scholarly journals Kajian Geologi, Radiometri dan Geokimia Granit Banggai dan Formasi Bobong Untuk Menentukan Daerah Potensial Uranium di Pulau Taliabu, Maluku Utara

EKSPLORIUM ◽  
2016 ◽  
Vol 37 (1) ◽  
pp. 13
Author(s):  
Ngadenin Ngadenin
Keyword(s):  
Host Rock ◽  
Uranium Mineralization ◽  
Geochemical Data ◽  
Potential Host ◽  
Geological Setting ◽  
Vein Type ◽  
The Future ◽  
Uranium Exploration ◽  
Lignite Coal

Kajian geologi, radiometri dan geokimia granit Banggai dan Formasi Bobong telah dilakukan untuk mendapatkan daerah potensial uranium. Pulau Taliabu dipilih sebagai lokasi kajian karena secara tektonik pulau Taliabu adalah benua mikro pecahan dari benua Gondwana yang terpisah pada akhir Mesozoikum hingga Paleogen. Beberapa tipe mineralisasi uranium terbentuk pada periode Gondwana antara lain adalah mineralisasi tipe batupasir, mineralisasi tipe batu bara lignit dan mineralisasi tipe urat. Pulau Taliabu merupakan serpihan dari benua Gondwana sehingga diharapkan di Pulau Taliabu akan ditemukan mineralisasi uranium atau paling tidak ditemukan indikasi keterdapatan mineralisasi uranium. Tujuan dari kajian ini adalah untuk mendapatkan lokasi potensial uranium untuk pengembangan eksplorasi uranium di masa mendatang. Metode yang digunakan adalah mengkaji data geologi, radiometri, dan geokimia yang berasal dari berbagai sumber. Hasil kajian menunjukkan bahwa data geologi, radiometri, dan geokimia memberikan indikasi positif terhadap pembentukan cebakan uranium tipe batupasir. Granit Banggai berpotensi sebagai sumber uranium. Batupasir pada Formasi Bobong berpotensi sebagai batuan induk. Lapisan batubara dan pirit berpotensi sebagai presipitan. Daerah potensial uranium terletak di wilayah Formasi Bobong dan sekitarnya. Geological, radiometrical, and geochemichal studies of Banggai granites and Bobong Formation have been conducted in order to obtain  potential uranium area. Taliabu island is selected for the study because Taliabu island is a micro continent fraction of the Gondwana super continent that separated at the end of the Mesozoic to Paleogene period. Some types of uranium mineralization formed in the period of Gondwana include sandstone-type, lignite coal types and vein-type. Taliabu island is a small part from the Gondwana super continent so it is expected will be found uranium mineralization or at least indications of uranium mineralization occurences. The aim of this study is to obtain uranium potential areas for the development of uranium exploration in the future. The methods used are reviewing geological, radiometric, and geochemical data from various sources. The results of review showed that geological setting, radiometric, and geochemical data gives positive indication to the formation of uranium mineralization for sandstone type. Banggai Granite is a potential uranium source. Sandstone of Bobong Formation as a potential host rock. Coal and pyrite as a potential precipitant. Potential areas for uranium is located around Bobong Formation.

scholarly journals Correlation of VLF-EM Data with Radiometric Measurements: Implications for Uranium Exploration around Beldih, South Purulia Shear Zone, India

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Saurabh Mittal ◽  
S. P. Sharma ◽  
Arkoprovo Biswas ◽  
D. Sengupta
Keyword(s):  
Shear Zone ◽  
High Surface ◽  
Uranium Mineralization ◽  
Subsurface Structure ◽  
High Radiation ◽  
Background Radiations ◽  
Radiometric Measurements ◽  
Uranium Exploration ◽  
Radioactive Minerals ◽  
Open Cast

This study is an attempt to correlate VLF-EM data with the radiometric measurements to decipher the subsurface structure and to locate uranium mineralization in the shear zone. The study area is around Beldih mine which is an open cast apatite mine located on the South Purulia Shear Zone. VLF method has been applied to map the structure and the presence of radioactive minerals has been delineated by the detection of highαandγcounts with respect to the background radiations. High radiation counts and high surfaceγactivity are found just above the higher apparent current-density zones in all the profiles studied, at various locations, indicating uranium and/or thorium mineralization as well as good correlation between these techniques.

