Relationship between reducing media and uranium mineralization in the Telaaobao uranium deposit, Ordos Basin
- 1Geologic Party NO. 208, CNNC, Baotou 014010, Inner Mongolia, China
- 2East China University of Technology, Nanchang 330013, Jiangxi, China
Abstract
Objective The Telaaobao uranium deposit is the first super-large uranium deposit hosted in the Lower Cretaceous strata in the northern Ordos Basin. Its sedimentary setting is markedly different from that of the numerous uranium deposits previously studied in the Middle Jurassic Zhiluo Formation. The uranium-bearing sandstone reservoirs in this deposit are notably deficient in traditional reducing agents, such as carbonaceous debris and pyrite. This limited understanding of reducing media has significantly hindered the refinement of uranium metallogenic models and the advancement of successful exploration. This study aims to identify the types and genetic characteristics of reducing media in the Telaaobao uranium deposit and elucidate their roles in uranium mineralization. Methods Optical microscopy, scanning electron microscopy (SEM) coupled with energy-dispersive spectroscopy (EDS), and electron probe microanalysis (EPMA) were employed, together with fluorescence analysis, sulfur isotope analysis, and acidolysis hydrocarbon analysis to characterize the reducing media and investigate their origins and roles in uranium mineralization. The findings were interpreted within the framework of the metallogenic model of the Telaaobao uranium deposit. Results Four types of reducing media were identified: carbonaceous debris, pyrite, hydrocarbon-bearing fluids, and chlorite. Hydrocarbon-bearing fluids were identified as the predominant reducing medium. The carbonaceous debris was mainly allochthonous and derived from older strata. Sulfur in pyrite primarily originated from bacteriogenic sulfides and organic sulfides. The hydrocarbon-bearing fluids were sourced from deep coal-, oil-, and gas-bearing strata and migrated into the deposit via faults in its vicinity. Chlorite can be subdivided into alteration products of mica and feldspar and authigenic chlorite. Conclusions Based on the Telao Bao metallogenic model, the types and roles of reducing media during different mineralization stages were discussed: (1) During the sedimentary-diagenetic stage in the early Early Cretaceous, the main reducing media were carbonaceous debris and metal sulfides such as pyrite; (2) In the late Early Cretaceous large-scale reduction stage, the principal reducing medium was deep-sourced hydrocarbon-bearing fluids; (3) From the Late Cretaceous to the Oligocene, during the secondary oxidation–mineralization stage, chlorite further enhanced the reducing capacity of the sandstone reservoirs, ultimately leading to termination of redox-driven mineralization. Significance These findings clarify the types, origins, and stage-specific roles of reducing media in the Telaaobao uranium deposit, highlighting the importance of deep-sourced hydrocarbon-bearing fluids in uranium mineralization. The results provide a basis for refining the metallogenic model of the deposit and may inform uranium exploration in comparable geological settings.
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BibTeX
@article{yunbiao2026relationship,
title = {{Relationship between reducing media and uranium mineralization in the Telaaobao uranium deposit, Ordos Basin}},
author = {PENG Yunbiao and JIANG Xiaojie and LU Chao and WANG Longhui and ZHONG Weihui and YANG Yong and LUO Wenta},
journal = {Dizhi lixue xuebao},
year = {2026},
month = sep,
doi = {10.12090/j.issn.1006-6616.2026074},
url = {https://doi.org/10.12090/j.issn.1006-6616.2026074},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Relationship between reducing media and uranium mineralization in the Telaaobao uranium deposit, Ordos Basin
AU - PENG Yunbiao
AU - JIANG Xiaojie
AU - LU Chao
AU - WANG Longhui
AU - ZHONG Weihui
AU - YANG Yong
AU - LUO Wenta
PY - 2026
DA - 2026/09/01
JO - Dizhi lixue xuebao
DO - 10.12090/j.issn.1006-6616.2026074
UR - https://doi.org/10.12090/j.issn.1006-6616.2026074
AB - Objective The Telaaobao uranium deposit is the first super-large uranium deposit hosted in the Lower Cretaceous strata in the northern Ordos Basin. Its sedimentary setting is markedly different from that of the numerous uranium deposits previously studied in the Middle Jurassic Zhiluo Formation. The uranium-bearing sandstone reservoirs in this deposit are notably deficient in traditional reducing agents, such as carbonaceous debris and pyrite. This limited understanding of reducing media has significantly hindered the refinement of uranium metallogenic models and the advancement of successful exploration. This study aims to identify the types and genetic characteristics of reducing media in the Telaaobao uranium deposit and elucidate their roles in uranium mineralization. Methods Optical microscopy, scanning electron microscopy (SEM) coupled with energy-dispersive spectroscopy (EDS), and electron probe microanalysis (EPMA) were employed, together with fluorescence analysis, sulfur isotope analysis, and acidolysis hydrocarbon analysis to characterize the reducing media and investigate their origins and roles in uranium mineralization. The findings were interpreted within the framework of the metallogenic model of the Telaaobao uranium deposit. Results Four types of reducing media were identified: carbonaceous debris, pyrite, hydrocarbon-bearing fluids, and chlorite. Hydrocarbon-bearing fluids were identified as the predominant reducing medium. The carbonaceous debris was mainly allochthonous and derived from older strata. Sulfur in pyrite primarily originated from bacteriogenic sulfides and organic sulfides. The hydrocarbon-bearing fluids were sourced from deep coal-, oil-, and gas-bearing strata and migrated into the deposit via faults in its vicinity. Chlorite can be subdivided into alteration products of mica and feldspar and authigenic chlorite. Conclusions Based on the Telao Bao metallogenic model, the types and roles of reducing media during different mineralization stages were discussed: (1) During the sedimentary-diagenetic stage in the early Early Cretaceous, the main reducing media were carbonaceous debris and metal sulfides such as pyrite; (2) In the late Early Cretaceous large-scale reduction stage, the principal reducing medium was deep-sourced hydrocarbon-bearing fluids; (3) From the Late Cretaceous to the Oligocene, during the secondary oxidation–mineralization stage, chlorite further enhanced the reducing capacity of the sandstone reservoirs, ultimately leading to termination of redox-driven mineralization. Significance These findings clarify the types, origins, and stage-specific roles of reducing media in the Telaaobao uranium deposit, highlighting the importance of deep-sourced hydrocarbon-bearing fluids in uranium mineralization. The results provide a basis for refining the metallogenic model of the deposit and may inform uranium exploration in comparable geological settings.
SN - 1006-6616
ER -