Discovery of a hidden BIF deposit in Anhui province, China by integrated geological and geophysical investigations

In China, banded iron formation (BIF) ore deposits of Precambrian age are found at different burial depths. Current exploration programs are focused on deep-seated concealed iron ore deposits. As a consequence, integrated geological and geophysical data are crucial in increasing the success-rate for exploration success. We propose a strategy by which the underlying geological model for the study area is first investigated. The corresponding electromagnetic response can then be modeled, simulating a geophysical type of survey with appropriate uncertainties in the analysis. Based on such an integrated approach, the required precision of detecting deeply-buried deposits can be investigated. In addition, by employing supplementary geophysical data acquired over known BIF deposits, further insight is gained into real geological models. The viability of this approach is demonstrated herein through a case study, where a hidden BIF deposit located in Anhui Province was successfully detected. The actual field measurements were carried out employing the grounded-wire Short-Offset TEM (SOTEM) technique. The analysis of the survey data revealed two new anomalies, one of which was subsequently drilled. Drilling results later confirmed that this anomaly was associated with an ore body that is 60 m thick at a burial depth of 750 m.