Abstract:
Mollassic Murree Formation of upper Eocene to Miocene age, derived from the Himalayan continental collisional belt is an important and persistent unit of Outer Himalayas of Azad Kashmir and Pakistan. It was deposited by a meandering river system and is predominantly composed of red shales/mudstones and grey to grayish red sandstones. The sandstones of this formation are fine to medium grained calcite cemented lithic arenites. The coarse grained lithic arenite are generally restricted to the channel bottoms. These lithic arenites are sub-angular to sub-rounded, compositionally immature and texturally sub-mature. The stable minerals/rock fragments are quartz, chert and quartzite. The unstable rock fragments include limestone, shale, slate, phylite and merro-crystalline volcanics. The accessory minerals are muscovite, biotite, garnet, actinolite, hornblendite, zircon, chlorite, epidote, tourmaline and glauconite. Carbonate cement is predominant while silica and iron oxide cements are minor. The deleterious constituents with Alkali Aggregate Reaction potential are chert, shale, slate, phyllite, and merro-crystalline acid volcanics. In scores of samples studied, the deleterious constituents generally exceed 6%. These sandstones are therefore invariably potentially reactive. Sandstone have a range of specific gravity 2.52 to 2.73, water absorption 0.40 to 1.85%, flakiness index 6.3 to 18.5%, elongation index 6.0 to 8.9, organic matter 0.30 to 0.49%, Los Angeles uniformity of wear 0.16 to 0.23% and sodium sulphate soundness 8.30 to 14.30%.
Page(s):
27-33
DOI:
DOI not available
Published:
Journal: Geological Bulletin of the Punjab University, Volume: 37, Issue: 1, Year: 2002