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Climate-environmental Deteriorations in a Greenhouse Earth System:Causes and Consequences of Short-Term Cretaceous Sea-Level Changes(a Report on IGCP 609)
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作者 Michael WAGREICH benjamin sames HU Xiumian 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第S01期144-146,共3页
Anthropogenic global warming and resulting sea-level rise in response to enhanced atmospheric greenhouse gases and melting of the Earth’s continental ice shields have become issues of continuously growing interest fo... Anthropogenic global warming and resulting sea-level rise in response to enhanced atmospheric greenhouse gases and melting of the Earth’s continental ice shields have become issues of continuously growing interest for the scientific community as well as the public,pointing to threads of societies in a future greenhouse Earth System. 展开更多
关键词 SEA-LEVEL change GREENHOUSE CRETACEOUS
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Advances in the Study of the Non-Marine Ostracods in Luanping Basin, Northern Hebei (North China): A Preliminary Result
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作者 Zuohuan Qin Dangpeng Xi +2 位作者 benjamin sames Qiqing Pang Xiaoqiao Wan 《Open Journal of Geology》 2019年第10期601-604,共4页
The Luanping Basin of northern Hebei, North China, is well known for its continuous nonmarine Lower Cretaceous deposits and the preservation of the Jehol Biota. However, there are still some controversies about the st... The Luanping Basin of northern Hebei, North China, is well known for its continuous nonmarine Lower Cretaceous deposits and the preservation of the Jehol Biota. However, there are still some controversies about the stratigraphic correlation in these regions. Here we report some advances on the study of the nonmarine ostracods of Luanping, focusing on its biostratigraphical utility. Preliminary results indicate that the nonmarine ostracods from Luanping Basin consist of 17 genera and around 44 species. The ostracod assemblages of the Dabeigou, Dadianzi and Xiguayuan formations of this Basin can be assigned to the Luanpingella-Ocrocypris-Eoparacypris (Late Valanginian-Early Hauterivian age), Cypridea-Timiriasevia-Daurina (Late Huaterivian-Barremian age) and Cypridea-Limnocypridea-Lycopterocypris (Aptian stage) zones, respectively. This temporary framework can be served as a stratigraphic correlation tool in northern Hebei, as well as contributed to a better understanding of the evolution of the Jehol Biota. 展开更多
关键词 OSTRACODA BIOSTRATIGRAPHY Luanping Basin Early CRETACEOUS Jehol BIOTA
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侏罗纪末至白垩纪非海相介形类生物地层学:回顾与展望 被引量:6
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作者 benjamin sames David J.HORNE 《地层学杂志》 CSCD 北大核心 2012年第2期266-288,共23页
以非海相介形类为依据而建立的侏罗纪末至白垩纪的生物地层学,尤其是欧洲所谓"Purbeck-Wealden层段"(提塘阶顶部至巴列姆阶/阿普特阶底部)和全球同期沉积层的生物地层学建立已久,但这一生物地层学存有很多问题与局限性。本文... 以非海相介形类为依据而建立的侏罗纪末至白垩纪的生物地层学,尤其是欧洲所谓"Purbeck-Wealden层段"(提塘阶顶部至巴列姆阶/阿普特阶底部)和全球同期沉积层的生物地层学建立已久,但这一生物地层学存有很多问题与局限性。本文对中生代晚期(聚焦于早白垩世)的非海相介形类生物地层学的基本原理、历史、目前进展、存在问题和前景进行了综述。因为介形类的繁殖、扩散与成种机制已有比较成熟的研究,所以介形类的生物地层学的应用潜力被认识已久。然而,全球不同地区中生代晚期的非海相介形类众多的研究积累已构成了一个丰富但常常混乱和矛盾的文献库。这些问题不仅存在于介形类的分类鉴定中,也见于关于古环境和系统发育的解释中。虽然地区性的盆地内的介形类生物地层学研究已产生了好结果,并可能能够用于局部地区的高精度对比。但是在进行地区间(盆地间至全球)的对比时,其实用性广遭怀疑。在过去的二十年间,许多学者采用了将今论古的古生物学研究方法,努力修订和更新中生代晚期的非海相介形类的生物地层学与古环境意义,从而促进了地区间生物地层学研究和对比的发展。古生物学家认识到,对于许多非海相介形类动物来讲,它们的分布和扩散不仅仅局限于单个的水系或较小的地理区域,而是和现生的非海相介形类一样,晚侏罗世至白垩纪的非海相介形类动物和它们的卵可被较大的动物或风长距离搬运,跨越迁移的屏障,进行扩散。