Porosity Evolution and Microfacies Analysis of the Khurmala Formation (Paleocene-Early Eocene) from Selected Sections in Kurdistan Region, Northern Iraq Revealed by Cathodoluminescence Spectroscopy

The microfacies analysis and porosity evolution of the Khurmala Formation (Paleocene-Early Eocene) were studied in Gomaspan Sheraswar sections High Folded Zone, northeastern Erbil City, Kurdistan Region (N-Iraq). Lithologically, section is about 23.5 m comprised thick to massive bedded brecciated grey dolomitic limestone lower middle parts interbedding medium beds yellow calcareous shale upper part. comprises 18.5 marl, yellowish-grey marly part, interbedded with thin blue shale, mudstone petrographic cathodoluminescence (CL) studies 20 carbonates show that most skeletal grains are shallow marine derivative faunas non-skeletal represent intraclasts, peloids, ooids, extraclasts (monocrystalline quartz). Five main identified rocks, they integrated into two facies associations relating their environmental interpretation: back reef/lagoon patch reef. A new eight pore types distinguished carbonate rocks Formation: interparticle, intraparticle, growth framework, intercrystalline, moldic, vuggy, fracture, stylolite porosities. Most primary was reduced by compaction cementation due effect intensive diagenesis. Secondary predominant both sections, common being moldic associated different fabrics. CL investigations revealed dolomitized lime wackestone has cementations late stages blocky calcite cement which discontinuous light dull orange luminescence without zoning, pure coarse very characteristic bright tight zoning.