scholarly journals Provenance of Jurassic Sediments from Yuqia Sandstone-Type Uranium Deposits in the Northern Margin of Qaidam Basin, China and Its Implications for Uranium Mineralization

Minerals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 82
Author(s):  
Guangwen Huang ◽  
Dehai Wu ◽  
Guangnan Huang ◽  
Wanwen Xue ◽  
Zhuang Min ◽  
...  
Keyword(s):  
Uranium Deposit ◽  
Qaidam Basin ◽  
Tectonic Setting ◽  
Active Continental Margin ◽  
Source Area ◽  
Reduction Reaction ◽  
Uranium Mineralization ◽  
Northern Margin ◽  
Target Layer ◽  
Oxygenated Water

The Yuqia uranium deposit is a newly discovered sandstone-type uranium deposit in the northern margin of the Qaidam Basin. Concerning the sources of sediment in the basin, most scholars have focused on the study of Cenozoic sediment sources in the northern part of the basin, rather than on the study of Jurassic provenance and its implications for uranium mineralization. In this paper, the Jurassic sandstones in the area were selected for petrography, petrogeochemistry and electron microprobe analysis (EPMA), and the significance of sedimentary provenance and uranium metallogeny were further discussed, based on the previous data of detrital zircon chronology. It is reported here for the first time that coffinite and pitchblende are the main contributors. Independent uranium minerals in the region mainly occur in strawberry pyrite, xenotime, and margins or of quartz. The rocks in the source area, Jurassic sandstones, were mainly formed under the tectonic setting of the active continental margin; however, the sediments are mainly derived from the Indosinian and Paleozoic granitoids exposed in the northern margin of the Qaidam Basin. The uranium-rich granites in the source area led to the preconcentration of uranium in the sandstone of the target layer, and the uranium was brought into the ore-bearing target layer through uranium-bearing oxygenated water. The reduction reaction occurred under the action of reducing matter, and finally, the U6+ was reduced to U4+ in the formation of coffinite and pitchblende.

Petrography and geochemistry of the siliciclastic Araba Formation (Cambrian), east Sinai, Egypt: implications for provenance, tectonic setting and source weathering

2015 ◽  
Vol 154 (1) ◽  
pp. 1-23 ◽  
Author(s):  
HOSSAM A. TAWFIK ◽  
IBRAHIM M. GHANDOUR ◽  
WATARU MAEJIMA ◽  
JOHN S. ARMSTRONG-ALTRIN ◽  
ABDEL-MONEM T. ABDEL-HAMEED
Keyword(s):  
Tectonic Setting ◽  
Source Area ◽  
Xrd Analysis ◽  
Climatic Conditions ◽  
Source Rocks ◽  
Northern Margin ◽  
Rock Fragments ◽  
Geochemical Parameters ◽  
Clastic Sediments ◽  
Chemical Index

AbstractCombined petrographic and geochemical methods are utilized to investigate the provenance, tectonic setting, palaeo-weathering and climatic conditions of the Cambrian Araba clastic sediments of NE Egypt. The ~ 60 m thick Araba Formation consists predominantly of sandstone and mudstone interbedded with conglomerate. Petrographically the Araba sandstones are mostly sub-mature and classified as subarkoses with an average framework composition of Q80F14L6. The framework components are dominated by monocrystalline quartz with subordinate K-feldspar, together with volcanic and granitic rock fragments. XRD analysis demonstrated that clay minerals comprise mixed-layer illite/smectite (I/S), illite and smectite, with minor kaolinite. Diagenetic features of the sandstone include mechanical infiltration of clay, mechanical and chemical compaction, cementation, dissolution and replacement of feldspars by carbonate cements and clays. The modal composition and geochemical parameters (e.g. Cr/V, Y/Ni, Th/Co and Cr/Th ratios) of the sandstones and mudstones indicate that they were derived from felsic source rocks, probably from the crystalline basement of the northern fringe of the Arabian–Nubian Shield. The study reveals a collisional tectonic setting for the sediments of the Araba Formation. Palaeo-weathering indices such as the chemical index of alteration (CIA), chemical index of weathering (CIW) and plagioclase index of alteration (PIA) of the clastic sediments suggest that the source area was moderately chemically weathered. On the northern margin of Gondwana, early Palaeozoic weathering occurred under fluctuating climatic conditions.

scholarly journals Geochemistry of the mudrocks and sandstones from the Bredasdorp Basin, offshore South Africa: Implications for tectonic provenance and paleoweathering

