The Recognition And Morphology Of The Shandong Clinoform In Offshore Area

Clinoform usually refers to the wedge muddy sediment in the river mouth areaat the continental margins. The Holocene Clinoform off Shandong Peninsula isformed in the area of northern South Yellow Sea and western North Yellow Seawhich could be called the offshore area of the eastern Shandong Peninsula. There isan abundance of Holocene sediment in the study area which is the marine invasionshelf sea.The high quality profiles in the research was picked up from the single channelseismic data in the North Yellow Sea and Northern South Yellow Sea. Themorphology analysis and the structure study were investigated by using seismicattributes. A seismic attribute is a quantity extracted or derived from seismic data thatcan be analysed in order to enhance information that might be more subtle in atraditional seismic image, leading to a better geological or geophysical interpretationof the data, and can be used to identify the structures of the sedimentary deposits.The amplitude envelope can be used to identify the top and upset of the clinoformwhile the instantaneous phase not only can be used to identify the top and upset ofthe clinoform but also the structure in the clinoform.There are four seismic units in different width of the Holocene mud wedge ofwestern Yellow Sea. There is significant disturbance in the widely distributing U1.The most important parts of the mud wedge, U2and U3, are just along the ShandongPeninsula. U3takes place in the whole research area in the steady width. The threeseismic units are correspond to three phases of the evolution process of the Holocenemud wedge which reflect the processes of the rise of the sea level after the LastGlaciation: seaward progration processes with the sea level rising in high speed,landward retrogration-accretion processes with the sea level rising in lower speed andlandward accretion processes in the high sea level. The formation time and theevolution can be concluded from the processes. The formation time of the Shandongclinoform can be inferred to11.9cal BP. U3in which there are lots of unconformitiesis deposited at about11.9-9.6cal kyr BP. U2which speard in succesion is deposited from9.6to6.5kyr BP. And the thin U1is deposited after6.5cal BP.