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Emily Keeble David I. Whiteside Michael J. Benton 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(2):99-119
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco. 相似文献
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专家系统作为一种人工智能技术,日益广泛地应用于各类专门问题的解答及技术咨询领域。矿山水文地质问题涉及因素多,不确确量亦较多,故引入专家系统是可行的。从专家系统知识库知识,矿山水文地质实例及理论分析成果等三方面知识为专家系统的知识来源。结合有色金属矿山水文地质调查资料及制做有色金属矿山水文地质评价专家系统(MHGEES)的实践,本文阐述了两类专家系统的划分及各自的特点,讨论了第二类专家系统推理框架, 相似文献
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本文讨论了在完整岩溶泉域内,从灰岩裸露的补给区,至灰岩隐伏于地下的径流区宜至深埋区,可溶岩矿物与水相互作用所发生的不同化学作用和分带性;以及不同化学作用下限确定原则和方法;岩溶水化学类型随深度变化规律;可溶岩矿物溶蚀(解)量的方法。 相似文献
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煤岩初次和二次生烃动力学及其对沾化凹陷孤北天然气成因的解释 总被引:5,自引:1,他引:4
沾化凹陷孤北地区石炭一二叠系(C-P)潜山产出煤成气,油气勘探需要搞清楚产出的煤成气是煤岩初次埋藏、还是抬升剥蚀后再次埋藏生成的.在查明该区煤岩地质演化的基础上,采用热模拟实验方法,探讨了煤岩初次和二次生烃过程中气态烃与主要单体烃生成动力学特征,发现煤岩二次生烃的活化能比一次生烃高40~50 kJ/mol,认为孤北地区C-P煤系源岩达到4200 m深度条件(R°约0.9%)才发生二次生烃作用.与煤岩初次生气相比,二次生气具有iC4/nC4<1、n(C6 C7)/i(C6 C7)>0.8、甲苯/苯<1.2等特征,据此认为孤北煤成气是煤岩二次生烃形成的. 相似文献
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