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Journal articles on the topic 'Geochemistry : Carbonate rocks'

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Published: 4 June 2021

Last updated: 13 February 2022

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1

E Webb, Gregory, and Balz S Kamber. "Biogenicity inferred from microbialite geochemistry." Microbiology Australia 25, no. 1 (2004): 34. http://dx.doi.org/10.1071/ma04134.

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Microbes utilise and/or concentrate diverse metal cations, whose detection may become a potent tool for reconstructing microbial processes and, in particular, for establishing the genesis of ancient carbonate rocks that were produced by microbes. Such rocks, termed microbialites, consist of trapped and bound sediment and, importantly, carbonate minerals precipitated as accidental byproducts of metabolic or decay processes within biofilms. Where trace metals are predictably incorporated into microbialites, they may reflect biofilm processes and allow interpretation of preserved carbonates. Holo

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Adam, Ludmila, Michael Batzle, and Ivar Brevik. "Gassmann's fluid substitution and shear modulus variability in carbonates at laboratory seismic and ultrasonic frequencies." GEOPHYSICS 71, no. 6 (2006): F173—F183. http://dx.doi.org/10.1190/1.2358494.

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Carbonates have become important targets for rock property research in recent years because they represent many of the major oil and gas reservoirs in the world. Some are undergoing enhanced oil recovery. Most laboratory studies to understand fluid and pressure effects on reservoir rocks have been performed on sandstones, but applying relations developed for sandstones to carbonates is problematic, at best. We measure in the laboratory nine carbonate samples from the same reservoir at seismic (3–3000 Hz) and ultrasonic [Formula: see text] frequencies. Samples are measured dry (humidified) and

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Eder, Vika G., Elena A. Kostyreva, Anna Yu Yurchenko, et al. "New data on lithology, organic geochemistry and accumulation conditions of the Bazhenov formation in Western Siberia." Georesursy 21, no. 2 (2019): 129–42. http://dx.doi.org/10.18599/grs.2019.2.129-142.

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This paper presents data on lithological composition, distribution, reservoir properties, geochemistry of organic matter and genesis of carbonate rocks of the Bazhenov formation within the central part of Western Siberia (the region of the Khantei hemianteclise). The following types of carbonates are distinguished: a) primary biogenic – shell rock interlayers and residues of coccolith; b) dia- and catagenetic – in varying degrees, recrystallized rocks with coccoliths, nodules and aporadiolarites; c) catagenetic – cracks healed with calcite in limestone of the foot of the Bazhenov formation. It

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Holail, Hanafy, Mohamed Tamish, Mohamed El-Askary, and Ahmed Sadek. "Geochemistry and diagenesis of Middle Miocene carbonate rocks, northern Western Desert, Egypt." Neues Jahrbuch für Geologie und Paläontologie - Monatshefte 1997, no. 4 (1997): 191–212. http://dx.doi.org/10.1127/njgpm/1997/1997/191.

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Verwer, Klaas, Hendrik Braaksma, and Jeroen A. Kenter. "Acoustic properties of carbonates: Effects of rock texture and implications for fluid substitution." GEOPHYSICS 73, no. 2 (2008): B51—B65. http://dx.doi.org/10.1190/1.2831935.

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More than 250 plugs from outcrops and three nearby boreholes in an undisturbed reef of Miocene (Tortonian) age were quantitatively analyzed for texture, mineralogy, and acoustic properties. We measured the P- and S-waves of carbonate rocks under dry (humidified) and brine-saturated conditions at [Formula: see text] effective pressure with an ultrasonic pulse transmission technique [Formula: see text]. The data set was compared with an extensive database of petrophysical measurements of a variety of rock types encountered in carbonate sedimentary sequences. Two major textural groups were distin

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Lacalamita, M., G. Balassone, E. Schingaro, et al. "Fluorophlogopite-bearing and carbonate metamorphosed xenoliths from theCampanian Ignimbrite (Fiano, southern Italy): crystal chemical, geochemical and volcanological insights." Mineralogical Magazine 81, no. 5 (2017): 1165–89. http://dx.doi.org/10.1180/minmag.2016.080.155.

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AbstractFluorine-, boron- and magnesium-rich metamorphosed xenoliths occur in the Campanian Ignimbrite deposits at Fiano (southern Italy), at ∼50 km northeast of the sourced volcanic area. These rocks originated from Mesozoic limestones of the Campanian Apennines, embedded in a fluid flow. The Fiano xenoliths studied consist of ten fluorophlogopite-bearing calc-silicate rocks and five carbonate xenoliths, characterized by combining mineralogical analyses with whole-rock and stable isotope data. The micaceous xenoliths are composed of abundant idiomorphic fluorophlogopite, widespread fluorite,

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Ghosh, Ranjana, and Mrinal K. Sen. "Predicting subsurface CO2 movement: From laboratory to field scale." GEOPHYSICS 77, no. 3 (2012): M27—M37. http://dx.doi.org/10.1190/geo2011-0224.1.

