Giant Quartz Veins of the Bundelkhand Craton, Indian Shield: New Geological Data and U-Th-Pb Age
А. И. Слабунов, Vinod K. Singh
Abstract
Giant quartz veins are widespread on the Bundelkhand Craton of the Indian Shield which precise ages with a SHRIMP-II, U-Th-Pb isotope are quantified in this article. Their relative geological age is well-documented: they cut the Paleoproterozoic (2150–1800 Ma) sediments of the Bijawar Group and are overlain by Proterozoic (1670–1030 Ma) sediments at the base of the Upper Vindhyan Supergroup. U-Th-Pb dating of zircon grains from a quartz vein was carried out to assess major event of their formation as 1866 ± 12 Ma. This data is consistent with the relative geological age of the veins. In addition, the quartz veins were shown to contain 2.86, 2.7, and 2.54 Ga xenocrystic zircon grains. Rocks with these ages are abundant in the craton. The formation of a giant quartz vein swarm is associated with the deformation of the Bundelkhand Craton lithosphere during 1.9–1.8 Ga ago triggered by compression caused by collision processes at the western flank of the Columbia Supercontinent on one side and plume activity on the other.