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ISSN : 1225-6692(Print)
ISSN : 2287-4518(Online)
Journal of the Korean earth science society Vol.34 No.6 pp.575-587
DOI : https://doi.org/10.5467/JKESS.2013.34.6.575

철광산 지역에서의 물리탐사 기술 적용 연구

김기연1·오석훈2,*
1기상청 국립기상연구소, 156-720, 서울특별시 동작구 여의대방로16길 61
2강원대학교 에너지·자원공학과, 200-701, 강원도 춘천시 강원대학길 1
철광산 지역의 매장량 평가를 위해 전기 및 전자탐사 방식의 물리탐사를 수행하였다. 철광산 조사에 적합한 물리탐사 기법을 결정하고 연구지역의 지질정보에 대해 파악하기 위해, 대상 지역의 시추 코어와 노두 파편으로부터 획득한 암석 코어를 분석하였다. 획득한 코어에 대해 비중, 밀도, 공극률, 비저항, P파 속도 등 5가지 물성을 측정한 결과, 자철광체가 전기적 특성에 민감하게 반응한다는 것을 확인하고 전기 탐사를 수행하기로 결정하였다. 전기비저항 탐사는 기존의 연구들을 통해서 적용 기법들이 다양하고 해상도 또한 높은 편이 알려져 있어 철광산의 조사에 적합할 것으로 판단되었으나, 심부에서는 해상도가 낮으며 탐사의 수행도 어렵다는 한계를 가지고 있다. 이에 전기비저항 탐사를 보완하기 위해 물리탐사법 중 비교적 깊은 탐사심도를 가지는 MT (MagnetoTelluric) 탐사를 추가적으로 수행하였다. 또한 MT 탐사의 천부 정보에 대한 취약성을 보완하기 위해 인공송신원을 사용하는 CSMT (Controlled Source MT) 탐사를 추가적으로 실시하였다. 전기 및 전자탐사를 통해 채광이 이루어진 광산 하부에 저비저항체가 있음을 발견하였으며, 향후 추가적인 이용 가치를 확인하였다.

A Geophysical Survey of an Iron Mine Site

*Corresponding author: gimul@kangwon.ac.kr

Tel: +82 33 250 6258

Fax: +82 33 250 5550
, Kiyeon Kim1and Seokhoon Oh2,*

1National Institute of Meteorological Research, Korea Meteorological Administration, Seoul 156-720, Korea
2Department of Energy and Resources Engineering, Kangwon National University, Gangwon 200-701, Korea

Abstract

DC electrical and electromagnetic survey was applied to evaluate the reserve of an iron mine site. We analyzedthe borehole cores and the cores sampled from outcrops in order to decide which geophysical method was efficient forthe evaluation of iron mine site and to understand the geological setting around the target area. Based on the core testsfor specific weight, density, porosity, resistivity and P wave velocity, showing that the magnetite could be distinguishableby the electrical property, we decided to conduct the electrical survey to investigate the irone mine site. According toprevious studies, the DC electrical survey was known to have various arrays with high resolutions effective to the surveyof the iron mine site. However it was also known that the skin depth is too shallow to grasp the deep structure of ironmine. To compensate the weakness of the DC electrical method, we applied the MagnetoTelluric (MT) survey. In addition,a Controlled Source MT (CSMT) method was also applied to make up the shortcoming of MT method which is weakfor shallow targets. From the DC electrical and MT survey, we found a new low resistivity zone, which is believed to bea magnetite reserve beneath the old abandoned mine. Therefore, this study was confirmed for additional utility value.

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