Sedimentology of the Ghazij Formation, Harnai, Baluchistan

Abstract

A petrographic study of the sediments of Ghazij Formation, supplemented by field observations, has been made with a view to studying the environment of sedimentation in the Ghazij Basin. It is concluded that the sediments were formed in marine and fluviatile environments. The principal source area lay to the north-west of Harnai and a palaeogeographic reconstruction of Ghazij times is attempted.

Lower Paleogene Tectonostratigraphy of Balochistan: Evidence for Time-Transgressive Late Paleocene-Early Eocene Uplift

“…By evaluating provenance changes through time, it is also possible to characterize local and regional crustal evolution of source areas [111]. Previous petrographic studies from the study area show considerable geographic variation in sandstone compositions [49,80,81,83,116]. Here we report new petrographic results from the Ghazij and correlative units to better understand the spatial variability of sandstone compositions and more fully reconstruct the tectonic setting of the western Himalayan suture zone during the early Paleogene.…”

Lithofacies, depositional environments, and regional stratigraphy of the lower Eocene Ghazij Formation, Balochistan, Pakistan

“…Along the outcrop belt from Shahrig to Harnai, the unit averages 6 m in thickness (Shah, 1990). Kazi (1968) reported the unit to be 11 m thick at Harnai. Near Shahrig the unit is 4 m thick, and the conglomerate appears to have a higher percentage of chert relative to the Sor Range conglomerate.…”

“…Only two petrographic studies of sandstones from the Ghazij Formation have been published to 1997. Kazi (1968) reported on 10 sandstone samples from the middle and upper parts of the formation near Harnai. To study the components of these rocks, Kazi disaggregated each of them with hydrochloric acid, passed the resulting fragments through a series of sieves, and mounted a selected fraction on glass slides.…”

“…Oldham (1890b) observed the conglomerate at the base of the upper part of the Ghazij near Shahrig and Harnai, and reported the presence of clasts of Cretaceous limestones. Kazi (1968) also examined the conglomerate near Harnai and recognized clasts from Jurassic units and from the Paleocene Dungan Formation. The conglomerate in the Ghazij near Urak was reported by Hunting Survey Corporation (1960) to contain clasts from the Jurassic Chilian Limestone, the Parh Limestone, and the Paleocene Brewery Limestone (a local equivalent of the Paleocene Dungan).…”

“…Most values indicate paleoflow toward the east-northeast. Kazi (1968) studied the Ghazij near Harnai and reported a southeast paleoflow for the middle part of the formation, and a south-southeast paleoflow for the upper part of the formation. Kazi determined these orientations from measurements of cross stratification, but his report gave no details on methodology.…”