Continuous resistivity profiling survey in Mersin Harbour, Northeastern Mediterranean Sea

No detailed information has previously been available on the geological and geophysical characteristics of the sea floor and the underlying strata of Mersin Harbour, Northeastern Mediterranean Sea (Turkey). Continuous resistivity profiling (CRP) and borehole data from Mersin Harbour were used to interpret geoelectric stratigraphy of Neogene-Quaternary sediments in the area. This represents one of few such detailed case studies that have applied these valuable CRP techniques for the purpose of marine stratigraphic imaging. It was found that the Neogene-Quaternary sedimentary succession in the area consists of three geoelectric units (GU1, GU2, and GU3 from base to top). The lowest unit, GU1, has a resistivity value of greater than 20.0 ohm-m and consists of Miocene aged limestone and marl. The middle unit, GU2, is characterized by resistivity values ranging from 3.0 to 20.0 ohm-m. Its thickness is greater than 90 m, with the upper section being composed of stiff clay sequences which are Plio-Pleistocene in age. The uppermost unit, GU3, has resistivity values varying from 1.0 to 3.0 ohm-m. This unit displays a maximum thickness of 15 m, and is composed of Holocene muds together with gravel, sand, silt and clay (sometimes incorporating shells) materials of the Plio-Pleistocene age and their various mixtures, silty/clay limestone, and conglomerate sandstone. Comparisons of the geoelectric units with the depositional sequences interpreted from the available seismic data outwith, but close to, Mersin Harbour reveal that the geoelectric unit GU3 corresponds to the depositional sequences C (mainly Holocene) and B (mainly Plio-Pleistocene). The geoelectric unit GU2 partly correlates with the depositional sequence B which appears to be Plio-Pleistocene in age. The geoelectric unit GU1, which has not been encountered in previous seismic surveys, is a new discovery within Mersin Harbour. Limited correlation between the seismic and resistivity structures in the study area is attributed to differences in the acoustic impedance and resistivity contrasts of sub-bottom layers, as well as the penetration versus resolution performance of the systems.

[1]  D. Stanley.  Post-Miocene Depositional Patterns and Structural Displacement in the Mediterranean , 1977 .

[2]  C. Johnson,et al.  Continuous resistivity profiling to delineate submarine groundwater discharge - Examples and limitations , 2006 .

[3]  D. Stanley,et al.  The Mediterranean Sea;: A natural sedimentation laboratory , 1973 .

[4]  M. Ergin,et al.  Seismic stratigraphy and late quaternary sediments in inner and mid-shelf areas of eastern Mersin Bay, northeastern Mediterranean Sea , 1992 .

[5]  Salvatore Passaro,et al.  Marine electrical resistivity tomography for shipwreck detection in very shallow water: a case study from Agropoli (Salerno, southern Italy) , 2010 .

[6]  Donald D. Snyder.  Application of Continuous Resistivity Profiling to Aquifer Characterization , 2001 .

[7]  F. T. Banner,et al.  Secchi disc depths, suspensions and circulation, northeastern Mediterranean Sea , 1979 .

[8]  M. Ergin.  Subaerially exposed Late-Quaternary basinal shelf of the inner Mersin Bay, Eastern Mediterranean: Paleoenvironmental evidence , 1996 .

[9]  J. Lane,et al.  Continuous‐Resistivity Profiling for Coastal Ground‐Water Investigations: Three Case Studies , 2003 .

[10]  G. Evans,et al.  Recent surficial shelf sediments of the Cilician Basin (Turkey), northeastern Mediterranean , 1997 .

[11]  M. N. Bodur,et al.  Holocene sedimentation patterns and bedforms in the wave-current-dominated nearshore waters of eastern Mersin Bay (eastern Mediterranean) , 1992 .

[12]  Lee Slater,et al.  Aquatic electrical resistivity imaging of shallow-water wetlands , 2007 .

[13]  P. Bush,et al.  The mineralogy and geochemistry of the Recent surface sediments of the Cilicia Basin, northeast Mediterranean , 1978 .

[14]  Toshihiro Uchida,et al.  Delineation of a Fault Zone Beneath a Riverbed By an Electrical Resistivity Survey Using a Floating Streamer Cable , 2005 .

[15]  L. Toran,et al.  Marine Resistivity As A Tool For Characterizing Zones Of Seepage At Lake Lacawac, Pa , 2007 .

[16]  J. Woodside.  Tectonic elements and crust of the eastern Mediterranean Sea , 1977 .

[17]  P. Swarzenski,et al.  Coastal groundwater dynamics off Santa Barbara, California: combining geochemical tracers, electromagnetic seepmeters, and electrical resistivity , 2009 .

[18]  A. Aksu,et al.  Quaternary sedimentary history of Adana, Cilicia and Iskenderun basins: northeast Mediterranean Sea , 1992 .

[19]  G. Evans,et al.  Seismic stratigraphy of Late Quaternary sediments of western Mersin Bay Shelf, (NE Mediterranean Sea) , 2005 .

[20]  D. Rosenberry,et al.  Electrical Resistivity As A Tool For Identifying Geologic Heterogeneities Which Control Seepage At Mirror Lake, Nh , 2008 .