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Finding an appropriate model for time-lapse seismic monitoring of [Formula: see text]-sequestered carbonate reservoir poses a great challenge because carbonate-rocks have varying textures and highly reactive rock-fluid system. We introduced a frequency-dependent model based on Eshelby’s inclusion and differential effective medium (DEM) theory that can account for heterogeneity in microstructure of rocks and squirt flow. We showed that the estimated velocities from the modified DEM theory match well with the laboratory measurements (ultrasonic) of velocities of carbonate rocks saturated with [F

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Levitskiy, V. I., L. Z. Reznitsky, and I. V. Levitskiy. "Geochemistry of carbonate rocks in early Precambrian and phanerozoic metamorphic complexes of East Siberia, north-west of Russia, Pamir." Геохимия 64, no. 4 (2019): 409–26. http://dx.doi.org/10.31857/s0016-7525644409-426.

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Geochemical study of carbonate rocks of Early-Precambrian and Phanerozoic metamorphic Complexes was carried out and their differences were revealed. Precambrian marbles and calciphyres studied in the Оnot Greenstone Belt, Kitoy and Sharyzhalgay granulitic Complexes Presayan uplift, Yenisei Series of the Angara-Kan Protrusion of the Siberian craton, the Belomorian and Lapland Complexes, North of the Pechenga Structure, Sortavala Suite of the Fennoscandian shield, Wakhan Complex of the Badakhshan Array; Phanerozoic – in Olkhon, Slyudyanka, Svyato nossky Complexes of the Baikal region, Boxon Seri

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Stoppa, F., A. R. Woolley, and A. Cundari. "Extension of the melilite-carbonatite province in the Apennines of Italy: the kamafugite of Grotta del Cervo, Abruzzo." Mineralogical Magazine 66, no. 4 (2002): 555–74. http://dx.doi.org/10.1180/0026461026640049.

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AbstractA new occurrence of a rare kamafugite near L'Aquila, Abruzzo, is described in detail to characterize its paragenesis and to establish possible genetic links with similar alkaline mafic igneous rocks from the Oricola-Camerata Nuova (OC) volcanic field, ˜20 km to the west. Both occurrences belong to the Umbria-Latium-Ultralkaline-District (ULUD), an igneous district represented by rare kamafugites and carbonatites and distinct from the much more voluminous Roman Region (RR) rocks. The new kamafugite was found in a cave known as Grotta del Cervo (GC), associated with epiclastic and pyrocl

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Chen, Jun-Qing, Xiong-Qi Pang, Song Wu, et al. "Method for identifying effective carbonate source rocks: a case study from Middle–Upper Ordovician in Tarim Basin, China." Petroleum Science 17, no. 6 (2020): 1491–511. http://dx.doi.org/10.1007/s12182-020-00489-z.

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AbstractHydrocarbon expulsion occurs only when pore fluid pressure due to hydrocarbon generation in source rock exceeds the force against migration in the adjacent carrier beds. Taking the Middle–Upper Ordovician carbonate source rock of Tarim Basin in China as an example, this paper proposes a method that identifies effective carbonate source rock based on the principles of mass balance. Data from the Well YW2 indicate that the Middle Ordovician Yijianfang Formation contains effective carbonate source rocks with low present-day TOC. Geological and geochemical analysis suggests that the hydroc

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Fantle, Matthew S., B. Davis Barnes, and Kimberly V. Lau. "The Role of Diagenesis in Shaping the Geochemistry of the Marine Carbonate Record." Annual Review of Earth and Planetary Sciences 48, no. 1 (2020): 549–83. http://dx.doi.org/10.1146/annurev-earth-073019-060021.

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Carbonate sediments and rocks are valuable archives of Earth's past whose geochemical compositions inform our understanding of Earth's surface evolution. Yet carbonates are also reactive minerals and often undergo compositional alteration between the time of deposition and sampling and analysis. These changes may be mineralogical, structural, and/or chemical, and they are broadly referred to as diagenesis. Building on work over the past 40 years, we present an overview of key carbonate diagenesis terminology and a process-based framework for evaluating the geochemical impacts of carbonate diag

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Bemer, Elisabeth, Youri Hamon, and Mathilde Adelinet. "Consistent experimental investigation of the applicability of Biot-Gassmann’s equation in carbonates." GEOPHYSICS 84, no. 4 (2019): WA97—WA113. http://dx.doi.org/10.1190/geo2018-0631.1.

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Carbonate formations are characterized by multiscale heterogeneities that control their acoustic response and flow properties. At the laboratory scale, carbonate rocks do not indicate a strong correlation between P- and S-wave velocities and porosity. The velocity disparities between carbonates of similar mineralogy and porosity result from different microstructures derived from their sedimentary facies and subsequent diagenetic transformations. The still-discussed applicability of Biot-Gassmann’s equation for fluid substitution in carbonate rocks remains another key issue. We have developed a

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Simandl, George J., Suzanne Paradis, Johnathan Savard, et al. "Mineral control on the geochemistry of the Rock Canyon Creek REE-F-Ba deposit, British Columbia, Canada." Geochemistry: Exploration, Environment, Analysis 21, no. 2 (2021): geochem2020–010. http://dx.doi.org/10.1144/geochem2020-010.

