关于韧性变形与成矿作用的一些实验结果

EXPERIMENTAL ACHIEVEMENTS ON DUCTILE DEFORMATION STRUCTURES AND METALLIZATION

本文通过以含丰富的成矿物质的广东河台金矿石和辽宁玉龙铅锌矿石为样品,在250～45℃和200～400MPa 的围压条件下进行变形实验,揭示出了某些成矿物质与韧性变形之间的内在联系。实验做出了三种韧性变形构造:它们是韧性剪切带、韧性挤压带、韧性扭曲带。伴随这些韧性变形,某些成矿物质如黄铁矿和闪锌矿等都发生了明显的迁移,向着韧性变形构造带集中。电子探针测出了在韧性扭曲构造带上金发生了高度集中。

To look into the genetic relationship between ductile deformation and metallization,specimens with rich metallogenic materials have deen used in deformation sxperiment under high temperature and high pressure.The temperature of the experiment ranged from 250℃ to 450℃ and the confining pres- sure from 200 MPa to 400MPa.Three types of ductile structures have developed during the experi- ments,which are ductile shear zone,ductile compression zone and ductile contortion zone.Followiog these ductile deformation,metallogenic materials,especially sulfide migrated and concentrated.It has been shown that pyrite and sphalerite can easily flowed plastically at 250℃.But with increasing tem- perature,sulfide will decompose and diffuse.For example,it is difficult to find sphalerite grains on the polishing section of specimens after experiment at 450℃.Most pyrite have also changed much.The re- sults of the experiments indicate that ductile contortion structure is an important structural pattern which can contribute much to enrichment of metallogenic materials.