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Jun Wang - One of the best experts on this subject based on the ideXlab platform.
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a new protophyllocladoxylon Wood from the induan lower triassic jiucaiyuan formation in the turpan hami basin southern bogda mountains northwestern china
Review of Palaeobotany and Palynology, 2019Co-Authors: Wan Yang, Jun WangAbstract:Abstract A silicified gymnospermous Wood, Protophyllocladoxylon zhaobishanensis sp. nov., is described from the Induan (Lower Triassic) Jiucaiyuan Formation in Zhaobishan section, Shanshan County, southern Bogda Mountains, Xinjiang Uygur Autonomous Region, northwestern China. The pycnoxylic Wood contains thick-walled tracheids and parenchymatous ray cells. It is characterized by uni- to triseriate araucarian radial tracheidal pitting, uniseriate rays, one to two large, simple pits in each cross-field, and uni- to biseriate tangential tracheidal pits. The presence of distinct and extensive growth rings in all Fossil Woods from the Induan of the research area were probably caused by the seasonal climate with great precipitation variability during the earliest Triassic in the Turpan–Hami Basin. This is also supported by the occurrence of Calcisols, vertic Calcisols, and calcic Argillisols from coeval deposits nearby. The occurrence of Fossil Wood with anatomical structures from the Induan confirms that Woody gymnosperms, probably conifers, were crucial elements on the Early Triassic landscape in northeastern Pangaea. It appears that some gymnosperms had survived the end-Permian biotic crisis based on the continuous records of Protophyllocladoxylon -type Woods from the Wuchiapingian (upper Permian) to Norian (Upper Triassic) in Bogda Mountains.
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plant arthropod and plant fungus interactions in late permian gymnospermous Woods from the bogda mountains xinjiang northwestern china
Review of Palaeobotany and Palynology, 2016Co-Authors: Mingli Wan, Lujun Liu, Wan Yang, Jun WangAbstract:Abstract Several lines of evidence of plant-arthropod and plant-fungus interactions are documented from the Wuchiapingian Wutonggou low-order cycle (approximate equivalent to the Wutonggou Formation) in Tarlong valley, southern Bogda Mountains, Xinjiang Uygur Autonomous Region, northwestern China. Fossil Wood, Septomedullopitys szei Wan, Yang et Wang, contains differentially-damaged areas. Spindle-shaped pockets in the Fossil Wood occurring in the secondary xylem are commonly free of organic remains. They are comparable in appearance to modern white-pocket rot caused by fungi. The tracheid walls around the decomposed areas are degraded from the middle lamellae to outer layers. Abundant branching and septate fungal hyphae in the decayed areas, ray parenchyma and tracheid lumina indicate that fungi are responsible for the Wood decay. These fungi are partially regarded as basidiomycetes because of the occurrence of clamp connections. According to the characteristic damages they caused to the host, ascomycetes are also viable candidates of the fungi because large parts of hyphae are without certain clamp connections. The other damaged excavations are branched and maze-like borings and galleries, which are filled with abundant fungal hyphae, cellular debris and spheroidal to ovoidal, dark-colored coprolites, ranging from 26 to 128 μm in diameter. The size, shape, and surface texture of these coprolites indicates that the coprolites are the feces of ancient oribatid mites. The fungal hyphae, coprolites, and degraded excavations in the pith of the late Permian Wood suggest that Wood-rotting and -boring were not limited to the xylem.
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xenoxylon junggarensis sp nov a new gymnospermous Fossil Wood from the norian triassic huangshanjie formation in northwestern china and its palaeoclimatic implications
Palaeogeography Palaeoclimatology Palaeoecology, 2016Co-Authors: Weiming Zhou, Peng Tang, Jun WangAbstract:Abstract A permineralized gymnospermous Wood, Xenoxylon junggarensis sp. nov., is described from the Norian (upper Triassic) Huangshanjie Formation in Dalongkou Section, Jimsar County, Xinjiang Uygur Autonomous Region, northwestern China. The pycnoxylic Wood consists of thick-walled tracheids and thin-walled rays. It is characterized by commonly rounded to very compressed, contiguous or sometimes separated uniseriate, occasionally rounded and alternate biseriate radial pits and one or two simple, large pits in each cross-field.. The Fossil Wood genus Xenoxylon Gothan is known to be an indicator of cooler and/or wetter climates in the boreal hemisphere during the Mesozoic. Its occurrence in the Huangshanjie Formation from Junggar Basin, together with the palaeobotanical and palynological data, indicates that a wet and temperate climate prevailed in the northern Xinjiang during the Norian interval. The mean sensitivity of analysis of 22 growth rings is 0.36, suggesting a seasonal response to climate. Growth rings in the Fossil Woods are large (2.3 mm average with a maximum of 5.44 mm), representing either a longer growing season or more favorable conditions for growth, including readily available water and higher temperature. Based on a considerable amount of earlyWood and a small percentage of lateWood and some indirect evidence, it is hypothesized that growth of X. junggarensis in the high-latitude Junggar Basin in the late Triassic was limited by light levels.