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The Rock Canyon Creek carbonate-hosted REE-F-Ba deposit has tectonic, stratigraphic and structural similarities with Mississippi Valley-type and sparry magnesite deposits in the SE Rocky Mountains. The main REE-fluorite zone is a steeply dipping body, extending 1100 m along-strike, 50 m wide and 100 m deep. It spatially coincides with pre-existing crackle breccias in carbonate rocks, and consists of dolomite, fluorite, barite, pyrite, quartz, K-feldspar, calcite, porous apatite, REE-fluorocarbonates and REE-phosphates. The main fluorocarbonates are bastnaesite, parisite and synchysite. Monazit

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Han, Tongcheng, and Sam Yang. "Dielectric properties of fractured carbonate rocks from finite-difference modeling." GEOPHYSICS 84, no. 1 (2019): MR37—MR44. http://dx.doi.org/10.1190/geo2018-0003.1.

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Fractures are common features in virtually all types of geologic rocks and tend to dominate their mechanical and hydraulic properties. Detection and characterization of fractures in rocks are of interest to a variety of geophysical applications. We have investigated the frequency-dependent dielectric properties of fractured porous carbonate rocks in the frequency range [Formula: see text] and their relationships with different types of fluids filling the fractures, fracture connectivity, and directions of electrical field applied to the rocks using numerical simulation methods based on a 3D fi

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Yu, Fu, Yan Jin, Kang Ping Chen, and Mian Chen. "Pore-pressure prediction in carbonate rock using wavelet transformation." GEOPHYSICS 79, no. 4 (2014): D243—D252. http://dx.doi.org/10.1190/geo2013-0277.1.

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Accurate prediction of pore pressure can assist engineers to better work out and optimize an oilfield development plan. Because the P-wave velocity only experiences small-scale fluctuations for pore-pressure change in carbonate rocks, existing well-known pore-pressure prediction methods are incapable of predicting pore pressure in carbonate rocks with field-required accuracy. We evaluated a new method based on the P-wave velocity decomposition and wavelet transformation to predict pore pressure in carbonate rocks. The P-wave velocity was decomposed into contributions from the pore fluid and th

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Adelinet, Mathilde, Jean-François Barthélémy, Elisabeth Bemer, and Youri Hamon. "Effective medium modeling of diagenesis impact on the petroacoustic properties of carbonate rocks." GEOPHYSICS 84, no. 4 (2019): WA43—WA57. http://dx.doi.org/10.1190/geo2018-0559.1.

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Carbonate formations are highly heterogeneous, and the velocity-porosity relationships are controlled by various microstructural parameters, such as the types of pores and their distribution. Because diagenesis is responsible for important changes in the microstructure of carbonate rocks, we have extended the standard effective medium approach to model the impact of diagenesis on the carbonate elastic properties through a step-by-step effective medium modeling. Two different carbonate rocks deposited, respectively, in lacustrine and marine environments are considered in this study. The first k

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Fournier, F., and J. Borgomano. "Critical porosity and elastic properties of microporous mixed carbonate-siliciclastic rocks." GEOPHYSICS 74, no. 2 (2009): E93—E109. http://dx.doi.org/10.1190/1.3043727.

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By integrating elastic-property measurements and quantitative mineralogic and petrographic analyses of 45 mixed carbonate-siliciclastic samples from two wells drilled in Late Cretaceous rock of the South Provence Basin (southeast France), we can (1) identify and quantify the parameters controlling elastic properties; (2) demonstrate that micrite can be considered as a porous medium with a low critical porosity, averaging 18%; and (3) relate diagenetic transformations, pore-structure modifications, and elastic-property changes. Microporous carbonates with compact anhedral and euhedral microrhom

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Dasgupta, Somnath, P. K. Bhattacharya, H. Banerjee, M. Fukuoka, N. Majumdar, and Supriya Roy. "Calderite-rich garnets from metamorphosed manganese silicate rocks of the Sausar Group, India, and their derivation." Mineralogical Magazine 51, no. 362 (1987): 577–83. http://dx.doi.org/10.1180/minmag.1987.051.362.12.

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AbstractManganiferous garnets occur in metamorphosed Mn silicate-oxide and silicate-carbonate-oxide rocks of the Sausar Group, India. The garnets of the carbonatic rock show maximum calderite content (∼50 mole%). Increased Ca content in the bulk has been observed to be sympathetically related to the concentration of calderite, rather than the expected andradite component of the garnets. This is the consequence of the preferential partitioning of Ca in coexisting pyroxmangite and/or carbonate. Petrochemical characteristics of the diverse assemblages in response to the physical conditions of met

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Rosatelli, G., F. Wall, and M. J. Le Bas. "Potassic glass and calcite carbonatite in lapilli from extrusive carbonatites at Rangwa Caldera Complex, Kenya." Mineralogical Magazine 67, no. 5 (2003): 931–55. http://dx.doi.org/10.1180/0026461036750152.

