景谷盆地原油的孢粉集合与生油岩之时代

SPORO-POLLEN ASSEMBLAGES OF CRUDE OIL AND AGES OF SOURCE ROCKS IN JINGGU BASIN

景谷盆地在大地构造上处于滇西准地槽的思茅坳陷中。盆地四周是老第三纪地层组成的群山,盆地内新第三纪陆相沉积发育,最厚达2000余米,蕴藏石油。为了研究该盆地的生油层,笔者用稀释过筛法分离了该盆地1号井的6件原油样品,获得孢子和花粉、菌孢共42属57种。同时也分析了该盆地储油层中的含孢粉样品44块,获得了丰富的孢粉化石。在此基础上将原油孢粉集合的组成特征与储油层中的孢粉植物群组合特征进行了比较,从而对该盆地原油的运移、储油层和生油岩的关系及其时代作了推论。

The spore, pollen and fungus collected from Neogene crude oil in Jinggu basin contain 42 genera and 57 species. The pollens of pteridophyta are dominated by Polypodiisporites, Polypodiidites, Ciavatosporis, Cyclophorusisporites and Extrapunctatosporis, etc., containingsporadic Concavisporites and fungus spores. The gymnospermous pollens are mainly Pinuspollenites, Abietineaepollenites, Tsugaepollenites, Cedripites, Piceaepollenites, etc., often with Araucariacites and Podocarpidites observed. The angiospermous pollens are largely Quercoidites, Caryapollenites, Ulmipollenites, Betulaepollenites, Cupuliferoipollenites, etc., with rarer Compositoipollenites, Liliacidites, Graminidites and Persicarioipoll, etc. According to correlation, the sporo-pollen assemblages of crude oil and those of oil-bearing rock series are basically consistencet. It can be definite that the sporo-pollens (including the fungus spores) of crude oil in this region are all from the Neogene oil-bearing rock aeries in which the crude oil are originated from the source rocks--a kind of melanocratic mudstone, belonging to the Miocene in age.