得尔布干成矿区黑山头以北地区重、磁、遥构造解译

STRUCTURAL INTERPRETATION BY GRAVI TY,MAGNETIC FORCE AND REMOTE SENSING ON THE NORTH OF HEISHANTOU IN DERBUGAN METALLOGENIC PROVINCE

得尔布干成矿区黑山头以北地区为森林-沼泽景观区,岩石露头极少,交通十分不便.因此,对该区的区域性重、磁、遥解译显得十分必要,可为地质、矿产调查提供重要信息.重、磁、遥解译认为,较发育的线性构造有NE、NW及NNE、E-W、S-N向等.在上黑龙江拗陷区及额尔古纳隆起区,线性构造主要为NE与NW向,并构成菱形格状构造.区内NE、NW及S-N向裂隙与控矿关系密切.磁、遥解译的环形构造常常是中生代火山-侵入中心,是成矿的重要热源或热液源.

Derbugan metallogenic province(northern part)falls into forest-marsh area,with a great potential of non-ferrous and precious metallic resou rces.Therefore it will provide important information for resources ass esment to have a comprehensive interpretation of th e regional gravity,magnetic force a nd remote sensing in the Derbugan metallogenic province(northern part).In this area the gravity contour of -50mGa is generally equivalent to the boundary between Upper Heilongjiang depression meta llogenic subprovince and Ergun dome metallogenic province.The maximum value of the former is -20mGa,and the minimum value of the latter is -80mGa.The dep th difference for the Moho discon-tinuity between them can reach 5km.T he NE-and NW-trending linear structures interpreted by gravity form a lozenge-shaped structure,which is closely related to the ore-controll ing structure.Faults,volcanic rock zones and vol-canic apparatuses are shown clearly at the aeromagnetic anomaly(△T)map.Faults or volcanic rock zones ap pear to be linear structures.The volcanic apparatuses appear mostly as isolated p ositive or negatvie anomalies.The v olcanic dome structures are in circular and round ed spot anomalous groups.The NNE-to-NE-trending fracture is compresso-shear,while the NW-trending fracture is te nsional.Both of them have a great effection on ore-controlling and ore-h ost.There is a good consistency and compl ementarity between the linear structures interpreted by remote sensing and those by gravity and magnetic force.Thus the interpretation of the fractures is reliable.The circular structures inter-preted by remote sensing can be class ified into two parts:one is the volcanic apparatuses or the dome structur es of volcanic groups,which are commonly the mineralizing centers of volcani c hydrothermal deposits;the other i s J 3 -K 1 intrusive rock structures,which co ntrol the distribution of porphyry Cu deposits or intrusive complex Au deposits.In this area,the comprehensive interpreta tion of gravity,magnetic force and r emote sensing is for the first time.So it is sig-nificant for the correct understand ing of the fundamental geology in the area.