2021 ◽  
Vol 13 (1) ◽  
pp. 1187-1225
Author(s):  
Temitope Love Baiyegunhi ◽  
Kuiwu Liu ◽  
Oswald Gwavava ◽  
Christopher Baiyegunhi ◽  
Maropene Rapholo
Keyword(s):  
South Africa ◽  
Chemical Weathering ◽  
Tectonic Setting ◽  
Active Continental Margin ◽  
Source Area ◽  
Major And Trace Elements ◽  
Rift System ◽  
Moderate Degree ◽  
East African Rift System ◽  
Major Oxide

Abstract An inorganic geochemical investigation of mudrocks and sandstone from the southern Bredasdorp Basin, off the south coast of South Africa was carried out to unravel the provenance, paleoweathering, and tectonic setting of the basin. Seventy-seven representative samples from exploration wells E-AH1, E-AJ1, E-BA1, E-BB1, and E-D3 underwent geochemical analysis involving major and trace elements. The major oxide compositions show that the sandstones could be classified as sub-arkose and sub-lithic arenite. The provenance discrimination diagrams based on major oxide geochemistry revealed that the sandstones are mainly of quartzose sedimentary provenance, while the mudrocks are of quartzose sedimentary and intermediate igneous provenances. The discrimination diagrams indicate that the Bredasdorp sediments were mostly derived from a cratonic interior or recycled orogen. The bivariate plots of TiO2 versus Ni, TiO2 against Zr, and La/Th versus Hf as well as the ternary diagrams of V–Ni–Th∗10 suggest that the mudrocks and sandstones were derived from felsic igneous rocks. The tectonic setting discrimination diagrams support passive-active continental margin setting of the provenance. Also, the closely similar compositions of the analysed samples and recent sedimentary rocks of the East African Rift System perhaps suggest a rifted basin tectonic setting for the Bredasdorp Basin. Chemical index of alteration (CIA) indices observed in the sandstones suggest that their source area underwent low to moderate degree of chemical weathering. However, the mudrocks have high CIA indices suggesting that the source area underwent more intense chemical weathering, possibly due to climatic and/or tectonic variations.

scholarly journals Geochemistry of the Paleocene Clastic Rocks From the Southwestern Jianghan Basin, Central China Reveal Their Provenance, Tectonic Setting, and Palaeoenvironment

2021 ◽  
Author(s):  
Kai Yan ◽  
Chun-lian Wang ◽  
Jiu-yi Wang ◽  
Xiao-can Yu ◽  
Xiao-hua Teng ◽  
...  
Keyword(s):  
Tectonic Setting ◽  
Active Continental Margin ◽  
Source Area ◽  
Source Rocks ◽  
Central China ◽  
Clastic Rocks ◽  
Ree Distribution ◽  
C Value ◽  
Tectonic Settings ◽  
Jianghan Basin

Abstract This paper intends to learn about the provenance, tectonic setting and paleoenvironment of the Paleocene Shashi Formation in the southern Jianghan Basin by the bulk-rock geochemistry. The K2O/Al2O3 and SiO2/Al2O3 ratios indicate that the major proportion of samples are litharenite. The chondrite-normalized REE distribution pattern of the Shashi Formation’s mudstones are characterized by enriched LREE and flat HREE similar to those of UC with negative Eu anomalies. Combined with the geochemical element ratio discriminant diagram, such as Al2O3-TiO2, Zr-TiO2, La/Sc-Co/Th, and Hf-La/Th, so on, these samples were sourced from mixed felsic/basic rock. Moreover, the discriminant diagrams of K2O/Na2O-SiO2/Al2O3, La-Th-Sc, and Th-Co-Zr/10 suggest that the samples were formed under the tectonic settings of active continental margin and continental island arc. The values of CIA, CIW, PIA, ICV, Zr/Sc-Th/Sc, and ternary diagrams of A-(CN)-K and Al2O3-Zr-TiO2 indicate that weathering in the source area was weak and source rocks have not been reformed by depositional recirculation and hydraulic sorting. And the palaeoenvironmental indicators of C-value, Ni/Co, V/Cr, V/(V+Ni) and Sr/Cu, Ga/Rb indicate that the climate was cool and arid during the evaporite deposition period in the southern Jianghan Basin, and the water was in the condition of oxidation.

scholarly journals Geochemistry of the Permian sandstones from the Malužiná Formation in the Malé Karpaty Mts (Hronic Unit, Western Carpathians, Slovakia): implications for source-area weathering, provenance and tectonic setting

