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DORTHE RENG ERBS‐HANSEN KAREN LUISE KNUDSEN ANTHONY CAVEDO GARY EYSTEIN JANSEN RICHARD GYLLENCREUTZ VINCENT SCAO KURT LAMBECK 《Boreas: An International Journal of Quaternary Research》2011,40(4):660-680
Erbs‐Hansen, D. R., Knudsen, K. L., Gary, A. C., Jansen, E., Gyllencreutz, R., Scao, V. & Lambeck, K. 2011: Late Younger Dryas and early Holocene palaeoenvironments in the Skagerrak, eastern North Atlantic: a multiproxy study. Boreas, 10.1111/j.1502‐3885.2011.00205.x. ISSN 0300‐9843 A high‐resolution study of palaeoenvironmental changes through the late Younger Dryas and early Holocene in the Skagerrak, the eastern North Atlantic, is based on multiproxy analyses of core MD99‐2286 combined with palaeowater depth modelling for the area. The late Younger Dryas was characterized by a cold ice‐distal benthic foraminiferal fauna. After the transition to the Preboreal (c. 11 650 cal. a BP) this fauna was replaced by a Cassidulina neoteretis‐dominated fauna, indicating the influence of chilled Atlantic Water at the sea floor. Persisting relatively cold bottom‐water conditions until c. 10 300 cal. a BP are presumably a result of an outflow of glacial meltwater from the Baltic area across south‐central Sweden, which led to a strong stratification of the water column at MD99‐2286, as also indicated by C. neoteretis. A short‐term peak in the C/N ratio at c. 10 200 cal. a BP is suggested to indicate input of terrestrial material, which may represent the drainage of an ice‐dammed lake in southern Norway, the Glomma event. After the last drainage route across south‐central Sweden closed, c. 10 300 cal. a BP, the meltwater influence diminished, and the Skagerrak resembled a fjord with a stable inflow of waters from the North Atlantic through the Norwegian Trench and a gradual increase in boreal species. Full interglacial conditions were established at the sea floor from c. 9250 cal. a BP. Subsequent warm stable conditions were interrupted by a short‐term cooling around 8300–8200 cal. a BP, representing the 8.2 ka event. 相似文献
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柴达木冷科1井不同沉积环境元素地球化学特征 总被引：1，自引：0，他引：1
冷科1井 3000~4418m泥岩的元素分析数据表明:不同沉积环境中形成的泥岩,其元素的含量明显不同。微量元素 Mn、Rb、Ni、U、V、B、Co、Th和 Ga在湖相泥岩中含量明显增高,而在辫状三角洲及河流泛滥平原泥岩中含量较低。常量元素 Ca、K和 Mg在不整合面附近及泛滥平原泥岩中含量较高,湖相泥岩中含量低且变化小,其中 Ca、Mg表现的尤为明显。沼泽相泥岩中所有元素含量均最低。冷科 1井该段的元素地球化学分析结果说明元素地球化学方法可作为层序界面识别的一种依据。 相似文献
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利用陇西县近20年的地质灾害与降水资料,分析发生地质灾害的主要区域和具体地点及危害程度和分布特征,研究了引发地质灾害的气象条件。研究结果表明:山体滑坡、地裂缝、塌陷和泥石流是陇西县主要的地质灾害类型,地质灾害时段主要集中在局部强降雨和暴雨出现的夏季(5～8月)。地质灾害发生有多方面因素构成,大—暴雨、暴雨降水过程是地质灾害发生的决定条件,其次是人为性破坏了地质原有结构,导致出现或诱发地质灾害。我们在探讨地质灾害形成的主要成因的基础上,确定了地质灾害发生的降水强度标准,再根据多年的预报经验,寻找出相关性较好的预报因子,应用气象资料分析判断引发地质灾害可能性大小,发布预警信号和地质气象灾害预警发布和防御流程。 相似文献