The Application Of Gravity And Magnetic Exploration On The Porphyritic Iron (Sulfur) Deposit

In recent thirty years, the speed development of the national economy and industrializationleads to the increase in external dependence degree and the resource price, so that to theserious contradiction of the resources supplies and demand. Meanwhile, the recovereddeposit of the strategic metal mineral is shortage which threats the continuous developmentof the national economy and security. Therefore, it is a prolonged mission to gain thereserve volume of the resource in the geological work.This paper is based on the study of deep porphyritic iron (sulfur) deposit exploration anddemonstration, it makes use of the gravity and magnetic data with the supplies of thegeological information and mineral-exploration result, it gets the primary inference withthe characteristic of the gravity and magnetic anomaly, it sums up that the metallogenicregularity of this deposit and builds the model of mineral exploration with gravity andmagnetic method which could supply some reference to the following work.In this paper, the main research work and achievements including the aspects are asfollows:(1) It sums up that the metallogenic regularity and the prospecting model of porphyriticiron (sulfur) deposit. The correspondence of the gravity and magnetic anomaly is the mainsign to the iron, the single gravity anomaly also need to be paid much attention. Thesubset gravity and magnetic anomaly in large-scale gradient is the key to the prospection.The combination of IP sounding anomaly, gravity anomaly, magnetic anomaly, thesecondary deviation of gravity anomaly and the residual gravity anomaly is important tothe comprehensive analysis.(2) Nihe iron deposit locates in eastwest air-magnetic anomaly zone ofLuohe-Qingshuitang in the northwest of Luzong basin. The magnetic anomaly is complex, the reduce-pole result shows the belt positive anomaly in northwest trend of Luzong basin.After the processing of reduce-pole and upward continuation, it shows the most part ofdeep positive anomaly in the shape of ellipse, of which the southeast part is penetrating bythe SN volcanic rock. With the field separation, the residual anomaly presents thepositive anomaly in the shape of whole ellipse which reflects the deep mineral deposit. The3D inversion of the gravity and magnetic anomaly gives the corroboration that thesouthwest part of the tested deposit is potential to find new mineral ore or increase thereserves which has been confirmed by the logging afterwards. The study is on thecharacteristic of gravity and magnetic anomaly in Nihe indicates, it is important to choosethe suitable methods of field separation and inversion for the predicting and digging of themineral deposit.(3) The separation of field and the reduce-pole affect the extracting of deep porphyriticiron (sulfur) directly. The inference of the existing, depth and size of the mineral oredepends on the effective separation, the accurate measurement, the inversion of3D. Thereare a variety of methods to separate the field, such as polynomial fitting, filter andinversion, the optimal method relates to the characteristic of the field. It is necessary tomeasure the physical property of the core which refers to the adjustment of the3D inversemodels, it deserves to be spread for its guidance to logging and deep mineral prospecting.