Chemical composition of detrital spinel from ultramafic complexes in Eastern Chugoku and Northern Kinki districts, Southwest Japan.

Abstract

There are many ultramafic complexes in the Oeyama ophiolite, eastern Chugoku and northern Kinki districts, southwest Japan. We are clarified the chemical composition of detrital chromian spinel from the ultaramafic complexes. Cr# of chromian spinels are 0.43-0.56 of Sekinomiya complex, 0.36-0.78 of Izushi complex, 0.43-0.69 of Oeyama complex, 0.78-0.90 of Wakasa complex and 0.25-0.86 of Oshima complex. And Cr# of chromian spinels from chromitite of Sekinomiya and Oeyama complexes are 0.38-0.46. Above Cr# of spinels from chromitite of eastern Chugoku and northern Kinki district are higher than those of central Chugoku district.