The Coles Hill Uranium Deposit, Virginia, USA: Geology, Geochemistry, Geochronology, and Genetic Model

2022 ◽  
Vol 117 (2) ◽  
pp. 273-304
Author(s):  
S. M. Hall ◽  
J. S. Beard ◽  
C. J. Potter ◽  
R. J. Bodnar ◽  
L. A. Neymark ◽  
...  
Keyword(s):  
Shear Zone ◽  
Titanium Oxide ◽  
River Basin ◽  
Host Rock ◽  
Uranium Deposit ◽  
Uranium Mineralization ◽  
Late Triassic ◽  
Pb Isotope ◽  
Igneous Complex ◽  
Mineralizing Fluids

Abstract The Coles Hill uranium deposit, with an indicated resource of about 130 Mlb of U3O8, is the largest unmined uranium deposit in the United States. The deposit is hosted in the Taconian (approx. 480–450 Ma) Martinsville igneous complex, which consists of the Ordovician Leatherwood Granite (granodiorite) and the Silurian Rich Acres Formation (diorite). The host rock was metamorphosed to orthogneiss during the Alleghanian orogeny (approx. 325–260 Ma), when it also underwent dextral strike-slip movement along the Brookneal shear zone. During the Triassic, extensional tectonics led to the development of the Dan River Basin that lies east of Coles Hill. The mineralized zone is hosted in brittle structures in the footwall of the Triassic Chatham fault that forms the western edge of the basin. Within brittle fracture zones, uranium silicate and uranium-bearing fluorapatite with traces of brannerite form veins and breccia-fill with chlorite, quartz, titanium oxide, pyrite, and calcite. Uranium silicates also coat and replace primary titanite, zircon, ilmenite, and sulfides. Sodium metasomatism preceded and accompanied uranium mineralization, pervasively altering host rock and forming albite from primary feldspar, depositing limpid albite rims on igneous feldspar, altering titanite to titanium oxide and calcite, and forming riebeckite. Various geothermometers indicate temperatures of less than ~200°C during mineralization. In situ U-Pb analyses of titanite, Ti-oxide, and apatite, along with Rb/Sr and U/Pb isotope systematics of whole-rock samples, resolve the timing of geologic processes affecting Coles Hill. The host Leatherwood Granite containing primary euhedral titanite is dated at 450 to 445 Ma, in agreement with previously obtained ages from zircon in the Martinsville igneous complex. A regional metamorphic event at 330 to 310 Ma formed anhedral titanite and some apatite, reequilibrated whole-rock Rb/Sr and U-Pb isotopes, and is interpreted to have coincided with movement along the Brookneal shear zone. During shearing and metamorphism, primary refractory uranium-bearing minerals including titanite, zircon, and uranothorite were recrystallized, and uranium was liberated and mixed locally with hematite, clay, and other fine-grained minerals. Uranium mineralization was accompanied by a metasomatic episode between 250 and 200 Ma that reset the Rb-Sr and U-Pb isotope systems and formed titanium oxide and apatite that are associated and, in places, intimately intergrown with uranium silicate dating mineralization. This event coincides with rifting that formed the Dan River Basin and was a precursor to the breakup of Pangea. The orientation of late-stage tectonic stylolites is compatible with their formation during Late Triassic to Early Jurassic basin inversion, postdating the main stage of uranium mineralization and effectively dating mineralization as Mesozoic. Based on the close spatial and temporal association of uranium with apatite, we propose that uranium was carried as a uranyl-phosphate complex. Uranium was locally reduced by coupled redox reactions with ferrous iron and sulfide minerals in the host rock, forming uranium silicates. The release of calcium during sodium metasomatic alteration of primary calcic feldspar and titanite in the host rock initiated successive reactions in which uranium and phosphate in mineralizing fluids combined with calcium to form U-enriched fluorapatite. Based on the deposit mineralogy, oxygen isotope geochemistry, and trace element characteristics of uranium silicate and gangue minerals, the primary mineralizing fluids likely included connate and/or meteoric water sourced from the adjacent Dan River Basin. High heat flow related to Mesozoic rifting may have driven these (P-Na-F-rich) fluids through local aquifers and into basin margin faults, transporting uranium from the basin or mobilizing uranium from previously formed U minerals in the Brookneal shear zone, or from U-enriched older basement rock.

