath the Red Sea rift system.

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Zhang, Chun Hua, Jin Bao Zhang, Mu Chao Qu et Jian Nan Zhang. « Toughness Properties of Basalt/Carbon Fiber Hybrid Composites ». Advanced Materials Research 150-151 (octobre 2010) : 732–35. http://dx.doi.org/10.4028/www.scientific.net/amr.150-151.732.

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Basalt fiber and carbon fiber hybrid with alternate stacking sequences reinforced epoxy composites have been developed to improve the toughness properties of conventional carbon fiber reinforced composite materials. For comparison, plain carbon fiber laminate composite and plain basalt fiber laminate composite have also been fabricated. The toughness properties of each laminate have been studied by an open hole compression test. The experimental results confirm that hybrid composites containing basalt fibers display 46% higher open hole compression strength than that of plain carbon fiber composites. It is indicated that the hybrid composite laminates are less sensitive to open hole compared with plain carbon fiber composite laminate and high toughness properties can be prepared by fibers' hybrid.

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Yang, Yong Xin, et Jie Lian. « Basalt Fiber Reinforced Concrete ». Advanced Materials Research 194-196 (février 2011) : 1103–8. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.1103.

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In this paper, mechanical performances of 480 specimens are tested and influences of basalt fiber ratio, slenderness, soakage material are studied. Results indicate that mechanical properties of BFRC are better than plain concrete. It can be found that the best mechanical performance may be get when the basalt fiber soaked by water-solubility material and its ratio at 8.4 to 14 kg per square meter as well as slenderness at 600 to 800.

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Joughin, Ian R., Slawek Tulaczyk et Hermann F. Engelhardt. « Basal melt beneath Whillans Ice Stream and Ice Streams A and C, West Antarctica ». Annals of Glaciology 36 (2003) : 257–62. http://dx.doi.org/10.3189/172756403781816130.

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AbstractWe have used a recently derived map of the velocity of Whillans Ice Stream and Ice Streams A and C, West Antarctica, to help estimate basal melt. Ice temperature was modeled with a simple vertical advection–diffusion equation,“tuned” to match temperature profiles. We find that most of the melt occurs beneath the tributaries, where larger basal shear stresses and thicker ice favor greater melt (e.g. 10–20mm a−1). The occurrence of basal freezing is predicted beneath much of the ice plains of Ice Stream C andWhillans Ice Stream. Modeled melt rates for when Ice Stream C was active suggest there was enough meltwater generated in its tributaries to balance basal freezing on its ice plain. Net basal melt for Whillans Ice Stream is greater due to less steep basal temperature gradients. Modeled temperatures on Whillans Ice Stream, however, were constrained by a single temperature profile at UpB. Basal temperature gradients for Whillans branch 1 and Ice Stream A may have conditions more similar to those beneath Ice Streams C and D, in which case, there may not be sufficient melt to sustain motion. This would be consistent with the steady deceleration of Whillans Ice Stream over the last few decades.

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Fan, Xiao Chun, Di Wu et Hu Chen. « Experimental Research on the Freeze-Thaw Resistance of Basalt Fiber Reinforced Concrete ». Advanced Materials Research 919-921 (avril 2014) : 1912–15. http://dx.doi.org/10.4028/www.scientific.net/amr.919-921.1912.

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Basalt fiber reinforced concrete has excellent basic mechanical properties. It has become a hot topic of engineering studies. Based on the freeze-thaw resistance of durability indices, through the comparative experiment on the dynamic elastic modulus and mass loss of plain concrete and basalt fiber reinforced concrete in the freeze-thaw cycles, this paper had discussed the impact of basalt fiber on the freeze-thaw resistance of concrete, and have considered whether the specimens were mixed with fly ash. The results showed that basalt fibers can improve the freeze-thaw resistance of concrete specimens significantly. After 100 freeze-thaw cycles, the dynamic elastic modulus of basalt fiber reinforced concrete specimens was 1.47 times as much as that of plain concrete specimens, and mass loss of basalt fiber reinforced concrete specimens was 0.64 times as much as that of plain concrete specimens. Fly ash had an influence on the freeze-thaw resistance of basalt fiber reinforced concrete. In engineering applications, the mixing amount of fly ash should be taken into consideration. This research had a certain reference value on the engineering applications of basalt fiber reinforced concrete.

