Journal of Palaeogeography最新文献

{"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":"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":"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}

{"title":"Scree conglomerate and its derivatives in the Upper Cretaceous Kallankurichchi Limestone, Ariyalur Group, Cauvery Basin, South India","authors":"Shilpa Srimani","doi":"10.1016/j.jop.2024.03.004","DOIUrl":"10.1016/j.jop.2024.03.004","url":null,"abstract":"<div><p>The repetitive influx of coarse clastics of mixed composition, siliciclastics and carbonates, locally common in the lower part of the Upper Cretaceous marine Kallankurichchi Limestone specifies a resurgence of tectonic unrest in the Cauvery rift basin, India. The basin-margin scree and its derivatives elicit diverse modes of emplacement and differ in many ways from denoting it only as basal conglomerate. The study meticulously reveals the depositional history of these basin-margin coarse clastics. The scree conglomerate bodies are wedge-shaped in appearance and often have flat, eroded tops. At places, their surfaces, tops and flanks, are encrusted with <em>Inoceramus</em> although internally, they are mostly unfossiliferous. They are clast-supported and extremely poorly sorted, having interstitial spaces filled by sand-sized grains at the basal part. The clasts can be traced into the underlying Sillakuddi Sandstone and the granitic basement. The clasts derived from the sandstone are angular and measure up to 60 cm in length, while the basement-derived clasts dominate the smaller (maximum diameter measured 5 cm) and more rounded population. The elongated clasts are chaotically arranged, even oriented sub-vertically, reclining on other clasts. The lowermost scree conglomerate has a sharp base, and the pebbles sunk into the underlying sandstone, although no discernible impact laminae wrapping their bottom were ever observed. Evidently, the scree fans were initiated under the sea, which permitted the slow sinking of assorted rock fragments dropped from above. The sporadic occurrence of marine fossils further corroborates this contention. The scree conglomerates at different stratigraphic levels transitioned laterally into conglomerates of mass flow origin and then to massive calcarenite, together forming wedge-shaped bodies. The initial alignment of clasts parallel to bedding transforms to a chaotic alignment representing the transition from internally sheared flow to debris flow and associated shapes. Matrix-supported fabric grades into massive calcarenite, suggesting gravity-driven transformation. Further down the wedge, the massive calcarenite turns into cross-stratified facies, making it evident that laminar flow turned turbulent in the course of body transformation of the sediment-driving flows. It can be presumed that these flows were triggered by subsidence, which resulted from renewed gaps in formation and led to the collapse of scree cones. Facies variability suggests scree deposits giving way downslope to debris flow and related deposits. Eventually, all the scree products pass laterally into the carbonate formation basinwards.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 3","pages":"Pages 495-508"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000269/pdfft?md5=d2b37bce8390ec682dddba4bda17fb63&pid=1-s2.0-S2095383624000269-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140403483","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":"Microfacies and palaeoenvironments of late Cisuralian and Guadalupian (Early to Middle Permian) alatoconchid-bearing limestone in Loei fold belt, Indochina Terrane","authors":"Mongkol Udchachon ,&nbsp;Hathaithip Thassanapak ,&nbsp;Clive Burrett ,&nbsp;Seksan Chaidrusamee ,&nbsp;Michał Krobicki ,&nbsp;Pradit Nulay","doi":"10.1016/j.jop.2024.03.003","DOIUrl":"10.1016/j.jop.2024.03.003","url":null,"abstract":"<div><p>This study presents the first record of Early Permian alatoconchid bivalves from Thailand, the Erawan section, in the north of Loei fold belt with prolific fusulines in association with gastropods, and brachiopods. Fusuline taxa are dominated by <em>Pseudofusulina</em> sp. with <em>Darvasites</em> sp., <em>Staffella</em> cf. <em>labanalensis</em>, <em>Staffella</em> sp., <em>Nankinella</em> sp., <em>Neofusulinella</em> sp., <em>Schubertella</em> sp., <em>Pamirina darvasica</em>, <em>Pseudoendothyra</em> sp. and others, indicating an Artinskian age. Fusuline wackestone with common, well-preserved smaller foraminifers, <em>Pseudovermiporella</em> sp. and ostracods indicates a restricted lagoon environment with low to moderate water circulation. These fossils, along with well-preserved, articulated alatoconchids in life-position, suggest the autochthonous nature of the deposits in an intertidal environment.