Journal of Palaeogeography最新文献

{"title":"Provenance and tectonic setting of sandstones of the Lomas Coloradas Formation, Cabullona Group, Sonora, México: Constraints on petrography and geochemistry","authors":"J. Madhavaraju ,&nbsp;D.G. Noriega-Montoya ,&nbsp;E. Ramirez-Montoya ,&nbsp;C.M. González-León ,&nbsp;John S. Armstrong-Altrin","doi":"10.1016/j.jop.2024.07.005","DOIUrl":"10.1016/j.jop.2024.07.005","url":null,"abstract":"<div><div>The sedimentary rocks of the Cabullona Group are well exposed in the Cabullona Basin of northeastern Sonora, México, which represent syntectonic sedimentation associated with Laramide-style deformation during the Campanian−early Maastrichtian. The sandstones of the Lomas Coloradas Formation deposited at the upper part of the Cabullona Group. Petrography and geochemical (major, trace, and rare earth elements) studies were carried out on the sandstones to interpret the palaeoweathering, provenance, and tectonic setting of the Lomas Coloradas Formation sandstones. Most of the sandstone modal analysis data plotted in the QFL and QmFLt ternary diagrams fall into the fields of dissected arcs and recycled orogens, respectively. Geochemically the sandstones are classified as litharenites while few samples plot into the arkosic field. The chondrite-normalized REE diagrams for sandstones have LREE-enriched, relatively flat HREE patterns with negative Eu anomalies. CIA values and the A‒CN‒K diagram indicate a low intensity of chemical weathering in the source area. The tectonic setting diagram suggests both arc and rift settings for the studied sandstones. The bivariate and ternary diagrams and elemental ratios suggest a felsic source for the Lomas Coloradas Formation. The average REE patterns of the studied sandstones are comparable with REE patterns of the granite from the Caborca block, the rhyolite and granite of the Tarahumara Formation, and the Mesozoic felsic volcanic rocks. The modeled mixture of 40% Proterozoic granite, 30% Triassic arc, 10% Jurassic arc, and 20% Laramide arc represents the probable source rocks for the Lomas Coloradas Formation.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 4","pages":"Pages 839-861"},"PeriodicalIF":0.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolution of a confined gravelly river to a braided-meandering river in the Late Cretaceous Khasi group, southern Shillong plateau, NE India","authors":"Adrita Choudhuri ,&nbsp;Prem Raj Uddandam ,&nbsp;Debarati Nag","doi":"10.1016/j.jop.2024.08.003","DOIUrl":"10.1016/j.jop.2024.08.003","url":null,"abstract":"<div><div>This paper intends to unravel the depositional condition of the Basal Conglomerate/Jadukata Formation and the Lower Mahadek Formation in southern Shillong Plateau, NE India deposited during the Late Cretaceous period. The studied succession is entirely siliciclastics in composition and was built up on the Precambrian basement rocks. State-of-art facies analysis and palaeocurrent evidence helped us to reconstruct the palaeogeography and palaeoenvironment. The facies tracts reveal that frequent hyperconcentrated mass flow deposits dominated the proximal part of the river channels. Gradually, the river evolved to a sandy braided and finally mud-dominated, meandering system. The river channel changed its pattern through onlapping and progressive elimination of the accommodation space created by the tectonic subsidence/upliftment. Major shifts in palaeocurrent direction at different stages of the river evolution confirm the role of tectonics on the river channel evolution. QFL detrital modes of the sandstones reflecting lithic wacke composition and the recycled orogeny corroborate the interpretation. Rapid lateral and vertical facies transition suggests a pull-apart type basin due to ongoing rifting. Geochemical analyses also show signatures of the overlapping tectonic conditions supporting the pull-apart basin model.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 4","pages":"Pages 754-774"},"PeriodicalIF":0.