Detrital mineral composition of the Datta Sandstone shows that sandstones are lithic greywacke to sub litharenite
. The Datta Sandstone is fine to coarse grained, moderate to well sorted with poor to moderate sorted and has sub-angular to well-rounded grains.
The XRD results show that the detrital components of the Baikouquan Formation comprise quartz (4.2-62.4%, average of 44.15%), feldspars (2.2-43.8%, average of 22.88%), and rock fragments (22.34-92.36%, average of 40.82%), indicating that the sandstones are mostly litharenite
and feldspathic litharenites
The voluminous litharenite
unit (HSla of Barr et al.
A logarithmic plot of Na2O/K2O and SiO2/Al2O3 ratios of 20 samples of lithofacies-3 and 4 of the Hangu Formation showed that the lithofacies were predominantly quartz arenite with subordinate quartz litharenite
to sub-litharenite (Fig.
The Sandy Lake Formation constitutes the upper part of the group and consists of pillow lavas with interbedded fine to coarse litharenite
of felsic volcanic derivation (locally termed 'arkose').
Prediction of engineering properties of selected litharenite
sandstone from its petrographic characteristics using correlation and multivariate statistical techniques.
17.5 18 Sandstone; light olive gray to yellowish gray 13.0 (5 Y 5/2 to 7/2) micaceous calcite-cemented litharenite
, parallel-laminated, trough and tabular cross-bedded, with thick beds of pebble conglomerate composed of carbonate nodules, sedimentary rock fragments, and chert.
The ternary plot indicates that the Xishanyao Formation sandstones are dominantly litharenite
and feldspathic litharenite
as they have an average framework composition of [Q.sub.28][F.sub.13][L5.sub.9] (Figure 4).
In his scheme majority of the sandstone samples plot on the boundary between greywacke and litharenite
field showing a tight linear pattern (Fig.
Shurijeh formation is mainly composed of medium grain calcareous ferrogenous submature litharenite
. The main cement in the section is calcareous and iron oxides (15 %).
The reservoir is 126 m thick and mainly composed of feldspathic quartz sandstone and feldspathic litharenite
. The porosity and permeability of the reservoir are 8.8-12.6% and 1.23 x [10.sup.-15]-5.99 x [10.sup.-15] m2, respectively [24,26, 30].
The Stirling Group consists dominantly of andesitic to basaltic lapilli turf, litharenite
, and siltstone, with subordinate basaltic flows and breccias, rhyolitic lapilli turf, and rhyolite porphyry (Macdonald and Barr 1993; Barr et al.