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Nguyen, Hoang, Ryuichi Shinjo, Thi Huong Tran, Duc Luong Le et Duc Anh Le. « Mantle geodynamics and source domain of the East Vietnam Sea opening- induced volcanism in Vietnam and neighboring regions ». Tạp chí Khoa học và Công nghệ biển 21, n^o 4 (31 décembre 2021) : 393–417. http://dx.doi.org/10.15625/1859-3097/16856.

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The spreading of the East Vietnam Sea (EVS, also known as Bien Dong, or the South China Sea), leading to the occurrence of syn-spreading (33-16 Ma) and post-spreading (< 16 to present) volcanism. Syn-spreading magma making up thick layers of tholeiitic basalt with a geochemical composition close to the refractory and depleted mid-ocean ridge basalt (MORB) is mainly distributed inside the EVS basin. The post-spreading magma is widely distributed inside the basin and extended to South and SE China, Hainan island, Southern Laos (Bolaven), Khorat Plateau (Thailand), and Vietnam, showing the typical intraplate geochemistry. Basaltic samples were collected at many places in Indochina countries, Vietnam’s coastal and continental shelf areas, to analyze for eruption age, petrographical, geochemical, and isotopic composition to understand the similarities and differences in the mantle sources between regions. The results reveal that basalts from some areas show geochemical features suggesting they were derived subsequently by spinel peridotite and garnet peridotite melting, forming high-Si, low-Mg, and low-Ti tholeiitic basalt to low-Si, high-Mg, and high-Ti alkaline basalt with the trace element enrichment increasing over time. Other basalts have geochemical and isotopic characteristics unchanged over a long period. The post-spreading basalt’s radiogenic Sr-Nd-Hf-Pb isotopic compositions show different regional basalts distribute in the various fields regardless of eruption age, suggesting that their mantle source feature is space-dependent. The post-EVS spreading basalts expose the regional heterogeneity, reflecting the mixture of at least three components, including a depleted mantle (DM) represented by the syn-EVS spreading source, similar to the DUPAL-bearing Indian MORB source; an enriched mantle type 1 (EM1), and type 2 (EM2). The DM may interact and acquire either EM1 or EM2 in the sub-continental lithospheric mantle; as a result, different eruption at different area acquires distinct isotopic signature, reflecting the heterogeneous nature of the subcontinental lithospheric mantle. The study proposes a suitable mantle dynamic model that explains the EVS spreading kinematics and induced volcanism following the India - Eurasian collision from the Eocene based on the research outcomes.

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Walker, Jeff, et Joseph Wheeler. « The smectite to corrensite transition : X-ray diffraction results from the MH-2B core, western Snake River Plain, Idaho, USA ». Clay Minerals 51, n^o 4 (septembre 2016) : 691–96. http://dx.doi.org/10.1180/claymin.2016.051.4.10.

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AbstractThe MH-2B borehole, a part of Project HOTSPOT, was drilled to a depth of 1821 m in late Cenozoic basalts, hyaloclastites and interbedded lake sediments, on the Mountain Home Air Force Base in southern Idaho, USA. Drillers encountered hot water (145°C) under artesian pressure at 1745 m in a narrow zone of highly fractured rock associated with a major sub-surface fault. X-ray diffraction (XRD) analysis identified corrensite (with and without smectite) between 1700 and 1800 m, but only smectite above 1700 m and below 1800 m. This corrensite horizon contains a relatively narrow zone of fracturing and hot artesian water near its centre but for the most part occurs in relatively massive basalt flows. No evidence was found for randomly interstratified chlorite-smectite.

