US-Colombia Cooperative Research: Geological Evolution of the Amaga Basin, Cauca Valley Colombian Andes

纽约州立大学宾汉普顿分校的William MacDonald博士和哥伦比亚安提奥基亚埃菲特大学的Gloria Maria Sierra博士开展的这一美国-哥伦比亚合作研究项目计划调查位于北安第斯山脉安第斯地块北端的早新生代阿玛加盆地的演化，重点是始新世阿玛加建造的磁性特征及其在解释沉积和构造过程中的应用。其目的是加强地层对比，破译沉积物流向，并解释这些碎屑大陆沉积的磁性成分来源。特别是将从盆地周围几个剖面的样品中进行磁极地层学、磁各向异性磁化率变化和重矿物分析。这些数据将与其他专家的数据结合起来，以解释阿马加盆地的沉积事件，这将为了解毗邻的中西部科迪莱拉盆地两侧的构造事件提供见解。它们还将有助于破译沿盆地边缘的边界断层的运动。这项研究的一个实际方面涉及煤矿床和相关的煤层气的分布：对地层学的更好了解将有助于估计资源以及勘探和回收这些资源，这些资源对当地经济很重要。

0003708MacDonaldThis US-Colombia collaborative research project between Dr. William MacDonald, SUNY, Binghampton and Dr. Gloria Maria Sierra, Eafit University, Antioquia, Colombia, proposes to investigate the evolution of the early Cenozoic Amaga Basin at the north end of the Interandean Graben of the northern Andes, with emphasis on magnetic characteristics of the Eocene Amaga formation and their uses in interpreting sedimentary and tectonic processes. The objectives are to improve stratigraphic correlation, to decipher sediment flow directions, and to interpret sources of magnetic components of these clastic continental sediments.In particular, magnetic polarity stratigraphy, variation of magnetic anisotropic susceptibility, and analysis of heavy minerals, will be undertaken from samples from several sections around the basin. These data will be integrated with those from other specialists to interpret sedimentary events in the Amaga Basin that will provide insights into tectonic events in the adjacent Central and Western Cordilleras bounding the basin on either side. They will also be helpful in deciphering movements along the bounding faults along the basin margins. A practical aspect of the study involves the distribution of coal deposits and associated coal-gas: an improved knowledge of the stratigraphy will help in estimating resources and in exploration and recovery of these resources which are important to the local economy.