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protophyllocladoxylon jingyuanense sp nov a gymnospermous Wood of the serpukhovian late mississippian from gansu northwest china
Acta Geologica Sinica-english Edition, 2010Co-Authors: Yi Zhang, Jun Wang, Lujun Liu, L I NanAbstract:: A new species of gymnospermous Fossil Wood, Protophyllocladoxylon jingyuanense sp. nov., is described from the lower part of the Tsingyuan Formation (Serpukhovian/Late Mississippian), near the coal mine of Ciyao, Gansu, northwestern China. The specimen is preserved only in silicified secondary xylem, while growth rings are absent Pits in radial tracheidal walls are araucaroid in type, uniseriate, occasionally biseriate. Xylem rays are homogeneous, uniseriate, occasionally biseriate. Cross-field pits are simple, large, one to two in number. Axial parenchyma is absent. The anatomical characters and geographic distribution of Protophyllocladoxylon Woods through geological ages are documented. Those species with axial parenchyma and without growth rings live in warm climate, whereas the species without axial parenchyma and with growth rings are present either in warm or cool climate. The ideal living climate for Protophyllocladoxylon Woods is warm and wet. Our new species, as a Fossil Wood of Early Carboniferous, is likely the earliest known species of Protophyllocladoxylon.
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zalesskioxylon xiaheyanense sp nov a gymnospermous Wood of the stephanian late pennsylvanian from ningxia northwestern china
Journal of Asian Earth Sciences, 2008Co-Authors: Zhuo Feng, Jun Wang, Guanglong ShenAbstract:Abstract A new Late Pennsylvanian species of gymnospermous Fossil Wood, Zalesskioxylon xiaheyanense sp. nov. is described from the Lower Taiyuan Formation (Stephanian B-C) near the village of Xiaheyan, Ningxia Hui Autonomous Region, northwestern China. The specimen consists only of silicified secondary xylem. The tracheids are pycnoxylic with 2–3 seriate bordered pits, arranged in subcircular or hexagonal alternate (araucaroid) pattern. The pores of the pits are small, linear, and regularly tilted. Xylem rays are homogeneous, uniseriate, 1–25 cells high. Cross-fields are filled with numerous mixed simple pits of various sizes. Growth rings, axial parenchymatous elements and resin canals are absent. The geographic distribution of Zalesskioxylon Woods is reviewed. Zalesskioxylon xiaheyanense sp. nov. grew at low latitudes, and because of the lack of growth rings, probably lived under relatively uniform climatic conditions. Our new species supplements the poorly known distribution of Carboniferous Wood in China.
Wan Yang - One of the best experts on this subject based on the ideXlab platform.
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a new protophyllocladoxylon Wood from the induan lower triassic jiucaiyuan formation in the turpan hami basin southern bogda mountains northwestern china
Review of Palaeobotany and Palynology, 2019Co-Authors: Wan Yang, Jun WangAbstract:Abstract A silicified gymnospermous Wood, Protophyllocladoxylon zhaobishanensis sp. nov., is described from the Induan (Lower Triassic) Jiucaiyuan Formation in Zhaobishan section, Shanshan County, southern Bogda Mountains, Xinjiang Uygur Autonomous Region, northwestern China. The pycnoxylic Wood contains thick-walled tracheids and parenchymatous ray cells. It is characterized by uni- to triseriate araucarian radial tracheidal pitting, uniseriate rays, one to two large, simple pits in each cross-field, and uni- to biseriate tangential tracheidal pits. The presence of distinct and extensive growth rings in all Fossil Woods from the Induan of the research area were probably caused by the seasonal climate with great precipitation variability during the earliest Triassic in the Turpan–Hami Basin. This is also supported by the occurrence of Calcisols, vertic Calcisols, and calcic Argillisols from coeval deposits nearby. The occurrence of Fossil Wood with anatomical structures from the Induan confirms that Woody gymnosperms, probably conifers, were crucial elements on the Early Triassic landscape in northeastern Pangaea. It appears that some gymnosperms had survived the end-Permian biotic crisis based on the continuous records of Protophyllocladoxylon -type Woods from the Wuchiapingian (upper Permian) to Norian (Upper Triassic) in Bogda Mountains.
