A Reconnaissance Microfacies Study of Kawagarh Formation Near Giah, Abbottabad-Nathiagali Road, Hazara, Pakistan

  • M Nawaz Chaudhry,
  • Tariq Mahmood
  • Riaz Ahmed a Ahmed
  • Munir Ghazanfar

Abstract

  The Kawagarh Formation of Upper Cretaceous age from near Giah, Abbottabad-Nathiagali Road, Hazara, has been studied in detail for internal units, microfacies and diagenetic fabrics. Atotal of eighteen microfacies and five internal units have been defined.
The eighteen microfacies based on depositional textures cum composition from bottom to top are Wackestone (Biomicrite)- Dolomitic Limestone, Dolomitic Limestone, Wackestone (Biomicrite), Dolospar, Wackestone (Biomicrite)-Dolomitic Limestone, Dolospar, Wackestone (Biomicrite)-Dolomitic Limestone, Calcitic Dolomite, Wackestone (Biomicrite), Wackestone (Biomlcrite)- Dolomitic Limestone, Wackestone (Biomicrite), Calcitic Dolomite, Wackestone (Biomicrite), Dolospar, Wackestone (Biomicrite), Sandy Wackestone (Biomicrite), Sandy Dolomitic Limestone and Sandy Dolospar.
A total of five facies units have been established which (internal units) from bottom to top are Mixed Dolomitic Limestone and Dolospar Unit, Biomicrite Unit, Sandy Biomicrite Unit, Sandy Dolomitic Limestone Unit and Sandy Dolospar Unit.
The lower three units contain predominantly Late Cretaceous planktonic foraminifera species of Globotruncana and deeper water Algae (Oligosteginids) and are considered to have been deposited in deep water low energy environments (outer shelf, close to the edge) while the upper two units which contain rare planktonic foraminifera and are sandy in nature are interpreted to have been deposited in shallower waters (Littoral to inner shelf) with ingress of detrital material.
There is evidence to suggest that the dolomitization in -the lower two units took place mainly during the deep burial diagenesis while dolomitization in the upper two units owes its origin to ground water mixing during early diagenesis.
A study of diagenetic fabrics shows that mechanical compaction is unimportant while chemical compaction is wide spread.

Published
1993-07-01
Section
Articles