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“碧口群”的时代、层序及划分,属长期未解决的问题,近几年虽获得一些新资料,但对其归属,仍存在以下不同意见: 1.将文县、康县一带“碧口群”划归为早中泥盆世。依据:在武都南琵琶至高家坝,见泥盆系灰岩(含床板珊瑚)与下伏“碧口群”的流纹英安凝灰岩,熔凝灰岩成互层出现,二者为连续过渡关系。 2.在1∶20万广元幅中提出“碧口群”中见海百合茎化石。故认为该群可能包括志留纪的沉积,其时代应划归前泥盆纪。 3.将原碧口群上部水晶组划为震旦系上统。下部保留“碧口群”,时代为下震旦
The era, sequence and division of the “Bikou Group” are long-standing issues that have not yet been solved. Although some new information has been obtained in recent years, the following opinions are still different for their ownership: 1. The “ Bikou group ”is classified as early Middle Devonian. Basis: In the Wudu Nanpo to Gaojiaba, the seepage metamorphite and melted limestone of the Devonian limestone (including bedplate coral) and the underlying “Bikou Group” appear as interbeds, and the two are in a continuous transitional relationship . In 1: 200000 Guangyuan amplitude proposed “Bikou group” see the sea lily stem fossils. Therefore, the group may include the deposition of Silurian, its era should be re-classified into the Pre-Devonian. 3. The original crystal group Bikou group zoned for the Sinian system. Lower reserved “Bikou group”, the era of the next Aurora