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Niu, Zhi Lin, Li Min Jin, Li Juan Yu, Bao Zhong Sun, Ping Chen et Jia Zhi Su. « Ballistic Penetration Damage of 2D Basalt Fiber Plain Woven Composite ». Advanced Materials Research 487 (mars 2012) : 530–33. http://dx.doi.org/10.4028/www.scientific.net/amr.487.530.

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This paper reports the ballistic penetration behavior of 2D basalt fiber plain woven composite (2DPWC). The residual velocity vs. strike velocity curve was recorded. The dissipated energy was also calculated for each strike velocity. Furthermore, the impact damage morphologies of the tested 2DPWC coupons were given to indicate the damage modes and the mechanisms of energy absorption.

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Zhao, Siyuan, Yuqi Qian, Long Xiao, Jiannan Zhao, Qi He, Jun Huang, Jiang Wang, Hui Chen et Weiyang Xu. « Lunar Mare Fecunditatis : A Science-Rich Region and a Concept Mission for Long-Distance Exploration ». Remote Sensing 14, n^o 5 (22 février 2022) : 1062. http://dx.doi.org/10.3390/rs14051062.

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Mare Fecunditatis is a ~310,000 km2 flat basalt plain located in the low-latitude area of the Moon. Plenty of volcanic features (multiple episodes of mare basalts, sinuous rilles, lava tubes, pyroclastic deposits, domes, irregular mare patches (IMP), ring-moat dome structures (RMDS), floor-fractured craters), tectonic features (grabens and wrinkle ridges), impact-related features, and other features (swirls, pit craters) are identified in Mare Fecunditatis. An in-situ mission to Mare Fecunditatis is scientifically significant to better understand the lunar thermal histories and other questions. All previous in-situ and human missions (Apollo, Luna, Chang’E) were limited to small areas, and no traverse longer than 40 km has been made yet. With the development of technology, long-distance movement will be possible in the future on the lunar surface, providing opportunities to explore multiple sites at one mission with complete documentation of the regional geology. Eight high-value targets (pit crater, IMPs, RMDSs, young basalts, high-Al basalts, pyroclastic deposits, swirls, and fresh craters) were found in Mare Fecunditatis, and a ~1400 km-traverse in 5 years is proposed to explore them to solve the most fundamental lunar questions.

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Shoaib, Shahrukh, Tamer El-Maaddawy, Hilal El-Hassan, Bilal El-Ariss et Marwa Alsalami. « Characteristics of Basalt Macro-Fiber Reinforced Recycled Aggregate Concrete ». Sustainability 14, n^o 21 (1 novembre 2022) : 14267. http://dx.doi.org/10.3390/su142114267.

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This study aims to examine the impact of using basalt macro-fibers (BMF) on characteristics of concrete made with recycled concrete aggregates (RCA). Test variables included the initial concrete grade (normal- and high-strength concrete (NSC and HSC)), RCA replacement percentage (30 and 60%), and BMF volume fraction (νf = 0.5 to 1.5%). The compressive strength reduction in the plain concrete caused by RCA was sensitive to the RCA replacement percentage rather than the initial concrete grade. The splitting and flexural strength reductions of the plain HSC caused by RCA were more significant than those of their NSC counterparts. The use of BMF compromised the concrete workability. Such a detrimental effect increased with the BMF content and was more pronounced for the HSC with 60% RCA. Reinforcing of RCA-based concrete with BMF tended to improve the mechanical properties. In some instances, the use of BMF at νf > 1% caused a decay in the strength gain. The addition of BMF to RCA-based concrete had a potential to fully restore the original splitting and flexural strengths of plain concrete mixtures made with natural aggregates (NA). The increase in the compressive strength of the RCA-based concrete caused by BMF was, however, not sufficient to fully restore the original strength of the NA-based plain concrete. The resistances to water penetration and abrasion of the RCA-based concrete improved by up to 17% and 47%, respectively, due to the addition of BMF. Idealized tensile softening laws were established for RCA-based concrete reinforced with BMF.

