论文部分内容阅读
对离石丰义剖面红土与黄土之间发育的厚约 2 m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 ,气候由干热向暖湿转变 ;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大量的强磁性微颗粒 ,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。
The 2 m-thick lithologic mixed layer developed between laterite and loess in Lifeng Fengyi section was analyzed and discussed from the aspects of magnetic stratum, stable isotopes and celestial impact events. It is preliminarily believed that the M / Ga boundary is located in the middle of the lithologic mixed layer , From N2 laterite to lithologic mixed layer, the climate changes from dry heat to warm and wet climate; from lithologic mixed layer to Quaternary loess, climate changes from warm and wet to dry and cold; a large amount of ferromagnetism is found in the lithologic mixed layer Microparticles, which may be micro-glass meteorites or iron meteorites, may mean an astronomical impact event.