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AbstractThe ∽16 Ma Rangwa Caldera Complex, part of the large Kisingiri nephelinite-carbonatite volcano, Homa Bay District, western Kenya (0º34’S; 34º09’E) contains carbonatitic lapilli and ash tuffs, agglomerate and tuffisite, and a number of intrusive calcite carbonatites. A detailed petrographic and electron microprobe study has been performed on 20 fresh samples from the collection at The Natural History Museum, London.Most of the juvenile lapilli and ash particles are either predominantly composed of devitrified silicate glass (now biotite/phlogopite but probably also originally potassic s

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Orlova, Aleksandra Yu, Rais S. Khisamov, Venera G. Bazarevskaya, Elena N. Poludetkina, Natalia P. Fadeeva, and Tatiana A. Shardanova. "Geochemistry of organic matter in carbonate Devonian sediments of the South Tatar arch." Georesursy 23, no. 2 (2021): 87–98. http://dx.doi.org/10.18599/grs.2021.2.8.

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The article deals with the lithology and geochemistry of organic matter of Upper Devonian-Lower Carboniferous deposits (Carbonate Devonian) of the eastern part of the South Tatar arch. Rocks of this age have a high generative potential due to increased concentrations of organic matter (OM) and its phytogenic and zoophytogenic composition. They refer to non-traditional sources of hydrocarbons. The generative potential depends on the facial environment and the transformation of OM. The highest potential have carbonate-siliceous and siliceous-carbonate rhythmites domannic horizon.

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Andersen, Tom. "Carbonatite-related contact metasomatism in the Fen complex, Norway: effects and petrogenetic implications." Mineralogical Magazine 53, no. 372 (1989): 395–414. http://dx.doi.org/10.1180/minmag.1989.053.372.01.

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AbstractIn the Fen complex (Telemark, S.E. Norway), carbonatites of different compositions have penetrated feldspathic fenites (alkali feldspar(s) + aegirine augite ± alkali amphibole) or older carbonatites, inducing different types of contact metasomatic alterations in their wall-rocks. (1) Pyroxene søvite has induced alkali metasomatism (i.e. fenitization s.s.), with alkali feldspars remaining stable and aegirine-augite transformed to nearly pure aegirine. (2) Søvite and dolomite carbonatite with phlogopite and/or alkali or alkali-calcic amphibole have caused replacement of feldspathic fenit

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Dawson, J. B., J. V. Smith, and I. M. Steele. "1966 ash eruption of the carbonatite volcano Oldoinyo Lengai: mineralogy of lapilli and mixing of silicate and carbonate magmas." Mineralogical Magazine 56, no. 382 (1992): 1–16. http://dx.doi.org/10.1180/minmag.1992.056.382.01.

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AbstractLapilli from the August 1966 eruption of the carbonatite volcano Oldoinyo Lengai consist of carbonate-cemented aggregates of (i) mono- and poly-mineralic fragments of ijolitic rocks, (ii) single grains and clusters of euhedral nepheline, Ti-andradite, and Ti-magnetite, and (iii) corroded pyroxene and wollastonite grains surrounded by coronas containing combeite, melilite, Ca-silicates (possibly larnite and rankinite), and rounded bodies of submicrometre intergrowths with complex bulk compositions dominated by Na,K,Ca-phosphate-carbonate and alkali-iron-sulphide-carbonate. The (ii,iii)

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Nesbitt, Bruce E., and Karlis Muehlenbachs. "Geochemistry of syntectonic, crustal fluid regimes along the Lithoprobe Southern Canadian Cordillera Transect." Canadian Journal of Earth Sciences 32, no. 10 (1995): 1699–719. http://dx.doi.org/10.1139/e95-134.

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In conjunction with the Lithoprobe southern Canadian Cordillera program, an extensive examination of geochemical indicators of origins, movement, chemical evolution, and economic significance of paleocrustal fluids was conducted. The study area covers approximately 360 000 km2from the Canadian Rockies to Vancouver Island. Research incorporated petrological, mineralogical, fluid-inclusion, δ18O, δD, δ13C, and Rb/Sr studies of samples of quartz ± carbonate veins and other rock types. The results of the study document a variety of pre-, syn-, and postorogenic, crustal fluid events. In the Rockies

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Cooke, Andy P., Quentin J. Fisher, Emma A. H. Michie, and Graham Yielding. "Permeability of carbonate fault rocks: a case study from Malta." Petroleum Geoscience 26, no. 3 (2019): 418–33. http://dx.doi.org/10.1144/petgeo2019-055.

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The inherent heterogeneity of carbonate rocks suggests that carbonate-hosted fault zones are also likely to be heterogeneous. Coupled with a lack of host–fault petrophysical relationships, this makes the hydraulic behaviour of carbonate-hosted fault zones difficult to predict. Here we investigate the link between host rock and fault rock porosity, permeability and texture, by presenting data from series of host rock, damage zone and fault rock samples from normally faulted, shallowly buried limestones from Malta. Core plug X-ray tomography indicates that texturally heterogeneous host rocks lea

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Fu, Jin, Ning Bo Zhao, Cheng Kai Pei, Xin Chun Li, and Tao Liu. "Indicator Elements Combination’s Characteristic and Genesis of Four Types of Uranium Mineralization in China." Applied Mechanics and Materials 737 (March 2015): 831–34. http://dx.doi.org/10.4028/www.scientific.net/amm.737.831.

