Engineering and petrographic properties of meta dolerite aggregates of Kirana Hills of Sargodha, Punjab, Pakistan.

Kirana, Rabwa and Chiniot areas of the Punjab province, Pakistan has a number of isolated hills jutting out of a flat alluvial plain. These rocks are Upper Proterozoic in age. The exposed volcano-sedimentary sequence is slightly metamorphosed (lower greenschist facies). The dolerites have also undergone auto metasomatic changes. The Kirana Hills are the main resource of aggregate in southern and middle Punjab. These aggregates are used in subbase, base course, in rail ballast, as riprap and for the cement and asphalt concrete. The main lithologies in Kirana Hills are dolerites and rhyolites, lithic greywackes, volcanogenic slates and quartz wackes. This paper deals only with the dolerites and their petrographic composition and engineering properties, as well as adhesion values. The variably auto metasomatized dolerites are now composed of variable amounts of plagioclase, chlorite, calcite and amphibole with quartz, magnetite, hydro mica, K-feldspar, epidote and sphene as subordinate to accessory minerals. Flakiness, Elongation, Specific Gravity, Water Absorption, Soundness, Los Angeles, Aggregate Crushing, Aggregate Impact and Adhesion Values are all within ASTM limits. Therefore, the dolerite aggregates of Kirana area have excellent Engineering Properties. They can also be used for subbase, base course and riprap material. However, quartzites, lithic greywackes, volcanogenic slates and rhyolites which can be used for these purposes are available in the area, therefore dolerites should not be used because they are the only good source of asphalt concrete and especially for the wearing course (since it gives a good road grip and resists polishing) in Punjab province with an area of 205344 km2. Dolerites should be reserved for cement and asphalt concrete. Petrographic studies show that dolerites do not have Alkali-Silica Reaction Potential and are hydrophobic and can be used for cement as well as asphalt concrete. This area has total estimated 3097.3 million tons of reserves of all types of aggregates. The aggregate resource map of this important area is being presented for publication for the first time. [ABSTRACT FROM AUTHOR]