scholarly journals Genesis of green sandstone/mudstone from Middle Jurassic Zhiluo Formation in the Dongsheng Uranium Orefield, Ordos Basin and its enlightenment for uranium mineralization

China Geology ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 52-66
Author(s):  
Ruo-shi Jin ◽  
◽  
Xiao-xi Feng ◽  
Xue-ming Teng ◽  
Feng-jun Nie ◽  
...  
Keyword(s):  
Middle Jurassic ◽  
Ordos Basin ◽  
Uranium Mineralization

First record of Eretmophyllum (Ginkgoales) with well-preserved cuticle from the Middle Jurassic of the Ordos Basin, Inner Mongolia, China

Palaeoworld ◽  
2018 ◽  
Vol 27 (2) ◽  
pp. 188-201 ◽  
Author(s):  
Yun-Feng Li ◽  
Chun-Lin Sun ◽  
Hongshan Wang ◽  
David L. Dilcher ◽  
Xiao Tan ◽  
...  
Keyword(s):  
Middle Jurassic ◽  
Inner Mongolia ◽  
Ordos Basin ◽  
First Record ◽  
The Ordos Basin

The Middle Jurassic coal-forming plants of the Ulug-Khem Basin (Republic оf Tyva, Russia)

Palaeobotany ◽  
2020 ◽  
Vol 11 ◽  
pp. 48-73
Author(s):  
E. V. Bugdaeva ◽  
S. A. Ondar ◽  
V. S. Markevich ◽  
D. A. Bushnev
Keyword(s):  
Plant Communities ◽  
Middle Jurassic ◽  
Environmental Changes ◽  
Ordos Basin ◽  
Reproductive Organs ◽  
Late Mesozoic ◽  
Northern Regions ◽  
Electron Microscopes ◽  
Main Components ◽  
Scanning Electron Microscopes

Dispersed cuticles of plants from coals of the Middle Jurassic Ulugkhem Formation (locality 229 near Mount Begreda, Ulug-Khem Basin, Republic of Tyva) were studied. As a result of the study of mesofossils using light and scanning electron microscopes, it was found that the coals are composed mainly of the remains of ginkgophytes. They are represented by the leaves of Pseudotorellia cf. angustifolia Doludenko, the female reproductive organs of this plant Umaltolepis sp., as well as the leaves of Eretmophyllum neimengguensis Li, Sun, Wang, Dilcher, Tan, Li, Na. The conifers played subordinate role. The palynospectrum of the coal seam is dominated by the spores of ferns; bisaccate and monosulcate pollen are next in importance. Thus, ginkgophytes and ferns predominated in the Middle Jurassic swamp communities in the Ulugh-Khem Basin. For the first time, the coal-forming role of the genus Eretmophyllum was revealed. The Middle Jurassic flora of Tyva is similar to the floras of the Kansk-Achinsk and Irkutsk basins of Eastern Siberia, Angren Basin of Uzbekistan, and the Ordos Basin of Inner Mongolia, China by predominance of Pseudotorellia. The vegetation was clearly differentiated into the lowland and the slope one. In the latter the leptostrobaleans, ginkgoaleans, and conifers were represented. Pseudotorellia is one of the main components of swamp plant communities in the more northern regions: in the Ulug-Khem and Irkutsk basins, and in the Aban and Pereyaslovka coal fields of the Kansk-Achinsk Basin. This genus disappears in the Nazarovo coal field of the Kansk-Achinsk Basin, being replaced by the leptostrobaleans. Here the compositions of swamp and slope communities practically do not differ. The Late Mesozoic swamp plant communities were characterized by conservatism, as well as by extreme sensitivity to environmental changes, which apparently developed because of their existence in the same conditions of high humidity. Degradation of the swamps led to the disappearance of swamp plant communities.

Ore characteristics of the sandstone-type Daying uranium deposit in the Ordos Basin, northwestern China

2017 ◽  
Vol 54 (8) ◽  
pp. 893-901 ◽  
Author(s):  
Mingjian Dai ◽  
Yunbiao Peng ◽  
Chenjun Wu ◽  
Yangquan Jiao ◽  
Lu Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Uranium Deposit ◽  
Ordos Basin ◽  
Uranium Mineralization ◽  
Low Grade ◽  
Uranium Deposits ◽  
The Ordos Basin ◽  
Thin Section Analysis ◽  
Oil Gas ◽  
Section Analysis

The Ordos Basin is one of the top oil-, gas-, and coal-producing basins in China and is increasingly recognized as an important uranium mineralization province. Uranium deposits occur near the margin of the basin and are mainly hosted in the sandstones of the Jurassic Zhiluo Formation. The Daying uranium deposit in the Ordos Basin is one of the most important large sandstone-type uranium deposits in China. Based on thin section analysis and electron microprobe measurements, we used analytical chemical data to study the characteristics of the Daying uranium deposit, including the type, structure, particle size, material composition, chemical composition, form, and valence state of the uranium. The uranium mainly exists in three forms: an absorbed form, independent minerals, and uranium-bearing minerals. Most of the uranium in the ore is U4+, and the proportion of U6+ ranges from 18% to 55%, with an average of 33%. The proportion of U6+ is relatively high in the cores containing low-grade ore. This study provides a reference for determining the best smelting technology with which to further develop this deposit.

An introductory report on the biodiversity of Middle Jurassic Phoenicopsis (Czekanowskiales) from the Ordos Basin, China

2015 ◽  
Vol 60 (21) ◽  
pp. 1858-1865 ◽  
Author(s):  
Chunlin Sun ◽  
Yunfeng Li ◽  
David L. Dilcher ◽  
Hongshan Wang ◽  
Tao Li ◽  
...  
Keyword(s):  
Middle Jurassic ◽  
Ordos Basin ◽  
The Ordos Basin

scholarly journals A New Species of Czekanowskia (Czekanowskiales) from the Middle Jurassic of Ordos Basin, China

2015 ◽  
Author(s):  
Chunlin Sun ◽  
◽  
Hongshan Wang ◽  
David L. Dilcher ◽  
Tao Li ◽  
...  
Keyword(s):  
New Species ◽  
Middle Jurassic ◽  
Ordos Basin ◽  
A New Species
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