摘要
海南岛昌江地区前人所称南好组第四段及第三段分别发现的牙形刺 Siphonodella isosticha- S.cooperi组合及 Mesogondolella clarki组合 ,表明该组包括了早石炭早期及晚石炭世早中期 ,而不是传统认为的属早石炭世并可能包括中 -晚泥盆世。同时还证实原南好组第三段层位远远高于第四段 ,而不是位于其下。从而纠正了前人长期沿用的该地区石炭系层序的错误。
The Carboniferous rocks crop out quite well at Changjiang area, Hainan Island, South China. They include the Nanhao Formation and Sanlengshan Formation of Lower Carboniferous, and Qingtianxia Formation of Upper Carboniferous. The lithological features of those formations are shown in text figure 2. Of them, the Nanhao Formation has a wide distribution, and was previousely subdivided into 4 members, in descending order as Member 1 to Member 4. Such corals as Cystophrentis kalaohoensis, Pseudouralinia irregularis, Zaphrentis sp., Amplex sp., Syringopora gracilis, Kweichowpora baijinensis, K. panxianensis have been found in the top part of Member 4. Accordingly, the Nanhao Formation (about 2 100m thick) has been formerly placed in the Lower Carboniferous, and the Member 3 to Member 1 have been referred to the Middle to Upper Devonian. The above mentioned stratigraphic sequence of Nanhao Formation was accepted and followed by all of the geologists who worked in Hainan Island in the past. Fairly abundant and well preserved conodonts including two assemblages:the Siphonodella isosticha S. cooperi assemblage and Mesogondella clarki assemblage have been found for the first time in Member 4 and Member 3 of Nanhao Formation from Jishi and Jixin villages, Shilu Town, Changjiang County, Hainan Island respectively (Figs.1 and 2). The former assemblage indicates that the top part of Member 4 of Nanhao Formation refers to the early Early Carboniferous. While the latter assemblage shows that Member 3 of Nanhao Formation is of middle early Late Carboniferous. Obviously, the stratigraphic position of Member 3 is much higher than that of Member 4. So that the previous stratigraphic sequence of Nanhao Formation at the area is clearly an upside down sequence, and has to be rejected. A new stratigraphic succession for the Carboniferous at Changjiang area is set up in the present paper.
出处
《微体古生物学报》
CSCD
北大核心
2001年第1期35-42,共8页
Acta Micropalaeontologica Sinica
基金
国家自然科学基金项目!(No.49772 0 94)
地质行业发展基金!(HY97982 0 )成果