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Jørgensen, Ole. « The regional distribution of zeolites in the basalts of the Faroe Islands and the significance of zeolites as palaeotemperature indicators ». Geological Survey of Denmark and Greenland (GEUS) Bulletin 9 (31 mai 2006) : 123–56. http://dx.doi.org/10.34194/geusb.v9.4865.

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The first maps of the regional distribution of zeolites in the Palaeogene basalt plateau of the Faroe Islands are presented. The zeolite zones (thomsonite-chabazite, analcite, mesolite, stilbite-heulandite, laumontite) continue below sea level and reach a depth of 2200 m in the Lopra-1/1A well. Below this level, a high temperature zone occurs characterised by prehnite and pumpellyite. The stilbite-heulandite zone is the dominant mineral zone on the northern island, Vágar, the analcite and mesolite zones are the dominant ones on the southern islands of Sandoy and Suðuroy and the thomsonite-chabazite zone is dominant on the two northeastern islands of Viðoy and Borðoy. It is estimated that zeolitisation of the basalts took place at temperatures between about 40°C and 230°C. Palaeogeothermal gradients are estimated to have been 66 ± 9°C/km in the lower basalt formation of the Lopra area of Suðuroy, the southernmost island, 63 ± 8°C/km in the middle basalt formation on the northernmost island of Vágar and 56 ± 7°C/km in the upper basalt formation on the central island of Sandoy. A linear extrapolation of the gradient from the Lopra area places the palaeosurface of the basalt plateau near to the top of the lower basalt formation. On Vágar, the palaeosurface was somewhere between 1700 m and 2020 m above the lower formation while the palaeosurface on Sandoy was between 1550 m and 1924 m above the base of the upper formation. The overall distribution of zeolites reflects primarily variations in the maximum depth of burial of the basalt rather than differences in heat flow. The inferred thinning of the middle and upper basalt formation from the central to the southern part of the Faroes is in general agreement with a northerly source area for these basalts, centred around the rift between the Faroes and Greenland. The regional zeolite distribution pattern is affected by local perturbations of the mineral zone boundaries that reflect local differences in the temperature, perhaps related to the circulation of water in the underground. The zonal distribution pattern suggests that these temperature anomalies are in part related to NW–SE-trending eruption fissures or zones of weakness separating the present islands and are subparallel to transfer zones in the Faroe–Shetland Basin. Both the regional and the local distribution of zeolite assemblages are probably a reflection of the basic volcanic-tectonic pattern of the Faroe Islands.

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Maciąg, Łukasz, Dominik Zawadzki, Gabriela A. Kozub-Budzyń, Adam Piestrzyński, Ryszard A. Kotliński et Rafał J. Wróbel. « Mineralogy of Cobalt-Rich Ferromanganese Crusts from the Perth Abyssal Plain (E Indian Ocean) ». Minerals 9, n^o 2 (29 janvier 2019) : 84. http://dx.doi.org/10.3390/min9020084.

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Mineralogy of phosphatized and zeolitized hydrogenous cobalt-rich ferromanganese crusts from Dirck Hartog Ridge (DHR), the Perth Abyssal Plain (PAP), formed on an altered basaltic substrate, is described. Detail studies of crusts were conducted using optical transmitted light microscopy, X-ray Powder Diffraction (XRD) and Energy Dispersive X-ray Fluorescence (EDXRF), Differential Thermal Analysis (DTA) and Electron Probe Microanalysis (EPMA). The major Fe-Mn mineral phases that form DHR crusts are low-crystalline vernadite, asbolane and a feroxyhyte-ferrihydrite mixture. Accessory minerals are Ca-hydroxyapatite, zeolites (Na-phillipsite, chabazite, heulandite-clinoptilolite), glauconite and several clay minerals (Fe-smectite, nontronite, celadonite) are identified in the basalt-crust border zone. The highest Ni, Cu and Co contents are observed in asbolane and Mn-(Fe) vernadite. There is significant enrichment of Ti in feroxyhyte−ferrihydrite and vernadite. The highest rare earth element (REE) content is measured in the phosphate minerals, less in phyllosilicates and Na-phillipsite. The geochemical composition of minerals in the DHR crusts supports the formation of crusts by initial alteration, phosphatization and zeolitization of the substrate basalts followed by oscillatory Fe-Mn oxyhydroxides precipitation of hydrogenous vernadite (oxic conditions) and diagenous asbolane (suboxic conditions).

