Chromite Mapping Using Induced Polarization Method Based on Spread Spectrum Technology

Abstract

Chromites mapping using geophysical methods proved difficulty during the past several decades, because most Chromites are feature as podiform deposits which always pinch out and reappear in the same survey line. Several ground-based geophysical methods including: Microgravity, Magnetic and Controlled Source Audio MagnetoTelluric (CSAMT) have been used for chromites mapping. However, the result did not satisfy the need of the mining geologists. A successful case history of chromites mapping using induced polarization method based on spread spectrum technology in Luobusa Ophiolite, Southern Tibet, is presented in this paper. Wireless Sensor Network (WSN) based electromagnetic system (SinoCGI) is used for the data acquisition, which is its first time using in China. Luobusa chromites mine is one of the chromites deposits with maximum mineral production in China. But drilling and ground-based geophysical exploration did not meet the good deposit for sustainable yield in the past several years. Experiment measurement in the lab indicates that the chromites samples and its host rocks sample characterize by different rock apparent resistivity and chargeability. Based on this, we conduct induced polarization method based on spread spectrum technology to map the potential favorite deposit. We carried out around 500 IP scanning stations and three 2-D IP sounding profiles in the working area with acreage of 0.5 square kilometer. The favorite chromites deposits which features as conduct and low polarizability has been mapped. Four boreholes have been drilled to verify the ore delineation by IP method, three of them met chromites, the other one met chromites mineralization. The result gives a new recognition on geophysical methods to chromites mining geologists in China.

A modified empirical mode decomposition method for multiperiod time-series detrending and the application in full-waveform induced polarization data

“…Nowadays, several distributed full-waveform IP instrument systems are developed, such as Newmont distributed IP data acquisition system (Eaton et al 2010;Sun et al 2012), Quantec's 3-D system (Gharibi et al 2012), IRIS instrument (Gourry et al 2003) and the distributed spread spectrum IP system (SSIP; Chen et al 2007;Xi et al 2013;Xi et al 2014). There are two advantages by using these distributed instruments for electrical prospecting.…”

“…Induced polarization (IP;Bleil 1953;Wait 1959;Zonge & Wynn 1975;He1997) is an effective electrical resistivity tomography (ERT) method for non-ferrous metallic mineral exploration (Xi et al 2013;Mary et al 2016;Tavakoli et al 2016) and environmental investigations (Revil et al 2015;Maurya et al 2018;Power et al 2018). Currently, there has been great development of IP in forward modelling (Karaoulis et al 2013;Commer et al 2017;Belliveau & Haber 2018;Qi et al 2019), data acquisition (Eaton et al 2010;Sun et al 2012;Olsson et al 2015;Mo et al 2017), inversion and interpretation (Li & Oldenburg 2000;Fiandaca et al 2018;Kim et al 2018;Soueid et al 2018;Zhdanov et al 2018).…”

An enhanced correlation identification algorithm and its application on spread spectrum induced polarization data

“…For example, the first variable-frequency approach was proposed by Wait (1959), then the spectrum approach of the complex resistivity was developed by Zonge and Wynn (1975), and the dual-frequency IP approach was presented and developed by He (1993) and Han et al (2013). Recently, spread spectrum induced polarization (SSIP) is a popular branch of FDIP which uses pseudorandom current pulses of opposite polarity as an excitation source (Chen et al, 2007;Xi et al, 2013Xi et al, , 2014He et al, 2015). According to the intrinsic broadband characteristics of the source itself, the spectral response of an observation system can be simultaneously calculated at multiple frequencies in electrical exploration (Liu et al, 2019).…”

An enhanced correlation identification algorithm and its application on spread spectrum induced polarization data

“…For example, the first variable-frequency approach was proposed by Wait et al in 1959, then the spectrum approach of the complex resistivity was developed by Zonge and Wynn in 1975, and the dual-frequency IP approach was presented and developed by He et al in 1993 andHan et al in 2013. Recently, 25 spread spectrum induced polarization (SSIP) is a popular branch of FDIP which uses pseudo-random current pulses of opposite polarity as an excitation source (Chen et al, 2007;Xi et al, 2013Xi et al, , 2014He et al 2015). According to the intrinsic broadband characteristics of the source itself, the spectral response of an observation system can be simultaneously calculated at multiple frequencies in electrical exploration .…”