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China uranium mineralization in accordance with different metallogenic host rocks are mainly divided into four types: granite type uranium mineralization, volcano rock type uranium mineralization, the carbonate-siliceous-politic rock type and sandstone type uranium mineralizations, four types of uranium mineralization is due to different genesis and metallogenic environment, the indicator elements also have bigger difference. In this paper, through the national uranium resources potential evaluation project research results, describes characteristics of indicator elements of four types uranium

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Miller, Kevin, Tiziana Vanorio, Sam Yang, and Xianghui Xiao. "A scale-consistent method for imaging porosity and micrite in dual-porosity carbonate rocks." GEOPHYSICS 84, no. 3 (2019): MR115—MR127. http://dx.doi.org/10.1190/geo2017-0812.1.

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Unlike many other clastic rocks, relating velocity and permeability to porosity for micrite-bearing carbonate rocks has been largely unsuccessful. Recent studies have shown that additional parameters, most notably the distribution and/or proportion of micrite, can be used to parameterize the velocity and permeability behavior. However, there is currently no scale-consistent, 3D methodology for differentiating macroporosity and microporosity from the total porosity measured on bench-top laboratory equipment. Previous studies estimated microporosity and micrite content by combining total porosit

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Melezhik, V. A., and A. E. Fallick. "Palaeoproterozoic, rift-related, 13C-rich, lacustrine carbonates, NW Russia. Part I: Sedimentology and major element geochemistry." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 95, no. 3-4 (2004): 393–421. http://dx.doi.org/10.1017/s0263593300001140.

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ABSTRACTThe 150-m-thick Kuetsjärvi Sedimentary Formation (KSF) from the Pechenga Greenstone Belt, NW Russia, is one of the key formations in the study of a positive δ13Ccarb excursion occurring globally in the Palaeoproterozoic. The KSF formed in an intracratonic rift setting and is sandwiched between two, 2-km-thick subaerially erupted volcanic units. The KSF was previously interpreted as shallow marine, but new data reported here indicate that it is a non-marine unit deposited on a deeply subaerially weathered surface mantling the underlying volcanic rocks. The lowermost part of the KSF repr

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Patey, Karen S., and Derek H. C. Wilton. "The Deer Cove deposit, Baie Verte Peninsula, Newfoundland, a Paleozoic mesothermal lode-gold occurrence in the northern Appalachians." Canadian Journal of Earth Sciences 30, no. 7 (1993): 1532–46. http://dx.doi.org/10.1139/e93-131.

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The Siluro-Devonian Deer Cove deposit, Baie Verte Peninsula, Newfoundland, is hosted by volcanic cover rocks of the Point Rousse Complex ophiolite. Mineralization consists of quartz vein lodes with gold, pyrite, lesser chalcopyrite, and minor arsenopyrite. Gold occurs as relatively pure gold intergrown with pyrite, and as solitary grains within the quartz gangue. Host rocks include basalt and gabbro at greenschist-facies metamorphic grade. The volcanic rocks have a general calcalkaline affinity, with (anhydrous) SiO2, TiO2, MgO, Al2O3, and Zr contents of 34–62%, 0.36–0.9%, 2.8–9%, 13.4–18.5%,

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Fabricius, Ida L., Gregor Baechle, Gregor P. Eberli, and Ralf Weger. "Estimating permeability of carbonate rocks from porosity and vp ∕ vs." GEOPHYSICS 72, no. 5 (2007): E185—E191. http://dx.doi.org/10.1190/1.2756081.

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We present a method for predicting permeability from sonic and density data. The method removes the porosity effect on the ratio [Formula: see text] of dry rock, and it addresses the specific surface as an indirect measure of permeability. We look at ultrasonic data, porosity, and the permeability of 114 carbonate core plugs. In doing so, we establish an empirical relationship between the specific surface of the solid phase (as calculated by Kozeny’s equation) and [Formula: see text] (linearly transformed to remove the porosity effect). One must view the specific surface derived by using Kozen

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Watson, Ken, Lawrence C. Rowan, Timothy L. Bowers, Carmen Anton‐Pacheco, Pablo Gumiel, and Susanne H. Miller. "Lithologic analysis from multispectral thermal infrared data of the alkalic rock complex at Iron Hill, Colorado." GEOPHYSICS 61, no. 3 (1996): 706–21. http://dx.doi.org/10.1190/1.1443998.

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Airborne thermal‐infrared multispectral scanner (TIMS) data of the Iron Hill carbonatite‐alkalic igneous rock complex in south‐central Colorado are analyzed using a new spectral emissivity ratio algorithm and confirmed by field examination using existing 1:24 000‐scale geologic maps and petrographic studies. Color composite images show that the alkalic rocks could be clearly identified and that differences existed among alkalic rocks in several parts of the complex. An unsupervised classification algorithm defines four alkalic rock classes within the complex: biotitic pyroxenite, uncompahgrite

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Seiedi, Omolbanin, Mohammad Zahedzadeh, Emad Roayaei, Morteza Aminnaji, and Hossein Fazeli. "Experimental and modeling study of wettability alteration through seawater injection in limestone: a case study." Petroleum Science 17, no. 3 (2020): 749–58. http://dx.doi.org/10.1007/s12182-019-00407-y.

