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Phototropism of Petrified Wood and Its Relation with the Rotation of Different Blocks in China and the Possibility of Application in the World
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作者 Zikun Jiang Benpei Liu +6 位作者 Yongdong Wang Min Huang Tom Kapitany Ning Tian Yong Cao yuanzheng lu Shenghui Deng 《Open Journal of Geology》 2019年第10期585-588,共4页
Normally, trees on the side directly exposed to sunlight will grow faster than the opposing side. This phenomenon is termed plant phototropism. Moreover, palaeomagnetists have revealed that the Junnar Block has never ... Normally, trees on the side directly exposed to sunlight will grow faster than the opposing side. This phenomenon is termed plant phototropism. Moreover, palaeomagnetists have revealed that the Junnar Block has never rotated since the Mesozoic. The petrified woods in the Jiangjunmiao area of Qitai County show the positive phototropism direction of SSW220. By compared with the modern normal growth stumps in plain area, which have positive phototropism direction of SSW 219 ± 5, this observation supports the conclusion of palaeomagnetic researchers: the Junggar basin has never rotated since the Late Jurassic. 展开更多
关键词 JURASSIC Petrified WOOD PHOTOTROPISM Plate ROTATION PALAEOGEOGRAPHY
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Subdivision and age of the Yanchang Formation and the Middle/Upper Triassic boundary in Ordos Basin, North China 被引量:4
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作者 Shenghui DENG yuanzheng lu +6 位作者 Zhong luO Ru FAN Xin LI Yi ZHAO Xueying MA Rukai ZHU Jingwei CUI 《Science China Earth Sciences》 SCIE EI CAS CSCD 2018年第10期1419-1439,共21页
The Yanchang Formation is extensively developed in the Ordos Basin and its surrounding regions. As one of the best terrestrial Triassic sequences in China and the major oil-gas bearing formations in the Ordos Basin, i... The Yanchang Formation is extensively developed in the Ordos Basin and its surrounding regions. As one of the best terrestrial Triassic sequences in China and the major oil-gas bearing formations in the Ordos Basin, its age determination and stratigraphic assignment are important in geological survey and oil-gas exploration. It had been attributed to the Late Triassic and regarded as the typical representative of the Upper Triassic in northern China for a long time, although some scholars had already proposed that the lower part of this formation should be of the Middle Triassic age in the mid-late 20 th century. In this paper, we suggest that the lower and middle parts of the Yanchang Formation should be of the Ladinian and the bottom possibly belongs to the late Anisian of the Middle Triassic, mainly based on new fossils found in it and high resolution radiometric dating results. The main source rocks, namely the oil shales and mudstones of the Chang-7, are of the Ladinian Age. The upper part of the Yanchang Formation, namely the Chang-6 and the above parts, belongs to the Late Triassic. The uppermost of the Triassic is missed in most parts of the Ordos Basin. The Middle-Upper Triassic Series boundary lies in the Yanchang Formation, equivalent to the boundary between Chang-7 and Chang-6. The Ladinian is an important palaeoenvironmental turning point in the Ordos Basin. Palaeoenvironmental changes in the basin are coincidence with that of the Sichuan Basin and the main tectonic movement of the Qinling Mountains. It indicates that tectonic activities of the Qinling Mountains are related to the big palaeoenvironmental changes in both the Ordos and Sichuan Basins, which are caused by the same structural dynamic system during the Ladinian. 展开更多
关键词 Yanchang Formation Zircon age dating geological age Middle/Upper Triassic boundary Tectonic-palaeoenvironment changing Ordos Basin
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