</p><p>In the central part of the fold belt, the Pak Chong section exhibits intervals of alatoconchid biostromes and coquinites. Carbonate build-ups of the alatoconchid biostromes with gregarious bivalves, in life-position embedded in a micritic wackestone matrix, suggest their preferred life habit and environment. The bivalve coquinites containing packed bivalve shells and fragments, however, indicate a high-energy event. This rock fabric along with common fusuline storm sheets suggests occasional storm events in a restricted, with moderate water circulation to open lagoon environment. Fusulines are predominated by staffellids and others including <em>Staffella sphaerica</em>, <em>Staffella</em> sp., <em>Sphaerulina croatica</em>, <em>Pisolina subsphaerica</em>, <em>Nankinella</em> sp., <em>Neoschwagerina simplex</em>, <em>Presumatrina</em> sp., <em>Afghanella</em> sp. and others, indicating a Wordian (Middle Permian) age.</p><p>In the southern portion of the fold belt along the Thai-Cambodian border, the Khao Taa Ngog section contains limestone with alatoconchid shells with massive rugose corals which formed local carbonate build-ups in high-energy open platform environments. Poorly-sorted bioclasts with common fusuline tests, shell fragments and coated grains suggest an open marine, lagoon, back reef environment. The occurrence of a fusuline assemblage including <em>Neoschwagerina</em> sp., <em>Yabeina</em> sp., <em>Lepidolina</em> sp., <em>Codonofusiella</em> sp., <em>Verbeekina verbeeki</em> and <em>Chusenella</em> sp. indicates the Capitanian (late Middle Permian) age.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 3","pages":"Pages 453-474"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000245/pdfft?md5=355a80f064e8adfc9f9a893ae73e118e&pid=1-s2.0-S2095383624000245-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140573966","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":"Earliest megafossils of scandent calamoid palms from the Deccan Intertrappean Beds of Central India and their paleobiogeographic implications","authors":"Sanchita Kumar ,&nbsp;Kaustav Roy ,&nbsp;Robert A. Spicer ,&nbsp;Mahasin Ali Khan","doi":"10.1016/j.jop.2024.05.001","DOIUrl":"10.1016/j.jop.2024.05.001","url":null,"abstract":"<div><p>Two well-preserved petrified palm stems from the latest Maastrichtian (Late Cretaceous) to earliest Danian (Early Paleocene) sediments of the Deccan Intertrappean Beds of Madhya Pradesh, Central India are described. Their significant anatomical characteristics include a Calamus-type general stem pattern, the presence of well-preserved fibrovascular bundles (fvbs) with two wide metaxylem vessel elements (230 μm–250 μm) and one phloem strand, uniform density of fvbs, lack of continuity between protoxylem and metaxylem vessel elements, and an absence of centrifugal differentiation of sclerenchymatous fibrous parts. These features reveal a close resemblance to those of extant genera of scandent Calamoideae. The permineralized stems are described as a new species namely, <em>Palmoxylon calamoides</em> Kumar, Roy et Khan sp. nov. The fossils represent the oldest reliable fossil records of this family, supporting their Gondwanan origin, their importance in tracing their migration pathways from India to Europe and other continents after the docking of the Indian subcontinent with Eurasia during the Paleocene, and an “Out-of-India” dispersal hypothesis. Today the subfamily Calamoideae is disjunctly occurred in Africa, Asia, Australia, Europe, and South America, but the poor deep-time fossil record of this subfamily with a small number of Cenozoic fossils makes hypotheses concerning its origin and dispersal difficult to evaluate. The present study has significant implications for the origin and migration of this subfamily and the paleoclimate.