Diagenesis using scanning electron microscopy of carbonates of Kirthar Formation, Lower Indus Basin, Sindh, Pakistan

Abstract

Diagenesis of the carbonate rocks has revealed different aspects of 
the sedimentology of the Kirthar Formation which is one of the 
significant rock units of the Lower Indus Basin. The formation is 
extensively distributed through the area that is the upper part of the 
Southern Indus Basin, and it is broadly dispersed in the Sindh 
Province. It comprises limestones, in places associated with shale 
and minor marl beds. The limestone is light grey, cream-coloured 
or chalky white, weathers in grey, brown or cream colours. One of 
the most extensively used tools in the area of earth sciences, which 
includes anything from materials to environmental research, is the 
scanning electron microscope. The investigation shows that after 
deposition, carbonates of the Kirthar Formation have been exposed 
to a range of diagenetic processes that brought about changes in 
porosity, mineralogy, chemistry, and texture. Unlike other 
carbonate minerals, the ones studied here are less prone to 
dissolution, recrystallization, and replacement. The present 
investigation of diagenesis is done with the assistance of scanning 
electron microscopy which has uncovered the understanding of 
various diagenetic processes, for example, cementation, 
dissolution, neomorphism and so on within the carbonates of the 
Kirthar Formation. Furthermore, the activities of the organisms on 
carbonates have also brought diagenetic changes to the textures 
through biogenic processes. Sediments have been reworked by 
leaving signs of microbes in certain locations.