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A total of 21 elements, Si, Al, K, Na, Ca, Mg, Fe, Mn, Ti, P, Cu, Co, Ni, Zn, Pb, Cr, Rb, Sr Ba, Cd and Corg(organic carbon), was determined in the trough. Average contents of most elements were found to be higher in the trough bottom than in the western and eastern slopes. We call these elements the indicator elements because of their “transition” property. This is in keeping with the “intermediate” geographical position of the trough where the continental crust turns to oceanic crust.Though the authigenic fraction of some elements here increases, the detrital fraction .of most elements is still dominant, indicating that the influences of terrigenous and volcanic detrital materials on the trough sediments are still dominant.The abundant biogenous component in the trough is characterized by the increase of Ca, Sr and Corg contents. Ca existes mainly in the form of CaCo3 that is mostly found in various shells. Sr often easily replaces Ca within the shells.A belt-shaped distribution pattern of elements wa
A total of 21 elements of Si, Al, K, Na, Ca, Mg, Fe, Mn, Ti, P, Cu, Co, Ni, Zn, Pb, Cr, Rb, Sr Ba, Cd and Corg (organic carbon) , was determined in the trough. Average contents of most elements were found to be higher in the trough bottom than in the western and eastern slopes. We call these elements the indicator elements because of their “transition ” property. This is in keeping with the “intermediate ” geographical position of the trough where the continental crust turns to oceanic crust.Though the authigenic fraction of some elements here increases, the detrital fraction. of most elements is still dominant, indicating that the influences of terrigenous and volcanic detrital materials on the trough sediments are still dominant. The abundant biogenous component in the trough is characterized by the increase of Ca, Sr and Corg contents. Ca ex3tes mainly in the form of CaCo3 that is mostly found in various shells. Sr often easily replaces Ca within the shells. A belt-shaped distribution pattern of elements wa