论文部分内容阅读
本文对云南东南部的文山盆地湖相地层开展了高分辨率的古地磁定年和地球化学研究.古地磁结果表明该剖面年龄为15.2~16.5 Ma,正好位于中中新世气候适宜期内.通过对高分辨率的全岩块状土样中的有机碳同位素、总有机碳、总氮和碳氮比研究,重建了湖盆的古环境变化,结果表明:尽管中中新世气候适宜期总体表现为气候温暖,但在早/中中新世交界期发生了明显的环境变化.这一结论为认识和研究中中新世气候适宜期提供了新的证据和视野.
In this paper, a high-resolution paleomagnetic dating and geochemical study of the lacustrine strata in the Wenshan Basin, southeastern Yunnan, has been carried out.The paleomagnetic results show that the age of the section is 15.2-16.5 Ma, which is exactly in the mid-Miocene climate, The organic carbon isotope, total organic carbon, total nitrogen and carbon to nitrogen ratio in the high resolution lumpy soil samples were studied to reconstruct the paleoenvironmental changes of the lake basins. The results show that although the overall Miocene climatic suitable period The result shows that the climate is warm, but the obvious environmental change happened during the early / middle Miocene boundary period, which provides new evidences and perspectives for understanding and studying the Mid-Miocene climate suitability period.