Pilot Exploration and Production Project Alternative Groundwater Sources Androy, Madagascar
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LRPS MADA-2017 - 9133458 Pilot Exploration and Production Project Alternative groundwater sources Androy, Madagascar Phases 1 & 2 Final report January 2018 BushProof Sàrl, N°stat 74133/11/2005/0/10019, NIF 2000011185, Capital social : 10’000’000 Ar Page 1 sur 55 Contents 1 INTRODUCTION AND PROJECT DESCRIPTION ...................................................................................... 3 2 ENVIRONMENTAL CONTEXT OF THE TARGET AREA ........................................................................... 5 2.1 GEOGRAPHY ............................................................................................................................................................. 5 2.2 CLIMATE ................................................................................................................................................................... 6 2.2.1 Pluviometry .................................................................................................................................................... 6 2.2.2 Evapotranspiration ......................................................................................................................................... 7 2.3 GEOLOGY ................................................................................................................................................................. 9 2.3.1 Morphology .................................................................................................................................................... 9 2.3.2 Sedimentary units .......................................................................................................................................... 9 2.3.3 Stratigraphy .................................................................................................................................................. 10 2.3.4 Precambrian basement ................................................................................................................................ 11 2.3.5 Androy volcanic event .................................................................................................................................. 11 2.3.6 Tectonics ..................................................................................................................................................... 11 2.3.7 General geological map of the region ........................................................................................................... 13 2.4 HYDROGEOLOGY ..................................................................................................................................................... 14 2.5 GEO-HYDROLOGY APPROACH ................................................................................................................................... 16 2.6 PRIMARY WATER GEO-HYDROLOGICAL CONTEXT ...................................................................................................... 16 3 METHODOLOGY .......................................................................................................................................21 3.1 PHASE : EXPLORATION ............................................................................................................................................. 21 3.2 FRACTURE TRACE ANALYSIS – ANDROY REGION OF MADAGASCAR ............................................................................. 22 3.3 PHASE : PRODUCTION .............................................................................................................................................. 23 3.4 IMPORTANT NOTE .................................................................................................................................................... 24 4 GEOPHYSICAL REPORT ..........................................................................................................................25 4.1 SITE 1 : AMBONDRO MAAR 2 - “CRATER LAKE” ........................................................................................................... 25 4.1.1 Summary ..................................................................................................................................................... 25 4.1.2 Radiometric Survey ...................................................................................................................................... 25 4.1.3 Passive Seismics ......................................................................................................................................... 26 4.1.4 Observations ................................................................................................................................................ 37 4.1.5 Recommendations ....................................................................................................................................... 38 4.2 SITE 2 : AMBOVOMBE “MAAR BRITTANY” ................................................................................................................... 39 4.2.1 Summary ..................................................................................................................................................... 39 4.2.2 Radiometric Survey ...................................................................................................................................... 40 4.2.3 Passive Seismics ......................................................................................................................................... 41 4.2.4 Observations ................................................................................................................................................ 42 4.2.5 Recommendations ....................................................................................................................................... 43 4.3 SITE 3 : TSIOMBE NORTH “STONE MOUNTAIN” ........................................................................................................... 44 4.3.1 Summary ..................................................................................................................................................... 44 4.3.2 Lineament Analysis ...................................................................................................................................... 44 4.3.3 Radiometric Survey ...................................................................................................................................... 46 4.3.4 Passive Seismics ......................................................................................................................................... 46 4.3.5 Observations ................................................................................................................................................ 48 4.3.6 Recommendations ....................................................................................................................................... 48 4.4 SITE 4 : AMBAZOA TOWN SQUARE ............................................................................................................................ 50 3.3.1. Summary ..................................................................................................................................................... 50 4.4.2 Radiometric Survey ...................................................................................................................................... 51 4.4.3 Passive Seismics ......................................................................................................................................... 51 4.4.4 Observations ................................................................................................................................................ 52 4.4.5 Recommendations ....................................................................................................................................... 53 5 CONCLUSION ...........................................................................................................................................54 UNICEF_Primary Water project_South Madagascar Page 2 sur 55 1 INTRODUCTION AND PROJECT DESCRIPTION This pilot project aims to implement modern geophysical exploration techniques, used today in the mining sector, to try to highlight alternative groundwater sources in an area where known groundwater sources are considered to be unproductive and mineralized (salty). These alternative sources highlighted, surveys will be conducted to assess the quantities of water that can be mobilized and the quality of the resource, before possible exploitation. The alternative groundwater sources discussed and targeted in this project are flows and upwelling of "primary" water, which are absent from the hydrological cycle (see concept note below). The geological context of the Androy region has a significant potential to find this type of upwelling. The targeted region is facing a persistent drought and its population has only very limited access to water, the exploitation of alternative water sources will improve locally this situation. The beneficiaries of the project are the communities living in villages located in the areas targeted by UNICEF Madagascar's interventions, prioritized by DREEH Androy. The pilot project will be divided into five distinct phases : 1. Description of the context and known hydrogeology of the target area. Detailed study of the lineaments, allowing to highlight the most favorable