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Bhutani, N., R. Sureshbabu, A. A. Farooqui, M. Behari, V. Goyal et A. Murthy. « Queuing of Concurrent Movement Plans by Basal Ganglia ». Journal of Neuroscience 33, n^o 24 (12 juin 2013) : 9985–97. http://dx.doi.org/10.1523/jneurosci.4934-12.2013.

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Wang, Dao-yuan, Jia-suo Qi, Guang-yao Cui, Yanling Yang et Jie Chang. « Model Test on Bearing Characteristics of Basalt Fiber-Reinforced Concrete Lining ». Advances in Materials Science and Engineering 2020 (11 mars 2020) : 1–10. http://dx.doi.org/10.1155/2020/3891343.

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Adding fiber can improve the brittleness of plain concrete. Compared with plain concrete, basalt fiber-reinforced concrete has the advantages of strengthening, toughening, and crack resistance. Compared with steel fiber-reinforced concrete, basalt fiber-reinforced concrete has better construction performance. Basalt fiber concrete is a type of inorganic material with environmental protection and high mechanical properties, which has an important mechanical advantage for controlling the deformation of the soft surrounding rock tunnel. Through the indoor model test of mechanical behavior of reinforced concrete and basalt fiber-reinforced concrete lining, the bearing characteristics of basalt fiber-reinforced concrete lining was studied. The results show that, compared with reinforced concrete, the initial crack load of basalt fiber-reinforced concrete is increased by 20%; the toughness of lining structure is enhanced by adding basalt fiber, and the lining can still bear large bending moment and deformation after the initial crack appears; after the initial crack appears, the bearing characteristic curve of reinforced concrete lining rises slowly and converges rapidly; the bearing characteristic curve of basalt fiber-reinforced concrete lining rises slowly, and there is no sign of convergence when it reaches 2 times of initial crack load. For the soft surrounding rock tunnel, it is necessary to seal the rock surface as early as possible, provide support as soon as possible, and have a certain deformation capacity. Basalt fiber-reinforced concrete can better meet these needs.

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Kumar, K. S., et D. Catoor. « OS0311 Crack Growth on Basal Planes in Zn Single and Bicrystals : Experiments and Computations ». Proceedings of the Materials and Mechanics Conference 2009 (2009) : 720–21. http://dx.doi.org/10.1299/jsmemm.2009.720.

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Simard, Renée-Luce, Jaroslav Dostal et Maurice Colpron. « Rifting of a Mississippian continental arc system : Little Salmon formation, Yukon–Tanana terrane, northern Canadian Cordillera ». Canadian Journal of Earth Sciences 44, n^o 9 (1 septembre 2007) : 1267–89. http://dx.doi.org/10.1139/e07-022.

