Implications of Very Low Electrical Resistivity In The Deep Crust of An Active Thick-Skinned Tectonics In Argentina

最近在安第斯山脉东部变形锋附近的图库曼进行的一项大地电磁（MT）试验得出结论，下地壳与西藏南部一样具有导电性。 这两个地区的共同点是地壳应变率。 如果人们能证明高电导率是高应变率的必然结果，那么人们就有了探测地壳深部活动变形的有力工具。 研究人员与阿根廷同事合作，建议收集和分析新的大地电磁数据，以（1）确定图库曼导电性很强的下地壳是局部特征还是区域特征。(2)阐明了变形前缘从电阻性地壳向导电性地壳的转变。(3)探讨地幔中存在浅软流圈的可能性。(4)将图库曼与安第斯山脉东部两个明显不同的变形区进行比较：（a）圣胡安，那里的地壳应变率很高，但俯冲板片非常平坦，可能没有软流圈介入;（B）科尔多瓦，平坦板片的最东部，那里的地壳应变很低，但运动学表明应该有软流圈楔。

Booker 9909390 A recent pilot magnetotelluric (MT) experiment near Tucuman across the eastern Andean deformation front concludes that the lower crust is as electrically conductive as under southern Tibet. Common to both areas is the rate of crustal strain. If one can show that high conductivity is an inevitable consequence of high strain rate one would have a powerful tool for probing active deformation of the deep crust. In collaboration with Argentine colleagues, the investigators are proposing to collect and analyze new MT data to (1) Determine whether very conductive lower crust at Tucuman is a local or regional feature. (2) Elucidate the transition from resistive to conductive crust at the deformation front. (3) Investigate the possibility of shallow asthenosphere in the mantle. (4) Compare Tucuman with two distinctly different regions of the eastern Andean deformation: (a) San Juan, where the crustal strain rate is high, but the subducted slab is very flat and there may be no intervening asthenosphere and (b) Cordoba, the most eastern extent of the flat slab, where crustal strain islow, but kinematics suggests there ought to be an asthenospheric wedge.