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Higher palaeoelevation in the Baoshan Basin: Implications for landscape evolution at the southeastern margin of the Tibetan Plateau","authors":"Yong-Jiang Huang ,&nbsp;Hao-Ran Zong ,&nbsp;Shi-Tao Zhang ,&nbsp;Arata Momohara ,&nbsp;Jin-Jin Hu ,&nbsp;Lin-Bo Jia ,&nbsp;Yun-Heng Ji ,&nbsp;Zhe-Kun Zhou","doi":"10.1016/j.jop.2024.05.004","DOIUrl":"10.1016/j.jop.2024.05.004","url":null,"abstract":"<div><p>Surface uplift at the southeastern margin of the Tibetan Plateau has been widely studied, but more palaeoaltimetry data are required to better understand the elevation history of this geologically complex region. In this study, fossil leaves of <em>Abies</em> (Pinaceae), a cool-temperate element, recovered from the latest Miocene–Pliocene Yangyi Formation of the southern Baoshan Basin, were used as a proxy to estimate the local palaeoelevation. Based on the regional modern altitude range (2100–4280 m) of the genus as well as regional temperature discrepancy (1.5 °C) between the past and present, the palaeoelevation of the study area was calculated to be &gt; 2360 m above sea level as compared to 1670 m at present. Our result suggests that the southern Baoshan Basin experienced pronounced uplift prior to the time of fossil deposition, probably as a result of crustal shortening and thickening of the northern Baoshan Terrane during the Eocene–Oligocene. We infer that surface growth in areas south of the Dali Basin may have been greater than previously interpreted, and that a widespread plateau or plateau patches higher than 2000 m probably extended southwards into at least the Baoshan Basin by the latest Miocene–Pliocene. We also infer that the elevation of the southern Baoshan Basin has decreased by at least 690 m since then, in contrast to most other scenarios in which the elevation of the southeastern margin of the Tibetan Plateau has increased or remained close to modern levels since the late Miocene. The major cause of the inferred altitude decline is likely tectonic deformation. As a transtensional graben basin, the Baoshan Basin has experienced pull-apart and base-fall movement since the late Miocene, which would reduce the altitude of its southern part located on the hanging wall. Surface erosion associated with the increased summer rainfall might also have played a role especially in reducing the local relief, although its contribution can be limited. Our study provides one of the few palaeoelevation estimates from areas south of the Dali Basin and an example of past elevation loss at the southeastern margin of the Tibetan Plateau, thus shedding important light on the landscape evolution of this region.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 3","pages":"Pages 563-580"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000440/pdfft?md5=944df30db3f6cb70de35209df35e5bf1&pid=1-s2.0-S2095383624000440-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141278008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sedimentary facies analysis of a thin-bed-dominated turbidite succession in the Miocene Temburong Formation, Kampung Bebuloh, Labuan Island, Malaysia","authors":"Farah Syafira Burhanuddin,&nbsp;Meor Hakif Amir Hassan","doi":"10.1016/j.jop.2024.04.005","DOIUrl":"10.1016/j.jop.2024.04.005","url":null,"abstract":"<div><p>Thin-bedded turbidites are important hydrocarbon-bearing reservoirs in many mature fields throughout the world. The type of turbidite depositional setting strongly influences vertical and horizontal continuity of the reservoir. However, distinguishing between lobe and levee associated thin-bedded turbidites remains challenging due to their generally similar facies characteristics. This study aims to contribute some insights to this problem by conducting a detailed bed-scale facies analysis on the Early Miocene Temburong Formation exposed at Kampung Bebuloh, Labuan Island, Malaysia, which may uncover features that can help in differentiating between both depositional types. Six facies are recognized in the Temburong Formation, which are interpreted as low density turbidites (F1–F4), hybrid event beds (F5), and sustained turbidites (F6). Detailed facies and ichnology analysis reveal features which are consistent with a lobe fringe deposit rather than levee-associated environment interpretation, including tabular bed geometries, presence of hybrid event beds, and the absence of thick-bedded channel-fill sandstones. Five facies associations are identified and interpreted as representing sub-environments within an overall lobe depositional setting. A diverse trace fossil assemblage, comprising the <em>Nereites</em> ichnofacies is consistent with a deep marine environment. Further identification of the <em>Paleodictyon</em> and <em>Nereites</em> sub-ichnofacies indicates a distal turbidite system setting, most likely lobe fringe. Based on the thick accumulation of FA2 and FA3 and no distinct observable vertical trend, the Early Miocene Temburong Formation in Labuan is interpreted as turbidites deposited at the fringes of lobe complexes rather than a single lobe fringe. Earlier works into the Temburong Formation in SW Labuan proposed a middle slope to proximal basin floor setting where the thin-bedded intervals were interpreted as potentially representing either levee deposits or the fringes of confined lobe deposits. Conversely, the Temburong Formation at Kampung Bebuloh exhibits characteristics of an unconfined lobe setting, suggesting an evolutionary change in depositional conditions over time.