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AbstractWater flooding is widely applied for pressure maintenance or increasing the oil recovery of reservoirs. The heterogeneity and wettability of formation rocks strongly affect the oil recovery efficiency in carbonate reservoirs. During seawater injection in carbonate formations, the interactions between potential seawater ions and the carbonate rock at a high temperature can alter the wettability to a more water-wet condition. This paper studies the wettability of one of the Iranian carbonate reservoirs which has been under Persian Gulf seawater injection for more than 10 years. The wetta

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Wang, Zhijing. "Seismic anisotropy in sedimentary rocks, part 2: Laboratory data." GEOPHYSICS 67, no. 5 (2002): 1423–40. http://dx.doi.org/10.1190/1.1512743.

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Part one of this paper presents a method for measuring seismic velocities and transverse isotropy in rocks using a single core plug. This method saves at least two‐thirds of the time for preparing core samples and measuring velocities in transversely isotropic (TI) rocks. Using this method, we have measured velocity and anisotropy of many shale and reservoir rocks from oil and gas fields around the world. We present some of the data in this paper, which include seismic velocity and anisotropy in 17 brine‐saturated shale samples, 1 gas‐ and brine‐saturated coal sample, 8 brine‐saturated sands,

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Kogarko, L. N. "Role of CO2 on differentiation of ultramafic alkaline series: liquid immiscibility in carbonate-bearing phonolitic dykes (Polar Siberia)." Mineralogical Magazine 61, no. 407 (1997): 549–56. http://dx.doi.org/10.1180/minmag.1997.061.407.07.

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AbstractThe Maimecha-Kotui province in the North of Siberian platform is the largest province of ultramafic alkaline rocks in the world. The province comprises thirty-seven central-type complexes together with numerous dykes. The majority of dykes are radially disposed around the ultramafic alkaline massifs. Data are presented for dykes of the Dolbykha carbonatite complex, which comprises olivine and melilite nephelinites; nosean, calcite and cancrinite phonolites; calcite trachytes and calcite carbonatites.Some peralkaline phonolitic dykes contain carbonate-bearing globules with sizes of 1−2

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Wang, Zizhen, Ruihe Wang, Ralf J. Weger, Tianyang Li, and Feifei Wang. "Pore-scale modeling of elastic wave propagation in carbonate rocks." GEOPHYSICS 80, no. 1 (2015): D51—D63. http://dx.doi.org/10.1190/geo2014-0050.1.

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The relationship between P-wave velocity and porosity in carbonate rocks shows a high degree of variability due to the complexity of the pore structure. This variability introduces high uncertainties to seismic inversion, amplitude variation with offset analysis, porosity estimation, and pore-pressure prediction based on velocity data. Elastic wave propagation in porous media is numerically modeled on the pore scale to investigate the effects of pore structure on P-wave velocities in carbonate rocks. We built 2D models of porous media using pore structure information and the similarity princip

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Chen, Sui Hai, He Ming Cheng, and Tian Chun He. "Pb Isotopic Geochemistry of Carbonate-Hosted Pb-Zn Deposits, NW Guizhou Pb-Zn Metallogenic District, China." Advanced Materials Research 524-527 (May 2012): 160–65. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.160.

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The NW Guizhou Pb-Zn metallogenic district is an important part of the Yunnan – Sichuan - Guizhou Pb-Zn metallogenic province (SYG), and also is one of the important Pb-Zn producers in China. We analyzed the Pb isotopic compositions of sulfides, hosting rocks and basement rocks, the results show that the206Pb/204Pb,207Pb/204Pb, and208Pb/204Pb ratios of sulfides range from 18.029 to 19.900, 15.357 to 17.716 and 38.004 to 40.695, respectively. The206Pb/204Pb,207Pb/204Pb and208Pb/204Pb ratios of hosting rocks and basement rocks range from 18.397 to 19.483, 15.545 to 16.700 and 38.204 to 39.140, r

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Mollai, Habib, Georgia Pe-Piper, and Rahim Dabiri. "Genetic relationships between skarn ore deposits and magmatic activity in the Ahar region, Western Alborz, NW Iran." Geologica Carpathica 65, no. 3 (2014): 209–27. http://dx.doi.org/10.2478/geoca-2014-0015.

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Abstract Paleocene to Oligocene tectonic processes in northwest Iran resulted in extensive I-type calc-alkaline and alkaline magmatic activity in the Ahar region. Numerous skarn deposits formed in the contact between Upper Cretaceous impure carbonate rocks and Oligocene-Miocene plutonic rocks. This study presents new field observations of skarns in the western Alborz range and is based on geochemistry of igneous rocks, mineralogy of the important skarn deposits, and electron microprobe analyses of skarn minerals. These data are used to interpret the metasomatism during sequential skarn formati

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Maslov, A. V., D. V. Grazhdankin, S. A. Dub, et al. "Sedimentology and geochemistry of the Uk Formation, Upper Riphean, the Southern Urals." LITHOSPHERE (Russia) 19, no. 5 (2019): 659–86. http://dx.doi.org/10.24930/1681-9004-2019-19-5-659-686.