鉴于以上事实,地区间的对比必须涉及两大内容:分类学的应用与古环境背景。缺乏适用于地区—全球的稳定和一致的分类学系统是进行正确对比的重要障碍。由于大量地方性分类命名、地方性特有动物的假设、与壳体特征相关的分类和生态型认识的混乱,以及对种内变异尺度的统一认识的缺乏,导致了对生物分异度的过高或过低的估量。非海相白垩纪介形类的地层记录受到诸多因素的影响:分类单元的演化与灭绝、扩散事件、当地的环境变化和地区性至全球的气候变迁。在生物地层学的应用中,我们可以通过不同手段去把握同时代的Cytheroidea,特别是Cypridoidea中具重要地层意义的Cypridea属及其亲近者(即CypridoideaMartin,1940)的分类单元的形态变异度。解释种内变异时需要格外谨慎。区分生物自生(内因)导致的变异(遗传的和形态的变异)和环境(外因)导致的变异(生态表型)是一大难题。比较保守的分类学观念(分类单元很少,但变异极大(分类单元中包含了多种生态表型))有助于不同古环境间的(生物地层)对比。另一方法是运用随着时间的古环境变化及其对介形类组合的组成的影响来进行(生物地层)对比。古生物工作者已在利用受环境控制的周期性介形类组合变化建立对比关系方面进行了大量有意义的尝试,但这些工作仍处在争议中。建立全球生物地层学方法,建立统一而持久的分类概念这一目标可以达到,但不可能在短期内实现。用现代的思想(概念)理解和研究非海相介形类的古生物学和古生物地理学及新资料将有助于修订工作的进展。尽管我们对中生代的非海相介形类的演化和分布的认识还很不全面,但目前我们已取得了可喜的进展。盆地间至大陆间的对比是否可行,早已不是问题。目前和未来的指导原则无疑是发展以介形类为基础,并与其他的年代地层学和地质年代学资料及方案相结合的从地区至全球范围的地层对比系统。因为我们正在迈向一个非海相晚中生代介形类生物地层学的重新解释和应用的新时代,我们必须承认我们还有许多东西需要学习。 展开更多
关键词 生物地层学 非海相介形类 Purbeck和Wealden层段 分类 应用 方法 晚中生代 欧洲
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Special Topic: Cretaceous greenhouse palaeoclimate and sea-level changes 被引量:2
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作者 XiuMian HU Michael WAGREICH benjamin sames 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第1期1-4,共4页
Earth's climate has oscillated between greenhouse (warm) and icehouse (cold) modes throughout Earth history. At present, Earth is in the midst of an icehouse climate interval, despite the anthropogenic contributi... Earth's climate has oscillated between greenhouse (warm) and icehouse (cold) modes throughout Earth history. At present, Earth is in the midst of an icehouse climate interval, despite the anthropogenic contribution to global warming and sea-level rise due to industrialization during the past two centuries. This led to a dramatic increase in atmospheric CO2, mainly caused by the extensive burning of fossils fuels. The Cretaceous (145 to 66 million years ago) is the youngest prolonged greenhouse climate interval in the Phanerozoic, marked by very high global mean temperatures with some extreme warming peaks ('hothouse' or 'supergreenhouse'), largely absence of permanent continental ice sheets, a mean global sea-level having been some 250 m higher than that of today, and levels of carbon dioxide 4 to 10 times higher than those of the pre-industrial era. If temperature will continue to rise as quickly as in the last three decades, we are close to being at the cusp to a new greenhouse climate interval facing quickly rising global sea-level and reaching atmospheric CO2 levels of the 'Cretaceous supergreenhouse' in about the years 2190-2260 (Hay, 2011). Evidence from Earth's history indicates that glacial-interglacial climate mode changes as well as past sea-level changes such as in the Cretaceous greenhouse occurred at rates orders of magnitude slower than observed at present. The recent rise in global sea-level in response to rising levels of atmospheric greenhouse gases, the associated global warm- ing, and the waning of continental ice shields is a primary concern for human society. To predict future sea-levels we need a better understanding of the record of past sea-level changes, especially in the greenhouse palaeoclimate modes. Therefore, understanding the Cretaceous palaeoclimate is essential for a more accurate prediction of future global climate, sea-level rise and environmental changes in a prospective 'Cretaceous-like' greenhouse Earth. 展开更多
关键词 GREENHOUSE CRETACEOUS warming ANTHROPOGENIC despite THROUGHOUT
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