Sensitivity of sediment magnetic records to climate change during holocene for the northern south China sea

Abstract

Magnetic property has been proved to be a sensitive proxy to climate change for both terrestrial and marine sediments. Based on the schedule frame established by AMS14 C dating of foraminifera, detail magnetic analyses were performed for core PC24 sediments at sampling intervals of 2 cm to discuss magnetic sensitivity of marine sediment to climate during Holocene for the northern South China Sea. The results indicated that: (1) Concentration dependent magnetic parameters are positive corresponding to variation of temperature. The frequency dependent susceptibility coefficient basically reflected the variation in humidity; (2) χARM/SIRM was more sensitive to detrital magnetite particles and SIRM/χ was more effective to bioge χARM/SIRM and SIRM/χ are corresponding to precipitation and temperature, respectively; (3) the Holocene Megathermal in the study area was identified as 7.5–3.4 cal. ka BP. The warmest stage of Holocene for the study area should be during 6.1–3.9 cal. ka BP; (4) The 8 ka cold event was characterized as cold and dry during 8.55–8.25 cal. ka BP; (5) During early and middle Holocene, the climate combinations were warm dry and cold wet. It turned to warm and wet after 2.7 cal. ka BP.