Journal of the Earth & Space Physics. Vol. 36, No. 4, 2011, P. 1-18 2D inversion of the Magnetotelluric data from Travale Geothermal Field in Italy Oskooi, B. 1* and Manzella, A. 2 1 Assistant Professor, Earth Physics Department, Institute of Geophysics, University of Tehran, Iran 2 Professor, National Research Council, Institute of Geosciences and Earth Resources, Pisa, Italy. (Received: 21 Oct 2007 , Accepted: 9 March 2010) Abstract A detailed study of the exploited geothermal field of Travale in Italy was conducted using Magnetotelluric (MT) data in 2004. This paper detects the main features of the conductivity structures of this area. For subsurface mapping purpose, the long period natural-field MT method proved very useful. For processing and modeling of the MT data, 2D inversion schemes were used and to have the best possible interpretation all modes of data were examined. The resistivity model obtained from MT data is consistent with the geological model of the Travale region down to five kilometers. The current MT results reveal the presence of a deep geothermal reservoir in the area. Recognition of the conductive zones in the resistive basement in many sites can clearly be interpreted as the flow of the fluids in the faults and fractures of the metamorphic rocks. Key words: Geothermal field, Magnetotelluric, Travale, 2D inversion, Resistivity دادهﻌﺪي دوﺑ ﺗﻔﺴﻴﺮ ﻣﻴﺪان ﻣﮕﻨﺘﻮﺗﻠﻮرﻳﻚ ﻫﺎي زﻣﻴﻦ ﮔﺮﻣﺎﻳﻲ اﻳﺘﺎﻟﻴﺎ در ﺗﺮاواﻟﻪ اﺳﻜﻮﺋﻲ ﺑﻬﺮوز 1 ﻣﻨﺰﻻ آدﻟﻪ و 2 1 اﺳﺘﺎدﻳﺎر، زﻣﻴﻦ، ﻓﻴﺰﻳﻚ ﮔﺮوه ژﺋﻮﻓﻴﺰﻳﻚ ﻣﺆﺳﺴﺔ، ﺗﻬ داﻧﺸﮕﺎه اﻳﺮان ﺮان، 2 اﺳﺘﺎد، ز ﻋﻠﻮم ﻣﻮﺳﺴﻪ ﻣﻠﻲ، ﭘﮋوﻫﺶ اﻧﺠﻤﻦ اﻳﺘﺎﻟﻴﺎ ﭘﻴﺰا، زﻣﻴﻦ، ﻣﻨﺎﺑﻊ و ﻣﻴﻦ ) درﻳﺎﻓﺖ: 29 / 7 / 86 ، ﻧﻬﺎﻳﻲ ﭘﺬﻳﺮش: 18 / 12 / 88 ( ﭼﻜﻴﺪه ﻣﻴﺪان ﺗﻔﻀﻴﻠﻲ ﺑﺮرﺳﻲ زﻣﻴﻦ ﮔﺮﻣﺎﻳﻲ ﺑﻬﺮه داده از اﺳﺘﻔﺎده ﺑﺎ اﻳﺘﺎﻟﻴﺎ در ﺗﺮاواﻟﻪ ﺷﺪه ﺑﺮداري ﻣﮕﻨﺘﻮﺗﻠﻮرﻳﻚ ﻫﺎي(MT) در ﺳﺎل2004 اﺳﺖ ﮔﺮﻓﺘﻪ ﺻﻮرت. ﻣﻲ آﺷﻜﺎر را ﻣﻨﻄﻘﻪ اﻳﻦ اﺻﻠﻲ رﺳﺎﻧﺎي ﺳﺎﺧﺘﺎرﻫﺎي ﺑﺮرﺳﻲ، اﻳﻦ ﻛﻨﺪ. ﻃﺒﻴﻌﻲ ﻣﻴﺪان روشMT ﺑﻠﻨﺪ دورة ﺑﺎ روش اﺳﺖ ﺷﺪه ﺷﻨﺎﺧﺘﻪ زﻳﺮﺳﻄﺢ درآوردن ﻧﻘﺸﻪ ﺑﻪ در ﻣﻔﻴﺪي ﺑﺴﻴﺎر. ﺑﻪ ﻣﺪل ﻣﻨﻈﻮر داده ﭘﺮدازش و ﺳﺎزي ﻫﺎيMT وارون ﺑﺮﻧﺎﻣﻪ از ﺳﺎزي داده ﻣﺪﻫﺎي ﻫﻤﻪ ﻣﻤﻜﻦ ﺗﻔﺴﻴﺮ ﺑﻬﺘﺮﻳﻦ داﺷﺘﻦ ﺑﺮاي و اﺳﺘﻔﺎدهﻌﺪي دوﺑ اﺳﺖ ﺷﺪه اﻣﺘﺤﺎن ﻫﺎ. داده از ﻛﻪ وﻳﮋه ﻣﻘﺎوﻣﺖ ﻣﻘﻄﻊ ﻫﺎيMT ﺑﻪ زﻣﻴ ﻣﺪل ﺑﺎ آﻣﺪه دﺳﺖ ﻦ ﻋﻤﻖ ﺗﺎ ﺗﺮاواﻟﻪ ﻧﺎﺣﻴﻪ ﺷﻨﺎﺳﻲ5 اﺳﺖ ﺳﺎزﮔﺎر ﻛﻴﻠﻮﻣﺘﺮ. ﺣﺎﺻﻞ ﻧﺘﺎﻳﺞ ﻣﺨﺰن وﺟﻮد ﺗﺤﻘﻴﻖ، اﻳﻦ از زﻣﻴﻦ ﮔﺮﻣﺎﻳﻲ ﻣﻲ آﺷﻜﺎر ﻧﺎﺣﻴﻪ اﻳﻦ در را ﻋﻤﻴﻘﻲ ﻛﻨﺪ. زون ﺗﺸﺨﻴﺺ ﺳﻨﮓ در رﺳﺎﻧﺎ ﻫﺎي در ﻣﻘﺎوم ﺑﺴﺘﺮ ﺳﺎﻳﺖ از ﺑﺴﻴﺎري ﻣﻲ وﺿﻮح ﺑﻪ ﻫﺎ ﺷﺎره ﺟﺮﻳﺎن درﺣﻜﻢ ﺗﻮاﻧﺪ ﮔﺴﻞ در ﻫﺎ ﺷﻜﺎف و درز و ﻫﺎ ﻫﺎي ﺳﻨﮓ ﺷﻮد ﺗﻔﺴﻴﺮ دﮔﺮﮔﻮﻧﻲ ﻫﺎي. واژه ﻛﻠﻴﺪي ﻫﺎي: ﻣﻴﺪان زﻣﻴﻦ ﮔﺮﻣﺎﻳﻲ وارون ﺗﺮاواﻟﻪ، ﻣﮕﻨﺘﻮﺗﻠﻮرﻳﻚ،، وﻳﮋه ﻣﻘﺎوﻣﺖﻌﺪي، دوﺑ ﺳﺎزي 1 INTRODUCTION Geothermal resources are ideal targets for electromagnetic (EM) methods since they produce strong variations in underground electrical resistivity. In thermal areas, the * Corresponding author: Tel: 021-61118238 Fax: 021-88009560 E-mail: boskooi@ut.ac.ir