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More systematic geoscience mapping in the country was started since the establishment of the Geological Survey of Ethiopia (GSE) in 1968. Since then, Regional geologic mapping, Regional geophysical mapping (land gravity and airborne (magnetic and radiometric), and Regional geochemical mapping have been conducted and administered respectively by Regional Geology and Geochemistry Department, Geophysics Department, and Economic Mineral Exploration and Evaluation Department (Geochemistry Team), in isolation by developing their own initiatives that didn't come together as a coherent change in addressing the public needs. Given the increasingly importance of geoscience mapping for the public, the GSE conducted Business Process Reengineering (BPR) to critically review, understand and redesign the existing performances and bringing the geoscience mapping together into one process called Basic GeoScience Mapping Directorate . The Directorate entered into full implementation as of July 2009, and re-organized to operate integrated activities under the Geological Survey of Ethiopia, is technically responsible for delivery of geoscience (geology, geophysics and geochemistry) maps and reports to customers and/or stakeholders and thereby contributes geoscience information to socio-economic development of the country.
Basic geoscience mapping is helpful in natural resources development, infrastructure development, environmental protection, natural hazard identification, and for scientific research and education. The mapping was done either independently by the Ethiopian government or in collaboration with other international organizations. Given the in - creasing importance of geoscience mapping for the public.
Systematically collect and interpret basic geoscience information that is required for infrastructure development and further studies in exploration and exploitation of the mineral resource potential of the country, and Carry out integrated geological, geophysical and geochemical investigations to attract investment in exploration and development of mineral resources.
To prepare integrated geoscience maps at the scale of 1:250,000 with accompanying reports for further studies in mineral exploration, agricultural development, natural hazard studies, master plan studies, ground water investigations, environmental management and earth science research studies, and To prepare geochemical maps for prospective target areas at the scale of 1:100,000 with accompanying reports that can be used as a tool in the search for and development of mineral
GEOSCIENCE MAPPING COVERAGE
The entire country is covered by 1:2,000,000 geological maps, which was first published in 1973 and edited in 1996, While the compilation of 1:250,000 scale maps are still ongoing. At present 57% of the country is covered by 1:250,000 scale maps. These maps are available both in hard copy print and soft copy.
Geochemical surveys at different scales were conducted in different parts of the country with particular emphasis has been given to assess the mineral potential of the Precambrian rocks. To date ~20% of the country is covered by 1:100,000 and less scale geochemical surveys. As of 2009 systematic geochemical mapping at scale of 1:250,000 integrated with geological and geophysical mapping is started. Along with 1:250,000 scale mapping, 1:100,000 scale geochemical surveys for prospective areas are started as of 2012.
Hunting (1968, 1971); Survair, 1970; Aeroservice, (1983); GSF, (1996) has been carried out Airborne geophysical surveys (EM. Rad, Mag) in different parts of the country for petroleum, ore mineral and geothermal resource explorations. The areas covered by the survey includes the Ogaden and Gambella basins, the Adola Gold field area, the Rift valleys,and some parts of northern, western, northeastern and southern Ethiopia. These surveys account to 30% coverage of the country.
Since the last three-four decades Land gravity survey at different scales has been carried out in different parts of the country. However, more systematic Regional gravity survey (1:500,000) was conducted between 1985 and 1996 in S and SW Ethiopia with the financial assistance of SIDA/SAREC (Swedish Government) and in collaboration with the Geophysical Observatory of Addis Ababa University. Since 2001 the GSE conducted independently the regional gravity survey. At present 85% of the country is covered by Land gravity survey at a scale of 1:500,000.
The Future plan
The Government of Ethiopia has approved a five year (2010/2011-2014/2015) Growth and Transformation Plan (GTP). In line with this strategic framework four Geoscience Mapping projects are planned with goals to
• complete the 1:250,000 scale geological map coverage of the country
• cover the country by low-to-medium resolution airborne geophysical survey
• compile 1:500,000 scale gravity map of the country
• increase the coverage of the 1:250,000 scale gravity map of the country to 49%
• increase the coverage of the 1:250,000 scale geochemical map of the country to 49%
• compile 1:2,000,000 scale geochemical atlas and metallogenic map of the country
Current Status of Geoscience Map Coverage
The Core Process has two versions; Basic Geoscience Mapping and Mineral-Focused Geochemical Mapping.
The Basic Geoscience Mapping Version
This version undertakes integrated geological mapping,geochemical, and gravity survey at a scale of 1:250,000 and produce maps with accompanying reports for further studies in mineral exploration, agricultural development, natural hazard studies, master plan studies, groundwater investigations, environmental management and earth science research studies.
The Mineral-focused Geochemical Mapping Version
This version is responsible to undertake geochemical survey at the scale of 1:100,000 for areas identified as prime target for mineral exploration by basic geoscience mapping. The main aim of the version is to collect, process and interpret geoscience data, and delineates economic mineral prospects for further detail investigations.