Fig 1.
Geological map of the study area [20].
a. Geotectonic map of the Hailar Basin. b. Tectonic subdivisions of the Hailar Basin. c. Geological map of the Kelulun Depression. Republished from [Meng F.M, Nie F.J, Xia F, Yan Z.B, Sun, D, Zhou W.B, et al. Sedimentary Environment, Tectonic Setting, and Uranium Mineralization Implications of the Yimin Formation, Kelulun Depression, Hailar Basin, China. 2024; 12, 763.] under a CC BY license, with permission from [Journal of Marine Science and Engineering], original copyright [2024].
Fig 2.
Photographs of thin sections under optical microscopy of the Yimin Formation sandstones.
a. Medium-to-fine grained sandstones (cross-polarized). b. Twinned plagioclase crystal (cross-polarized). c. Grid-twinned microcline (cross-polarized). d. Granite fragment (cross-polarized). e. Andesite tuff (cross-polarized). f. Crystal tuff (plane-polarized). g. Chloritized biotite (plane-polarized). h. Pyrite vein (plane-polarized). i. Bitumen vein (plane-polarized).
Fig 3.
Upper continental crust-normalized trace element spidergram for samples from the Yimin Formation [34].
Fig 4.
(a) Chondrite-normalized REE diagram [36]. (b) NASC-normalized REE diagram [37].
Fig 5.
Cathodoluminescence images of detrital zircons from the Yimin Formation sandstones, with circles marking laser spot placement and number indicating the obtained 206Pb/238U ages.
Fig 6.
Relationship between zircon ages and Th/U in the Yimin Formation sandstones.
Fig 7.
Concordia diagram of detrital zircon LA-ICP-MS U-Pb ages.
Fig 8.
Age spectrum of detrital zircons from the Yimin Formation sandstones.
Fig 9.
Chondrite-normalized REE fractionation curves of detrital zircons from the Yimin Formation sandstones [36].
Fig 10.
Zircon trace element discrimination diagrams for the Yimin Formation sandstones [41].
a. Y-U diagram. b. Nb-Ta diagram. c. Y-Nb/Ta diagram. d. Y-Yb/Sm diagram.
Fig 11.
Major element discrimination diagrams for the parent rocks of the Yimin Formation sandstones.
a. TiO2-Al2O3 diagram [47]. b. F2-F1 diagram [48]. c. K2O-Rb diagram [49]. d. TiO2-Ni diagram [50].
Fig 12.
Trace element discrimination diagrams for the parent rocks of the Yimin Formation sandstones.
a. Co/Th-La/Sc diagram [51]. b. Th/Sc- Cr/Th diagram [52]. c. Th/Sc-Zr/Sc diagram [53]. d. La/Th-La/Yb diagram [54]. UCC: Upper continental crust. PAAS: Post-archean Australian shale. TTG: Trondhjemite-tonalite-granodiorite.
Fig 13.
Triangular trace-element discrimination diagrams for the parent rocks of the Yimin Formation sandstones.
a. La-Th-Sc diagram [55], b. Th-Hf-Co diagram [34], c. V-Ni-Th×10 diagram [52]. UCC: Upper continental crust. TTG: Trondhjemite-tonalite-granodiorite. PAAS: Post-archean Australian shale.
Fig 14.
Major element discrimination diagrams for the tectonic setting of the Yimin Formation sandstones.
a. K2O/(Na2O+CaO)-SiO2/Al2O3 diagram [56]. b. K2O/Na2O-SiO2 diagram [57]. c. TiO2-(Fe2O3T+MgO) diagram [58]. d. Al2O3/SiO2-(Fe2O3T+MgO) diagram [59]. PM: Passive continental margin. ACM: Active continental margin. ARC: Oceanic island arc margin. OIA: Oceanic island arc. CIA: Continental island arc.
Fig 15.
Trace element discrimination diagrams for the tectonic setting of the Yimin Formation sandstones.
a. La-Th-Sc diagram, b. Th-Sc-Zr/10 diagram, c. Th-Co-Zr/10 diagram [58]. PM: Passive continental margin. ACM: Active continental margin. OIA: Oceanic island arc. CIA: Continental island arc.
Fig 16.
Discrimination diagrams for the paleoweathering characteristics of the source region of the Yimin Formation sandstones.
a. A-CN-K diagram [70]. b. ICV-CIA diagram [63]. UCC: Upper continental crust.
Fig 17.
Sedimentary facies map of the Yimin Formation in the Kelulun Depression [19].
Republished from [Zhou W.B, Zhang R, Liu T, Mu H.Q, Zhao Z.W, Huang X. Metallogenic Geological Features and Prospective Study for Sandstone-type Uranium Deposit in Bel-Ulson Depression 2020; 53(03), 201–209.] under a CC BY license, with permission from [Northwestern Geology], original copyright [2020].
Fig 18.
U-Pb age spectra of detrital zircons from the Yimin Formation sandstones and geological bodies around the Kelulun Depression [76–85].
(n represents the number of zircons).
Fig 19.
Stages of uranium mineralization in the sandstone uranium deposits of the Kelulun Depression [20].