The Tectonic Mechanism for Uplift and Rotation of Crustal Blocks in the Central Basin Platform, Permian Basin, Texas and New Mexico

YANG, KENN-MING, and STEVEN L. DOROBEK, Texas A&M University, College Station, TX

The Central Basin platform is a positive tectonic element in the subsurface of the Permian basin. This enigmatic platform strikes north-northwest-south-southeast and at a high angle to the Marathon fold-and-thrust belt to the south. Although the uplift of the platform was related temporally to major overthrusting in the orogenic belt to the south and east, its formative mechanisms are still poorly understood. The regional structural analysis discussed here is part of a broader study on the structural and stratigraphic history of the Central Basin platform.

Previously compiled tectonic maps and cross sections were analyzed to identify the significant characteristics of this complicated structure. (1) Much of the platform is bounded by laterally discontinuous, high-angle faults with large vertical displacements. (2) The bounding faults suggest that the platform is composed of several discrete blocks that are arranged in a dextral en echelon pattern. (3) The southwest and northeast corners of each block typically are bounded by major faults; block uplift is greatest at the southwest and northeast corners. (4) Blocks are separated by west-northwest-east-southeast-trending transfer zones. These characteristics suggest that the Central Basin platform was subjected to a north-northwest-south-southeast-trending dextral couple that caused the pl tform to split into several blocks. Individual blocks rotated in the same clockwise sense and produced the maximum uplift observed at the southwest and northeast corners of blocks. In addition to the above characteristics, the amount of uplift and the width of individual blocks progressively decrease toward the north; block boundaries also become less defined northward. However, these additional complexities are not fully understood yet.

Individual block movements can explain the structural pattern of the Central Basin platform and probably affected depositional patterns during Permian time. Ongoing regional stratigraphic and structural studies also will elucidate the complicated interactions between the Central Basin platform and the adjacent Midland and Delaware basins.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)