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辽东复州湾中石炭世地层兼论华北地台中石炭统的划分   总被引:3,自引:0,他引:3  
华北地台中石炭统本溪组一般仅代表中石炭世晚期沉积。从已知的几十个海陆交互相本溪组剖面来看,其中(虫筳)类生物群为Fusulina-Fusulinella带;牙形石生物群为Idtognathodus magnificus-Ⅰ.claviformis-Neognathodus ruondyi带,在整个华北地台均可依此进行对比。但在辽东半岛南缘的复州湾一带,中石炭世沉积特征却恰好与本溪剖面相反,下部层段以灰岩为主,上部层段以碎屑岩为主。下部含6层灰岩,(虫筳)类以Profusulinella的丰富种群为特征,可建立Profusulinella带,并可进而划分为3个亚带。牙形石则为Idiognathoides sinuatus-Ⅰ.corrugatus-Declinognathodus lateralis带。复州湾含灰岩为主的下部层段和本溪含碎屑岩为主的下部层段对比,依前者之生物组合建立本溪组下部复州湾段(c21),代表华北地台中石炭世早期沉积;复州湾以碎屑岩为主的上部层段和本溪含5层灰岩的上部层段对比,依后者之生物组合限定为本溪组上部牛毛岭段(c22),代表华北地台中石炭世晚期沉积。  相似文献   
2.
The point at issue: The Kurosegawa Terrane is composed of continental fragments transecting Mesozoic terranes of accretionary complex in Southwest Japan (Fig. 1). It is an attenuated tectonic sliver and considered to be allochthonous with respect to the main part of Southwest Japan. The problem of which continental block in the East Asian continental margin is the source of the Kurosegawa Terrane has puzzled Japanese geologists for many years. Firstly, we try to approach this issue based on the analysis of fusulinacean assemblage in accreted terranes composed of subduction complex in the Pacific Rim. Secondly, by applying the result of this analysis we try to locate the source of the continental fragments of the Kurosegawa Terrane. Thirdly, we try to prove its validity with a new paleomagnetic study.  相似文献   
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The study area, Nan Province, northern Thailand is geotectonically situated within the Nan-Uttaradit Suture, the once back-arc basin between the Sukhothai Zone and Indochina Block. Permian Fusulinacean fauna from limestone blocks within the suture has been investigated and the Nan area has been mapped in detail. These may provide the useful information for understanding the faunal assemblage and overall ge-ometry of stratigraphic successions in the basin. The strata were intensely folded and thrust. Scattered Per-mian limestones found in Nan area are blocks within shale interbedded with tuffaceous rock. The contact between this unit and the adjacent units, the strongly foliated shale and tuffaceous sedimentary strata that are mildly metamorphosed and giving phyllitic tex-tures, has been interpreted as a west-dipping normal fault, namely the Pha Sing Fault. This fault runs par-allel to the Highway no.1080 (Nan-Tha Wang Pha). Middle and early Late Permian fusulinacean fauna found in the Nan area contains Neoschwagerina, Pseudodoliolina, Colania, Lepidolina, and Colaniella. Additionally, late Early Permian fusulinacean and Middle Triassic radiolarian fauna have been reported in this area (e.g., Fontaine, 2002; Saesaengseerung et al. 2008). These paleontological data show the existence of Nan Back-arc Basin during late Early Permian (Artin-skian) to Middle Triassic. Moreover, the similarity of fusulinacean assemblage yielding Permian limestone blocks of the Nan Back-arc Basin and the ones of the Indochina Block has been interpreted that the Permian limestone blocks in the Nan Back-arc Basin were part of the continental shelf within the Indochina Block.  相似文献   
4.
贵州省盘县特区火铺镇茅口组的 类动物群共有 类26属83种(不含未定种),Neoschwagerina 带自下而上可分为Cancellinaprimigena亚带、Praesumatrinaschellwieni亚带、Afghanellaschencki亚带、Neoschwagerinadouvillei亚带和ChusenellaishanensisYabeinagigantea等5个亚带。研究结果表明,贵州地区茅口阶底部最早出现的Neoschwagerina类群以及与其共生的Cancellina分子在不同剖面不尽相同,茅口阶底界的精确对比尚有待于进一步明确代表该地茅口阶底界的 类标志种。  相似文献   
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