我国前寒武纪非金属矿产的分布及其特征

本文总结了我国前寒武纪非金属矿产的分布和特征，指出菱镁矿、硼矿、磷矿、滑石、石墨等非金属矿产赋存于不同的沉积建造、火山堆积以及不同变质岩系之中，是由古陆块的构造部位所决定的。前寒武纪非金属矿床的成矿作用与大陆地壳演化关系密切，古元古代大陆拼合焊接的造山带和新元古代稳定地块的海相沉积是两个十分重要的非金属矿产成矿构造环境，前者在中国北方（如胶辽裂谷、佳木斯地块）形成菱镁矿、硼矿、滑石矿和石墨矿等矿床，后者在南方（如扬子陆块、苏鲁大别带）主要形成磷矿床。前寒武纪产出大型、超大型非金属矿床数十个，成因类型主要有沉积变质型、岩浆热液型和沉积（弱变质）型，文中着重对硼、石墨、菱镁矿、滑石、磷矿等五个主要矿种的资源分布及矿床地质特征作了叙述。

Characteristics and Distributions of the Precambrian Nonmetal Deposits in China

The Precambrian nonmetal deposits take a very important position in China.Based on the distribution and characteristics of the Precambrian nonmetal deposits in China,it is suggested that the main kinds of Precambrian nonmetal minerals,such as magnesite,borium,phosphorite,talc,graphite minerals etc,occur in the sedimentary formation,volcanic rocks and various metamorphic rock systems,and are restricted in some particular tectonic locations of the old blocks.The ore-forming events related closely to the crustal evolution.There are two very important ore-forming periods,one is from the formation of the continental matching and regional metamorphism during Neoarchean to Paleoproterozoic Eras,the other is originated in marine deposit in Neoproterozoic Era.The magnesite,borium,talc and graphite ore deposits formed during the former period,especially in Jiao-Liao Blocks and Jiamusi Block in North China,and the phosphorite ore deposits formed during the latter period in Yangtz Block and Su-Lu-Dabie Blocks in South China.Several tens of the large and super-large Precambrian nonmetal deposits can be mainly divided into 3 genetic types: sedimentary-metamorphic type,magmatic-thermal-fluid type and sedimentary(with lightly metamorphic) type.Five kinds of ore minerals and their typical deposits of magnesite,borium,graphite, talc and phosphorite are respectively gone to particulars in this paper.