摘要
深海钻探揭示的古新世-始新世界线许多全球性变化引起了地质学家的普遍关注。这些变化表现在岩性、粘土矿物组合、大陆植物群、大陆哺乳动物、钙质超微化石、底栖有孔虫、氧碳同位素、大气环流强度、海洋环流模式、海平面等方面。通过对古新世-始新世地层沉积学、古生物学、古气候学和古海洋学的研究,确认古新世-始新世地层界线是全球构造事件的结果,表现为全球板块边界重组、扩张中心和转换断层模式改变、海底热液活动是一至二个数量级加强。
Lots of global changes at the Paleocene-Eocene boundary, Which were discovered by Deep Sea Drilling Project and which have been attracting geologists' s attention, include: a change in lithology from glauconitic quartz sand to clay; a change in clay mineral suites from illite/smectite-dominated to kaolinite-dominated; the extinction and migration in the terrestrial flora; an increased species turnover rate in marine calcareous nanofossils; the extinction and lower diversity in the benthic foraminiferal assemblages; a considerable excursion in δ18O and δ13C values; a change in the evolution of land mammals; a significant reduction of the intensity of atmospheric circulation; a change in the style of abyssal circulation; an increase in water depth; and one to two order of magnitude increase in hydrothermal activity at the Paleocene-Eocene boundary. The Paleocene-Eocene boundary was the result of global tectonic events by researching lithology, palaeobiology, palaeoclimatology, palaeoceanography of the Paleocene-Eocene stratigraphic sections. The events include that global plate boundary rearrangement, changes in patterns of spreading centers and transform faults, and increase in hydrothermal activity.
出处
《地球科学进展》
CAS
CSCD
1996年第3期288-293,共6页
Advances in Earth Science
关键词
古新世
始新世
全球事件
地层界线
Paleocene, Eocene, Boundary, Global event, Tectonics.