Demystifying Mining Industry
by Bob Gabuna
As a preface of this column, let me qualify, I am not going to write an exhaustive commentary regarding the surrounding controversy over the Sibuyan project. Other writers have already tackled the matter. However, to be upfront about it, I admit, I am not averse to mining ventures per se; nonetheless, I am concerned too of untoward eventualities particularly if the operation would affect the island's foundation considering its size. That being said let me share what I know about mining exploration.\
According to the lectures I learned from the Chamber of Mining Industry jointly conducted with the Philippine Stock Exchange, there are two types of exploration. These are grass roots or basic mineral exploration, and mining exploration. The former activity is to discover or locate unknown mineral deposits. While the latter is the routine activity of operating mines to locate the continuation or extension of ore bodies in the mines.
There are varied elements of grass roots or basic mineral exploration. This mode, as defined by law, The Philippine Mining Act of 1995, exploration means searching or prospecting for mineral resources by geological, geophysical surveys, remote sensing, test pitting, trenching, drilling or any other means for the purpose of determining the existence, extent, quality and quantity, and the feasibility of mining the ore for profit.
The above described means is a scientific process of searching for mineral deposits with possible economic or commercial value through geophysical techniques in selected areas. Specifically, the major activities involves identifying the type, character, mineral composition, and fractures of rocks in the surface; and collecting samples of exposed rocks, stream sediments, and soil which are chemically analyzed.
Afterwhich, the field and laboratory data are then collated and evaluated to ascertain if the samples really indicate subsurface mineral deposit with possible commercial value. Subsequently, the depths, limits, shape, tonnage and grade of the indicated mineral deposit underground are determined mainly by trenching, test pitting, and drilling.
When we speak of mineral resource from the understanding of a geologist, the term means there is a concentration or occurrence of a material of intrinsic economic interest on earth's crust in such forms and quantify that there are reasonable possibilities for eventual economic extraction. The quantity and quality, geological characteristics and continuity of a mineral resource are known and interpreted are further sub-divided in three categories: inferred, indicated, and measured categories.
Inferred mineral resource means the estimate has a low level of confidence. In other words, the tonnage and grade is uncertain. Indicated mineral resource, however, offers a reasonable level of confidence based on sampling and testing information confirming density, shape, and grade continuity.
The third category, measured mineral resource is a high level of confidence wherein the physical characteristics, mineral content, tonnage and grade estimate is suffice to determine whether ore extraction is justified or not.
Whether Sibuyan Island has the measured mineral resource or not for nickel, I construe is not the question. The question, I think, is the highly emotionally charge environmental issue.