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Science China Earth Sciences 2011年第8期54卷 1136-1148页

作者： YAO HuaZhou ZHANG RenJie DUAN QiFa SHENG XianCai NIU ZhiJun WANG JianXiong ZENG BoFu WU JianHui Wuhan Center of Geological Survey China Geological Survey Wuhan 430223 China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China Institute of Exploration and Development Jianghan Petroleum Administration Bureau Qianjiang 443124 China Hubei Vocational College of Land and Resources Jingzhou 434000 China

Jurassic rocks are abundantly developed in the source area of the Yangtze River,South Qinghai,with the greatest thickness of 6311 m,including five stratigraphic units:Qoimaco Formation,Buqu Formation,Xiali Formation,Suowa Formation,and Xueshan *** on sufficient fossils of bivalves,ammonites,and brachiopods,the major part of these formations is ascribed to the Middle Jurassic Bathonian to *** diagnostic fossils have been found from the Lower Qoimaco Formation or Upper Xueshan Formation,which could possibly contain in part Bajocian and Oxfordian taxa respectively.

关键词： Source area of Yangtze River Jurassic rocks bivalves depositional environments

Microfacies and depositional environments of Miocene Isolated Carbonate Platforms from Central Luconia, Offshore Sarawak, Malaysia

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Acta Geologica Sinica(English Edition) 2017年第5期91卷 1778-1796页

作者： Hammad Tariq JANJUHAH José Antonio GáMEZ VINTANED Ahmed Mohamed Ahmed SALIM Ibrahima FAYE Mumtaz Muhammad SHAH Deva Prasad GHOSH SEACARL Department of Geoscience University Technology PETRONAS Perak Malaysia 32610 Department of Geoscience University Technology PETRONAS Perak Malaysia 32610 Department of Fundamental and Applied Science University Technology PETRONAS Perak Malaysia 32610 Department of Earth Science Quaid-i-Azam UniversityIslamabad Pakistan 45320 CoE in CSIf Department of Geoscience University Technology PETRONAS Perak Malaysia 32610

The Luconia Province-offshore Sarawak-is a key geological unit for understanding the distribution of hydrocarbon resources in Malaysia. Nevertheless, little effort has been made to address the palaeoenvironmental characteristics of the Tertiary carbonates in the key sector of Central *** study the sedimentology and petrography of core samples from a well in Central Luconia, for which thirteen microfacies have been identified reflecting different depositional settings. This is the first microfacies scheme elaborated for Luconian carbonates. Lithofacies and microfacies distribution are compatible with deposition in a reef complex, originating around a framework reef, within the euphotic zone. Sediments were deposited in environments of backreef, reef crest, and forereef. The fair weather wave base is marked by the presence of coralline red algae, foraminifera, decreasing degree of bioclast fragmentation and other microfacies features. As a result, a depositional-environmental model is constructed, depicting a reef complex built around a framework reef developed on the margin of an isolated platform. In addition, an innovative, preliminary time series analysis of facies, microfacies and depositional environment data reveal the existence of seasonal cycles in the stacking patterns of facies and microfacies.

关键词： central Luconia sedimentology microfacies reef complex depositional environments time series

Geochemical,mineralogical,and petrological characteristics of the Cretaceous coal from the middle Benue Trough Basin,Nigeria:Implication for coal depositional environments

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Energy Geoscience 2022年第3期3卷 300-313页

作者： Segun A.Akinyemi James C.Hower Henry Y.Madukwe Bemgba B.Nyakuma Mohammed B.Nasirudeen Timileyin A.Olanipekun Rabelani Mudzielwana Mugera W.Gitari Luis F.O.Silva Department of Geology Faculty of ScienceEkiti State UniversityP.M.B 5363Ado EkitiEkiti StateNigeria Energy Environmental and Nanosciences GroupDepartment of GeologyEkiti State UniversityP.M.B 5363Ado-EkitiEkiti StateNigeria University of Kentucky Centre for Applied Energy Research2540 ResearchPark DriveLexingtonKY40511USA Department of Earth&Environmental Sciences University of KentuckyLexingtonKY40506USA Department of Chemistry Faculty of SciencesBenue State UniversityP.M.B.102119MakurdiBenue StateNigeria Department of Chemistry Faculty of ScienceFederal University of LafiaP.M.B.146LafiaNasarawa StateNigeria Institute of Earth and Environmental Sciences Albert Ludwigs Universitat FreiburgAlbert Straße 23-B79104Freiburg Breisgau Germany Department of Ecology and Resources Management University of VendaPrivate BagX5050Thohoyandou0950LimpopoSouth Africa Department of Civil and Environmental Universidad de la CostaCalle 58#55-66080002BarranquillaAtlanticoColombia

