In 1988, Luis J. Mejia et al. mapped the carbon bearing units between El Hoyo and Mosquera (scale of 1:25,000). They updated the geological description of the Mosquera Formation and confirmed that the formation could be divided into three members (Lower, Middle and Upper). They reported the presence of a number of coal plies exhibiting thicknesses of 1 m or more (9 plies in the El Vergel area). They produced a non-compliant resource estimate for the entire belt.
In 1991-1992 Carbocol carried out a preliminary reconnaissance survey for coal over the entire area.
Ingeominas executed a geological program in 1993. This report provides the best geological information available for the area and comprises the following features:
- Mapping of the entire belt at the scale of 1:10,000 (80 km X 20 km)
- 1,436 m of trenching (with sampling)
- Various geophysical surveys (density, Mag, Resistivity and caliper)
- Development of stratigraphic columns
- 1,308.55 m of drilling in five holes
- Collection of numerous samples from trenches and outcrops for analysis according to CARBOCOL standards
- Detailed descriptions of geological units
- Correlation of coal plies through the area
- Production of surface maps and cross-sections with carbon plies
- Resources estimates (according to international standards, 1994)
- Preliminary evaluation of the quality of the coal
- Age determination of units
- Description of the local infrastructure
- Report with conclusions and recommendations (No. 2240)
In 1996, Ingeominas produced a new geological map of the area at 1:100,000 (Plancha 364) and a summary geological report (Orrego and Acevedo, 1996). This map is a compilation of various studies done over the years and is quite inaccurate for the area of interest.
In 1997, Ecocarbon produced a report on environmental issues related to the exploration and development of coal mines in the area (BioDesa Ltda., 1997). This document reproduces the geological interpretation developed in report No 2240.
From 1997 to 1999, Ingeominas carried out various surveys in the area including drilling, downhole geophysics, and topographic measurements in order to located the resource and evaluate the coal potential of the area (Ingeominas, 1999).
License DJU-071 was granted to El Gran Porvenir Limitada by the MINERCOL (government agency) on December 19, 2002. The license covers an area of 40 hectares. Porvenir started to work in the region near 2002. The company initiated limited production from nearby its concession and bought all the coal from informal miners working in the Hoyo region (around the concession). The area where limited mining took place was believed (by Porvenir) to be within the limit of the concession but, AM personal realized that it is not the case, possibly due to a surveying or an administrative error.
All the coal of the region was transported and piled at the company’s gathering facility in Piedra Sentada (20 km from the property). It is then shipped by semi-trailer trucks (called mula) to a pulp and paper plant near Cali. In 2016, Porvenir stopped production on its concession but continued to buy the coal from informal miners. Monthly regional production is estimated at about 5,000 tonnes per month.
In 2016, AM signed an agreement to purchase 80% of Porvenir’s business in the region, including the mining title and the coal collecting and marketing business.
In November of 2016, AM has applied to acquire a block of ground to the north of Porvenir’s mining title (Solicitud de Contrato No. RKG-09241). This extension has actually been granted although the administrative process has not yet been finalized with the authorities.