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The Yukon–Tanana terrane in the northern Canadian Cordillera records the development of a series of mid- to late Paleozoic arc systems, punctuated by intra-arc deformation, uplift, and episodic rifting coeval with back-arc extension, built upon a metasedimentary basement of northwestern Laurentian affinity. In central Yukon, the Little Kalzas formation records the development of one of these Mississippian continental arcs, whereas the Little Salmon formation records the development of an intra-arc rift basin within a continental arc. The Little Salmon formation lower succession comprises mainly volcaniclastic rocks derived from erosion of Early Mississippian and older units, including rocks of the Little Kalzas continental arc. Above a medial limestone member, the upper succession of the Little Salmon formation includes alkali basalt, breccia, and crystal and ash tuffs in the north and predominantly epiclastic rocks interbedded with crystal and ash tuffs in the south. The alkali basalts have the geochemical characteristics of ocean-island basalts and their positive ε Nd 340 (+7.3) and low 87Sr/86Sr values (0.705) suggest a primitive magma source with little or no involvement of continental crust. The transition between the northern and southern facies of the upper succession of the Little Salmon formation coincides with a northeast-trending synvolcanic fault inferred to have controlled alkali basalt eruptions and deposition of Mn-bearing exhalite in the north and basin plain sedimentation in the south. The environment of deposition of the Little Salmon formation resembles that of the modern Sumisu rift in the Izu–Bonin–Mariana arc system or the early stages of development of the Japan island-arc system.

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Černý, Martin, Martina Halasová, Jana Schwaigstillová, Zdeneˇk Chlup, Zbyneˇk Sucharda, Petr Glogar, Jaroslava Svítilová, Adam Strachota et Šárka Rýglová. « Mechanical properties of partially pyrolysed composites with plain weave basalt fibre reinforcement ». Ceramics International 40, n^o 5 (juin 2014) : 7507–21. http://dx.doi.org/10.1016/j.ceramint.2013.12.102.

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Huang, Jiao, Zhi Li Zhong, Hua Wu Liu et Jing Hai Bao. « Study on the Performance of Woven Basalt Filament Diaphragm Fabric ». Applied Mechanics and Materials 217-219 (novembre 2012) : 1170–73. http://dx.doi.org/10.4028/www.scientific.net/amm.217-219.1170.

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The tensile properties of basalt filament were measured and compared with these of E-glass fiber. The plain basalt filament fabric (PBFF), twill basalt filament fabric (TBFF) and plain glass filament fabric (PGFF) that woven by the CSW-03 loom under the same fabric density were used to make diaphragm preforms. Thermoplastic acrylic resin was chosen to coat on the diaphragm preforms using Werner Mathis AG LTF97885 coating machine when the coating thickness is 0.1mm, curing time is 30min. Tensile test was carried out on the diaphragm performs and coating diaphragm by 3380Instron advanced testing machine. Effect of curing temperature (<200°C) on tensile properties of diaphragm materials was investigated. The coating PBFF and the coating TBFF were compared to analysis the effect of organization structures on the elastic modulus. The results indicated that the best elastic modulus of diaphragm materials was achieved when the curing temperature was 120°C. PBFF is more suitable for diaphragm materials than PGFF and TBFF. The proposed curing temperature for making diaphragm with different elastic modulus ranges from 100°C to 140°C.

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Sevigny, James H., Frederick A. Cook et Elizabeth A. Clark. « Geochemical signature and seismic stratigraphic setting of Coppermine basalts drilled beneath the Anderson Plains in northwest Canada ». Canadian Journal of Earth Sciences 28, n^o 2 (1 février 1991) : 184–94. http://dx.doi.org/10.1139/e91-018.

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Basalts drilled in the Petro-Canada – Canterra Tweed Lake M-47 well in the Anderson Plains of northwestern Canada have geochemical characteristics, including of major, trace, and rare earth elements, that are similar to those of the most enriched Coppermine lavas but significantly different from those of the younger Proterozoic volcanics, such as the Natkusiak basalts. This result provides a geological tie and timing constraint for structures observed on seismic reflection data in this area. Correlation of stratigraphic data from the well to seismic data shows that the lavas are within a sequence of layered reflections that onlap, and are thus younger than, easterly verging structures, and that were themselves probably uplifted prior to deposition of the Mackenzie Mountains Supergroup. These relationships thus show that at least two stages of Proterozoic compressional deformation, one that predated and one that postdated the basalts, produced structures beneath the Anderson Plains.

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Bonsu, Alex Osei, Comfort Mensah, Wenyan Liang, Bin Yang et Yunsheng Ma. « Mechanical Degradation and Failure Analysis of Different Glass/Basalt Hybrid Composite Configuration in Simulated Marine Condition ». Polymers 14, n^o 17 (25 août 2022) : 3480. http://dx.doi.org/10.3390/polym14173480.