Swelling and osmotic flow in a potential host rock

2007 ◽  
Vol 32 (1-7) ◽  
pp. 408-420 ◽  
Author(s):  
S.T. Horseman ◽  
J.F. Harrington ◽  
D.J. Noy
Keyword(s):  
Host Rock ◽  
Potential Host ◽  
Osmotic Flow

Integrated application of heliborne and ground electromagnetic surveys for mapping EM conductor for uranium exploration and its subsurface validation, North Delhi Fold Belt, Rajasthan, India: A case study

Geophysics ◽  
2013 ◽  
Vol 78 (1) ◽  
pp. B13-B24 ◽  
Author(s):  
A. K. Chaturvedi ◽  
Cas Lotter ◽  
Shailesh Tripathi ◽  
A. K. Maurya ◽  
Indrajit Patra ◽  
...  
Keyword(s):  
Time Domain ◽  
Uranium Mineralization ◽  
Model Parameters ◽  
Fold Belt ◽  
The North ◽  
Geophysical Surveys ◽  
Uranium Exploration ◽  
Time Domain Electromagnetic ◽  
Conducting Bodies ◽  
Electromagnetic Surveys

A fracture-controlled uranium deposit was identified in Proterozoic Ajabgarh metasediments of the North Delhi Fold Belt within the Khetri subbasin at Rohil, Sikar district, Rajasthan, India. Uranium mineralization in the area is associated with geologic structures, albitization, and pyroxenization of metasediments and conductors such as metallic sulfides and carbonaceous phyllites/graphitic schists. To locate uranium mineralization akin to Rohil in nearby thick soil covered areas, this association was targeted through heliborne geophysical surveys. High-resolution heliborne magnetic and time domain electromagnetic (TEM) surveys were conducted around Rohil. The survey delineated several targets with favorable geologic structures and conductors such as graphitic schist for further uranium exploration. One favorable target near Chappar village was taken up for follow-up exploration work. The EM conductor mapped from heliborne survey was subsequently validated through ground time-domain electromagnetic surveys and subsurface exploration. Modeling of heliborne and ground-based electromagnetic data revealed the presence of subsurface conducting bodies with comparable model parameters. Drilling established the presence of a subsurface conductor up to a depth of 300 m, which was attributed to the presence of graphite and sulfides (pyrrhotite) along foliation plane of carbon phyllite/graphitic schist/quartz-biotite schist and calc-silicate rock. Further detailed laboratory investigations (petrology/X-ray diffraction) of selected core samples from the conductive zones confirmed the presence of pyrrhotite and graphite responsible for EM signature. This study, carried out by using multiparameter data sets, proved the efficacy of heliborne surveys in locating favorable targets for uranium exploration in Ajabgarh group of rocks.

scholarly journals Characterizing mineralogy and redox reactivity in potential host rocks for a UK geological disposal facility

2015 ◽  
Vol 79 (6) ◽  
pp. 1353-1367 ◽  
Author(s):  
J. Quirke ◽  
C. M. B. Henderson ◽  
R. A. D. Pattrick ◽  
K. M. Rosso ◽  
A. Dent ◽  
...  
Keyword(s):  
Iron Content ◽  
Host Rock ◽  
Azo Dye ◽  
Total Iron ◽  
Geological Disposal ◽  
Potential Host ◽  
Fine Grained ◽  
Reducing Conditions ◽  
Redox Reactivity ◽  
Host Rocks

