四川雅安地区早第三纪地层

Early Tertiary strata in the Ya'an area, Sichuan

下第三系名山组广泛分布于雅安地区，地层出露良好。本文简要介绍雅安国光山背斜东西两翼新测的地层剖面，将名山组（包括芦山组）划分成４段（砂岩粉砂岩段、粉砂岩泥岩泥灰岩段、泥岩粉砂岩段、泥岩段），并将芦山组归于名山组上部（Ⅳ段），从而取消该名称，综述了岩石组合特征、沉积环境，进行了生物地层和年代地层划分。

The Lower Tertiary Mingshan Formation is extensively distributed and exposed very well in Ya'an area. On the basis of our regional geological suvey on 1/50000 Tianquan width (formation map) from 1989 to 1991 and others' reserch, we made a progressive study of the Mingshan Formation. Frist, two new measured sections on the eastern and western limbs of Yuanguangshan Anticline are introduced. Secondly, the Mingshan Formation (including Lushan Formation) is divided into four informal members of mapping units (Sandstone-siltstone member, Silistone-marlite member, Mudstone-siltstone member and Mudstone member), and the name of Lushan Formation is abolished here. Third, the rock assemblage characteristics, sedimentary environment, biostratigraphy and chronostratigraphy of Mingshan Formation are described and studied in detail.