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 3","pages":"Pages 401-429"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000324/pdfft?md5=63453d549f702c0aa5250586837b18e3&pid=1-s2.0-S2095383624000324-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141047465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Middle Devonian ostracods from Jiwozhai patch reef (Dushan, Guizhou Province, South China): Biostratigraphic and palaeoecological implication","authors":"Jun-Jun Song ,&nbsp;Jia-Yuan Huang ,&nbsp;Wen Guo ,&nbsp;Kun Liang ,&nbsp;Yu-Cong Sun ,&nbsp;Zhi-Hong Wang ,&nbsp;Wen-Kun Qie","doi":"10.1016/j.jop.2024.06.001","DOIUrl":"10.1016/j.jop.2024.06.001","url":null,"abstract":"<div><p>The Middle Devonian ostracods from the Jiwozhai patch reef in Dushan, Guizhou Province, South China were described for the first time in this study. Twenty-nine species belonging to 20 genera were identified and figured, including a new species named <em>Wangshangkia jiwozhaiensis</em> sp. nov. The ostracod fauna in the Jiwozhai patch reef represents a Givetian age. The ostracod assemblage belongs to the smooth-podocopid association, which is also ecologically equivalent to the Eifelian Mega-Assemblage III. This association is indicative of shallow open-marine environments. The Jiwozhai patch reef fauna is primarily comprised of suspension feeders, including filter-feeding ostracods, corals, brachiopods and bryozoans. Ostracods from the Jiwozhai patch reef were compared to the ostracod faunas from Laurentia–Baltica at generic level, which reveals limited faunal exchanges between South China and Laurentia–Baltica during the Middle Devonian.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 3","pages":"Pages 581-593"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000452/pdfft?md5=476484be9397c03de0cce16bfceb0ae2&pid=1-s2.0-S2095383624000452-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141401712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mammal-bearing Pleistocene deposits, Vranić, southwestern Pannonian Basin System","authors":"Adriano Banak ,&nbsp;Zsófia Ruszkiczay-Rüdiger ,&nbsp;Anita Grizelj ,&nbsp;Martina Đuras ,&nbsp;Krešimir Petrinjak ,&nbsp;Alexander Wieser ,&nbsp;Monika Milošević ,&nbsp;Davor Pavelić","doi":"10.1016/j.jop.2024.04.001","DOIUrl":"10.1016/j.jop.2024.04.001","url":null,"abstract":"<div><p>Vranić site is a sand quarry that is located on the southern foothills of Papuk Mountain. From bottom to top of the succession, three sedimentary units have been recognized as: Unit 1 containing massive sand with scattered gravel-sized clasts, marl cobbles and boulders, and abundant marine mammal and fish fossils; Unit 2 consisting of sand intercalated with silt, clay and gravel, which may be horizontally bedded; and Unit 3, which is an erosionally-based lenticular matrix to clast-supported structureless gravel. The basal part of Unit 1 shows numerous reworked skeletal remains of Miocene marine mammals. Cosmogenic radionuclides constrain the age of burial of Unit 1 to 895 ± 211 ka, while the source area of Unit 1 had a quick denudation.</p><p>The massive sands deposited on the slopes of Papuk Mountain were vulnerable to erosion due to the absence of clay. Heavy rainfall or water from snow melting created flash floods that infiltrated the sands, thereby causing slope destabilization and deformation. This process led to slumps that were transformed into a sandy debris flow. This sediment was probably deposited during the interglacial marine isotope age (MIS) 21 period when the scarce vegetation and a warmer climate favored the melting of permafrost ice and consequently triggered slope movements during MIS 22. The reworked skeletal material sampled at the Vranić site comprises fossilized fish along with mammal bones and teeth. Thus, the Vranić site represents an important site for cetacean fossil remains and serves as an important data source for marine life in the Central Paratethys.