Geochemical evolution of structure-bedding controlled hydrothermal dolomites of the Kinta Valley, Western Malaysia

Abstract Study of secondary dolomitization and documentation the evolution basinal fluids host rock, especially that fine-grained deepwater carbonate mudstone are interest toward reservoir characterization. From this perspective, field characteristics in relation to mineralogy, petrography geochemistry Paleaozoic carbonates Kinta Valley, Peninsular Malaysia, were investigated documented. A total 33 samples collected across various degree analyzed for their petrographic properties ( n = 55), while mineralogical geochemical compositions 33) using XRD, ICP ICPMS analysis, respectively. These analyses performed elucidate diagenetic events, episodic development fluid as a function regional tectono-thermal events during Permian Cenozoic. It is interpreted calcareous mudstones (HCMs) deposited oxygenated, open marine seawaters. The studied retain original seawater despite negligible, minor alterations REE due diagenesis detrital input. Though concentrations trends REEs dolomitic facies modified certain extent, affinities with HCMs preserved. Enrichments Mg, Mn, Na depletion Sr linked effect under system diagenesis. redox conditions fluctuated show distinct, recognizable variations between different dolomite phases. MREE enrichments other trace elements such Fe low content indicate association deep-circulating crustal hydrothermal fluids. Hydrothermal influence has been recorded along fractures, which might have originated from sub-surface litho units facilitated dolomitization, significant events. This study affirms occurrence, dolomites Valley controlled by magmatic whereas intensity replacement was rock texture, varied bulk chemistry circulating temperature.