Deep electrical resistivity tomography and geothermal analysis of Bradano foredeep deposits in Venosa area (Southern Italy): preliminary results
Deep electrical resistivity tomography and geothermal analysis of Bradano foredeep deposits in Venosa area (Southern Italy): preliminary results
复制标题
维诺萨地区（意大利南部）布拉达诺前深矿床的深电阻率层析成像和地热分析：初步结果
DOI：
10.4401/ag-3045
复制
发表时间：
2008
影响因子：
1
通讯作者：
A. Siniscalchi
中科院分区：
文献类型：
--
作者：
G. Tamburriello;M. Balasco;E. Rizzo;P. Harabaglia;V. Lapenna;A. Siniscalchi
进行了地球物理调查，以确定地层和构造环境的特征，并更好地了解位于阿彭尼尼俯冲南部前部的维诺萨地区(意大利南部)的深水循环系统。在这一地区有一些深水井，测得水的电导率约为3ms/cm，温度约为35℃。用偶极-偶极阵列进行了10000米的深部地电层析成像，探测深度约为900m，并用六个台站组成的宽带大地电磁剖面，推断了深达数千米的电阻率分布。大地电磁剖面与地电等值线基本吻合。所采用的方法使我们能够对数据进行相互控制和综合解释。数据的高分辨率是重建埋深约600m的碳酸盐岩地垒构造资产的关键。来自数据井、地热分析和地球物理数据的最终结果突出了一个饱含咸水的地垒和60°C/公里的异常局部梯度。提出的机制是化石和淡水循环系统的混合机制。
Geophysical surveys have been carried out to characterize the stratigraphical and structural setting and to better understand the deep water circulation system in the Venosa area (Southern Italy) located in the frontal portion of the southern Appenninic Subduction. In this area there are some deep water wells from which a water con- ductivity of about 3 mS/cm and a temperature of about 35°C was measured. A deep geoelectrical tomography with dipole-dipole array has been carried out along a profile of 10000 m and an investigation depth of about 900 m. Furthermore a broad band magnetotelluric profile consisting of six stations was performed to infer the resis- tivity distribution up to some kilometres of depth. The MT profile was almost coincident with the geoelectrical outline. The applied methods allow us to obtain a mutual control and integrated interpretation of the data. The high resolution of the data was the key to reconstruct the structural asset of buried carbonatic horst whose top is located at about 600 m depth. The final results coming from data wells, geothermal analysis and geophysical da- ta, highlighted a horst saturated with salted water and an anomalous local gradient of 60°C/km. The proposed mechanism is that of a mixing of fossil and fresh water circulation system.