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This work aims to evaluate the failure mechanisms of plain glass and basalt fiber reinforced composites and a selected glass/basalt hybrid composite sequence subjected to artificial seawater conditions. Sets of plain and five hybrid composite configurations were fabricated by vacuum assisted resin injection technique (VARI), and subjected to seawater aged for 258 days at 30 °C and 70 °C followed by tensile, flexural and charpy impact testing, respectively. Failure analysis for dry and seawater-aged composites were undertaken using scanning electron microscopy (SEM). Results showed that some hybrid laminates with sandwich-like and alternating sequencing exhibited superior mechanical properties and ageing resistance than plain laminates. GB3 ([B2G2]S) type hybrid composite with basalt fiber outer plies retained 100% tensile strength and 86.6% flexural strength after ageing, which was the highest among all the laminates. However, GB4 ([BGBG]S) type specimen with alternating sequencing retained the highest residual impact strength after ageing. SEM analysis on the failed specimens showed fiber breaking, matrix cracking and debonding caused by fiber–matrix interface degradation due to seawater exposure. However different hybrid configurations to a considerable extent prevented crack propagation across specimens, hence altering the overall damage morphology among different specimens.

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Pujol, J., et S. Smithson. « Seismic wave attenuation in volcanic rocks from VSP experiments ». GEOPHYSICS 56, n^o 9 (septembre 1991) : 1441–55. http://dx.doi.org/10.1190/1.1443164.

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Seismic wave attenuation in the Columbia Plateau basalts and Snake River Plain volcanics was analyzed using vertical seismic profiling (VSP) data. The computation of attenuation coefficients is based on fitting a straight line to the logarithm of amplitude ratios computed for fixed values of frequency and variable depth. This approach does not require any assumptions on the dependence of Q on frequency. For the Columbia Plateau basalts, the attenuation coefficients obtained from the field data are smaller than those computed from the synthetic VSP generated using the sonic and density logs, indicating that the observed attenuation is related to scattering effects and is substantially larger than the intrinsic attenuation of basalt. Therefore, it is concluded that only a lower bound for Q can be established, in agreement with recent findings by other authors. The effective attenuation of seismic energy in basalts (about [Formula: see text] for the peak frequency) is comparable to the effective attenuation observed in sedimentary rocks (between [Formula: see text] and [Formula: see text]). Results from two VSPs recorded in the Snake River Plain volcanics using air gun and vibrator sources show some frequency‐dependent effects. The depth range analyzed covers two different lithologic units (rhyolitic rocks with interbedded volcanic sediments above more homogeneous rhyodacitic rocks). The air gun energy (with a peak frequency near 15 Hz) clearly detects a difference in the attenuating properties of the two types of rocks. The vibrator energy, on the other hand, also detects this difference, but only for the lower frequencies. For frequencies near the peak frequency (31 Hz), attenuation is almost the same in the two units. The difference in attenuation for the two types of rocks is real and cannot be explained as processing artifacts, because it can be observed for both sources by analyzing the amplitude decay in the time domain. The peak‐frequency attenuation coefficients for the lower section are [Formula: see text] and [Formula: see text] for the vibrator and air gun sources, respectively. For the upper section, the corresponding values are [Formula: see text] and [Formula: see text]. The difference in attenuation implied by the last two coefficients is probably not real, because the decay of energy in the time domain for the two sources is much closer to each other. The Columbia Plateau and Snake River Plain VSPs show that the poor quality of reflection data commonly associated with volcanic rocks cannot be explained by unusually high attenuation.

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Chhorn, Buntheng, et WooYoung Jung. « Experimental investigation of the flexural fatigue performance of plain woven basalt fiber/epoxy ». Science Progress 104, n^o 3 (juillet 2021) : 003685042110294. http://dx.doi.org/10.1177/00368504211029451.