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 3","pages":"Pages 430-452"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000282/pdfft?md5=11c82b1082ff0af7553ecb66ac0b281b&pid=1-s2.0-S2095383624000282-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140573976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Origin of iron-rich minerals, ooids and pisoids in the Jurassic ooidal ironstones of the Labino-Malkin region (Caucasus)","authors":"Natalia A. Kalinina ,&nbsp;Maxim A. Rudmin ,&nbsp;Mikhail Sherstyukov ,&nbsp;Prokopiy Maximov ,&nbsp;Abdul-Gapur Kerimov","doi":"10.1016/j.jop.2024.04.003","DOIUrl":"10.1016/j.jop.2024.04.003","url":null,"abstract":"<div><p>This study investigates the Middle Jurassic rocks of the Labino-Malkin zone (Caucasus), represented by ooidal ironstones, biogenic limestones, and nodular phosphorites. All rocks contain ooids/pisoids. Based on the mineral composition, nine types of ooids and three possible scenarios for their formation have been identified. The mineral composition of ooids indicates the variable conditions of their deposition and repeated changes in physical and chemical conditions of the environment, including fluctuations in theredox regime. The access of oxygen in the bottom environment as a factor of increasing oxic conditions was associated with the regression of the sea and/or the inflow of meteoric waters. The main sources of ooids are the drift of material from the continent and convecting metal-bearing meteoric and/or deep solutions.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 3","pages":"Pages 475-494"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000336/pdfft?md5=29003ed081a17578737b25d182cc3aa3&pid=1-s2.0-S2095383624000336-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140932237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discovery of the choristodere Hyphalosaurus baitaigouensis from the Lower Cretaceous Jiufotang Formation of western Liaoning, China and its paleobiogeographic significance","authors":"Li-Jun Zhang ,&nbsp;Shu-An Ji ,&nbsp;Hai-Chun Zhang","doi":"10.1016/j.jop.2024.05.003","DOIUrl":"10.1016/j.jop.2024.05.003","url":null,"abstract":"<div><p>The water-living reptile genus <em>Hyphalosaurus</em> was previously discovered in the Lower Cretaceous Yixian Formation bearing the middle Jehol Biota in western Liaoning, China. Two complete skeletons of <em>Hyphalosaurus</em> are reported for the first time from the Jiufotang Formation bearing the late Jehol Biota at two sites in western Liaoning. They show the typical characteristics of <em>Hyphalosaurus baitaigouensis</em> in terms of the contact between some cranial bones and the number of cervical and dorsal vertebrae, and therefore are assigned to <em>H</em>. <em>baitaigouensis</em>. This discovery extends the stratigraphic range of this species from the Yixian Formation to the overlying Jiufotang Formation. This paper further briefly compares the main characteristics of the two skeletons, summarizes the temporal and spatial distribution of <em>Hyphalosaurus</em>, and discusses the palaeogeographic evolution of western Liaoning at the middle and late Jehol Biota stages based on the aquatic habits of <em>Hyphalosaurus</em> and the geological background of western Liaoning. The analytical results show that the volcanic downwarped lakes, with distinct geographical divisions in western Liaoning during the deposition of the Yixian Formation, had not completely disappeared till the deposition of the Jiufotang Formation. The palaeo-lake in the Fuxin-Yixian Basin underwent the process of generation, expansion and shrinkage during the depositional period of the Yixian Formation and finally merged into a large lake. The palaeo-Dalinghe River, which connected the main basins in western Liaoning during the depositional period of the Jiufotang Formation, was formed simultaneously.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 3","pages":"Pages 547-562"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000373/pdfft?md5=d44ec8fa3bbdc9ca5b64b72634ff617c&pid=1-s2.0-S2095383624000373-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141136679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics and origin of low-organic-matter carbonate source rocks in the Middle–Upper Ordovician, Tarim Basin, northwestern China","authors":"Jun-Qing Chen ,&nbsp;Fu-Jie Jiang ,&nbsp;Xiong-Qi Pang ,&nbsp;Hai-Jun Yang ,&nbsp;Kan-Yuan Shi ,&nbsp;Bo Pang ,&nbsp;Hong Pang ,&nbsp;Jian-Fa Chen ,&nbsp;Zhuo-Heng Chen ,&nbsp;Xin-Gang Zhang ,&nbsp;Song Wu","doi":"10.1016/j.jop.2024.04.002","DOIUrl":"10.1016/j.jop.2024.04.002","url":null,"abstract":"<div><p>The continually-discovered large volumes of marine hydrocarbons indicate a huge exploration potential within the carbonate rocks of Ordovician in the Tarim Basin, northwestern China. The Middle–Upper Ordovician (O₂₊₃) carbonate source rocks are at a highly mature stage. These rocks presently contain a low amount of total organic carbon (TOC_pd ≤0.5%) (TOC_pd means the present-day TOC). A mass balance approach is used to identify the source rocks that have expelled hydrocarbons. The characteristics and origin of hydrocarbon expulsion