Phong Nha-Ke Bang can be compared to a huge geological museum thanks to its complicated geological structure with different categories of stone including sandstone, quartz, schist, siliceous limestone
, granite, granodiorite, diorite, applet, pegmatite, etc.
The sedimentary section ranging in thickness from 500 to 1000 m is composed of carbonates, chert, and siliceous limestone
, overlying an irregular basement.
On the basis of physical and chemical characteristics, the Limestone has been classified as High grade limestone (HLS), Darukhula limestone (DLS) and Siliceous limestone (SLS).
Siliceous limestone (SLS) is occurring as minor bodies in Darukhula and its surrounding areas.
Siliceous limestone on the other hand, is different from both high grade limestone and Darukhula limestone due to a greater percentage of silica.
ABSTRACT Field studies were conducted to compare quartzitic sandstone to siliceous limestone in its ability to collect oyster spat, and to determine if sandstone is a suitable cultch for oysters.
Quartzitic sandstone, unlike sedimentary sandstone, does not have loose abrasive sand particles and, unlike gravel, has a rough texture similar to the siliceous limestone used in this investigation.
The quartzitic sandstone was quarried in Arkansas~ whereas the siliceous limestone (>5% silica) was quarried in Kentucky; the materials met industry size (and strength) standards of #4 railroad ballast (2.