The Magnetostratigraphic Characteristics of some Shorter Cores from the Deep South China Sea Basin

Key words: 
• Magnetostratigraphy /
• Deep sea cores /
• South China Sea

Abstract: During the一marine comprehensive investigation of the Central South China Basin(12一20^。N )from the October 1983 to June 1984,38 sediment cores were obtained by the piston一sampler. The cores are generally not longer than 4m. The paleomagnetic measurement of 5 sediment cores selecting from the continental slope and deep plain has been carried out. The result shows:(1)all cores are mainly positive polarity and belong to Brunhes epoch;(2)the magnetostratigraphic differences exist between the slope cores and deep plain cores. The lower of slope cores reveals the existence of negative magnetic excursion. The chronology of the excursion has been stuffed by various methods, such as ¹⁴C,Th一230,δ¹⁸O and CaC0₃%,etc. We got two satisfying cycle curves of δ¹⁸O and CaC0₃% in the slope cores. In comparison with the magnetostratigraphy and Quaternary geochronology from the neighbour borehole of Tianyang Lake,it can be seen that the nagative polarity section of studied slope cores is in the lower stage 3 of δ¹⁸O and CaC0₃% curves .its stratum is approximately equal to that located Mungo magnetic excursion in the borehole from Tianyang Lake.