苏北东海榴辉岩、斜长角闪岩原岩及其成因初步研究

On the Protolith and Origin of Ecologite and Amphibolite in Donghai - GanyuArea, Northern Jiangsu

江苏省东北部东海—赣榆地区,断续出露一套中—深变质岩系,称东海群,其上为海州群不整合覆盖。东海群的原岩形成于晚太古代—早元古代。在东海群下部分布区,

Abstract: Lots of evidence show that these ecologite and amphibolite masses in Donghai and Ganyu area, Northern Jiangsu Province are ophilites, the relic fragments of oceanic crust, restore their protolith: mafic cumulate and mafic lave of Ophiolites. Their basalt have chemical composition of ridge tholeiite, the geochemistry of their rock are characterized of exhibits high LIL, rare earth elements and light rare earth elements contents, so it belongs to the E-MORB. The y were ocean basin range from terrain in the Subei-Jiaonan terrain to the Jiaobei terrain. Their magma was derived from partial melting of the enriched mantle and inner mantle flow (mantle plume). With plate subduction and collision, these abyssal ecologite and amphibolite mass were emplaced onto different position of the Donghai Group.