川西雅安-名山地区白垩系泥岩的地球化学特征及古气候探讨

摘要

川西雅安-名山地区白垩纪地层发育,本文通过对不同层位地层中泥岩样品的微量元素、常量元素及粘土矿物成分测试分析,从地球化学特征对该区白垩纪古盐度、古水温及古气候进行初步探讨.研究表明,该区白垩纪水温相对较高.从早白垩世(夹关期)至晚白垩世(灌口期)水体盐度明显增加,古气温也明显增高.总体处于热带-亚热带背景,受干旱期-半干旱期交替变化影响明显.%An approach to the palaeosalinity, palaeotemperature and palaeoclimatology is treated in this study on the basis of trace elements, major elements and clay mineral compositions in the mudstones from the Cretaceous strata in the Ya' an-Mingshan zone, western Sichuan. The palaeotemperatures in waters were relatively higher, and the palaeosalinities in waters were also noticeably higher from the Early Cretaceous ( Jiaguanian) to the Late Cretaceous (Guankouan). The palaeoclimatic conditions displayed the variations of alternating arid and semiarid palaeoclimates in the overall tropical to subtropical zones during the Cretaceous.