ABSTRACT

We present the geological-structural map of the Tuscan Nappe exposed on the eastern border of the Apuan Alps metamorphic dome (Tuscany, Italy). The 1:6,500 scaled Main Map covers an area of about 10 km². It contains the first detailed overview of the fault tectonics affecting the Tuscan Nappe during the exhumation and uplift of the Tuscan Metamorphic Units. We documented a polyphase fault tectonics that initially produced low-angle extensional faults and later high-angle faults. The latter started within a transtensional tectonic regime that produced left-lateral strike-slip faults. Lately a pure extensional tensor, indicating a switch of the maximum compression σ1 axis from sub-horizontal to sub-vertical, produced faults with a dominant dip-slip component. In our reconstruction the lateral thickness variations documented in several formations of the Tuscan Nappe is mainly controlled by tectonics and not by stratigraphy, as previously suggested.

摘要

我们介绍了在阿普安阿尔卑斯山变质穹顶（意大利托斯卡纳）东部边界上露出的托斯卡纳纳皮的地质构造图。1：6,500比例缩放的主地图覆盖约10 km ²的面积。它包含了在托斯卡纳变质单元的发掘和抬升过程中影响托斯卡纳纳普的断裂构造的第一份详细概述。我们记录了一个多相断层构造，它最初产生了低角度伸展性断层，后来又产生了高角度断层。后者始于产生左走向走滑断层的张性构造体系。最近，一个纯张量张量指示最大压缩σ1轴从水平方向转换为垂直方向，产生了具有主要倾滑分量的断层。在我们的重建中，托斯卡纳纳皮的几种形式所记录的横向厚度变化主要是由构造学控制的，而不是如先前所建议的地层学控制的。