摘要
新疆库鲁克塔格奥陶系特别发育,分布较广,化石丰富。本文根据岩性和化石,分为下统雅尔当组、巷古勒塔格组、雅尔当布拉克组;上统却尔却克组、穆赫来布拉克组、乌里格孜塔格组和元宝山组,上与石炭系呈假整合接触,下与上寒武统为整合接触。
The Ordovician is well developed and widely exposed in Kuruktag, Xinjiang. It may be divided in ascending order into 7 formations based on the lithology and fossils.Lower OrdovicianYardang Formation: Gray and dark gray limestone and nodular limestone with shale, equivalent to the Hysterolenus Zone, 65.10m thick. It overlies conformably the Upper Cambrian Xiangguletag Formation Black shale with grayish green shale and silty sandstone. Its lower part is represented by the Tetragraptus pendensDicellograptus of. abnormis Zone, while its upper part by the Isograptus caduceus Zone. Its total thickness is 26.56m. Yardangbulak Formation. Its lower part is marked by alternating beds of purplish gray and grayish purple sandstone and siltstone, with shale, equivalent to the Amplexograptus confertus Zone, 29.24m thick. Its upper part is represented by alternating beds of dark gray and grayish block sandstone, siltstone, shale and sandy limestone, yielding the Glyptograptus dentatus pusillis Zone, 72.46m thick.Upper OrdovicianQurquk Formation:It is marked by alternating beds of grayish green and grayish black sandstone, siltstone and shale with grit and limestone, 584.25m thick. Its lower part is equivalent to the Climacograptus eximius Ruedemann Zone, while its upper part the Dicellograptus sexlans Hall-D. divaricatus Zone. Muhelaibulak Formation: Its lower part consists of grayish green and purplish red shale with siltstone, 75.52m thick: and its upper part is composed of gray and grayish green sandstone and siltstone, with limestone and shale, yielding trilobites: Taklamakania yinganensis Zhang, Madegenia of. communis Ju and Lisogorites sp., 135.51m thick. Wuligezitag Formation: It is represented by alternating beds of yellowish gray conglomeratic grit, sandstone, siltstone and shale, yielding trilobites: Nankinolithus sp., Lonchodomas sp. and Ovalocephalus kanlingensis Zhang, 260.78m. Yuanbaoshan Formation: It consists of alternating beds of gray and grayish green sandstone, siltstone and shale, equivalent to the Orthograptus truncatus Zone. It underlies disconformably the Carboniferous.
出处
《地质论评》
CAS
CSCD
北大核心
1990年第5期404-413,共10页
Geological Review
