【摘要】：武當(dāng)?shù)貐^(qū)地處南秦嶺造山帶關(guān)鍵地帶,受俯沖碰撞造山作用的影響,區(qū)內(nèi)印支期韌性剪切帶控制的金銀多金屬礦床發(fā)育。本文選擇武當(dāng)西緣地區(qū)的六斗金礦和銀洞溝銀多金屬礦床為研究對(duì)象,在礦床地質(zhì)特征、穩(wěn)定同位素、及流體包裹體等方面分別進(jìn)行解剖分析,探討成礦機(jī)制,確定礦床成因。論文對(duì)比總結(jié)了武當(dāng)?shù)貐^(qū)成礦規(guī)律,為該區(qū)金、銀金礦床成礦理論提供了新的線索。六斗金礦位于武當(dāng)西緣十堰斷裂以北。耀嶺河群與上部陡山坨組之間的韌性滑脫剪切構(gòu)造帶為主控礦構(gòu)造。金礦體呈似層狀、透鏡狀分布于南北向及北西向和北東向次級(jí)斷裂中。礦化類型有破碎帶蝕變巖型和石英脈型兩種。充填礦物穩(wěn)定同位素研究表明,初始成礦流體為變質(zhì)流體,后不同程度混入大氣降水,成礦物質(zhì)來源于賦礦圍巖。原生流體包裹體形態(tài)規(guī)則,氣液比均一。礦床形成于中溫(210~220℃)、中壓(140~150Mpa)環(huán)境。銀洞溝銀多金屬礦床位于武當(dāng)西緣、十堰斷裂以南。礦床受銀洞溝背斜和韌性剪切帶聯(lián)合控制。礦體具向西傾斜、平面?zhèn)攘屑按怪狈謳卣?由淺及深,從銀礦體逐漸過渡為鉛鋅礦體。銀洞溝主體礦化經(jīng)歷石英-鉛鋅礦化階段、銀金礦化階段(包括糖粒狀石英-銀金礦化亞段、糖粒狀石英-含鉛、鋅的銀金礦化亞段)、塊狀石英-鐵白云石脈弱礦化階段等三個(gè)階段。礦脈以高角度近東西走向陡脈為主,少量低角度緩脈發(fā)育,為同期成礦作用結(jié)果。礦體成礦后受到明顯的構(gòu)造改造,如礦體的石香腸化、揉皺及X共軛剪節(jié)理,推測(cè)主要是南北向擠壓的結(jié)果。充填礦物穩(wěn)定同位素研究表明,初始成礦流體為變質(zhì)流體,但大氣降水對(duì)銀洞溝成礦作用也有貢獻(xiàn)。流體包裹體類型多樣,揭示礦床形成于中溫(280~290℃)、中壓(200~220Mpa)環(huán)境,成礦深度為11.5~12.5km。結(jié)合現(xiàn)有的年代學(xué)數(shù)據(jù),認(rèn)為六斗金礦為典型的造山型金礦,形成于印支晚期;銀洞溝銀多金屬礦床為韌性剪切帶控制的中溫?zé)嵋好}型礦床(類似于造山型銀礦),形成于印支早期。
[Abstract]:The Wudang area is located in the key zone of the South Qinling orogenic belt. The gold and silver polymetallic deposits controlled by the Indosinian ductile shear zone are developed under the influence of subduction and collision orogeny. In this paper, the Ludou gold deposit and Yindonggou silver polymetallic deposit in the western margin of Wudang are selected as the research objects. The geological characteristics, stable isotopes and fluid inclusions of the deposit are anatomically analyzed, the metallogenic mechanism is discussed and the genesis of the deposit is determined. This paper contrasts and summarizes the metallogenic law in Wudang area, which provides a new clue for the metallogenic theory of gold and silver deposits in this area. Ludou gold deposit is located north of Shiyan fault in the west margin of Wudang. The ductile detachment shear zone between the Yaolinghe group and the upper Doushantuo formation is the main ore-controlling structure. The gold orebody is layered and lenticular distributed in the NNE and NW and NE secondary faults. There are two types of mineralization: altered rock type and quartz vein type. The stable isotopic study of filling minerals shows that the initial ore-forming fluid is metamorphic fluid, and then mixed into the atmospheric precipitation to varying degrees, and the ore-forming material originates from the host rock. The primary fluid inclusions are regular in shape and homogeneous in gas-liquid ratio. The deposit was formed in a medium temperature (210 ~ 220 鈩，

本文編號(hào)：2280574