from low-TOC_pd source rocks are studied, which are significant for oil exploration in the basin. The results showed that a low-TOC_pd O₂₊₃ source rock having expelled hydrocarbons was type I and had a very narrow oil window. With a high rock maturity and a high original TOC (TOC_o) value exceeding 1%, nearly 80% of the generated hydrocarbons were expelled. The content of gammacerane and C₂₈ steranes in the oil and source rock extracts were relatively lean, with a V-shaped distribution of regular steranes, suggesting a possible genetic relation between the low-TOC_pd source rocks and the marine oil in the Tabei area. Hydrogen-rich planktonic algae or acritarchs were the main hydrocarbon parent materials, distributed in the subsiding platform-slope facies. Organic matter was preserved under reducing conditions, and source rocks were formed with a favorable kerogen type and a moderate hydrocarbon generation potential. This study illustrates the hydrocarbon expulsion of low TOC_pd source rocks in northern Tarim Basin, which is greatly significant for analyzing the genesis of marine crude oil in Tarim Basin, and evaluating the distribution of marine source rocks. This research method is theoretically significant for oil and gas exploration in the same type of highly-mature carbonate paleobasins.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 3","pages":"Pages 594-619"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000312/pdfft?md5=83dceefaef02a3761a957747ff272819&pid=1-s2.0-S2095383624000312-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140793932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Palaeodepositional environment, implications of Glossopteris flora, and organic matter characteristics from the Lower Permian, Karo Open Cast Mine, East Bokaro Coalfield, Damodar Basin, India","authors":"Sankar Suresh Kumar Pillai ,&nbsp;Rose Ann Sebastian ,&nbsp;Runcie Paul Mathews ,&nbsp;Srikanta Murthy ,&nbsp;Anju Saxena ,&nbsp;Mrutyunjaya Sahoo ,&nbsp;Suraj Kumar Sahu ,&nbsp;Gulshan Kumar Dhingra","doi":"10.1016/j.jop.2024.04.004","DOIUrl":"10.1016/j.jop.2024.04.004","url":null,"abstract":"<div><p>The present study deals with the Early Permian floral diversity, palaeoenvironment, palaeoclimate and depositional setting using a multiproxy approach that includes morphotaxonomy, palynology, and organic geochemistry of Karo OCM (Open Cast Mine), East Bokaro Coalfield, Damodar Gondwana Basin, India. The Permian sediments of Peninsular India are widely regarded as fluvial, along with some marine incursions. The macroplant fossil assemblage exhibits the presence of Glossopteridales, comprising <em>Glossopteris</em>, <em>Gangamopteris</em>, and <em>Vertebraria</em>, as well as Coniferales, which includes <em>Noeggerathiopsis</em>. The palynological assemblage encompasses the dominance of the striate bisaccate pollen <em>Faunipollenites</em> sp. and the sub-dominance of the non-striate bisaccate pollen <em>Scheuringipollenites</em> sp. with glossopterid affinities. The megafloral and palynofloral assemblage confirms the biostratigraphical age to be Late Barakar palynoflora of Kungurian affinity. The studied morphological characteristics, including small to large <em>Glossopteris</em> leaves exhibiting a lanceolate shape, acute apices, and acute cuneate or tapering bases, as well as entire margins with narrower lamina and narrow meshes, suggest the existence of a dense forest with the prevalence of a warm and humid climate during their deposition. The organic geochemical characterization based on functional group and biomarker analyses reveals the diagenetic effects on organic matter. Aliphatic symmetric (∼2865–2855 cm^-1) and asymmetric stretching (∼2930–2910 cm^-1) peaks are identifiable in coal samples, whereas they are absent in carbonaceous shale. The A-factor vs. C-factor plot suggests that the kerogen type is type III, which can generate mainly gaseous kerogen. The vitrinite reflectance studies (<em>R_r</em> av. 1.1%) show increased maturity of the samples, which is supported by the <em>n</em>-alkane distribution pattern and the absence of hopane terpenoids. The Indian floral assemblages in contemporary of southern Gondwana continents reveal a stronger inclination/affinity with the flora of Africa than that of South America, thereby supporting the age to be of Artinskian–Kungurian.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 3","pages":"Pages 528-546"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000361/pdfft?md5=e4193f42ac2c4e311551350817993b08&pid=1-s2.0-S2095383624000361-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141034647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}