PALAEOMAGNETIC RECORDS FROM SHUINAN CAVE SEDIMENTS, GUILIN AND ITS BEARING ON PALAEOCLIMATIC CHANGES

A detailed palaeomagnetic study of a 2.5m thick section of cave sediment has been made in order to retrieve a record of palaeoenvironmental change in Guilin area. The palaeomagnetic results and geological evidence show that the sediments might have been deposited during the Jaramillo Polarity subchron, i.e. from 0.97 Ma to 0.90 Ma. Based on the susceptibility, the magnetic minerals(S ratios, SIRM etcs.), and sediments characteristics), and a correlation with the loess records in north China, a conceptual model of the palaeoclimatic changes in Guilin area in proposed as follows:1. a warm and wet period (since 0.90 Ma) characterised by travertine deposit; 2. a dry and cold period(0.92 to 0.90 Ma) characterised by yellowish-brown clay with less calcareous content, high coercivity minerals and low susceptibility; 3. a warm and period (0.94 to 0.92Ma) characterised by the interbedded redish-brown clay, calcareous material and travertine, low coercivity minerals and high susceptibility; 4. a dry and cold period (0.96 to 0.94Ma) characterised by greyish-brown clay with less calcareous material, high coercivity minerals and low susceptibility; and 5. a warm and wet period(>0.96 Ma) characterised by the sandy gravel (underground river facies).