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Research subject. This article presents new data on carbonate facies of the upperUk subformation, Upper Riphean of theSouth Urals. A particular attention is paid to the distribution of rare-earth elements (REE) and yttrium (Y) in stromatolitic and intraclastic limestones and calcareous shales (bulk samples and their acetic acid leachates).Materials and methods. We have studied lithological features of limestones in the geological section and in thin sections. The contents of trace elements in rocks were determined by the ICP-MS method at the IGG UB RAS (Yekaterinburg), the composition of organ

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Dvorkin, Jack, and Abrar Alabbad. "Velocity–porosity–mineralogy trends in chalk and consolidated carbonate rocks." Geophysical Journal International 219, no. 1 (2019): 662–71. http://dx.doi.org/10.1093/gji/ggz304.

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SUMMARY Published laboratory elastic-wave velocity versus porosity data in carbonate rocks exhibit significant scatter even at a fixed mineralogy. This scatter is usually attributed to the strong variability in the rock-frame or pore-space geometry, which, in turn, is driven by the richness and complexity of diagenetic alteration in these very reactive sediments. Yet, by examining wireline data from oil-bearing high-to-medium porosity chalk deposits, we find surprisingly tight velocity–porosity trends. Moreover, these trends are continued into the low-porosity domain by data from a location th

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Sokol, Ella, Svetlana Kokh, Olga Kozmenko, et al. "Mineralogy and Geochemistry of Mud Volcanic Ejecta: A New Look at Old Issues (A Case Study from the Bulganak Field, Northern Black Sea)." Minerals 8, no. 8 (2018): 344. http://dx.doi.org/10.3390/min8080344.

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We characterise the mineralogy and geochemistry of Oligo-Miocene Maykopian shales that are currently extruded by onshore mud volcanoes of the Kerch-Taman Province (the Northern Black Sea) from the depths of ~2.5–3 km. The ejected muds are remarkable by highly diverse authigenic mineralogy that comprises glauconite, apatite, siderite, mixed Fe–Mg–Mn–(Ca) and Mn–Ca–Fe-carbonates, pyrite, marcasite, sphalerite, cinnabar, chalcopyrite, nukundamite, akantite, native Cu, Au and Au–Ag alloys. Precise geochemical techniques and high-resolution methods are applied to study the composition of bulk rocks

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Thi Luan, Bui, and Lieu Kim Phuong. "Petrographic characterization and petroleum potential of Mesozoic carbonate rock in Block 106, Northern Red river basin." Science and Technology Development Journal - Natural Sciences 2, no. 6 (2020): 146–64. http://dx.doi.org/10.32508/stdjns.v2i6.876.

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Petroleum exploration and exploitation in Red River basin has been carried since the early 1960s of the 20th century, however until now its effectiveness has been still limited. Recently, the oil price is constantly changing so the efficiency of petroleum exploration and exploitation is particularly considered. Therefore, the assessment of petroleum potential and the direction of exploration are not only scientific research but also economic problem for developing countries in which there is Vietnam. The article considers that characteristic of carbonate petrography is along with intergration

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Verwer, Klaas, Gregor Eberli, Gregor Baechle, and Ralf Weger. "Effect of carbonate pore structure on dynamic shear moduli." GEOPHYSICS 75, no. 1 (2010): E1—E8. http://dx.doi.org/10.1190/1.3280225.

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Elastic shear moduli from ultrasonic measurements of carbonate rocks show an increase or decrease when saturated from the dry state with brine. The induced changes on the moduli have been attributed to several rock-fluid interaction effects, including viscous coupling, reduction in free surface energy, and dispersion caused by local flow with a subsequent effect on acoustic velocities. As many studies have recognized that acoustic velocity in carbonate rocks is dependent on pore structure, a relationship between the pore structure and observed changes must, to a certain extent, exist. We make

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Sun, Huafeng, Hasan Al-Marzouqi, and Sandra Vega. "EPCI: A new tool for predicting absolute permeability from computed tomography images." GEOPHYSICS 84, no. 3 (2019): F97—F102. http://dx.doi.org/10.1190/geo2018-0653.1.

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We have developed a new and fast MATLAB algorithm for predicting absolute permeability. The developed tool relies on measuring the connectivity of pores in a given 3D microcomputed tomography rock image. An index of pore connectivity is evaluated. After a calibration step, the developed index is used to estimate permeability in a variety of rocks with challenging pore structures (e.g., complex carbonate formations). The developed algorithm was tested on sandstone and carbonate rock samples. It offers large computational and memory savings when compared with algorithms based on the lattice Bolt

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Cardona, Alejandro, and J. Carlos Santamarina. "Carbonate rocks: Matrix permeability estimation." AAPG Bulletin 103, no. 1 (2020): 131–44. http://dx.doi.org/10.1306/05021917345.