2013 ◽  
Vol 64 (1) ◽  
pp. 23-38 ◽  
Author(s):  
Marek Vďačný ◽  
Anna Vozárová ◽  
Jozef Vozár
Keyword(s):  
Continental Margin ◽  
Tectonic Setting ◽  
Active Continental Margin ◽  
Source Area ◽  
Chemical Index ◽  
Fold Belts ◽  
Rifted Continental Margin ◽  
Bulk Chemical ◽  
Chemical Index Of Alteration ◽  
Ree Patterns

Abstract The Permian sandstones of the Malužiná Formation in the northern part of the Malé Karpaty Mts are dominantly quartzofeldspathic and quartzolithic in composition with abundant feldspars and volcanic, plutonic igneous and less metasedimentary lithic fragments, indicating the sand grains were derived from a basement uplift and recycled orogen. The Malužiná Formation sandstones have moderate to high SiO2 contents (68-85 wt. %; on average 76 wt. %), TiO2 concentrations averaging 0.3 wt. %, Al2O3 contents of about 12 wt. %, and Fe2O3 (total Fe as Fe2O3) + MgO contents of around 2.9 wt. %. The Chemical Index of Alteration (CIA) values for the Permian Malužiná Formation sandstones vary from 45 to 68 with an average of 55, indicating low to moderate weathering of the source area. The bulk chemical composition and selected trace elements preserve the signatures of a felsic and intermediate igneous provenance, and suggest mostly an active continental margin tectonic setting of the source area for the Malužiná Formation sandstones. The Eu/Eu* (~0.78), La/Sc (~7.28), Th/Sc (~2.10), La/Co (~6.67), Th/Co (~1.85), and Cr/Th (~6.57) ratios as well as the chondrite-normalized REE patterns with flat HREE, LREE enrichment, and negative Eu anomalies indicate derivation of the Malužiná Formation sandstones from felsic rock sources. The deposition of the Malužiná Formation sandstones took place in a rifted continental margin environment supplied from collision orogen on a thick continental crust composed of rocks of older fold belts.

scholarly journals Sandstone petrography and geochemistry of the Nayband Formation (Upper Triassic, Central Iran): Implications for sediment provenance and tectonic setting

2019 ◽  
Vol 112 (1) ◽  
pp. 20-41 ◽  
Author(s):  
Asghar Etesampour ◽  
Asadollah Mahboubi ◽  
Reza Moussavi-Harami ◽  
Nasser Arzani ◽  
Mohammad Ali Salehi
Keyword(s):  
Tectonic Setting ◽  
Active Continental Margin ◽  
Source Area ◽  
Major Elements ◽  
Upper Triassic ◽  
Late Triassic ◽  
Sediment Provenance ◽  
Provenance Areas ◽  
Nayband Formation ◽  
Southwestern Margin

AbstractThe Upper Triassic (Norian–Rhaetian) Nayband Formation is situated at the southwestern margin of Central East Iranian Microcontinent and records Eo-Cimmerian events. The formation is composed of mixed carbonate-siliciclastic deposits. This study presents information on the tectonic reconstruction and palaeoclimate of the southwestern margin of Central East Iranian Microcontinent during the Late Triassic. Petrography and modal analyses of sandstones show a variety of quartz-rich petrofacies including subarkose, lithic arkose, sublitharenite, feldspathic litharenite and litharenite. The combined modal analysis and geochemical results of major and trace elements of the sandstone samples represents mixed sedimentary, intermediate, felsic igneous rocks and moderate- to high-grade metamorphic provenance areas. The major elements and modal analyses of the Nayband Formation sandstone samples suggest an active continental margin tec-tonic settings. The palaeoclimatic conditions were sub-humid to humid with relatively low to moderate weathering in the source area which is in agreement with the palaeogeography and palaeotectonic history of southwestern margin of Central East Iranian Microcontinent during the Late Triassic.

scholarly journals Geochemical and Petrographical Characteristics of the Madzaringwe Formation Coal, Mudrocks and Sandstones in the Vele Colliery, Limpopo Province, South Africa: Implications for Tectonic Setting, Provenance and Paleoweathering