The Benue Trough Basin (BTB) of Nigeria is geologically and geo-morphologically subdivided into upper,middle, and lower segments. The BTB is the subject of geological research due to its rich coal depositsthat have the potential for oil and gas. The purpose of the present study is to examine the origins,depositional environments, and thermal history of the selected coals and the processes that influencetheir quality. Coal samples from different open cast coal mines in the middle BTB were examined usingproximate and ultimate, x-ray diffraction (XRD), x-ray fluorescence (XRF), laser ablation induced coupledplasma (LA-ICPMS), and petrographical analyses. The coal samples contained mainly quartz, kaolinite,and organic carbon. The XRD spectra peaks revealed the triclinic and monoclinic structure of kaolin. TheSiO2/Al2O3 ratios confirmed the dominance of quartz and kaolinite. The Ni/Co versus V/Cr, Cu/Zn, and V/Mo values in the studied coals suggest oxic depositional environments, whereas the V/(Ni þ V) and V/(V þ Cr) values indicate oxic to suboxic conditions. The Ce/Ce* values are slightly below 1, which indicates a suboxic depositional environment. Maceral texture is indicative of transformations from subbituminous to high volatile C or B bituminous coal. The maceral components and mineral matter(10%) of the studied coals imply deposition in the planar margin mire, and a river system of planarmargin mire environments, respectively. The high gelification index (GI) and tissue preservation index(TPI) values indicate peat accumulation developed within a wet forest swamp. The ternary diagram ofthe maceral component suggests deposition in a wet moor environment with intermittent moderate tohigh flooding episodes. The studied coals are sub-hydrous vitrinite inferring hydrogen-poor and thermally immature characteristics. The low V and Ni contents, low H/C and high O/C, indicate Type IIIterrestrial organic matter with the potential to generate gaseous hydrocarbons. The investi

关键词： Coal Maceral Trace elements Mineralogy depositional environments

Microfacies Patterns and depositional environments of the Sarvak Formation in the Abadan Plain, Southwest of Zagros, Iran

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Open Journal of Geology 2016年第3期6卷 201-209页

作者： Shahab Soleimani Asl Mohsen Aleali Department of Geology Science and Research Branch Islamic Azad University Tehran Iran

The Sarvak Formation is the second major oil-bearing reservoir in the south and south west of Iran. The Middle Cretaceous Sarvak formation in the Zagros Mountains (Zagros Basin) is mainly composed of carbonate sequences. Based on facies studied, thirteen microfacies were recognized in the studied area, which were categorized in the three facies groups: including inner ramp, mid ramp and outer ramp. Evidences such as the gradual changes in the facies (basin slope), the absence of extensive uninterrupted barrier reef, the lack of calciturbidite and gravity sediments as well as the high proportion of grain-supported indicated that the Sarvak Formation was deposited in the ramp like depositional system, particularly on an inner ramp setting. Inner ramp facies group is the principal setting and subdivided to tidal flat, restricted and unrestricted lagoon as well as shoal sub-environments.

关键词： Microfacies depositional environments Sarvak Formation Zagros Iran

Paleoenvironmental Characteristics of Paleogene Lacustrine Source Rocks in the Western Bozhong Sag,Bohai Bay Basin,China:Evidence from Biomarkers,Major and Trace Elements

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 220-240页

作者： WANG Xiang LIU Guangdi SONG Zezhang SUN Mingliang WANG Xiaolin WANG Feilong CHEN Rongtao GENG Mingyang LI Yishu State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing 102249China College of Geosciences China University of PetroleumBeijing 102249China China National Offshore Oil Co. Ltd.(CNOOC)Tianjin Branch CompanyTianjin 300459China CNOOC Research Institute Beijing 100028China

The organic matter(OM)enrichment mechanisms and depositional environment characteristics of lacustrine source rocks in the western Bozhong Sag,Bohai Bay Basin in Northeast China remain *** address these issues,based on Rock-Eval pyrolysis,kerogen macerals,H/C and O/C ratios,GC-MS,major and trace elements,the Dongying Formation Member(Mbr)3(E_(3)d_(3)),the Shahejie Formation mbrs 1 and 2(E_(2)s_(1+2)),and the Shahejie Mbr 3(E_(2)s_(3))source rocks in the western Bozhong Sag were *** above methods were used to reveal their geochemical properties,OM origins and depositional environments,all of which indicate that E_(2)s_(1+2)and E_(2)s_(3)are excellent source rocks,and that E_(3)d_(3)is of the second good quality.E_(3)d_(3)source rocks were formed under a warm and humid climate,mainly belong to fluvial/delta facies,the E_(3)d_(3)sediments formed under weakly oxidizing and freshwater ***,the depositional environments of E_(2)s_(1+2)source rocks were arid and cold climate,representing saline or freshwater lacustrine facies,and the sediments of E_(2)s_(1+2)belong to anoxic or suboxic settings with large evaporation and *** the period of E_(2)s_(3),the climate became warm and humid,indicating the freshwater lacustrine facies,and E_(2)s_(3)was characterized by freshwater and abundant ***,compared with other intervals,the OM origin of E_(3)d_(3)source rocks has noticeable terrestrial *** OM origin of the E_(2)s_(1+2)and E_(2)s_(3)are mainly plankton and *** subsidence and climate change have affected the changes of the depositional environment in the western Bozhong Sag,thus controlling the distribution of the source rocks,the geochemical characteristics in the three intervals of lacustrine source rocks have distinct ***,these factors are effective to evaluate the paleoenvironmental characteristics of source rocks by biomarkers,major and trace *** established models

