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吉林晚石炭世威宁期石头口门裂陷槽位于长春市东50km。该裂陷槽以海底火山沉积—硅质岩沉积为主。早期以含锰结核的碎屑岩和泥岩、硅质岩为主,并有少量的凝灰岩和玄武岩;中期以海底火山喷发的高钠质细碧岩、角斑岩为主,并伴有规模不大的蛇纹岩;晚期以硅质岩、长石杂砂岩、泥岩、生物碎屑灰岩为主,在生物碎屑灰岩中首次发现Fusulina lanceolata、F.sp.、Pseudostaffella khotunensis、P.sp.、Schubertella sp.、Endothyrd sp.等晚石炭世威宁期标准化石。该裂陷槽具有典型的裂陷槽沉积特征,它不仅具有海底火山沉积的细碧-角斑岩组合的全部特征,而且具有完整的裂陷槽沉降—拉张—上升的全过程、具有拉张强度较大、较深、地壳相对较薄的特点。地层剖面中具有岩性、岩相、变质程度的一致性,并不同于省内和大区内其他岩石地层,故提出新建石头口门组,用以代表吉林省晚石炭世威宁期海底火山喷发沉积岩系。
The late Carboniferous Weining period stone mouth rift slot in Jilin is located 50km east of Changchun City. The rift trough submarine volcano sedimentary - mainly silicalite deposition. In the early stage, the clastic, mudstone and silicalite with Mn-bearing nodules were dominant with a small amount of tuff and basalt. In the medium-term, the high-sodium pyrochlore and angular porphyry erupted by submarine volcanic eruptions, with a large scale Large serpentinite; late to siliceous rocks, feldspar miscellaneous sandstone, mudstone, bioclastic limestone, the first in bioclastic limestone found Fusulina lanceolata, F.sp., Pseudostaffella khotunensis, P.sp ., Schubertella sp., Endothyrd sp. And other Late Carboniferous Weining period fossils. The rift trough has the typical characteristics of rift trough deposition. It not only possesses all the features of the sub-Bi-amphibolite assemblage of submarine volcanic deposits, but also has the complete process of settlement-tension-rise of rift trough, Zhang intensity is larger, deeper, the crust is relatively thin. The stratigraphic section has lithology, lithofacies and degree of metamorphism consistent with other rock strata within the province and within the region. Therefore, a new group of the Shitoukoumen Formation is proposed to represent the late Carboniferous Weining Period submarine volcano in Jilin Province Eruption sedimentary rock series.