2021 ◽  
Vol 11 (6) ◽  
pp. 2782
Author(s):  
Elelwani Denge ◽  
Christopher Baiyegunhi
Keyword(s):  
Tectonic Setting ◽  
Active Continental Margin ◽  
Sedimentary Rocks ◽  
Source Area ◽  
Granite Gneiss ◽  
Major Elements ◽  
Limpopo Province ◽  
Source Areas ◽  
Mgo Support ◽  
Chemical Index Of Alteration

The sedimentary rocks of the Madzaringwe Formation in the Tuli Basin have been investigated using geochemical and petrographic methods to reveal their source area composition, tectonic setting, provenance and paleoweathering conditions. The petrographic studies show that the rocks consist mostly of clay minerals and quartz. The major elements geochemistry indicates that the rocks of the Madzaringwe Formation have the same source area. Based on the discriminant function plots, it can be inferred that the rocks are of quartzose sedimentary provenance, suggesting that they were derived from a cratonic interior or recycled orogen. The binary plots of TiO2 versus Zr and La/Sr against Th/Co shows that the rocks were derived from silicic or felsic igneous rocks. The tectonic setting discrimination diagrams of SiO2 against Log (K2O/Na2O), Th–Sc–Zr/10, and TiO2 versus (Fe2O3 + MgO) support passive-active continental margin settings of the provenance. The A–CN–K (Al2O3–CaO + Na2O–K2O) ternary diagram and binary plot of the index of compositional variability (ICV) against chemical index of alteration (CIA) shows that the rocks have been subjected to moderate to intensive weathering. Geochemical and petrographic characteristics of the rocks point to uplifted basement source areas predominantly composed of sedimentary rocks and/or granite-gneiss rocks. These source areas might have been from adjacent areas near the Tuli coalfield which include the Limpopo Belt (igneous and sedimentary rocks), and basement uplifted rocks of the Beit-Bridge Complex, consisting of the granite, granite-gneisses and schists.

Petrography and geochemistry of the Carboniferous–Triassic Trinity Peninsula Group, West Antarctica: implications for provenance and tectonic setting

2014 ◽  
Vol 152 (4) ◽  
pp. 575-588 ◽  
Author(s):  
PAULA CASTILLO ◽  
JUAN PABLO LACASSIE ◽  
CARITA AUGUSTSSON ◽  
FRANCISCO HERVÉ
Keyword(s):  
Antarctic Peninsula ◽  
Tectonic Setting ◽  
Active Continental Margin ◽  
Source Area ◽  
Major And Trace Elements ◽  
Cold Climate ◽  
West Antarctica ◽  
Continental Arc ◽  
Uplift And Erosion ◽  
The Antarctic

AbstractThe Carboniferous-Triassic Trinity Peninsula Group is a metasedimentary sequence that crops out widely in the northern Antarctic Peninsula. These are some of the most extensive outcrops in the area and hold the key to evaluating the connections of the Antarctic Peninsula in Gondwana; however, they are still poorly understood. Here we present our provenance study of the Trinity Peninsula Group using petrographic and geochemical approaches in combination with cathodoluminescence of detrital quartz in order to constrain its source characteristics and tectonic setting. Using differences in modal composition and quartz cathodoluminescence characteristics, we define three petrofacies derived from the progressive uplift and erosion of a volcano-plutonic continental arc, which exposed the plutonic-metamorphic roots. As indicated by major and trace elements, the source is felsic with a composition ranging from tonalitic to granodioritic. The relatively unweathered condition of the source area points to a dry and cold climate at the time of deposition, but this does not necessarily mean that it was glaciated. Deposition of the sediments occurred within an active continental margin, relatively close to the source area, probably along the south Patagonia–Antarctic Peninsula sector of Gondwana. Strong chronological, petrological and chemical similarities with the sediments of the Duque the York Complex in Patagonia suggest that they were derived from the same source.

Petrogenesis and tectonic significance of the middle Neoproterozoic highly fractionated A-type granite in the South Qinling block

2021 ◽  
pp. 1-20
Author(s):  
Xiao-Fei Qiu ◽  
Qiong Xu ◽  
Tuo Jiang ◽  
Shan-Song Lu ◽  
Long Zhao
Keyword(s):  
Tectonic Setting ◽  
Eastern China ◽  
Continental Rift ◽  
The South ◽  
Yangtze Craton ◽  
Dabie Orogen ◽  
Northern Margin ◽  
South Qinling ◽  
Type Granite ◽  
High Alkali

