A COMPARATIVE STUDY OF THE COMPOSITIONS AND EVOLUTION OF THE LOW-MATURE HYDROCARBON AND THEIR CONTROLLING FACTORS FOR THE CORE SEDIMENTS FROM MID-PACIFIC AND EAST-PACIFIC BASINS

Organic carbon, soluble organic matter (chloroform extractive) and group composition (total hydrocarbon, saturated hydrocarbon, arene, nonhydrocarbons and asphaltine), and biomarkers (n-alkannes, isoprenoids and terpenoids) of the samples from two stations MP2001-01 and ES0103 in the equatorial Pacific were analyzed. The organic matters from the two stations were recognized as the low-mature hydrocarbon. The physical properties and the source materials of the hydrocarbon as well as their similarity and difference were studied. There are obvious difference in their content, group compositions, evolutionary history, source materials, sedimentary environment and controlled factors. These differences were mainly dependant upon environment. The two stations were separated by the Line Volcanic Chain in the central Pacific basin. There are obvious differences of source materials and sedimentary environment (oxidation/reduction) between the two stations. Antarctic bottom current is the major factor influencing the composition and evolution of the low-mature hydrocarbon.