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plant arthropod and plant fungus interactions in late permian gymnospermous Woods from the bogda mountains xinjiang northwestern china
Review of Palaeobotany and Palynology, 2016Co-Authors: Mingli Wan, Lujun Liu, Wan Yang, Jun WangAbstract:Abstract Several lines of evidence of plant-arthropod and plant-fungus interactions are documented from the Wuchiapingian Wutonggou low-order cycle (approximate equivalent to the Wutonggou Formation) in Tarlong valley, southern Bogda Mountains, Xinjiang Uygur Autonomous Region, northwestern China. Fossil Wood, Septomedullopitys szei Wan, Yang et Wang, contains differentially-damaged areas. Spindle-shaped pockets in the Fossil Wood occurring in the secondary xylem are commonly free of organic remains. They are comparable in appearance to modern white-pocket rot caused by fungi. The tracheid walls around the decomposed areas are degraded from the middle lamellae to outer layers. Abundant branching and septate fungal hyphae in the decayed areas, ray parenchyma and tracheid lumina indicate that fungi are responsible for the Wood decay. These fungi are partially regarded as basidiomycetes because of the occurrence of clamp connections. According to the characteristic damages they caused to the host, ascomycetes are also viable candidates of the fungi because large parts of hyphae are without certain clamp connections. The other damaged excavations are branched and maze-like borings and galleries, which are filled with abundant fungal hyphae, cellular debris and spheroidal to ovoidal, dark-colored coprolites, ranging from 26 to 128 μm in diameter. The size, shape, and surface texture of these coprolites indicates that the coprolites are the feces of ancient oribatid mites. The fungal hyphae, coprolites, and degraded excavations in the pith of the late Permian Wood suggest that Wood-rotting and -boring were not limited to the xylem.
Alexis Licht - One of the best experts on this subject based on the ideXlab platform.
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Fossil Woods from the lower Miocene of Myanmar (Natma Formation): paleoenvironmental and biogeographic implications
2021Co-Authors: Nicolas Gentis, Alexis Licht, Anais Boura, Dario De Franceschi, Zaw Win, Day Wa Aung, Guillaume Dupont-nivetAbstract:The paleobotanical record of Myanmar is poorly documented despite its importance for understanding the evolution of Asian monsoonal ecosystems through time. Here, we describe seventeen species of Fossil Wood from silicified specimens collected in the upper lower to lowermost middle Miocene Natma Formation, central Myanmar. These species share affinities with modern Fabaceae, Dipterocarpaceae, Burseraceae, Moraceae and Cupressaceae. Five new species are described, belonging to genera KoompassioxylonKramer (K. kalewensis n. sp.), Pahudioxylon Chowdhury, Ghosh & Kazmi (P. adenantheroides n. sp.), Dipterocarpoxylon (Holden) Den Berger (D. fugax n. sp.), ShoreoxylonDen Berger(S. glomeratum n. sp.), Artocarpoxylon Prakash& Lalitha (A. informe n. sp.). They include the first record of genus Dryobalanoxylon Den Berger in Myanmar, as well as a great variety of Fossil dipterocarps (7 species) as found in today’s Southeast Asian rainforests. The nearest living relatives of this assemblage reflect different ecotones of seasonal forests with coastal, mixed to dry deciduous, and wet evergreen species. This reconstruction implies a wet, warm, and monsoonal climate in Myanmar during the late early Miocene. The presence of Fossil dipterocarp species typical of wet evergreen forests contrasts with Burmese Eocene dry dipterocarp assemblages and indicates wetter conditions during the Miocene. Our reconstructions support a long-term change from seasonal to everwet ecosystems for dipterocarp trees.
