【摘要】：研究區(qū)位于揚子地臺北緣,秦嶺造山帶南側,該區(qū)富含Pb、Zn、Au、Cu、Hg、Ag、Sb、Mn、V、U、As等多種金屬元素,是我國最重要的多金屬成礦帶之一,目前已發(fā)現多個大型-超大型金屬礦床。此外,該區(qū)發(fā)育極好的生、儲、蓋組合條件和優(yōu)越的構造圈閉及成藏條件,具有良好的含油氣遠景,其含油氣潛力和勘探遠景被大家所關注。研究區(qū)以Pb、Zn等為代表的層控型淺成低溫熱液礦床形成深度一般在1500m內,溫度介于50℃~200℃之間,礦床形成后的構造抬升剝蝕作用對其勘探潛力評價極為重要。同樣地,后期構造隆升對油氣藏的形成和保存條件具有重要影響,目前普遍認為中生代以來的構造演化控制了氣藏的成藏特征和成藏模式。本文使用地層回剝技術恢復和重建研究區(qū)的沉積史。大巴山經歷了三個演化階段:①太古宙~元古宙基底形成階段,其中震旦系的沉積速率約為6.11m/Ma;②寒武紀~二疊紀碳酸鹽巖臺地沉積階段;③中~新生代陸內造山~前陸盆地構造演化階段。碑壩穹窿經歷了三個演化階段:①基底形成演化階段;②古生代盆地構造演化階段;③中生代造山構造演化階段。應用磷灰石裂變徑跡反演研究區(qū)的熱歷史,結果表明:大巴山構造帶和碑壩穹窿分別于153Ma和135Ma開始隆升,都受到燕山運動的影響,由于碑壩穹窿受漢南古陸的阻擋,燕山運動對其影響較晚,故開始隆升時間也較晚。大巴山構造帶和碑壩穹窿都在153Ma~80Ma期間處于較快速的隆升狀態(tài),這一隆升剝蝕反映了研究區(qū)白堊紀的區(qū)域性剝蝕事件。大巴山構造帶和碑壩穹窿在5Ma(或7Ma)有一次極快速的隆升剝蝕過程,此時青藏高原的東部和東北部抬升加劇,再次激活了秦嶺一帶的老構造并導致了大巴山顯著的剝蝕,漢南穹窿-米倉山一帶作為秦嶺的南緣也受到了影響。另外,在中新世以來發(fā)生的氣候環(huán)境的巨變對研究區(qū)的快速剝蝕也具有極大的影響。
[Abstract]:The study area is located in the Taibei margin of the Yangtze platform and the southern side of the Qinling orogenic belt. It is rich in various metal elements, such as PbPbZZZZOU, HgCU, SbAg-Mn-MNMn-VGU / as, and is one of the most important polymetallic metallogenic belts in China. At present, several large and super-large metal deposits have been discovered in the study area, which is one of the most important polymetallic metallogenic belts in China. In addition, the area is well developed in terms of source, reservoir, cap assemblage, favorable structural traps and reservoir forming conditions, and has a good oil and gas potential, and its oil and gas potential and exploration prospects have attracted much attention. In the study area, the formation depth of stratabound epithermal hydrothermal deposits, such as Pb, Zn, and so on, is generally within 1500 m and the temperature is between 50 鈩，

本文編號：2171141