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Fatigue of composite materials is a very complex phenomenon, to date a numerous research effort is being spent on it. Because of deficiencies in study of flexural fatigue performance basalt fiber reinforced polymer (BFRP), the main objective of this work is to investigate the flexural fatigue performance of BFRP. The laminates of 4.0 mm average thickness were fabricated using the vacuum infusion technique. Three different stress levels of (162.90, 122.24, and 81.44) MPa were considered. A failure criterion was considered to be a 20% stiffness reduction of flexural fatigue test. Also, the stiffness reduction zones in the history of fatigue specimen were investigated. The failure mode of specimen at 20% reduction stiffness was inspected. The Weibull distribution function was used to obtain the failure probabilities and scatter. The S–N curve of composite laminates was constructed using five specimens at each number of cycles. This study indicated that under fatigue loading, the stiffness degradation process of composite materials was divided into three stages: the first is the high rate of stiffness degradation at the first few thousand cycles. The second stage then takes place with slow gradual stiffness degradation, which covers a sizeable portion of the component life. Finally, more grave types of damage occur, like fiber fracture, and induce complete material failure.

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Lv, Yang, Xueqian Wu, Mengran Gao, Jiaxin Chen, Yuhao Zhu, Quanxi Cheng et Yu Chen. « Flexural Behavior of Basalt Fiber Reinforced Polymer Tube Confined Coconut Fiber Reinforced Concrete ». Advances in Materials Science and Engineering 2019 (3 février 2019) : 1–7. http://dx.doi.org/10.1155/2019/1670478.

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Basalt fiber has arisen new perspectives due to the potential low cost and excellent mechanical performance, together with the use of environmental friendly coir can be beneficial to the development of sustainable construction. In this study, a new composite structure called basalt fiber reinforced polymer (BFRP) tube encased coconut fiber reinforced concrete (CFRC) is developed. The 28-day compression strength of the plain concrete is about 15 MPa, which represents the low-strength poor-quality concrete widely existing in many old buildings and developing countries. Three types of BFRP tubes, i.e., 2-layer, 4-layer, and 6-layer, with the inner diameter of 100 mm and a length of 520 mm, were prepared. The plain concrete (PC) and CFRC were poured and cured in these tubes to fabricated BFRP tube confined long cylindrical beams. Three PC cylindrical beams and 3 CFRC cylindrical beams were prepared to be the control group. The four-point bending tests of these specimens were carried out to investigate the enhancement due to the BFRP tube and coir reinforcement. The load-carrying capacity, force-displacement relationship, failure mode, and the cracking moment were analyzed. Results show that both BFRP tube confined plain concrete (PC) and BFRP tube confined CFRC have excellent flexural strength and ductility, and the inclusion of the coir can further enhance the ductility of the concrete.

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Vosáhlo, Josef, et Martina Ryvolová. « Basalt Reinforced Plastic - Development and Modeling of Part ». Materials Science Forum 994 (mai 2020) : 115–24. http://dx.doi.org/10.4028/www.scientific.net/msf.994.115.

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Basalt fibers are increasingly emerging as reinforcement of composite materials. Their use is purely technical, depending on the properties of the basalt fibers: thermal, chemical and electrical resistance, good mechanical properties and low environmental impact. Basalt fibers reinforced plastics penetrate to automotive, aerospace, building construction and building reparation, industrial applications, oil industry and sport tools. The topic of the paper is to find out the mechanical properties of basalt fiber reinforced plastic (BFRP) and to create a model of split pin that is originally made of steel. Basalt woven fabric was selected for this experiment. Two weave - plain and twill was available. Tensile strength test was made in three basic directions: 0°, 90° and 45°. Epoxy resin was used for production composite plates with one layer basalt reinforcement. Tensile strength test of composite plates provided input parameters for numerical model of small composite part - split pin. Real composite split pin will produced according to modeling properties. Weight decrease was supposed, this assumption was confirmed.

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