DISTRIBUTION OF DETRITAL MINERALS IN THE CORE ZK2 AT THE LIAOHE DELTA AREA SINCE LATE PLEISTOCENE: IMPLICATION FOR PROVENANCE

A total of 92 samples taken from the core ZK2 (depth 0~32 m) at the Liaohe Delta are analyzed for detrital minerals. It is revealed that the mass percentages of light minerals, which mainly consist of quartz and feldspar, are above 95% in these samples. The average mass percentage of heavy minerals is only about 0.82%, which include hornblende, epidote, actinolite, garnet, hematite, limonite and authigenic pyrite. The assemblages and percentage compositions of light minerals remain relatively stable while those of heavy minerals vary significantly since Late Pleistocene. According to the order cluster analysis on all detectable heavy minerals by software Tilia, we divide heavy minerals into 4 assemblages for the core ZK2 since Late Pleistocene, which approximately correspond to 4 sedimentary facies, namely river channel, marsh, tidal flat-shallow sea and deltaic environments. The research suggests that the percentage composition of each heavy mineral is mainly dependent upon the depositional environment, the sedimentary hydrodynamic conditions and the distance from estuary, especially for metallic minerals. There is no significant change in provenance for the sediments deposited since Late Pleistocene. The sediments were mainly derived from the Liaohe River and secondary the Daliaohe River.