AbstractGeological disposal facilities (GDF) are intended to isolate and contain radioactive waste within multiple protective barriers, deep underground, to ensure that no harmful quantities of radioactivity reach the surface environment. The last line of defense in a multi-barrier GDF is the geosphere, where iron is present in the host rock mineralogy as either Fe(II) or Fe(III), and in groundwater as Fe(II) under reducing conditions. The mobility of risk-driving radionuclides, including uranium and technetium, in the environment is affected significantly by their valence state. Due to its low redox potential, Fe(II) can mediate reduction of these radionuclides from their oxidized, highly mobile, soluble state to their reduced, insoluble state, preventing them from reaching the biosphere. Here a study of five types of potential host rocks, two granitoids, an andesite, a mudstone and a clay-rich carbonate, is reported. The bulk rocks and their minerals were analysed for iron content, Fe(II/III) ratio, and for the speciation and fine-grained nature of alteration product minerals that might have important controls on groundwater interaction. Total iron content varies between 0.9% in clays to 5.6% in the andesite. X-ray absorption spectroscopy reveals that Fe in the granitoids and andesite is predominantly Fe(II), and in mudstones, argillaceous limestone and terrestrial sandstone is predominantly Fe(III). The redox reactivity of the potential host rocks both in the presence and absence of Fe(II)-containing 'model' groundwater was investigated using an azo dye as a probe molecule. Reduction rates as determined by reactivity with the azo dye were correlated with the ability of the rocks to uptake Fe(II) from groundwater rather than with initial Fe(II) content. Potential GDF host rocks must be characterized in terms of mineralogy, texture, grain size and bulk geochemistry to assess how they might interact with groundwater. This study highlights the importance of redox reactivity, not just total iron and Fe(II)/(III) ratio, when considering the host rock performance as a barrier material to limit transport of radionuclides from the GDF.

A review of the geochronology of the Precambrian of Saskatchewan—some clues to uranium mineralization

1981 ◽  
Vol 44 (336) ◽  
pp. 371-378 ◽  
Author(s):  
Keith Bell
Keyword(s):  
Hydrothermal Activity ◽  
Uranium Mineralization ◽  
Dyke Swarm ◽  
Thermal Activity ◽  
Late Proterozoic ◽  
Vein Type ◽  
Close Relationship ◽  
Basic Magmatism ◽  
Granitoid Rocks ◽  
Depositional Age

AbstractAssessment of available geochronological information, as well as new whole-rock Rb-Sr data from several granitoid rocks of Saskatchewan, shows a close relationship between magmatic-metamorphic events in the Hudsonian orogen and uranium mineralization. Most uranium deposits lie to the west of the Needle Falls Shear Zone and occur as either: (i) vein-type deposits or (ii) unconformity-type deposits close to the contact between the Athabasca sediments and their basement. At least two metamorphisms have affected the pre-Athabasca rocks: the Kenoran at about 2500 Ma ago, and the more pervasive ‘main’ Hudsonian event at 1740 Ma. A much younger thermal event (perhaps associated with uplift and cooling) at 1540 Ma is also indicated. The post-Kenoran K-Ar dates suggest prolonged thermal activity from about 1900 Ma through to about 1500 Ma ago. Granitoid events at 1870 Ma and 1740 Ma ago are outlined by both U-Pb zircon and Rb-Sr whole-rock isochron data. Whole-rock Rb-Sr data from the unmetamorphosed Athabasca sediments suggest an approximate depositional age of 1450±50 Ma, a figure that is consistent with the age of the underlying Hudsonian basement and the truncation of the sediments by the Cree Lake diabase dyke swarm at about 1200–1300 Ma ago. Although several episodes of uranium deposition have been documented, the main ones seem to have occurred at 1860 Ma (syngenetic uraninite in pegmatites), 1740 Ma (the Beaverlodge vein-type deposits) and between 1300 and 800 Ma (the epigenetic uranium of the unconformity-type deposits). Whereas the two earlier episodes can be correlated with periods of either magmatic or metamorphic activity, the late Proterozoic episodes cannot. The close agreement between the age of the Cree Lake dyke swarm and the late Proterozoic mineralization suggests that at about 1300 Ma ago possible hydrothermal activity from relatively deep-seated fractures may have been responsible for the solution and transportation of the uranium of the unconformity-type deposits. The period 1300 Ma to about 900 Ma, in other parts of the Canadian Shield, was a time of crustal rifting, basic magmatism, carbonatite activity, and intense deformation. Prior to the deposition of the Athabasca sediments uranium was concentrated by Hudsonian magmatic and metamorphic processes whereas subsequently, transportation and intermittent deposition of the unconformity-type deposits were related to fairly long-lived, low-temperature hydrothermal activity.

