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 ◽  
...  

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.

Author(s):  
Daniel Peter Ferguson ◽  
Guoxiang Chi ◽  
Charles Normand ◽  
Patrick Ledru ◽  
Odile Maufrais-Smith

The Athabasca Basin in northern Saskatchewan is host to many world-class uranium deposits associated with the unconformity between the Paleoproterozoic sandstone of the basin and the underlying crystalline basement (Jefferson et al., 2007).  While the style and tonnage of these deposits vary, the current genetic model for unconformity-related uranium deposits has been a practical tool for exploration in the Athabasca Basin. However, the factors which control the location and formation of these deposits is still not fully understood. A paragenetic and petrographic study of mineralization along the Midwest Trend, located on the northeastern margin of the Athabasca Basin, aims to refine the current model and to address the general problem: What are the factors which control mineralization and non-mineralization? The Midwest Trend will be used as a "modèle réduit" for uranium mineralization, as it displays many features characteristic of unconformity type deposits. The Midwest Trend comprises three mineral leases that encompass two uranium deposits, the Midwest Main and Midwest A (Allen et al., 2017a, b). Mineralization occurs along a NE-trending graphitic structure, and is hosted by the sandstone, at the unconformity, and in much lesser amounts in the underlying basement rocks. Petrographic observations aided by the use of RAMAN spectroscopy and SEM-EDS, have been used to create a paragenetic sequence of mineralization (Fig.1). Future work will focus on fluid inclusion studies using microthermometry, LA-ICP-MS, and mass spectrometry of contained gases. References:Allen, T., Quirt, D., Masset, O. (2017a). Midwest A Uranium Deposit, Midwest Property, Northern Mining District, Saskatchewan, NTS Map Area 741/8: 2017 Mineral Resource Technical Report. AREVA Resources Canada Inc. Internal Report No. 17-CND-33-01. Allen, T., Quirt, D., Masset, O. (2017b). Midwest Main Uranium Deposit, Midwest Property, Northern Mining District, Saskatchewan, NTS Map Area 741/8: 2017 Mineral Resource Technical Report. AREVA Resources Canada Inc. Internal Report No. 17-CND-33-01. Jefferson, C.W., Thomas, D.J., Gandhi, S.S., Ramaekers, P., Delaney, G., Brisbin, D., Cutts, C., Portella, P., and Olson, R.A., 2007: Unconformity-associated uranium deposits of the Athabasca Basin, Saskatchewan and Alberta. Geological Survey of Canada, Bulletin 588, p. 23–67.


2012 ◽  
Vol 512-515 ◽  
pp. 1795-1802
Author(s):  
Bo Lin Wu ◽  
Liang Hu ◽  
Chi Yang Liu ◽  
Fei Bian ◽  
Hai Tong Wang ◽  
...  

Dongsheng deposit at the northeast Ordos Basin is one of the largest sandstone-type uranium deposits in China. Its characteristics are quite different from that of sandstone-type uranium deposit in Turpan Basin and Yili Basin, Xinjiang province. One of the important aspects is that Zhiluo group of ore-bearing stratum in Dongsheng deposit was developed with more discontinuous lenticular carbonation and phenomenon of calcified wood rather than the unique non-plant fossils. This phenomenon of calcified-wood alike carbonation is rarely observed in other uranium deposits in Ordos Basin. The identified rock slice is composed of micritic calcite cemented sandstone and crystalline calcite. The former was formed by sedimentary diagenesis. The latter consists of calcite inclusions, which have been observed in water-based solution and CO2 or CH4-based gas inclusions. The temperature of the most inclusions were in the range of 140~170°C. It indicated that carbonate played an important role as hydrothermal fludis in the process of the formation of calcified wood. The analytic results of sparry calcite carbon and oxygen isotope showed that the most of the carbon sources were provided by the organic matter rather than from the process of diagenesis. Combined with the formation and characteristics of Dongsheng deposit where the area oil and gas dispersion exists, the formation of calcified-wood alike carbonation was the result of geological dispersion of oil and gas, which came from the middle of the basin area in the Paleozoic atmosphere filled by calcite crystals. Understanding the formation mechanism of Zhiluo group of ore-bearing stratum has great significance in prospecting for Dongsheng deposit.


2021 ◽  
Vol 1 (1) ◽  
pp. 1-12
Author(s):  
Wira Cakrabuana ◽  
◽  
Ekky Novia Stasia Argianto ◽  
Roni Cahya Ciputra ◽  
Dhatu Kamajati

BATAN has been carried out uranium exploration in West Borneo since 1969. So far, the exploration is focused on metamorphite-type uranium deposits in Kalan Area. The previous study concluded that mineralized uranium is originated from Sepauk Tonalite consisted of felsic-intermediate igneous rocks, and is hosted in medium-grade foliated and non-foliated metamorphic rocks of Pinoh Metamorphite. As uranium exploration develops, the International Atomic Energy Agency (IAEA) introduces the sandstone-type uranium mineralization concept that offers a more cost-effective mining process. The Melawi Basin becomes an attractive probable location for sandstone-type uranium deposit exploration since it is situated downstream of Schwaner Mountain's Sepauk Tonalite. The sandstone-dominated Tebidah Formation of Melawi Basin can be the host rock for sandstone-type uranium deposit if there is a reduction zone to trap the mobile uranium in the groundwater. The geological mapping, geochemical sampling, and radiometric survey were conducted in Menukung Area to prove the hypothesis. It is located in the eastern part of the Tebidah Formation, which contains abundant carbonaceous mudstones associated with coal seams. Mobile uranium content analysis showed the anomaly of 36–60 ppm at the central of Tebidah Formation at the study area, while radiometric data denoted the anomaly of 6.5–11.3 ppm eU. At those locations, coal and carbonaceous sandstone were observed. Those data indicate the presence of a reductive environment that gives the advantage to uranium trapping. It can be concluded that there is a possibility of the occurrence of sandstone-type uranium mineralization in the Menukung Area.


Author(s):  
Shuxun Zhou ◽  
Yan Zhou ◽  
Jian Shi ◽  
Yujie Zhu ◽  
Wulin Xiao ◽  
...  

AbstractIn order to explore the influence of the micropore structure of the tight sandstone reservoir in the water driving characteristics, the studies on the Chang 6 tight sandstone reservoir of the middle-western part of Ordos Basin are carried out by various experiments such as cast-thin section analysis, scanning electron microscopy, high-pressure mercury injection and micro-water driving. The result shows that the permeability contribution curves of samples shift to the left as the sample permeability decreases, indicating that the greater the permeability, the greater the proportion of large pores. The permeability is mostly dominated by pores with the radius larger than R50–R60. There are big differences in the water driving type, oil-driven efficiency and residual oil distribution characteristics between reservoirs of different types. The type II reservoir is the major target of subsequent exploration and development, where water driving types consist of mesh and finger, leaving the residual oil mainly locked by water or isolated as oil drops. The size and distribution feature of pores are the key factors dominating the oil-driven efficiency.


Sign in / Sign up

Export Citation Format

Share Document