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late middle eocene Fossil Wood of myanmar implications for the landscape and the climate of the eocene bengal bay
Review of Palaeobotany and Palynology, 2015Co-Authors: Alexis Licht, Anais Boura, Dario De Franceschi, Torsten Utescher, Chit Sein, Jean-jacques JaegerAbstract:Abstract The late middle Eocene Pondaung Formation, Myanmar, has yielded a diversified assemblage of silicified Wood including some of the earliest recorded Dipterocarpaceae. However, mid-Palaeogene Fossil Wood from Asia remains rarely described. We present here three additional species of Fossil Wood from the upper member of the Pondaung Formation, including a new species of Menispermoxylon ( M. mowglii nov. spec.) with successive cambia and included phloem, and two specimens of the Fossil genera Glutoxylon ( G. burmense Chowdhury) and Heritieroxylon ( H. arunachalensis Lakhanpal, Prakash et Awasthi). These three Fossil species are related to modern taxa of mangrove and coastal forests in the Bengal Bay and complete the floral assemblage already identified in the Pondaung Formation. The late middle Eocene Fossil Woods of Myanmar followed a toposequence with mangroves along the seashore, riparian elements similar to those of modern Terai ecosystem in the upper delta plain, and dry dipterocarp forests in the upstream areas of the drainage basin. The latter two assemblages and their association in the landscape are typical of monsoonal areas with significant rainfall and a marked dry season, thus confirming recent studies showing that the Bengal Bay has experienced a significant monsoonal regime as early as 40 Ma ago. The climatic parameters obtained by two quantitative botanical approaches on the Pondaung Fossil Wood, the coexistence and Wood anatomical approaches, suggest similar-to-modern rainfall amount, marked dry season, and warmer annual temperature for the Eocene of Myanmar. They thus support the hypothesis that monsoonal rainfall at that time may have been favored by Eocene greenhouse conditions. However, despite the homogeneity of the Pondaung floral assemblage, several resulting climatic parameters, such as the mean annual temperature (for the coexistence approach) or the mean annual rainfall (for the Wood anatomical approach), display large but incomplete uncertainty intervals or unlikely values (for the coexistence and Wood anatomical approaches respectively). These limitations can be attributed to the lack of super-warm and super-seasonal stations in their modern databases. It thus indicates that results from both quantitative approaches should be interpreted with caution for palaeo-monsoon reconstruction.
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Fossil Woods from the late middle eocene pondaung formation myanmar
Review of Palaeobotany and Palynology, 2014Co-Authors: Stephane Ducrocq, Aung Naing Soe, Alexis Licht, Anais Boura, Dario De Franceschi, Jean-jacques JaegerAbstract:article i nfo Article history: Twelve species of Fossil Wood were identified from silicified specimens collected in the late middle Eocene Pondaung Formation, Myanmar. These species display affinities with modern Fabaceae, Moraceae, Combretaceae, Sapindaceae, Malvaceae, Dipterocarpaceae and Theaceae. They include five new species of the Fossil genera Ficoxylon (F. mogaungense sp. nov.), Sapindoxylon (S. burmense sp. nov.), Bombacoxylon (B. pondaungense sp. nov.), Shoreoxylon (S. panganense sp. nov.) and Schimoxylon (S. benderi sp. nov.). This mate- rial represents the oldest record of Fossil dipterocarps so far reported outside the Indian subcontinent. It reflects different ecotones of a dry dipterocarp forest, with coastal, riparian, and inland elements. The Burmese Fossil assemblage further contrasts with the common idea that lowland rainforests were widespread in Southeast Asia during the Eocene. It suggests that the climate in the proto-Bengal Bay was more seasonal than previously thought. This confirms that early Dipterocarpaceae were adapted to seasonally dry climates, despite the modern prevalence of warm humid tropical species.
Aowei Xie - One of the best experts on this subject based on the ideXlab platform.
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Sequoioxylon zhangii sp. nov. (Sequoioideae, Cupressaceae s.l.), a new coniferous Wood from the Upper Cretaceous in Heilongjiang Province, Northeast China
Review of Palaeobotany and Palynology, 2018Co-Authors: Ning Tian, Marc Philippe, Zhipeng Zhu, Yongdong Wang, Chunyong Chou, Aowei XieAbstract:A new coniferous species Sequoioxylon zhangii sp. nov. is described on the basis of an anatomically well-preserved Fossil Wood specimen from the Upper Cretaceous in Keshan County of Heilongjiang Province, NE China. S. zhangii is anatomically characterized by abundant axial Wood parenchyma, uni-biseriate bordered pits, taxodioid cross-field pits, uniseriate rays 1–31 (usually 3–15) cells in height, and the occurrence of axial and horizontal traumatic resin canals. Such a combination of Wood anatomy features agrees well with the diagnostic characters of Fossil Wood morphogenus Sequoioxylon Torrey. The new species may represent an extinct taxon of the subfamily Sequoioideae of the Cupressaceae s.l. This new finding represents the first record of Sequoioxylon Torrey from China, and provides insights into the origin and evolution of the extant taxodiaceous Cupressaceae, especially the subfamily Sequoioideae. Anatomically, the new species shows a combination of anatomical characters of different groups of the extant Sequoioideae. This Fossil may provide additional evidences to support the view that Sequoia was originated from a recombination between Metasequoia and Sequoiadendron as a result of reticulate evolution.
