江苏徐州塔山橄榄玄武玢岩地球化学特征及其与金刚石成因关系  

Geochemical feature of olivine basaltic porphyrite in Tashan area of Xuzhou, Jiangsu Province, and its relation to diamond origin

作　　者：黄友波[1] 周琦忠 张琪[1] 冯学知[1] 王国强[1] 张凤鸣 蔡逸涛[2] HUANG Youbo;ZHOU Qizhong;ZHANG Qi;FENG Xuezhi;WANG Guoqiang;ZHANG Fengming;CAI Yitao(No. 5 Geological Party, Jiangsu Bureau of Geology and Mineral Resources, Xuzhou 221004, Jiangsu, China;Nanjing Center, China Geological Survey, Nanjing 210016, Jiangsu, China)

机构地区：[1]江苏省地质矿产局第五地质大队,江苏徐州221004 [2]中国地质调查局南京地质调查中心,江苏南京210016

出　　处：《地质通报》2019年第1期132-142,共11页Geological Bulletin of China

基　　金：江苏省地质勘查基金项目<江苏省徐州市塔山地区原生矿地质普查>(编号:苏财建[2014]278号);中国地质调查局项目<华北和扬子地区金刚石矿产调查>(编号:DD20160059)

摘　　要：通过研究徐州塔山地区橄榄玄武玢岩的地球化学特征,对其岩石成因及构造环境进行判别,并进一步对其金刚石成矿前景进行探讨。结果表明,橄榄玄武玢岩属于大陆板内玄武岩,总体上略富集轻稀土元素,是在板内拉张构造背景下由石榴子石相的富集地幔经不同程度部分熔融形成的,且在岩浆结晶过程中存在一定程度的斜长石堆晶作用。其所含微粒金刚石与安徽栏杆金刚石相似,显示出金刚石生长初期的特点,应为幔源捕获成因。与金伯利岩相比,橄榄玄武玢岩在地球化学特征方面存在明显差异,整体表现为古近纪伸展期玄武岩浆的特征,不具备携带大量深源包体的条件,难以形成原生金刚石矿床。The petrogenesis and tectonic environment of olivine basaltic porphyrites were judged according to their geochemical characteristics in Tashan area of Xuzhou. Then the exploration prospect of diamond was discussed. The result shows that they are plotted in the intraplate tholeiitic series and are slightly enriched in LREE. They were formed by partial melting of the enriched mantle of the garnet facies through varying degrees of partial melting in the intraplate extensional tectonic background. Besides, there was a certain degree of plagioclase intergranular effect in the process of magma crystallization. The particle diamond it contains is similar to that of the Lanling area in Anhui, which shows the characteristics of the early growth of diamond. The origin should be the capture of the mantle source. In terms of geochemical characteristics, they are obvious different from the kimberlite. They had characteristics of basaltic magma in the extensional period of Paleogene and did not have the conditions to carry a large number of deep source inclusions. Therefore, it was unfavorable to form a primary diamond deposit.

关 键 词：徐州塔山 橄榄玄武玢岩 地球化学特征 金刚石 成因关系 

分 类 号：P619.241[天文地球—矿床学] P588.134[天文地球—地质学]