辽宁分水金矿床地质及成因

分水金矿属岩浆期后中温热液(石英脉)型矿床,位于石棚峪超单元北西外接触带上,二者有着密切的空间分布关系.铅同位素特征显示,金矿成矿物质来源于186±13Ma及2800Ma的两个源区.燕山早期阶段,石棚峪超单元黑云母碱长花岗岩中深成侵入活动(186±13Ma)所分异的岩浆期后热液在运移就位过程中萃取了部分围岩(约2800Ma)的成矿物质,稍晚于186±13Ma形成金、铅矿床.

GEOLOGY AND GENESIS OF FENSHUI GOLD DEPOSIT

Fenshui gold deposit,located in northeast of Dashiqiao,Liaoning Province,occurs in the external contact belt of Shipengyu super unit,belonging to post magmatic mesothermal deposit.Archean metamorphic plutonite,upper crustal rock and Liaohe group metamorphic formation are distributed in Fenshui gold field.The former is the main wall rock of gold ore body.The biotite alkali feldspar granite of Shipengyu super unit, formed in early Yanshanian stage (Rb Sr 186± 13 Ma),is the ore forming parent rock of Fenshui gold deposit.The main gold ore bodies occur in single quartz veins in plate,vein or lenticle shapes,10- 129.5 meters long and 0.25- 2.98 meters thick.The mean grade of gold ore is 11.71× 10- 6,with a variation of 71.9% to 234% , belonging to even most uneven type.There are 46 ore bodies with 1839.5 kg of total reserves in Fenshui gold deposit.More than 5000 kg of gold have been mined since 1939.The characteristics of lead isotope show that the ore forming material of Fenshui gold deposit originated from two sources of 186± 13 Ma and 2800 Ma± .In early Yanshanian stage, the post magmatic hydrothermal solution that derived from middle plutonic intrusion (186± 13 Ma)of biotite alkali feldspar granite in Shipengyu ultra unit extracted ore forming materials from country rock (2800 Ma± ) to form gold deposits little later than 186± 13 Ma.