Stephen P Hesselbo - One of the best experts on this subject based on the ideXlab platform.
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first record of the early toarcian oceanic anoxic event from the southern hemisphere neuquen basin argentina
Journal of the Geological Society, 2010Co-Authors: A H Alsuwaidi, Stephen P Hesselbo, Hugh C Jenkyns, G N Angelozzi, Francois Baudin, Susana E Damborenea, Miguel O Mancenido, Alberto C RiccardiAbstract:Abstract: The first record of the Early Toarcian Oceanic Anoxic Event ( c . 183 Ma) from the Southern Hemisphere is described from the Neuquen Basin, Argentina, identified chemostratigraphically on the basis of a relative increase in marine organic carbon and a characteristic negative carbon-isotope excursion (δ 13 C org ) in bulk rock and Fossil Wood. The negative excursion of −6‰ in bulk organic carbon (falling to −31.3‰) crosses the boundary of the tenuicostatum – hoelderi Andean ammonite Zones, equivalent to the tenuicostatum – falciferum / serpentinum zones of Europe. These data indicate that the Early Toarcian Oceanic Anoxic Event was a global phenomenon. Supplementary material: A detailed stratigraphic log, chemostratigraphic data and nannoFossil data are available at http://www.geolsoc.org.uk/SUP18411.
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carbon isotope record of the early jurassic toarcian oceanic anoxic event from Fossil Wood and marine carbonate lusitanian basin portugal
Earth and Planetary Science Letters, 2007Co-Authors: Stephen P Hesselbo, Luis V Duarte, Hugh C Jenkyns, Luiz Carlos Veiga De OliveiraAbstract:TheToarcianOceanicAnoxicEvent(OAE)intheEarlyJurassic(∼183Maago)wascharacterizedbywidespreadnear-synchronous deposition of organic-rich shales in marine settings, as well as perturbations to several isotopic systems. Characteristically, two positive carbon-isotope excursions in a range of materials are separated by an abrupt negative shift. Carbon-isotope profiles from Toarcian Fossil Wood collected in England and Denmark have previously been shown to exhibit this large drop ( ∼− 7‰ )i nδ 13 C values, interpreted as due to an injection of isotopically light CO2 into the ocean–atmosphere system. However, the global nature of this excursion has been challengedonthebasisofcarbon-isotopedatafromnektonicmarinemolluscs(belemnites),whichexhibitheavierthanexpectedcarbonisotope values. Here we present new data, principally from Fossil Wood and bulk carbonate collected at centimetre scale from a hemipelagic section at Peniche, coastal Portugal. This section is low in organic carbon (average TOC= ∼0.5%), and the samples should not have suffered significant diagenetic contamination by organic carbon of marine origin. The carbon-isotope profile based on Wood shows two positive excursions separated by a large and abrupt negative excursion, which parallels exactly the profile based on bulk carbonate samples from the same section, albeit with approximately twice the amplitude ( ∼− 8‰ in Wood versus ∼− 3.5‰ in carbonate). These data indicate thatthe negative carbon-isotope excursion affected the atmosphereand,by implication,the global ocean as well. The difference in amplitude between terrestrial organic and marine carbonate curves can be explained by greater water availability in the terrestrial environment during the negative excursion, for which there is independent evidence from marine osmiumisotope records and, plausibly, changes in atmospheric CO2 content, for which independent evidence is also available. The Peniche succession is also notable for the occurrence of re-deposited sediments: their lowest occurrence coincides with the base of the negative excursionandtheirhighestoccurrencecoincideswithitstop.Thus,slopeinstabilityandsedimentsupplycouldhavebeenstronglylinked to the global environmental perturbation, an association that may misleadingly simulate the effects of sea-level fall.
