Keywords : Sandstone


Petrography of Sandstone for Hussainiyat Formation and the Climatic and Tectonic Evidence in Western Desert-Iraq

Abed AL-Satar A. Al-Sanjary; Ahmad N. Thanon; Rafe I. Al-Ehmeedy

Iraqi National Journal of Earth Sciences, 2014, Volume 14, Issue 1, Pages 19-32

The petrography of the detrital part of Hussainiyat Formation Jurassic
(Upper Liassic) in its ideal section, at the western Desert, Iraq, was studied. The aim of this study was to infer the climatic and tectonic evidence that affected the deposition of the sandstones of this formation.
It has been shown that the most abundant mineral in these sandstones was quartz. These sandstones were derived from a scarce area with relatively low relief topography with an equatorial humid environment.
Most of these rocks were derived from continental regions of cratonic zones. However, some of them were derived from orogenic belt marginal to continental regions as a first cycle, them recycled into deposits within the craton. These rocks are mostly of granitic igneous origin, and to a less extent of metamorphic and redeposited sedimentary rocks derived from the Arabian shield.

Petrography and Diagentic Processes in Sandstone of Injana Formation in Kand Fold, North Iraq

Mohammed A. AL-Rashedi Thamer A. Aghwan

Iraqi National Journal of Earth Sciences, 2006, Volume 6, Issue 2, Pages 11-24

The sandstone of Injana Formation (Late Miocene) in Kand anticline consists dominently of carbonate rock fragments, among other types, followed by quartz, feldspars and mica. The ground mass is represented by higher amount of calcite cement in comparison to silica, clay and ferrigenous cements.
Classification of the sandstones indicates their calclithic litharenite type. The source rocks embrace sedimentary, metamorphic and igneous rocks.
The sandstones have been affected by early-diagentic events which mainly include carbonate cement and consequently subduced compaction. The processes of early-mesogentic diagenesis resulted in a decrease of primary porosity with a concomittant increase of secondary porosity during late diagenetic stage due to dissolution of carbonate cement.