Petrology
Mahboobeh Jamshidibadr; Narges Sadat Faramarzi
Abstract
Hormuz Island, a salt diapir in southern Iran, mostly composed from evaporite-carbonate sediments of Neoproterozoic. So far, no significant studies have been done belong to the petrography and geochemistry of the Hormuz evaporite-carbonate sediments. Moreover, Salt movements made it difficult to distinguish ...
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Hormuz Island, a salt diapir in southern Iran, mostly composed from evaporite-carbonate sediments of Neoproterozoic. So far, no significant studies have been done belong to the petrography and geochemistry of the Hormuz evaporite-carbonate sediments. Moreover, Salt movements made it difficult to distinguish rocks relationship only based on field observations. In the recent study, with the understanding of field evidences (e.g. the salt thickness, type and amounts of enclaves, as well as field relationship between evaporite unit and volcanic rocks), mineralogical studies (such as studying fluid inclusions within evaporite unit, studying enclaves from evaporite-carbonate unit as well as the mineralogy of dolomite, pyrite and rhyolitic tuffs) and doing geochemical analysis (e.g. Inductively coupled plasma- mass spectrometry and Scanning Electron Microscope), not only the evaporite-carbonate sediments, but also the reconstruction of the events occurring in the Hormuz sedimentary basin, have been investigated. The existence of evaporites with different thicknesses, enclaves and interlayers indicate that deposition of evaporites occurred in two separate stages. The island’s rhyolitic volcanism happened in the gap between sedimentation of lower and upper evaporite units. The volcanoclastic rocks are coexistence with deposition of upper evaporite unit. The deposition of both evaporite units occurred during the upper Ediacaran.
