赣东北中—新生代超基性岩与金刚石找矿前景

赣东北地区发现有中－新生代超基性岩。超基性岩侵入白垩系红色盆地中，主要有玻基辉橄岩、角砾状玻基辉橄岩等。角砾状玻基辉橄岩呈岩筒状。岩石化学分析结果显示，该处超基性岩中，SiO2含量为38．19％－44．28％，K2O＋Na2O含量为2．01％－2．93％，MgO含量为7．67％－11．10％，CaO含量为8．25％－12．67％，Al2O3含量为11．94－14．51％，与曲型的玻基辉橄岩岩石化学成分相近。赣东北地区中－新生代超基性岩的发现，为重新分析评价赣东北地区金刚石找矿前景提供了重要的信息。

Analysis on Mesozoic-Caenozoic Ultrabasic Rocks in Northeast Jiangxi Provinc e and Perspective of Diamond Prospecting

The ultrabasic rocks of Mesozoic Caenozoic era have been found in the northeastern Jiangxi Province. They are mainly limburgite and breccia like limburgite and intruded the Cretaceous red basins. The breccia like limburgite is pipe shaped. The results of petrochemical analyses indicate that these ultrabasic rocks contain 38.19-44.28% SiO 2, 2.01-2.93% K 2O+Na 2O, 7.67-11.10% MgO, 8.25-12.67% CaO and 11.94-14.51% Al 2O 3 etc. These ultrabasic rocks are quite similar to the typical limburgite in chemical composition. The discovery of Mesozoic Caenozoic ultrabasic rocks provides an important information for reevaluation of the perspective for the diamond prospecting in the northeastern Jiangxi Province.