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 3","pages":"Pages 509-527"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000348/pdfft?md5=dc3b9eda089c9bfc0cba1d85ecbb49da&pid=1-s2.0-S2095383624000348-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141057349","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":"Geochemistry and mineralogy of beach sediments in the northern Gulf of Mexico, Tamaulipas state, Mexico: implication for provenance","authors":"Mayank Shukla ,&nbsp;Sanjeet K. Verma ,&nbsp;Mayla A. Ramos-Vázquez ,&nbsp;John S. Armstrong-Altrin ,&nbsp;Karla R. Hernández-Martínez ,&nbsp;Sumit Mishra ,&nbsp;Vivek P. Malviya ,&nbsp;Héctor Hernández-Mendoza","doi":"10.1016/j.jop.2024.05.002","DOIUrl":"10.1016/j.jop.2024.05.002","url":null,"abstract":"<div><p>Geochemical and mineralogical studies were performed in the La Pesca (LP) and Tesoro Altamira (TA) beach sediments, located in the Tamaulipas state, northern Gulf of Mexico. The main aim of this study is to infer the weathering history and provenance and to discriminate the tectonic environment of the beach sediments. The sediments are composed of quartz with small amounts of accessory minerals such as plagioclase, calcite, orthoclase, microcline, and zircon. Both beach sediments are classified as fine-grained and very well sorted, however LP has coarse skewed and leptokurtic sediments, whereas TA has fine-skewed and very leptokurtic sediments. The chemical index of weathering (CIW’) indicates intense weathering in the source area. The quartz grain microtextures in the LP and TA are classified into mechanical, chemical, and mechanical/chemical origin. Mechanical features such as fractures, pits, percussion marks, abrasion fatigue, and V-shaped marks favor high-energy littoral, fluvial, subaqueous-marine, and aeolian environments. The chemical features indicate solution pits and crystalline overgrowth, which suggests a silica saturated marine environment. The mechanical/chemical features display adhering particles and elongated depressions suggest formation in a sub-aqueous nearshore marine environment. Major and trace elements-based provenance discrimination diagrams indicate a felsic source derived from the Mesa Central (MC), Sierra Madre Oriental (SMOr) and Oaxaquia terranes. The major and trace element concentrations imply a passive margin setting for the northern Gulf of Mexico, which is consistent with the general geology.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 3","pages":"Pages 375-400"},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S209538362400035X/pdfft?md5=915273efc2e961a2128443ad3125c2c8&pid=1-s2.0-S209538362400035X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141058355","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":"Global paleobiogeography of Albian–Cenomanian (mid-Cretaceous) marine ostracods","authors":"Bernardo Vázquez-García ,&nbsp;Jorge Villegas-Martín ,&nbsp;Gerson Fauth ,&nbsp;Leonardo Borghi ,&nbsp;Aristóteles De Moraes Rios Netto","doi":"10.1016/j.jop.2024.02.002","DOIUrl":"10.1016/j.jop.2024.02.002","url":null,"abstract":"<div><p>Despite their potential for providing important information for paleobiogeography, studies using ostracod assemblages compiled from global datasets have been scarce so far. In this study, the paleogeographic implications of the relationship between different ostracod assemblages are analyzed and discussed for the Albian and Cenomanian. We compiled an ostracod dataset at the genus level, with 168 genera for the Albian and 174 for the Cenomanian, to which different multivariate statistical methods of grouping were applied. The affinity between different ostracod assemblages from different regions allowed for the delineation of 30 operational geographic units (OGUs) for the Albian, and 32 OGUs for the Cenomanian, grouped in three paleobiogeographic units (PBUs; Megatethys, Persia, and Austral) and one sub-unit (PBSU; Maghreb associated to the Megatethys). The Maghreb PBSU showed minor changes between the Albian and Cenomanian. The relationship among the OGUs grouped in each PBU is related to different factors, such as eustatic sea level events, similar climatic zones, and marine current circulation patterns. A relationship was observed between the Gabon and Nigeria OGUs with the Persia PBU, which suggests a direct east<strong>–</strong>west connection between them during the Cenomanian. The affinity observed in the Austral PBU between the South American, South African, and Australian regions during the Albian can be explained by their relative geographic isolation due to the Walvis Ridge barrier. The eventual flooding of this barrier led to the relationship observed between the SE Brazilian and Bolivian regions with the Austral PBU. Finally, the data also suggested that the separation of the Indian subcontinent from the Austral PBU took place during the Cenomanian.