GEOLOGICAL FORMATION CHARACTERISTICS AND UTILIZED POSSIBILITY FOR QUATERNARY DUNE SAND AS AN ENGINEERING MATERIALS IN QUANG TRI COASTAL PLAIN

Abstract

This paper aims to present a series of the investigation for geological characteristics including geological formations, strata, distributions, chemical and mineral compositions, grain size distribution and physical mechanical properties of Quaternary dune sandy sediments in Quang Tri coastal plain. The dune sand is described as yellow sand belonged to Phu Xuan formation combined with gray-white sand from the Nam O formation. The data have shown that distributed area of dune sand is totally expanded by 200 km2. The main dune sand component comprises from fine to medium particle size with loose to dense structure. The sand’s mineral composition is essentially quartz, heavy minerals are inconsiderable. Contents of clay, dust and silt particle size in the Nam O sand are low (0,15 wt.%), but those in the Phu Xuan sand are relatively high (6,60 wt.%); nevertheless, the sands all do not contain any clots clay nor impurities, Cl- concentrations are also very low (0,007-0,009 wt.%) and their fineness module Ms = 1,18. These reflect initially the possible utilize for manufacturing low and medium strength engineering materials as concrete and mortars according to the National Standard TCVN 7570:2006.