Geophysical and geochemical study of geropotamos aquifer in the north-central coast of crete

The geological setting of Geropotamos aquifer on the north-central coast of Crete, Greece, is considered complex, while the local tectonic regime of the study area is characterized by two sets of faults orientated NW-SE and NE-SW. Investigation of the aquifer using the Transient ElectroMagnetic method (TEM) has resulted initially in 1D models of geoelectric structures and a final 3D geoelectrical model was constructed, depicting the zones of salination of groundwater in the aquifer. Groundwater samples were analysed and the most important chemical parameters were determined to provide an independent dataset for comparison with the TEM results, while Groundwater Quality Maps were produced. TEM and geochemical data correspond and provide verification of the TEM approach. As a result, saline intrusion is likely to occur along fractures in a fault zone through bedrock, and this work emphasises the critical role of fracture pathways in salination problems of coastal aquifers

Groundwater resources assessment using integrated geophysical techniques in the southwestern region of Peninsular Malaysia.

Combined geophysical techniques such as multi-electrode resistivity, induced polarization, and borehole geophysical techniques were carried out on volcano-sedimentary rocks in the north of Gemas as part of the groundwater resource’s investigations. The result identifies four resistivity units: the tuffaceous mudstone, tuffaceous sandstone, the tuff bed, and the shale layer. Two types of aquifer systems in terms of storage were identified within the area: one within a fracture system (tuff), which is the leaky area through which vertical flow of groundwater occurs, and an intergranular property of the sandy material of the aquifer which includes sandstone and tuffaceous sandstone. The result also reveals that the aquifer occupies a surface area of about 3,250,555 m2 with a mean depth of 43.71 m and a net volume of 9.798 × 107 m3. From the approximate volume of the porous zone (28 %) and the total aquifer volume, a usable capacity of (274.339 ± 30.177) × 107 m3 of water in the study area can be deduced. This study provides useful information that can be used to develop a much broader understanding of the nature of groundwater potential in the area and their relationship with the local geology

Geochemistry and quality of the groundwater from the karstic and coastal aquifer of Geropotamos River Basin at north central Crete, Greece.

In Geropotamos River Basin, located on the north-central part of Crete, Greece, two main factors were believed to be affecting the geochemistry of the ground- water with high salt contents: seawater intrusion and/or Miocene evaporates. To identify the origin of the high salinity in groundwater, a hydrogeochemical and isotopic study was performed. Water samples from 22 wells and 2 springs were analyzed for physico-chemical parameters, major ions analysis, as well as stable isotopes (d18O, dD). From the present survey, in which detailed hydrogeo- chemical investigation was conducted, the uncertainty of the contamination sources was decreased in the northern part of Geropotamos Basin. The results complement the scenario in which seawater and the widespread human activities are the principal sources of groundwater con- tamination. Moreover, the results of the stable isotopes analyses (d18O and dD) support the same hypothesis and make seawater intrusion the most probable cause for the highest salinity waters. It is indicated that saline intrusion is likely to occur along fractures in a fault zone through otherwise low-permeability phyllite–quartzite bedrock, which demonstrates the critical role of fracture pathways in salination problems of coastal aquifers

Geophysical and geochemical study of geropotamos aquifer in the north-central coast of crete, Greece. Conference poster at Near Surface Geoscience 2014,

The geological setting of Geropotamos aquifer on the northcentral coast of Crete, Greece, is considered complex, while the local tectonic regime of the study area is characterized by two sets of faults orientated NW-SE and NE-SW. Investigation of the aquifer using the Transient ElectroMagnetic method (TEM) has resulted initially in 1D models of geoelectric structures and a final 3D geoelectrical model was constructed, depicting the zones of salination of groundwater in the aquifer. Groundwater samples were analysed and the most important chemical parameters were determined to provide an independent dataset for comparison with the TEM results, while Groundwater Quality Maps were produced. TEM and geochemical data correspond and provide verification of the TEM approach. As a result, saline intrusion is likely to occur along fractures in a fault zone through bedrock, and this work emphasises the critical role of fracture pathways in salination problems of coastal aquifers.Operational Program "Education and Lifelong Learning" and is cofinanced by the European Union (European Social Fund) and Greek national fund