Abstract:
This study is aimed to evaluate marbles from Nawagai Melange (Nawagai
marble) exposed in Mohmand Agency. Samples were collected from four different
locations, two from Ziarat, one from Spingay Tangay and one from Tora Khwa.
Physical and mechanical tests were performed that include water absorption, porosity,
specific gravity, bulk density, uniaxial compressive strength test, uniaxial tensile
strength test, ultrasonic pulse velocity test and schmidt hammer test. Furthermore,
geochemical and petrographic studies were also carried out. The obtained results were
then compared with designated ASTM standards in order to establish their suitability
as dimension stone. The average values for studied marble specimens were: specific
gravity 2.71, water absorption 0.014 %, porosity 0.04 % and bulk density 2.70 g/cm3.
Average values for mechanical tests are such that UCS 53.391 and UTS 4.46 Mega
pascal (Mpa). Among non-destructive tests, average values for UPV and SH is
5057.56 m/sec and 48.75 respectively. Petrographic studies showed that all the marble
varieties were pure calcitic in composition, having 0.31 to 0.35 mm average grain
size. It was observed that marble which has coarser grain size (ZSW) has lower
strength than the other which has a smaller grain size (ZGW, STBD and TKRW). All
the investigations confirmed that the marble varieties are suitable for use as indoor
dimension stone. Comparison of studied marbles (Nawagai marble) with Chitral
(Gahiret marble) and Khyber marble (Mullagori) showed that they are almost same in
composition but the engineering properties of current studied marble are lower than
Chitral (Gahiret) and Khyber (Mullagori) marble and higher than Buner marble
(Nowshera Formation).
