Magnetic Method Surveying and Its Application for the Concealed Ore-Bodies Prospecting of Laba Porphyry Molybdenum Ore Field in Shangri-La, Northwestern Yunnan Province, China

Nguyen Ba Dai, Chuan Dong Xue, Kun Xiang, Kun Xiang, Tran Trong Lap, Qureshi Javed Akhter, Shi Lei Li

Department of Earth Sciences, Kunming University of Science and Technology, Kunming, China.

DOI: 10.4236/gep.2014.23006                

Abstract

Recently, a number of large molybdenum (-copper) deposits have been discovered successively in the Laba area, Shangri-La county, northwestern Yunnan province. The investigation confirmed that there is a superlarge porphyry-skarn hydrothermal vein type molybdenum-polymetallic- metallogenic system with the total prediction reservoir of more than 150 mt molybdenum. The porphyry intrusions contributed to the mineralization closely, the superficial little vein molybdenum (-copper, lead, silver) ore-bodies are usually located in faults and fractures, and the deep porphyry type ore-bodies occurred in the granodiorite porphyries, the skarn type ore-bodies occurred in the contact zone intrused into Triassic limestone or Permian basalts. Laba ore block is a new exploration area with great prospecting potential. In order to reduce the target area and guide the further exploration work, the magnetic method measurement about 3.3 square kilometres was carried out in the ore field. This paper presents an application of analyzing the horizontal and vertical derivative, using Fast Fourier Transform (FFT) filter (FFT high-pass, low-pass, cosine roll-off, suscepbility), calculated spectra frequency energy to predict the depth and intensity of the apparent remanence magnetization of source (Hilbert). The calculated results and magnetic anomalous show that the remanence anomaly is caused by the intrusions into the Triassic limestone and Permian basalts with small anomalies, and the depth of located source is not great. We have identified a number of positions to the three drilled well, the drilled result specify interpretation with very high accuracy. The magnetic method is helpful to identify porphyry mineralization, and judge the shape and depth of the concealed ore-bearing intrusive bodies under the similar geological condition.

Keywords

Magnetic Method, Physical Property Parameters, Concealed Ore-Bodies Prospecting, Laba Porphyry Molybdenum (-Copper) Ore Field, Northwestern Yunnan Province

Conflicts of Interest

The authors declare no conflicts of interest.

References

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[22]	Pejman, S., Michel, C., & Denis, M. (2011). 3D Stochastic Inversion of MAGNETIC Data. Journal of Applied Geophysics, 73, 336-347. http://dx.doi.org/10.1016/j.jappgeo.2011.02.005
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