福建尤溪肖板金矿床金的赋存状态及金矿物特征

肖板金矿床属受构造控制的中低温岩浆热液矿床，矿化类型为构造蚀变岩型。金多呈独立金矿物形式出现，少许呈分散状；金矿物以自然金为主，平均成色９３０，有少量银金矿和碲金矿。金矿物以包体金、裂隙金、连生金和粒间金等形式嵌布于黄铁矿、黄铜矿、石英、方铅矿及方解石等主要载金矿物中，且石英、方解石中较金属硫化物中占优势。金矿物形态各异，粒度以中细粒为主。

Modeof Occurrence of Gold and Characteristics of Gold Minerals in Xiaoban Gold Deposit, YouxiCounty, Fujian Province

The Xiaoban gold depsit, belonging to altered fractured rock type ,is a medium-low temperature magmatic hydrothermal deposit controllex by the low angle detachment fault northwest of the puyang metamorphic core complex. In the Early Yanshanian, mineralization of the deposit took place. The mineral association of the gold ore consists of quartz, calcite, pyrite, chalcopyrite, galena and tellurobismuthite.Gold occurs mainly as independent gold minerals, and subordinately as mechanical mixture,solid solution and adsorbed matter in auriferous minerals. The essential gold mineral is native gold with average gold content of 91.13%(1000×Au/(Au+Ag)=933); the auxiliary minerals are electrum with 79.77%Au and 19.98% Ag(1000×Au/(Au +Ag)=797) and Te- bearing native gold with 79.77% Au and 13.17% te.Gold minerals in the msjor auriferous minerals (pyrite, chalcopyrite, quartz, calcite and galena)occurs in the interganular, interlocking, crevice and enclosure forms,and gold in quartz and calcite is higher than gold in other minerals. Mainly as hypidiomorphic- granular ones and secondarily as idiomorphic-granular and veinlet ones, the gold minerals are commonly mediumfine grains, with 0.05~0.005 mm grains making up 59.13~84.45%.The high Au/(Au+Ag)ratio of the gold minerals in the area is similar to things of other deposits in the greenstonebelt of China but is different from character of the volcanic hydrothermal type gold deposits such as the Zhilingtou gold deposit in east China .These features show that the source materials of the deposit were mainly derived from the metamorphic rocks of Middle Proterozpic Mayuan Group and that the metallization of gold was closely related to the intermediate-acid intrusive rocks at a relatively high temperature in Early Yanshanian. The high Te content indicates that metallization was also rrrelated to the magma. Although there are quite a few differences in country rocks, attiudes of orebodies, types of mineralization and alterations between Xiaoban gold deposit and Shangcun gold deposit, the similar characteristics of gold minerals suggest that they result from different structural dynamic conditions in the same mineralizing process and identical mineralizing setting. These conclusions are consistent with the genetic understanding of the ore deposit.