Triassic Paleocurrent Study in the Middle-northern Part of the Nanpanjiang Deep Basin
doi: 10.14027/j.cnki.cjxb.2016.06.010
- Received Date: 2015-12-11
- Rev Recd Date: 2016-02-02
- Publish Date: 2016-12-10
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Key words:
- Nanpanjiang Basin /
- Triassic /
- flysch /
- Bouma sequence /
- paleocurrent
Abstract: The later Permian-Triassic Nanpanjiang deep marine basin is located in the adjacent areas among Guangxi, Guizhou, and Yunnan, which developed based on the rift system during the later Permian. The space and the depth of the basin increased during the middle-Triassic and a set of deepwater flysch sediment was preserved in the basin. The environment of the basin was identified as foreland basin where there was a set of clastic and carbonate sediment in the northern part of the basin. The main study areas lie in the northern and middle part of the Nanpanjiang Basin(NPJB). Some kinds of flysch sedimentary structures can be used in the field work to get paleocurrent such as small oblique bedding, small climbing ripple bedding, convolute bedding, flute cast and so on. Based on the field measurement, stratum attitude correction and the rose diagrams drawing of paleocurrent, this article discusses the paleocurrent of the sediment during the Triassic time. 49 sets of paleocurrent data were exhibited here by which sedimentary provenances of NPJB can be constrained. During the middle Triassic time the sedimentary provenance of the southern part of NPJB(for example near Guangnan, Dixu, Bada, Funing) would be the Vietnam Block to the south of NPJB, the sedimentary provenance of the eastern part of NPJB(for example near Bama, Longchuan, Wangmo) would be the Jiangnan Block to the east, and the sedimentary provenance of the northern part of NPJB would be the inner Yangtze Platform to the north. The centre of subsidence is located at the areas south to Ceheng and north to Lucheng. Two palaeohigh belts were indentified between Longlin city and Xilin city, between Yangxu town and Boai town. The paleocurrent changed significantly during the late Triassic time at the northern part of the NPJB which was considered as a consequence of the tectonic fragment change.
Citation: | PENG ChengMing, WANG Gang, CHEN YuanLin, LI ZhengYou, XUE LingWen, YANG Hui, LU YingHui, HOU Yun. Triassic Paleocurrent Study in the Middle-northern Part of the Nanpanjiang Deep Basin[J]. Acta Sedimentologica Sinica, 2016, 34(6): 1120-1132. doi: 10.14027/j.cnki.cjxb.2016.06.010 |