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the mid oxfordian late jurassic positive carbon isotope excursion recognised from Fossil Wood in the british isles
Palaeogeography Palaeoclimatology Palaeoecology, 2005Co-Authors: Christopher R Pearce, Stephen P Hesselbo, Angela L. CoeAbstract:The carbon-isotope ratios of Fossil Wood have recently been confirmed as a proxy for changes in the isotopic composition of palaeoatmospheres. Carbon-isotope data from Fossil Wood samples collected from the Jurassic (Oxfordian) Staffin Shale Formation on the Isle-of-Skye, Scotland (Boreal/Sub-Boreal ammonite zonation) reveal a long-term positive carbon-isotope excursion of at least 3‰. This excursion reaches a maximum in the mid-Oxfordian, and closely matches the carbon-isotope ratios previously reported from belemnites collected from the same section and carbon-isotope data from carbonates in other European sections. This confirms that the mid-Oxfordian positive carbon-isotope excursion affected the total exchangeable carbon reservoir. Fossilised Wood samples collected at a higher stratigraphic resolution, but over a shorter interval from the Corallian Group in Dorset, England (antecedens, parandieri and cautisnigrae subzones; NW European ammonite zonation) show considerable scatter in their carbon-isotope ratios, and no trends are discernable. The combined Isle-of-Skye and Dorset dataset shows that the long-term Oxfordian positive carbon-isotope trend coincides with a long-term relative sea-level change, and that the most positive carbon-isotope ratios occur across the plicatilis–transversarium biozonal boundary (Sub-Mediterranean ammonite zonation). This implies that the carbon-isotope excursion was not caused by the well-documented rise in sea-level in the transversarium Zone. Although very low carbon-isotope ratios from Fossil Wood samples are recorded from the Nodular Rubble Member (parandieri Subzone) of Dorset, there is not a sufficiently coherent signal to ascribe these values to the gas–hydrate dissociation event previously hypothesized from the carbon-isotope ratios of Tethyan marine carbonates. A microscopal analysis of the charcoalified debris from the Staffin Shale Formation indicates a prevalence of the Wood genus Cupressinoxylon, derived from a cheirolepidiaceaen conifer.
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carbon cycle perturbation in the middle jurassic and accompanying changes in the terrestrial paleoenvironment
The Journal of Geology, 2003Co-Authors: Stephen P Hesselbo, Helen S Morgansbell, Jennifer C Mcelwain, Mcallister P Rees, Stuart A Robinson, Elizabeth C RossAbstract:Abstract Carbon‐isotope analyses of Fossil Wood from the Middle Jurassic Ravenscar Group, Yorkshire, NE England, reveal a significant excursion toward light isotopic values (δ13C change of −3 to −4‰) at about the Aalenian‐Bajocian boundary (∼174 Ma). A positive carbon isotopic excursion is also shown for the middle Bajocian (∼170 Ma) but is less clearly defined. These isotopic patterns are very similar to the few published marine carbonate records available for this time, in particular one based on belemnites from the Hebrides basin, NW Scotland, and others from pelagic limestones in Italy. The similarity of the terrestrial and marine isotope curves is an indication that the observed isotopic signal is a global phenomenon. Through parts of the Ravenscar Group (the Scarborough Formation), supplementary data from bulk organic carbon and palynofacies analysis confirm that isotopic curves based on bulk analyses may be strongly influenced by the balance of terrestrial versus marine organic matter present in th...
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massive dissociation of gas hydrate during a jurassic oceanic anoxic event
Nature, 2000Co-Authors: Stephen P Hesselbo, Hugh C Jenkyns, Darren R Grocke, Christian J Bjerrum, Paul Farrimond, Helen Morgans S Bell, Owen R GreenAbstract:In the Jurassic period, the Early Toarcian oceanic anoxic event (about 183 million years ago) is associated with exceptionally high rates of organic-carbon burial, high palaeotemperatures and significant mass extinction1,2,3,4. Heavy carbon-isotope compositions in rocks and Fossils of this age have been linked to the global burial of organic carbon, which is isotopically light. In contrast, examples of light carbon-isotope values from marine organic matter of Early Toarcian age have been explained principally in terms of localized upwelling of bottom water enriched in 12C versus 13C (refs 1,2,5,6). Here, however, we report carbon-isotope analyses of Fossil Wood which demonstrate that isotopically light carbon dominated all the upper oceanic, biospheric and atmospheric carbon reservoirs, and that this occurred despite the enhanced burial of organic carbon. We propose that—as has been suggested for the Late Palaeocene thermal maximum, some 55 million years ago7—the observed patterns were produced by voluminous and extremely rapid release of methane from gas hydrate contained in marine continental-margin sediments.