The name Kra Al Maru has been assigned to the additional unit at the lowermost part of the Middle<br>Triassic Jilh Formation in Mutriba and Kra Al-Maru area in western Kuwait. Stratigraphically the interval<br>corresponds to the Jilh C Member of Jilh Formation, and it is divisible into a lower (KM-B) and an upper<br>(KM-A) unit. Microfacies comprises anhydrite, dolomudstone, dolowackestone, argillaceous dolostone<br>and dolomitic shales with minor dolopackstone, dolograinstone, lime mudstone, lime wackestone.<br>Carbonaceous matter and terrigenous material is present at places. Anhydrite is present as early<br>nodules and crystals, as well as late cement and vug fillings. Facies associations of both units are<br>bioturbated, highly variable with common organic matters. The distinguishing feature of the lower unit<br>(KM-B) is having less anhydrite than the upper unit (KM-A). The lower unit was deposited in intertidal<br>to subtidal and lagoonal environments, as a shallowing upward sequence that grade upward to algal<br>laminated wackestone and anhydrite. The presence of few sub-aerial exposure surfaces indicate<br>dissolution that might have developed at the end of cycle and are indicative of slightly humid<br>conditions. The upper unit was deposited in an intertidal to supratidal, Sabkha environments under arid<br>climate. Diagenetic events include compaction, dolomitization, and replacement by anhydrite,<br>fracturing and stylolization. Primary porosities were reduced by compaction, overdolomitisation and<br>late stage cementation. Both cemented and uncemented fractures are observed in the core and<br>microfractures are seen in core plugs and have led to increased fracture porosity and permeability. The<br>Lower unit is ranked and pursued as new prospective units within the Jilh Formation.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error