三道溜河地区太古宙岩浆－构造事件

THE ARCHEAN MAGMA TECTONIC EVENT OF THE SANDAOLIUHE AREA

三道溜河地区处于中朝准地台北东缘，北西起自著名的夹皮沟金矿，南东至四道砬子河，太古宇出露广泛。笔者在此进行１：５万区调时，共发现了六次岩浆－构造事件，由老至新依次为：７８７角闪辉石岩、岭东片麻岩、大朝阳沟斜长角闪岩、三道溜河ＴＴＧ岩组、唐胡店沟二长花岗岩、五道砬子河变辉长辉绿岩（发生在元古宙早期，在时空上与太古宇关系密切）。上述事件，表现为基性岩类与酸性岩类交替出现。基性岩事件依次为超基性岩－基性岩－偏碱性基性岩，稀土元素总量由高至低，微量元素Ｂａ、Ｍｎ、Ｚｒ递增，Ｐｂ、Ｚｎ递减。酸性岩事件依次为中酸性岩－酸性岩－偏碱性酸性岩，稀土元素的Ｌａ／Ｌｕ、ΣＣｅ／ΣＹ由低到高，总量变化不大，微量元素Ｃｏ、Ｃｒ、Ｎｉ、Ｃｕ递减。本区的构造运动与岩浆侵入活动相辅相成，古穹窿构造及北西向韧性剪切带控制了Ａｕ、Ａｇ、Ｃｕ等矿产的展布。

The Sandaoliuhe area lies in the north margin of the Sino-Korean paraplatfofm.Fromthe well known Jiapigou gold deposit in the northwest to the Sidaolazihe in the southeast,theArchean outcropped extensively.Through the regional investigation(scale:1:50 000),6magma-tectonic events are discovered,frorn old to young.they are 787 Hornblende pyroxen-ite, Lingdong gneisses,Dachaoyanggou amphibolite,Sandaoliuhe TTG petrofabrics, Tanghu-diangou adamellite,Wudaolazihe metagabbro diabases(early Proterozoic is closely associatedwith the Archean in spstial and temporal).The events mentioned above show that basic rocks and acid rocks are formed alternatively。Basic rock events is occurred as following sequence:ultrabasic rocks,basic rocks and metaalkali basic rocks. The total of REE is from high tolower;Ba and Zr of REE progressively increase;Pb and Zn progressively decrease。Acid rockevent is as the following sequence from midacid rocks-acid rocks-metaalkali rocks。La/Luand ΣCe/ΣY of REE are from lower to high in contents,the total content has not obviouslychange。Co,Cr and Ni of REE progressively decrease. The tectonic movements in this areaare closely associated with magrnatic intrusion。Au,Ag,Cu and other minerals distributionare controlled by the paleodome structures and the WN trending ductile shear belts。