关键词： petroleum geology source rocks depositional environments biomarkers major elements trace elements Bozhong Sag

Microfacies analysis and depositional environment of the Upper Devonian Dankovo-Lebedyansky sediments,Tatarstan,Volga-Ural Basin,Russia

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Petroleum Research 2023年第2期8卷 244-255页

作者： Ibrahem Yousef V.P Morozov A.N Kolchugin V.Sudakov I.Idrisov A.Leontev Kazan Federal University Institute of Geology and Petroleum Technologies420008Russian Federation

The Upper Devonian,Middle Famennian Dankovo-Lebedyansky sediments in Southeast Tatarstan territory are a carbonate sequence composed of limestone and dolomite,which is important hydrocarbon reservoir units,therefore,it is necessary to conduct in-depth study on its microfacies and depositional *** this study,a multidisciplinary approach that combines core observation with thin section examination is *** limestone contains abundant skeletal grains(echinoderms,foraminifera,algae,gastropods,and calcispheres),as well as non-skeletal grains(intraclasts and peloids).On the basis of detailed petrographic investigations,six sedimentary microfacies can be identified,including(i)peloidal grainstone(MF 1),(ii)cemented bioclastic peloidal grainstone(MF 2),(iii)echinodermconcentrated packstone(MF 3),(iv)algae packstone(MF 4),(v)bioclastic wackestone(MF 5),(vi)whole-fossil wackestone(MF 6),as well as dolomite or dolostone as diagenetic facies(MF 7).Based on microfacies analysis,the Dankovo-Lebedyansky sediments were deposited in three distinct sedimentary facies belts(shoal,lagoon and open marine environment).In order to reflect dispositional energy condition,the microfacies were grouped into facies associations:(i)low-energy microfacies associations including MF 5 and MF 6,(ii)moderate energy microfacies associations including MF 1,MF 2,MF 3,and MF *** dolomite,or diagenetic facies(MF 7),is the result of slightly to extensively dolomitization of limestone in the Dankovo-Lebedyansky *** of frequent dolostone types are euhedral planar-e and subhedral *** to petrographic characteristic of the dolostone,a seepage reflux model can be used to explain the dolomitization process of Dankovo-Lebedyansky sediments.

关键词： Microfacies depositional environments Carbonate Dolomitization Upper devonian Dankovo-lebedyansky Volga-ural basin

Palaeogeographical zonation of gypsum facies:Middle Miocene Badenian of Central Paratethys (Carpathian Foredeep in Europe)

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Journal of Palaeogeography 2013年第3期2卷 225-237页

作者： Tadeusz Marek Peryt Polish Geological Institute National Research Institute

Studies on Middle Miocene Badenian gypsum in various parts of Central Paratethys,the oldest widespread primary marine gypsum,in western Ukraine,southern Poland and Moravia (Czech Republic) indicate that there are three principal gypsum facies:crystalline gypsum,stromatolitic gypsum and clastic *** latter typically occurs between crystalline and stromatolitic gypsum and between stromatolitic gypsum and the *** addition,it is common in channels within gypsum microbialites,and is the main facies during the deposition of the upper part of Badenian gypsum when important bathymetric differences existed within the marginal part of the Carpathian Foredeep Basin,the largest foredeep basin in *** crystalline gypsum facies,it is observed the overall size of the crystals increases and that the layering declines towards the permanent,stabilized brine body,and thus the giant gypsum intergrowths-non-layered coarse-crystalline selenite is the end-member of gypsum facies *** it passes into layered selenites although owing to fluctuations of pycnocline level,some transitional gypsum subfacies may be missing both in the vertical section as well as in particular *** following important controls on the development of gypsum facies have been identified:pycnocline level fluctuations,brine level fluctuations including brine sheets and floods,rare marine transgressions,pedogenesis leading to "alabastrine" gypsum development,and rate of inflow of continental water.

