Physico-Mechanical And Petrographic Analysis Of Lockhart Limestone Exposed In Taxila, Margalla Hill Ranges, Punjab, Pakistan

Abstract

A very thorough and detailed geological investigation of Paleocene Lockhart Limestone at Ratta Shah Taxila was carried out to determine its microfacies, mechanical and physical properties and to build a correlation between them. Six bulk samples were collected out of which six intact core specimens were obtained and were utilized for mechanical testing and petrographic analysis. Four microfacies are determined i.e. mudwackestone, wackestone, bioclastic-packstone and wacke-packstone. A plethora of diagenetic alterations have taken place in Lockhart Limestone including micritization, neomorphism, compaction and fractures of many sorts. The determined microfacies points towards a mid-ramp to outer ramp depositional setting. Unconfined compressive strength test (UCS), Schmidt Rebound Hammer (SRH), and Ultra Sonic Pulse Velocity (UPV) mechanical tests were carried out and correlated with micrite and bioclasts (petrography), where the mechanical tests showed positive correlation with micrite % and negative correlation with bioclasts %. Linear regression analysis of UCS (R² = 0.9134), SRH (R² = 0.5825) and UPV (R² = 0.739) showed positive relations and high R2 values. Mechanical tests had a positive correlation and high linear regression R2 values among them.