Integrated Interpretation of Regional Geoscientific Data for Mineral Exploration in Colombia: Marmato Target Example

Author(s):  
I. Moyano ◽  
E. Goméz ◽  
G. Prieto ◽  
S. Walker ◽  
M. Puentes ◽  
...  
Geophysics ◽  
2013 ◽  
Vol 78 (3) ◽  
pp. B111-B119 ◽  
Author(s):  
Xiangyun Hu ◽  
Ronghua Peng ◽  
Guiju Wu ◽  
Weiping Wang ◽  
Guangpu Huo ◽  
...  

A controlled-source audio-frequency magnetotelluric (CSAMT) survey has been carried out to investigate potential iron (Fe) and polymetallic (Pb-Zn-Cu) deposits in Longmen region, which is one of the main metallogenic belts in southern China. Conducting geophysical surveys in this area is quite difficult due to mountainous terrain, dense forest, and thick vegetation cover. A total of 560 CSAMT soundings were recorded along twelve surveying lines. Two-dimensional Occam’s inversion scheme was used to interpret these CSAMT data. The resulting electric resistivity models showed that three large-scale highly conductive bodies exist within the surveying area. By integrated interpretation combined with available geologic, geophysical, and geochemical data in this area, three prospective mineral deposits were demarcated. Based on the CSAMT results, a borehole penetrating approximately 250-m depth was drilled at the location of 470 m to the northwest end of line 06, defined with a massive pyrite from the depth of 52–235 m with 7%–16% Fe content, as well as locally high-grade Pb-Zn- and Ag-Ti-bearing ores.


SEG Discovery ◽  
2019 ◽  
pp. 21-29
Author(s):  
Roderick Carlson

Editor’s note: The Geology and Mining series, edited by Dan Wood and Jeffrey Hedenquist, is designed to introduce early-career professionals and students to a variety of topics in mineral exploration, development, and mining, in order to provide insight into the many ways in which geoscientists contribute to the mineral industry. Abstract The role of geology in advanced mining studies, such as feasibility studies, is commonly dwarfed by the technical inputs from mining, metallurgical, and social license issues. Understanding and planning for geologic risk in the feasibility process is often overlooked for the higher-profile aspects required to establish an ore reserve. If the geologic model of a deposit cannot be reliably forecast, then there will be lower confidence in many of the modifying factors (which include mining, processing, environmental, social, governmental, and economic factors that influence the conversion of identified mineral resources into economic reserves). Understanding geologic risk requires characterization of all the chemical, physical, and spatial properties of mineralization and waste that form part of the mined material. It is essential to understand the scope of the professionals who use geoscientific data in order to assist the outcomes of the study, with the data types first identified, then collected in a comprehensive manner, and finally interpreted at the appropriate time to contribute to the outcomes of the study. If the study is not comprehensive, remedial collection of data is required at a cost to development timeline and budget; a worse scenario is that the development fails economically after it is built. Developing projects to a construction stage after a mining study typically involves international standards of assessment and verification, although the standards of geoscientific data collection differ between companies and countries. For this reason, recent efforts by international bodies such as the Committee for Mineral Reserves International Reporting Standards (CRIRSCO) are assisting many countries to work toward a standardized terminology in a feasibility study. There are many examples where the mining outcomes have not met the feasibility study forecast, with variable causes for a failure to deliver to plan; geoscientific data shortfalls often contribute significantly to these negative outcomes. Examination of case histories, knowledge of international standards for risk reporting, advances in measurement technology, and an understanding of the end users of geoscientific data will help geologists to better prepare the scope of a feasibility study for a potential mine, in order to deliver a product with lower risk related to geologic uncertainty.


1993 ◽  
Vol 159 ◽  
pp. 10-16
Author(s):  
H.K Schønwandt ◽  
P.R Dawes

Part of the 1992 promotion campaign to North America and Europe, to provide geoscientific data to exploration and mining audiences was an oral presentation of Greenland's exploration potential. The background and aims of the campaign are outlined elsewhere in this report by Dawes et al. The oral presentation focused on the main geological provinces of Greenland and their mineral occurrences (excIuding fossil fuels), but geographical and logistic subjects were also broached. This paper gives a summary of the geological part of the presentation and concentrates on metalliferous potential.


2021 ◽  
Author(s):  
Ranee Joshi ◽  
Kavitha Madaiah ◽  
Mark Jessell ◽  
Mark Lindsay ◽  
Guillaume Pirot

Abstract. Exploration and mining companies rely on geological drill core logs to target and obtain initial information on geology of the area to build models for prospectivity mapping or mine planning. A huge amount of legacy drilling data is available in geological survey but cannot be used directly as it is compiled and recorded in an unstructured textural form and using different formats depending on the database structure, company, logging geologist, investigation method, investigated materials and/or drilling campaign. It is subjective and plagued with uncertainty as it is likely to have been conducted by tens to hundreds geologists, all of whom would have their own personal biases. However, this is valuable information that adds value to geoscientific data for research and exploration, specifically in efficiently targeting sustainable new discoveries and providing better shallow subsurface constraints for 3D geological models. dh2loop (https://github.com/Loop3D/dh2loop) is an open-source python library that provides the functionality to extract and standardize geologic drill hole data and export it into readily importable interval tables (collar, survey, lithology). In this contribution, we extract, process and classify lithological logs from the Geological Survey of Western Australia Mineral Exploration Reports Database in the Yalgoo-Singleton Greenstone Belt (YSGB) region. For this study case, the extraction rate for collar, survey and lithology data is respectively 93 %, 865 and 34 %. It also addresses the subjective nature and variability of nomenclature of lithological descriptions within and across different drilling campaigns by using thesauri and fuzzy string matching. 86% of the extracted lithology data is successfully matched to lithologies in the thesauri. Since this process can be tedious, we attempted to test the string matching with the comments, which resulted to a matching rate of 16 % (7,870 successfully matched records out of 47,823 records). The standardized lithological data is then classified into multi-level groupings that can be used to systematically upscale and downscale drill hole data inputs for multiscale 3D geological modelling. dh2loop formats legacy data bridging the gap between utilization and maximization of legacy drill hole data and drill hole analysis functionalities available in existing python libraries (lasio, welly, striplog).


Author(s):  
Bjørn Thomassen ◽  
Johannes Kyed ◽  
Agnete Steenfelt ◽  
Tapani Tukiainen

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Thomassen, B., Kyed, J., Steenfelt, A., & Tukiainen, T. (1999). Upernavik 98: reconnaissance mineral exploration in North-West Greenland. Geology of Greenland Survey Bulletin, 183, 39-45. https://doi.org/10.34194/ggub.v183.5203 _______________ The Upernavik 98 project is a one-year project aimed at the acquisition of information on mineral occurrences and potential in North-West Greenland between Upernavik and Kap Seddon, i.e. from 72°30′ to 75°30′N (Fig. 1A). A similar project, Karrat 97, was carried out in 1997 in the Uummannaq region 70°30′–72°30′N (Steenfelt et al. 1998a). Both are joint projects between the Geological Survey of Denmark and Greenland (GEUS) and the Bureau of Minerals and Petroleum (BMP), Government of Greenland, and wholly funded by the latter. The main purpose of the projects is to attract the interest of the mining industry. The field work comprised systematic drainage sampling, reconnaissance mineral exploration and spectroradiometric measurements of rock surfaces.


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