scholarly journals VEIN-TYPE URANIUM MINERALIZATION IN THE EASTERN DESERT OF EGYPT

2018 ◽  
pp. 33-38 ◽  
Author(s):  
Mohamed Mahmoud Fathy Ghoneim ◽  
◽  
Ahmed El Sayed Abdel Gawad ◽  
◽  
Keyword(s):  
Eastern Desert ◽  
Uranium Mineralization ◽  
Vein Type

scholarly journals Estimasi Sumber Daya Uranium Tipe Batupasir di Sektor Aloban, Sibolga, Tapanuli Tengah

EKSPLORIUM ◽  
2019 ◽  
Vol 40 (1) ◽  
pp. 1
Author(s):  
Roni Cahya Ciputra ◽  
Adi Gunawan Muhammad ◽  
Tyto Baskara Adimedha ◽  
Heri Syaeful ◽  
I Gde Sukadana
Keyword(s):  
Correlation Coefficient ◽  
Uranium Mineralization ◽  
Geochemical Data ◽  
Resource Estimation ◽  
Geological Section

ABSTRAKEksplorasi uranium di daerah Sibolga telah dilakukan sejak tahun 1978 oleh BATAN dan berhasil menemukan mineralisasi uranium tipe batupasir. Penelitian mengenai konsep mineralisasi uranium pada batupasir dan konglomerat di Sektor Aloban, Sibolga, telah dilakukan melalui data 22 titik bor yang menghasilkan penampang geologi, peta sebaran anomali, serta data cacahan radiometri dan geokimia. Penelitian ini bertujuan untuk mengetahui sumber daya uranium di Sektor Aloban dengan mencari hubungan antara nilai cacahan radiometri dan data geokimia pada data hasil penelitian sebelumnya menggunakan pendekatan geostatistik. Pengolahan geostatistik menggunakan perangkat lunak SGeMS menunjukkan nilai koefisien korelasi 0,5 sehingga data radiometri dan geokimia diinterpretasikan memiliki korelasi yang baik. Estimasi sumber daya uranium dihitung pada Satuan Konglomerat I dan Batupasir I yang memiliki sebaran lapisan mineralisasi tebal dan luas. Nilai kadar rata-rata uranium untuk Satuan Konglomerat I dan Satuan Batupasir I adalah 173,03 ppm U dan 161,54 ppm U secara berurutan. Estimasi sumber daya uranium di Sektor Aloban adalah 415 ton uranium sebagai sumber daya tereka.ABSTRACTUranium explorations in Sibolga Area have been conducted since 1978 by BATAN and successfully result in sandstone-type uranium mineralization. Research related to uranium mineralization concept on sandstone and conglomerate at Aloban Sector, Sibolga has been conducted through 22 boreholes data which resulted in the geological section, anomaly distribution along with radiometry counting and geochemistry data. This research objective is to obtain uranium resources in Aloban Sector by correlating radiometry counting and geochemical data from previous research by using a geostatistic approach. Geostatistical processing using SGeMS software shows a correlation coefficient of 0.5 so that the radiometry and geochemical data are interpreted to have a good correlation. Uranium Resources estimation was measured on Conglomerate I and Sandstone I units which are considered to have thick and wide mineralization distribution. The average uranium grade for Conglomerate I and Sandstone I units are 173.05 ppm U and 161.54 ppm U respectively. Uranium resource estimation at Aloban Sector is 415 tons as inferred resources.  

Sign in / Sign up

Export Citation Format

Share Document