Monday, 27 February 2017

SIGMA training in Chile, the UK and Africa...by Leanne Hughes

Leanne demonstrating SIGMA in the field in Chile. 
Last month I undertook work which involved me being in three continents within a week. This is not bad going since I had only previously visited three in a lifetime! The first visit was to the geological survey of Chile (SERNAGEOMIN) and ENAMI the National Mining Company, this was part of a collaborative project with BGS to discover how we can use high resolution state of the art remote sensing imagery and elevation models to better define and understand geological problems for further study. For the interpretation of this data we used  virtual field reconnaissance software ‘GeoVisionary’ to enable a team of BGS and Chilean geologists to understand the virtual terrain as a group and record the interpretations as digital lines. This allowed the geologists to make decisions about which field sites needed a visit in order to constrain the remote interpretation. Once the field sites were identified, we flew to the north of Chile near Ovalle to field verify the interpretations using BGS SIGMA mobile.  SIGMA is a GIS-based geological mapping system, which spatially references geological observations interpretations and line work. It allowed us to collect a great deal of data into one system. The temperature in North Chile was in the mid-30s and very dry, there were lots of cactus with vicious spines – one small round variety stuck in my mind as the Chilean name translated as “A cushion for the mother-in-law”!

"A cushion for the mother-in-law"!
Whilst in the north, ENAMI showed us around the copper sulphate and silicate mines in the area and explained how viewing the workings in 3D would be useful to understand the relations of the different deposits. Once fieldwork was completed and we had collected as many interpretations as was practical, BGS and SERNAGEOMIN headed back to the head office in Santiago. By importing the SIGMA field observations into GeoVisionary we were able to discuss the interpretations and decide on what to indicate on the final geological map. The geological map was compiled in small teams who focused on areas of their expertise; I worked alongside Juan-Pablo to create a new geological interpretation of the area north of Ovalle. It was a privilege to have been able to contribute new interpretations and line work to one of their geological maps. At the end of the visit, we presented the work we had done to the department and discussed the merits of workflow we had used.

I then flew back to the UK to spend a few days setting up four tablet PCs to deliver SIGMA training the following week with Eimear Deady.

The third continent was Africa at the Liberian Geological Survey where we were delivering a course on digital geological mapping using SIGMA. I thought I was used to the hot weather after Chile but I was not ready for the hundred percent humidity and the sauna-like working environment in Liberia! With funding provided by the UK Government (DFID), a team from the BGS has been building capacity at the Liberian Geological Survey (LGS) so that staff there are better equipped to manage the country’s land-based mineral resources. The course involved a mixture of office-based training supported by practical exercises undertaken outside at various locations in Monrovia. Some of the office-based training was a little challenging. Several power cuts meant that being adaptable was key!

Classroom training (L) and teaching field skills (R) in Liberia. 
The initial few days of the course focused on familiarity with GIS and downloading the background data needed when undertaking mapping, such as aerial photographs and topographic maps. We then focused on field skills, such as finding your location on a map using triangulation and measuring dip/strike. The final exercises for the  LGS geologists was to then create a geological and topographical map of a compound in Monrovia which had a good outcrop of dolerite with jointed faces that could be measured. This utilised all the skills they had learned during the course.  At the end of the course, the trainees described what they had learned in a presentation to the Director of the LGS.

Overall, working in Chile (S. American Continent) and Liberia (African Continent) (with a few days in the UK (European Continent) between the two), were two very different experiences using SIGMA and provided me with a great opportunity to better understand the geology of these two countries.

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