摘要
甘肃夏河-青海同仁一带位于西秦岭造山带的西段,区内中二叠世大关山组发育,经本次研究为生物礁灰岩.大关山组产出丰富的古生物化石,主要种类为串管海绵,纤维海绵,苔藓虫,钙质藻类,复体珊瑚,,非有孔虫,腕足,腹足,棘皮和双壳等.本次在大关山组中共发现11属16种,其中包括10个未定种,非有孔虫共16属23种,其中包括11个未定种.根据和非有孔虫属种在大关山组中的逐层分布,自下而上划分为2个组合和一个带:Pseudofusulina-Para-fusulina组合,Cancellina cf.houchangensis带和Afghanella-Sphaerulina组合;2个小有孔虫组合:Pachyphloia-Cribro-generina-Nodosaria组合和Cribrogenerina-Hemigordius组合.通过将研究区的化石组合与国内外其他地区相同层位的带对比,将西秦岭大关山组的时代厘定为中二叠世罗甸期—冷坞期.
The middle Permian Daguanshan Fm. , consisting of reef limestone, is well developed in Xiahe County, Gansu Province and Tongren County, Qinghai Province, China. There exist abundant fossils, such as fibrous sponges, calcisponges, bryozoans, foraminiferas, fusulinidas, calcareous algae and corals. Our research is based on 39 species of foramninfera that belong to 27 generas, which include 16 species of fusulinida pertaining to 11 generas. The foraminifera fauna in this area may be divided into two Non-fusulinida assembldges, two fusulinida assembldges and one fusulinida zone respectively in ascending order as follows： Non-fusulinida assembldges： Pachyphloia-Cribrogenerina-Nodosaria and Cribrogenerina-Hemigordius; two fusulinida assembldges： Parafusulina-Pseudofusuluna assembldge, Cancellina cf. houchangensis Zone Afghanella-Sphaerulina assembldge. We compared the Fusulinida assembldges of Daguanshan Formation with the Fusulinida zones worldwide at the same stratum, and concluded that the age of Daguanshan Formation is Luodian-Lengwu stage, Middle Permian.
出处
《地球科学（中国地质大学学报）》
EI
CAS
CSCD
北大核心
2007年第5期691-702,共12页
Earth Science-Journal of China University of Geosciences
基金
高等学校全国优秀博士学位论文作者专项资金项目(No200228)
教育部长江学者和创新团队发表计划资助项目(NoPCSIRT0546)
中国地质调查局'1:25万临夏市幅
定西县幅数字区域地质调查'(No200413000007)