Abstract The South Qinling block, a segment of the Yangtze craton involved in the Qinling–Dabie orogen, is critical for understanding the tectonic evolution of eastern China. However, the tectonic setting of the South Qinling block and the northern margin of the Yangtze block during middle Neoproterozoic time has long been the subject of debate, with two distinctly different models (continental rift or volcanic arc) proposed. Here, a comprehensive study of zircon U–Pb geochronology and geochemistry has been carried out on the Chengwan granitic pluton from the Suizao terrane in the South Qinling block. The granites are monzogranite and syenogranite in lithology, and are mainly composed of potash feldspar, quartz, plagioclase and biotite. This suite has long been regarded as a Palaeozoic magmatic pluton, but zircon U–Pb ages of 809 ± 9 Ma and 816 ± 4 Ma are obtained in this study. The granites are metaluminous to strongly peraluminous with high alkali contents, and exhibit highly fractionated features, including high SiO2, low Zr/Hf ratios, rare earth element tetrad effects and enrichment of K and Rb. They show Hf–Nd isotopic decoupling, which may be genetically related to their petrogenetic process. Based on the geochemical features and the positive εHf(t) values of the zircons, it is indicated that the granites may have been derived from partial melting of juvenile tonalitic rocks by biotite breakdown under fluid-absent conditions. The Chengwan granite geochemically belongs to the A2-subtype granites, suggesting that it might have formed in a post-orogenic tectonic setting. The highly fractionated A-type granite in this study may represent extensional collapse shortly after the collisional events in the South Qinling block, and thus indicate a tectonic regime switch, from compression to extension, as early as middle Neoproterozoic time. Integrating our new data with documented magmatic, metamorphic and sedimentary events during middle Neoproterozoic time in the region may support a continental rift model, and argues against arc models.

scholarly journals Impact of Diagenesis on the Low Permeability Sandstone Reservoir: Case Study of the Lower Jurassic Reservoir in the Niudong Area, Northern Margin of Qaidam Basin

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 453
Author(s):  
Wenhuan Li ◽  
Tailiang Fan ◽  
Zhiqian Gao ◽  
Zhixiong Wu ◽  
Ya’nan Li ◽  
...  
Keyword(s):  
Physical Properties ◽  
Oil And Gas ◽  
Qaidam Basin ◽  
Isotope Analysis ◽  
Lower Jurassic ◽  
Low Permeability ◽  
Hydrocarbon Generation ◽  
Northern Margin ◽  
Pore Evolution ◽  
Sandstone Reservoir

The Lower Jurassic reservoir in the Niudong area of the northern margin of Qaidam Basin is a typical low permeability sandstone reservoir and an important target for oil and gas exploration in the northern margin of the Qaidam Basin. In this paper, casting thin section analysis, scanning electron microscopy, X-ray diffraction, and stable isotope analysis among other methods were used to identify the diagenetic characteristics and evolution as well as the main factors influencing reservoir quality in the study area. The predominant types of sandstone in the study area are mainly feldspathic lithic sandstone and lithic arkose, followed by feldspathic sandstone and lithic sandstone. Reservoir porosity ranges from 0.01% to 19.5% (average of 9.9%), and permeability ranges from 0.01 to 32.4 mD (average of 3.8 mD). The reservoir exhibits robust heterogeneity and its quality is mainly influenced by diagenesis. The Lower Jurassic reservoir in the study area has undergone complex diagenesis and reached the middle diagenesis stage (A–B). The quantitative analysis of pore evolution showed that the porosity loss rate caused by compaction and cementation was 69.0% and 25.7% on average, and the porosity increase via dissolution was 4.8% on average. Compaction was the main cause of the reduction in the physical property of the reservoir in the study area, while cementation and dissolution were the main causes of reservoir heterogeneity. Cementation can reduce reservoir space by filling primary intergranular pores and secondary dissolved pores via cementation such as a calcite and illite/smectite mixed layer, whereas high cement content increased the compaction resistance of particles to preserve certain primary pores. δ13C and δ18O isotopes showed that the carbonate cement in the study area was the product of hydrocarbon generation by organic matter. The study area has conditions that are conductive to strong dissolution and mainly occur in feldspar dissolution, which produces a large number of secondary pores. It is important to improve the physical properties of the reservoir. Structurally, the Niudong area is a large nose uplift structure with developed fractures, which can be used as an effective oil and gas reservoir space and migration channel. In addition, the existence of fractures provides favorable conditions for the uninterrupted entry of acid fluid into the reservoir, promoting the occurrence of dissolution, and ultimately improves the physical properties of reservoirs, which is mainly manifested in improving the reservoir permeability.

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