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Bérubé, Charles L., Gema R. Olivo, Michel Chouteau, and Stéphane Perrouty. "Mineralogical and textural controls on spectral induced polarization signatures of the Canadian Malartic gold deposit: Applications to mineral exploration." GEOPHYSICS 84, no. 2 (2019): B135—B151. http://dx.doi.org/10.1190/geo2018-0404.1.

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Applications of the spectral induced polarization (SIP) method to mineral exploration are limited by our knowledge of the relationships among rock texture, mineral composition, and electrical properties. Laboratory SIP responses were measured on rock samples from the Canadian Malartic gold deposit. Field SIP responses were also measured at the outcrop scale, along a profile that intersects a well-studied mineralized zone. The mineralogy and the texture of sedimentary rocks from this deposit were quantitatively determined with mineral liberation analysis. A systematic decrease (Pearson [Formula

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Sen, Pabitra N. "Resistivity of partially saturated carbonate rocks with microporosity." GEOPHYSICS 62, no. 2 (1997): 415–25. http://dx.doi.org/10.1190/1.1444152.

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Simple Archie's relations relate average conductivity to average porosity and average saturation, and seem to work when the fluctuations of local porosity and local saturation are small. In general, carbonates are extremely inhomogeneous and Archie's relations fail—the saturation exponent n can depend on saturation itself, and n can be anomalously large or small. The resistivity of rocks with a mixture of micropores, macropores, and vugs is computed using effective medium theories. Quantitative mathematical modeling is used to study the influence of textural details. Geometries that lead to an

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Garrouch, Ali A. "Predicting the cation exchange capacity of reservoir rocks from complex dielectric permittivity measurements." GEOPHYSICS 83, no. 1 (2018): MR1—MR14. http://dx.doi.org/10.1190/geo2017-0035.1.

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Dimensional analysis was performed to understand the physics of ionic dispersion in reservoir rocks and to identify the factors influencing the cation exchange capacity (CEC) of these rocks. Dimensional analysis revealed the existence of a general relation independent of the unit system between two dimensionless groups denoted as the cationic dispersion number [Formula: see text] and the conductivity number [Formula: see text]. The former group [Formula: see text] stands for the ratio of the CEC to the electrical double-layer dispersion. The latter group [Formula: see text] represents the rati

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Braunger, S., M. A. W. Marks, B. F. Walter, et al. "The Petrology of the Kaiserstuhl Volcanic Complex, SW Germany: The Importance of Metasomatized and Oxidized Lithospheric Mantle for Carbonatite Generation." Journal of Petrology 59, no. 9 (2018): 1731–62. http://dx.doi.org/10.1093/petrology/egy078.

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Abstract The Miocene Kaiserstuhl Volcanic Complex (Southwest Germany) consists largely of tephritic to phonolitic rocks, accompanied by minor nephelinitic to limburgitic and melilititic to haüynitic lithologies associated with carbonatites. Based on whole-rock geochemistry, petrography, mineralogy and mineral chemistry, combined with mineral equilibrium calculations and fractional crystallization models using the Least Square Fitting Method, we suggest that the Kaiserstuhl was fed by at least two distinct magma sources. The most primitive rock type of the tephritic to phonolitic group is rare

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Pitawala, H. M. T. G. A. "Mineralogy, petrography, geochemistry and economic potential of carbonate rocks of Sri Lanka." Journal of the Geological Society of Sri Lanka 20, no. 1 (2019): 1. http://dx.doi.org/10.4038/jgssl.v20i1.24.

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Saenger, Erik H., Stephanie Vialle, Maxim Lebedev, et al. "Digital carbonate rock physics." Solid Earth 7, no. 4 (2016): 1185–97. http://dx.doi.org/10.5194/se-7-1185-2016.

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Abstract. Modern estimation of rock properties combines imaging with advanced numerical simulations, an approach known as digital rock physics (DRP). In this paper we suggest a specific segmentation procedure of X-ray micro-computed tomography data with two different resolutions in the µm range for two sets of carbonate rock samples. These carbonates were already characterized in detail in a previous laboratory study which we complement with nanoindentation experiments (for local elastic properties). In a first step a non-local mean filter is applied to the raw image data. We then apply differ

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Hogarth, D. D. "Chemical Composition of Fluorapatite and Associated Minerals from Skarn Near Gatineau, Quebec." Mineralogical Magazine 52, no. 366 (1988): 347–58. http://dx.doi.org/10.1180/minmag.1988.052.366.06.

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AbstractSixteen fluorapatite specimens from regional skarns in granulite terrain were associated with Al-zoned diopside ± scapolite ± actinolite ± calcite(+ rare phlogopite). Apatite was low in Ce (ave. 0.19% Ce2O3) and enriched in LREE relative to HREE (La/Yb = 31 to 74 in 4 specimens). Some specimens showed small negative Eu anomalies and some crystals were zoned in REE. SrO averaged 0.36%. The mineral contained some carbonate (ave. 0.5% CO2 in 5 specimens), appreciable silica (ave. 0.5%), and variable sulphate (0.1 to 1.2% SO3). Excess charge due to S6+ was largely compensated by Si4+. Chlo

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