Abstract:
Kingriali Formation at Nammal Gorge Section in Salt Range, Mianwali is
selected for research study. Research is based on geochemical analysis and
petrographic analysis. Lithologically it consists of light grey to brownish thin to thickbedded, massive, fine to coarse-grained dolostone and dolomitic limestone with
interbedded shale, marl, and dolomite. Petrographic observation revealed three types
of dolomites which includes i) fine grained anhedral dolomite (D1) ii) medium grained
subhedral to anhedral dolomite (D2) and coarse grained euhedral dolomite (D3) .
Paragenetic sequence of Kingriali Formation revealed several other diagenetic events
which are micritization, compaction, dissolution, calcitization and fracturing. Calcite
veins, elephant skin weathering and brecciation was also observed in the studied
formation. The stable oxygen isotopic signatures of D1 ranges from -2 to -2.8‰
VPDB and that of Carbon ranges from 0.8 to 1 ‰ VPDB, D2 oxygen isotopic
signatures is -2.9 to -1.5‰ . VPDB, while its Carbon isotopic values ranges from 0.4 to
0.6 ‰. Dolomite D3 oxygen isotopic signatures ranges from -3.3 to -3.7‰ VPDB and
its Carbon isotopic values ranges from 0.9 % to 1‰ VPDB this indicate Carbon and
isotopic values lie within the late Triassic marine signatures. Elemental analysis of all 3
types of dolomite was carried out forManganese (Mn), Iron (Fe), Sodium (Na) and
Stronium (Sr) in all the three types of dolomite that were identified during the
petrographic study. Based on our field observation, petrographic analysis and
geochemical analysis it is suggested that the dolomite is formed by evaporation and
burial dolomitization.