关键词： gypsum depositional environments facies Badenian palaeogeography

Interpretation of depositional Environment of Fusulinid Bearing Middle Permian Succession of Bolula and Khaja Ghar Formation, Bamian Zone, Central Afghanistan

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International Journal of Geosciences 2022年第7期13卷 499-530页

作者： Mohammad Naeem Sarwary Chaman Shah Alamy Mohammad Ltif Rahimi Pramod Kumar Faculty of Geology & Mine Ghazni Technical University Ghazni Afghanistan Department of Geology Delhi University Delhi India

The study area belongs to the north Afghanistan having complex tectonic setting, because of separation of the Afghanistan plate from Pangea in Early Permian and its subsequent northward journey and collision with Eurasian plate. The rock exposed in the area belongs to Paleozoic, Mesozoic to Quaternary with Proterozoic basement. Particularly the Permian succession of Afghanistan is rich in fusulinids (larger foraminifera), is age diagnostic, provides strong biostratigraphic tool for the Permian deposits, and has paleobiogeographic applications. The Bamian zone of north Afghanistan has good exposure to Middle Permian and is designated as Bolula and Khaja Ghar Formation is undertaken in this study. The Bolula Formation overlies the greenschist and basalts, composed mainly of carbonate rocks (Dolostone and limestone), having massive limestone, with some quartz and secondary calcite vein in the succession. The intermittent siliciclastic wedges within the carbonate succession are identified as input within the platform with tectonic pulses in the hinterland. Bolula and Khaja Ghar succession is divided into 8 lithofacies ( Facies A to H) and 6 carbonate Facies viz. Sparry calcites limestone, Micritic limestone, Fossiliferous limestones (Biomicrite), Peloidal limestone (Fecal pellets), Interlaminated micritic and sparite limestone, and sandy limestone (micritic). The Bolula and Khaja Ghar Formation in the Bamian area have deposited in a shallow marine shelf environment because of predominance of carbonate rocks and presence of shallow-water marine fossils including fusulinids, small benthic foraminifera, algae, bivalve, brachiopods fragments, corals and bryozoans, etc. In the Bamian zone the unconformity between Upper Carboniferous and Lower Permian;indicates extensive gap in sedimentation, traceable to many parts of Afghanistan as unconformity or tectonic contact is considered here as sequence boundary.

关键词： Permian of Afghanistan Bolula and Khajagarh Formation Fusulinid Foraminifera depositional environments Paleogeographic Significance

Paleohydrological Reconstruction from Late Holocene Records in Interdune Lakes(N’Guigmi,Northern Bank of the Lake Chad,Niger)

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Open Journal of Geology 2013年第2期3卷 143-155页

作者： David Sebag Alain Durand Zibo Garba Eric P.Verrecchia Laboratoire Morphodynamique Continentale et Cotiere Universite de RouenCentre National de la Recherche Scientifique(CNRS)RouenFrance Laboratoire HydroSciences Montpellier Institut de Recherche pour le Developpement(IRD)Universite de NgaoundereCamerounFrance Departement de Geologie Universite Abdou MoumouniNiameyNiger Institut des Sciences de la Terre Universite de LausanneLausanneSwitzerland

An old erg covers the northern part of the Lake Chad basin. This dune landform allowed the formation of many interdune ponds of various sizes. Still present in certain zones where the groundwater level is high (e.g. Kanem, southern Manga), these ponds formed in the past a vast network of lacustrine microsystems, as shown by the nature and the distribution of their deposits. In the Manga, these interdune deposits represent the main sedimentary records of the Holocene environmental succession. Their paleobiological (pollens, diatoms, ostracods) and geochemical (δ18O, δ13C, Sr/Ca) contents are often the basis for paleoenvironmental reconstruction. On the other hand, their sedimentological characters are rarely exploited. This study of palustro-lacustrine deposits of the Holocene N’Guigmi lake (northern bank of the Lake Chad;Niger) is based on the relationships between the sedimentological features and the climato-hydrological fluctuations. The mineralogical parameters (e.g. calcium carbonate content, clay mineralogy) and the nature of autochthonous mineralization (i.e. amorphous silica, clays, calcium carbonates) can be interpreted using a straightforward hydro-sedimentary model. Established to explain the geochemical dynamics of Lake Chad, this model is based on a biogeochemical cycle of the main elements (i.e. silicium, calcium) directly controlled by the local hydrological balance (i.e. rainfall/evaporation ratio). All these results show that a detailed study of sedimentological features can provide important paleohydrological informations about the regional aridification since ca 6500 14C BP.

关键词： Sahel Lake Chad Holocene Mineralogy depositional environments Climate Change