从蜓类和植物化石论臭牛沟组的地质时代

ON GEOLOGICAL AGE OF CHONIUKOU FORMATION BASED ON FUSULINIDS AND PLANT FOSSILS

据新发现的蜒类和植物化石,本文论证了臭牛沟组为维宪晚期至纳缪尔晚期沉积,建立了两个蜒类和两个植物化石组合带。石炭系的中间界线在臭牛沟剖面上从该组的中、上部之间通过。

The Choniukou Formation used to be considered as a standard biostratigraphic unit of the Late Visean in China, for a long time. The discovery of both fusulinids and plant fossils indicates that the choniukou Formation was deposited from the Late Visean to the Late Namurian in the geological age. Two fusulinid biozones, the Namurian A Eostaffella hohsienica-Eostaffella mosquensis Zone below and the Namurian B-C Millerella marblensis-Eostaffella postmosquensis Zone above, and two plant zones, the Late Visean Archaeocalamites scrobiculatus-Triphyllopteris sp. Zone below and the Namurian Paripteris gigantea-Linopteris neuropteroides Zone above, are established here. The Mid-Carboniferous boundary in this formation seems to cross between the middle and upper parts due to the first occurrence of fusulinids Millerella marblensis Thompson and Millerella pressa Thompson.