Tectonic Evolution of the Chortis Block: Implications for Caribbean Tectonics

Chortis地块(洪都拉斯、萨尔瓦多和周边地区)是加勒比板块西北端的一个微大陆地块，可能是在开曼海槽新生代开放期间从墨西哥南部向东输送的。然而，人们对这个地块的构造历史知之甚少。该项目将收集新生代断裂的运动学数据，以帮助确定滑动方向，推断应力状态和估计位移，以查看块内是否吸收了显著的开曼海槽偏移量。为了对构造历史进行年龄限制，将对花岗岩类和火山岩进行U-Pb、40Ar/39Ar和裂变径迹年龄的测定。这些数据将验证Chortis地块起源于墨西哥被截断的南缘的假设，并总体上提高对微大陆地块沿大偏置转换断层的运输的理解。

The Chortis block (Honduras, El Salvador and environs) is a microcontinental block at the northwestern end of the Caribbean plate which may have been transported east from southern Mexico during the Cenozoic opening of the Cayman Trough. However little is known about the tectonic history of this block. This project will gather kinematic data on Cenozoic faulting to help determine slip directions and to infer stress regime and estimate displacements to see if significant Cayman Trough offset is absorbed within the block. In an effort to place age constraints on the tectonic history, U-Pb, 40Ar/39Ar and fission track ages on granitoids and volcanic rocks will be carried out. These data will allow testing of the hypothesis that the Chortis block originated from the truncated southern margin of Mexico, and generally improve the understanding of the transport of microcontinental blocks along a large offset transform fault.