中国地质
中國地質
중국지질
CHINESE GEOLOGY
2014年
4期
1190-1204
,共15页
中生代岩浆活动%碰撞后阶段%成矿构造背景%北山%中亚造山带
中生代巖漿活動%踫撞後階段%成礦構造揹景%北山%中亞造山帶
중생대암장활동%팽당후계단%성광구조배경%북산%중아조산대
Mesozoic magmatism%post-collisional period%metallogenic tectonic setting%Beishan%Central Asian Orogenic Belt
中亚造山带是古亚洲洋演化与最终消亡的产物。北山地区处于该造山带中段南部，是中国重要的铜、钼、金、铁多金属成矿带。北山地区在晚古生代-早中生代曾发生过2次碰撞造山作用，一次发生于晚古生代末，与古亚洲洋的最终闭合有关；另一次发生于早中生代三叠纪，与北山南带发育的石炭纪-二叠纪裂谷封闭有关。因此，从时间演化看，中生代三叠纪北山地区为碰撞-碰撞后造山阶段，发育大规模剪切带和强烈的岩浆活动及伴生的金属成矿作用。北山地区中生代岩浆活动以深成侵入相发育并缺失相应的喷出相为特征；岩石类型以中酸性侵入岩为主，基性侵入岩局部可见，S、I、A型花岗岩均有产出。与中生代岩浆活动有关的矿床类型主要包括与I-A型花岗岩伴生的斑岩钼矿床、与S型花岗岩伴生的钨（锡）矿床、与中酸性侵入体有关的矽卡岩型金、银铜铅锌多金属矿床和与中酸性侵入体有关并受剪切带控制的金矿床。中生代印支期是该地区最晚一次大规模岩浆活动与金属成矿时期，其发育的范围、规模和强度均比原来认识的要广泛的多，值得进一步关注。
中亞造山帶是古亞洲洋縯化與最終消亡的產物。北山地區處于該造山帶中段南部，是中國重要的銅、鉬、金、鐵多金屬成礦帶。北山地區在晚古生代-早中生代曾髮生過2次踫撞造山作用，一次髮生于晚古生代末，與古亞洲洋的最終閉閤有關；另一次髮生于早中生代三疊紀，與北山南帶髮育的石炭紀-二疊紀裂穀封閉有關。因此，從時間縯化看，中生代三疊紀北山地區為踫撞-踫撞後造山階段，髮育大規模剪切帶和彊烈的巖漿活動及伴生的金屬成礦作用。北山地區中生代巖漿活動以深成侵入相髮育併缺失相應的噴齣相為特徵；巖石類型以中痠性侵入巖為主，基性侵入巖跼部可見，S、I、A型花崗巖均有產齣。與中生代巖漿活動有關的礦床類型主要包括與I-A型花崗巖伴生的斑巖鉬礦床、與S型花崗巖伴生的鎢（錫）礦床、與中痠性侵入體有關的矽卡巖型金、銀銅鉛鋅多金屬礦床和與中痠性侵入體有關併受剪切帶控製的金礦床。中生代印支期是該地區最晚一次大規模巖漿活動與金屬成礦時期，其髮育的範圍、規模和彊度均比原來認識的要廣汎的多，值得進一步關註。
중아조산대시고아주양연화여최종소망적산물。북산지구처우해조산대중단남부，시중국중요적동、목、금、철다금속성광대。북산지구재만고생대-조중생대증발생과2차팽당조산작용，일차발생우만고생대말，여고아주양적최종폐합유관；령일차발생우조중생대삼첩기，여북산남대발육적석탄기-이첩기렬곡봉폐유관。인차，종시간연화간，중생대삼첩기북산지구위팽당-팽당후조산계단，발육대규모전절대화강렬적암장활동급반생적금속성광작용。북산지구중생대암장활동이심성침입상발육병결실상응적분출상위특정；암석류형이중산성침입암위주，기성침입암국부가견，S、I、A형화강암균유산출。여중생대암장활동유관적광상류형주요포괄여I-A형화강암반생적반암목광상、여S형화강암반생적오（석）광상、여중산성침입체유관적석잡암형금、은동연자다금속광상화여중산성침입체유관병수전절대공제적금광상。중생대인지기시해지구최만일차대규모암장활동여금속성광시기，기발육적범위、규모화강도균비원래인식적요엄범적다，치득진일보관주。
The Central Asian Orogenic Belts (CAOB) resulted from evolution and final closure of the Plaeo-Asian Ocean(s). Located in the central segment of the southern portion of the CAOB, the Beishan area, which refers to the conjunction region of Inner Mongolia, Gansu and Xinjiang, is one of the most important metallogenic belts in China, with abundant Cu, Mo, Au, Fe and base metal deposits. Two collisional events took place in the Beishan area during Late Paleozoic-Early Mesozoic:one occurred at the end of Late Paleozoic, which was related to the final closure of the CAOB, and the other took place in Early Mesozoic, resulting from the closure of the Carboniferous-Permian rifts in southern Beishan. As a consequence, the Beishan area was involved, in terms of temporal relations, in a collision to post-collision stage in Indosinian epoch of Mesozoic period, during which large-scale ductile shear zones and intensive magmatism as well as associated metallic mineralization occurred. The Mesozoic magmatism, which is predominated by intermediate-felsic intrusions locally with minor basic ones, is characterized by plutonic intrusive facies, without extrusive counterpart. Petrogenically, S-, I-and A-type granites have been delineated in the area. Types of Mesozoic mineral deposits in the area mainly include porphyry-type Mo mineralization, which is associated with I-and/or A-type granites, W (Sn) deposits associated with S-type granites, skarn-type Au-Ag-Cu polymetallic deposits associated with intermediate-felsic intrusions, and Au deposits related to granitic intrusions and controlled by ductile shear zones. Indosinian epoch is the latest period of major magmatism and metallic mineralization in the area, to which more attentions should be paid since the Indosinian granitoid intrusions and associated mineral deposits may be much more extensive and abundant than recognized presently.
