Sedimentology and Diagenesis of the Early–Middle Eocene Carbonate Deposits of the Ceno-Tethys Ocean

An integrated study based on field observation, petrography, and scanning electron microscopy (SEM) the Early–Middle Eocene carbonate rocks has been carried out, which were deposited in Ceno-Tethys Ocean. The area of Yadgaar Section lies eastern margin Upper Indus Basin, Pakistan. Margalla Hill Limestone Chorgali Formation act as reservoir other parts basin are also present Section. lack comprehensive this makes these highly attractive for sedimentological evaluations future exploration hydrocarbons. divided into nine microfacies: dolomicritic foraminiferal mudstone–wackestone microfacies (EMI); green algae dominated, mixed wackestone–packstone (EMII); ostracod, gypsum dominating (EMIII); (EMIV); Nummulites (EMV); algal limestone mudstone (EMVI); Assilina bed (EMVII); micritized larger benthic (EMVIII); limestone, (EMIX). transgressive-regressive environment Ocean leads to deposition platform interior, open marine platform, edge, reef, toe slope apron, arid–humid restricted respectively. Initial post-depositional diagenetic stages identified from base top strata by their respective cement types, i.e., base–lower middle part demonstrates an eogenetic sub-stage with appearance drusy cement, section indicates a mesogenetic blocky while portion again reveals diagenesis presence types cement. ascending–descending hierarchy generations is directly proportional grade strata. Variable effects various increase secondary porosity range enhance characteristics Formations. foraminifera microfossils determined that formations date Eocene.