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 2","pages":"Pages 212-236"},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000075/pdfft?md5=0da81baf40dfe530e711933cbab237d8&pid=1-s2.0-S2095383624000075-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140182026","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":"Cyclicity of the Lower Buntsandstein in the eastern part of the Central European Basin: implications for Early Triassic palaeogeography and for geochronological calibration","authors":"Anna Becker","doi":"10.1016/j.jop.2024.01.002","DOIUrl":"10.1016/j.jop.2024.01.002","url":null,"abstract":"<div><p>Lower Buntsandstein small–scale cycles recognized in the Central European Basin (CEB) are readily used for astrochronological calibration of the Early Triassic time scales, although they are not well studied sedimentologically. Three borehole sections from the eastern part of the CEB, forming a south-north transect perpendicular to the basin axis, were studied in terms to better understand the depositional history of the Lower Buntsandstein developed as the Baltic Formation in the studied Polish part of the basin. Eleven sedimentary facies were recognized, based on lithological and sedimentological investigations of 655.7 m of drill cores from the Otyń IG 1, Gorzów Wielkopolski IG 1 and Kamień Pomorski IG 1 boreholes. The facies can be grouped according to a lithological criterion into facies of predominantly siliciclastic lithology (including 9 facies types) and facies of predominantly carbonate lithology (including 2 facies types). Facies analysis allowed to distinguish 8 facies associations of: 1) alluvial fan, 2) playa, 3) sandy-muddy coastal plain, 4) embayment and distal delta, 5) lagoon, 6) sand bars or shoals, 7) ooidal shoals or bars, and 8) offshore. Deepening-upward (DC) and shallowing-upward (SC) sedimentary cycles were recognized in parts of the Baltic Formation, with DCs dominating in the southernmost located Otyń IG 1, and SCs dominating in Gorzów Wielkopolski IG 1, located in the axial part of the basin. Symmetrical cycles are very rare. The statistical significance of the sedimentary cycles is relatively low according to Markov-chain analysis conducted with the phpSedistat software of Stanova <em>et al.</em> (2009). Analysis of small–scale cycles performed on well logs of investigated boreholes and additional boreholes in the vicinity of Otyń IG 1, implementing the earlier study of Becker (2005), showed that the correlation of well-log cycles (GR cycles) and sedimentary cycles is not obvious. GR cycles can be roughly correlated with lithological carbonate–siliciclastic cycles (c-s cycles), reflecting alternations of facies groups of predominantly carbonate and siliciclastic lithology. Calibration of GR cycles to earlier magnetostratigraphic results of Nawrocki (1997) and Becker and Nawrocki (2014) showed that neither the boundaries of GR cycles serve as reference horizons, nor the cycles document equal time periods. All existing depositional models of the Lower Buntsandstein were discussed, stressing the possible simultaneous interaction of allochthonous and autochthonous processes. Moreover, the tectonic overprint of the Central European Basin system during the Early Triassic should be taken into account. The presented results suggest that the Lower Buntsandstein cyclicity of the CEB cannot serve as a basis for astrochronological analysis.</p></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"13 2","pages":"Pages 252-292"},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2095383624000026/pdfft?md5=1f53f5a276f84fd9cf628236e8551cb0&pid=1-s2.0-S2095383624000026-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139457632","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}