| 离石丰义剖面2.50 MaB.P.前后地质事件研究 |
| |
| 引用本文： | 罗运利,夏正楷,曹家欣.离石丰义剖面2.50 MaB.P.前后地质事件研究[J].海洋地质与第四纪地质,2000,20(2):83-86. |
| |
| 作者姓名： | 罗运利 夏正楷 曹家欣 |
| |
| 作者单位： | 中国科学院植物研究所!北京100093(罗运利)，北京大学城市与环境学系!北京100871(夏正楷，曹家欣) |
| |
| 基金项目： | 国家自然科学基金资助项目!( 4 92 72 12 7) |
| |
| 摘 要： | 对离石丰义剖面红土与黄土之间发育的厚约２ｍ的岩性混杂层从磁性地层、稳定同位素、天体撞击事件等方面进行了分析与探讨，初步认为Ｍ／Ｇａ界限位于岩性混杂层中部，从Ｎ２红土到岩性混杂层，气候由干热暖湿转变；由岩性混杂层到第四纪黄土，气候由暖湿向干冷转化 ；在岩性混杂层中发现有蛎量的强磁性微颗粒，可能为微玻璃陨石或铁质陨石，这可能意味着一次天体撞击事件的发生。
|
| 关 键 词： | 地质事件 离石丰义剖面 磁性地层学 古气候 |
| 修稿时间： | 1999-09-30 |
GEOLOGIC EVENTS AROUND 2.50 MAB.P. SHOWN IN FENGYI SECTION IN LISHI |
| |
| LUO,Yunli.GEOLOGIC EVENTS AROUND 2.50 MAB.P. SHOWN IN FENGYI SECTION IN LISHI[J].Marine Geology & Quaternary Geology,2000,20(2):83-86. |
| |
| Authors: | LUO Yunli |
| |
| Abstract: | There is a 2 m thick mixtite between laterite and loess in Fengyi section of Lishi area.The mixtite is studied on the basis of magnetostratigraphy,stable isotopes and celestial impact event.It is preliminarily suggested that M/Ga boundary lies in the middle of the mixtite,the part from laterite to mixtite represents a climate turning from dry hot to humid warm,the part from mixtite to loess indicates a climate from humid warm to dry cold,and the large number of strong magnetic micrograins found in the mixtite may be microtektites or iron meteorites,probably meaning a celestial impact event. |
| |
| Keywords: | mixtite magnetostratigraphy C and O isotope micrograins 2 50 MaB P |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
