TY - JOUR
T1 - U-Pb zircon and 40Ar/39Ar geochronology of sericite from hydrothermal alteration zones
T2 - new constraints for the timing of Ediacaran gold mineralization in the Sukhaybarat area, western Afif terrane, Saudi Arabia
AU - Harbi, Hesham M.
AU - Ali, Kamal A.
AU - McNaughton, Neal J.
AU - Andresen, Arild
N1 - Funding Information:
The data presented in this paper is part of a project funded by Deanship of Scientific Research at KAU (King Abdulaziz University), Project No. 1431/296/145. The authors gratefully acknowledge the logistical and other support that they received during the project from the exploration and mining geologist staff of the Saudi Ma’aden Mining Company and the Sukhaybarat and Bulghah mining camps. U/Pb analyses were undertaken at the SHRIMP facilities of the John de Laeter Centre, supported by a university-Government Consortium and the Australian Research Council. We thank the University of Oslo, for help with the LA-ICPMS analyses. Tom Andersen is thanked for developing the software transferring the raw LA-ICP-MS data into meaningful ages and isotope ratios. Thanks to Geologist Mr. Hashim Hussein for providing some maps of the study areas. The authors would like to thank Dr. Peter Johnson for editing the English language of the final version of the manuscript. We appreciate the assistance of Prof. Terry Spell for Ar-Ar age dating at the University of Nevada at Las Vegas. We are indebted to Dr. Walter Witt and Dr. Paul Duuring for their constructive comments and suggestions that greatly helped to improve the manuscript. Much thanks to the associated editor Dr. Steffen Hagemann and Editor-in-Chief Prof. Bernd Lehmann for handling the manuscript.
Funding Information:
Acknowledgments The data presented in this paper is part of a project funded by Deanship of Scientific Research at KAU (King Abdulaziz University), Project No. 1431/296/145. The authors gratefully acknowledge the logistical and other support that they received during the project from the exploration and mining geologist staff of the Saudi Ma’aden Mining Company and the Sukhaybarat and Bulghah mining camps. U/ Pb analyses were undertaken at the SHRIMP facilities of the John de Laeter Centre, supported by a university-Government Consortium and the Australian Research Council. We thank the University of Oslo, for help with the LA-ICPMS analyses. Tom Andersen is thanked for developing the software transferring the raw LA-ICP-MS data into meaningful ages and isotope ratios. Thanks to Geologist Mr. Hashim Hussein for providing some maps of the study areas. The authors would like to thank Dr. Peter Johnson for editing the English language of the final version of the manuscript. We appreciate the assistance of Prof. Terry Spell for ArAr age dating at the University of Nevada at Las Vegas. We are indebted to Dr. Walter Witt and Dr. Paul Duuring for their constructive comments and suggestions that greatly helped to improve the manuscript. Much thanks to the associated editor Dr. Steffen Hagemann and Editor-in-Chief Prof. Bernd Lehmann for handling the manuscript.
Publisher Copyright:
© 2017, Springer-Verlag GmbH Germany.
PY - 2018/4/1
Y1 - 2018/4/1
N2 - The Sukhaybarat East and Red Hill deposits, in the northeastern part of the Arabian Shield, are mesothermal vein-type gold deposits hosted by late Cryogenian-Ediacaran intrusive rocks of the Idah suites (diorite, tonalite, granodiorite) and, at Sukhaybarat East, also by Ediacaran metasedimentary rocks. Gold mineralization comprises quartz-arsenopyrite veins (Sukhaybarat East), quartz-carbonate-pyrite veins (Red Hill), and subordinate gold-base metal sulfide veins. In the Red Hill deposit, alteration is complicated due to multiple overprinting hydrothermal events and is characteristically affected by pervasive, pink quartz-K-feldspar-hematite alteration which is overprinted by potassic alteration characterized by a quartz-biotite-carbonate-muscovite/sericite-rutile-apatite assemblage. This assemblage is associated with molybdenite veins which appear to form late in the paragenetic sequence and may represent either evolution of the ore fluid composition, or a later, unrelated mineralized fluids. Hydrothermal alteration at the Sukhaybarat East deposit is dominated by quartz-carbonate-sericite-arsenopyrite assemblages. Zircon from ore-hosting tonalite at Sukhaybarat East yields a U-Pb age of 629 ± 6 Ma, and biotite from the same rock gives an 40Ar/39Ar age of 622 ± 23 Ma. The 40Ar/39Ar age is within the uncertainty range for the U-Pb age of the host intrusion and is interpreted as a minimally disturbed cooling age for the tonalite. In the Red Hill area, granodiorite was emplaced at 615 ± 5 Ma, whereas muscovite/sericite separated from a mineralized sample of a quartz-carbonate-pyrite vein, that was overprinted by molybdenite-bearing veinlets, yields an 40Ar/39Ar age of 597 ± 8 Ma. We interpreted this age to represent the maximum age of the molybdenite mineralization and the probable minimum age of gold mineralization in the Red Hill deposit.
AB - The Sukhaybarat East and Red Hill deposits, in the northeastern part of the Arabian Shield, are mesothermal vein-type gold deposits hosted by late Cryogenian-Ediacaran intrusive rocks of the Idah suites (diorite, tonalite, granodiorite) and, at Sukhaybarat East, also by Ediacaran metasedimentary rocks. Gold mineralization comprises quartz-arsenopyrite veins (Sukhaybarat East), quartz-carbonate-pyrite veins (Red Hill), and subordinate gold-base metal sulfide veins. In the Red Hill deposit, alteration is complicated due to multiple overprinting hydrothermal events and is characteristically affected by pervasive, pink quartz-K-feldspar-hematite alteration which is overprinted by potassic alteration characterized by a quartz-biotite-carbonate-muscovite/sericite-rutile-apatite assemblage. This assemblage is associated with molybdenite veins which appear to form late in the paragenetic sequence and may represent either evolution of the ore fluid composition, or a later, unrelated mineralized fluids. Hydrothermal alteration at the Sukhaybarat East deposit is dominated by quartz-carbonate-sericite-arsenopyrite assemblages. Zircon from ore-hosting tonalite at Sukhaybarat East yields a U-Pb age of 629 ± 6 Ma, and biotite from the same rock gives an 40Ar/39Ar age of 622 ± 23 Ma. The 40Ar/39Ar age is within the uncertainty range for the U-Pb age of the host intrusion and is interpreted as a minimally disturbed cooling age for the tonalite. In the Red Hill area, granodiorite was emplaced at 615 ± 5 Ma, whereas muscovite/sericite separated from a mineralized sample of a quartz-carbonate-pyrite vein, that was overprinted by molybdenite-bearing veinlets, yields an 40Ar/39Ar age of 597 ± 8 Ma. We interpreted this age to represent the maximum age of the molybdenite mineralization and the probable minimum age of gold mineralization in the Red Hill deposit.
KW - Ar/Ar dating
KW - Arabian shield
KW - Arabian shield
KW - Bir Tawilah shear zone
KW - Gold mineralization
KW - U-Pb zircon dating
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U2 - 10.1007/s00126-017-0751-7
DO - 10.1007/s00126-017-0751-7
M3 - Article
AN - SCOPUS:85021940304
SN - 0026-4598
VL - 53
SP - 459
EP - 476
JO - Mineralium Deposita
JF - Mineralium Deposita
IS - 4
ER -