GRAVITY AND MAGNETIC ANOMALIES OF JIAXIE GUYOTS AND THEIR STRUCTURAL AND SEDIMENTARY CHARACTERISTICS

Gravity data of the Jiaxie Guyots are processed with vertical derivative (VDR) method and magnetic data processed with analytical signal amplitude (ASM) method. VDR gravity data show several low anomalies in some areas of the slope and foot of the guyots, indicating low-density sediments. ASM magnetic data, however, show high anomalies in some areas of the guyots slope and top, indicating highly magnetized bodies. After the comprehensive analysis of the data, we come to the conclusion that the low VDR gravity anomalies probably suggest the debris flow deposits caused by gravity slide, and the high ASM magnetic anomalies probably indicate dyke intrusion and volcanic activities caused by flank rifting which also leads to the formation of ridges on guyots slope and uplift in some areas of the guyots top. Phenomenon that debris flow sediments are mainly distributed around flank rift zones suggests that dyke intrusion and volcanic activities in flank rift zones are probably the reason of large-scale gravity slides.