A New Structural Type of Basic-Ultrabasic Complex with Ni-Cu Mineralization

• 责任者：Li Li (Xi’an Institute of Geology and Mineral Resources ; Xi’an 710054 ; China) ; Wang Yuxi
• 刊名：Northwestern Geology
• 出版年：2010
• 卷期：43(3)
• 关键词：杂岩 ; complexes ; 甘肃 ; Gansu Province
• 页码：p.47-56
• 图表：9 illus., 4 tables, 19 refs.
• 分类号：0801
• issnNo：ISSN1009-6248
• isbnNo：CN61-1149/P

The study shows that the Guaishishan basic-ultrabasic complex with Ni-Cu mineralization in Beishan area, Gansu Province, is a typical example of intrusion bodies related with the magma under-plating and uplifting orogenic movement. The main evidences are discussed. Therefore, the rock-forming mechanism is that, under the decompression conditions of continental lithosphere extending, the peridotite from mantle were partially melted to form picritic magma with a Mg value of 0. 831. The magma intruded upward to crust or crust-mantle boundary and caused partial melting of the gabbroic in lower crust to form mixed magma with TTG assemblage. Subsequently, the magma developed in terms of magma under-plating according to tense-shearing brush structure series and then intruded into the upper crust to form rocks during the uplifting orogenic movement.