206 Strain and Displacement: Patterns, Gradients, Partitioning, and Reconstructions

This session aims to bring together researchers from structure-related disciplines to facilitate discussions of approaches that inform our understanding of strain and displacement. We welcome contributions from observations, experiments, theory, and modeling that characterize deformation from micro to tectonic scales.

Tuesday, 21 October 2025
1:30 PM - 5:30 PM
HBGCC, 217C

The SANGRE TAPHROGENY: Neogene/Quaternary Stress Distribution and Kinematics of the Clockwise Rotation of the Colorado Plateau Microplate

Paper number: 206-6
Program: Technical Sessions
Time: 3:10 PM – 3:25 PM

Authors

Abstract

The Sangre Taphrogeny is a unifying kinematic model that links the late Cenozoic (Neogene and Quaternary) mountain building, rifting, magmatism, regional elevation, sedimentation, and incision surrounding a roughly circular, lithospheric microplate. The taphrogen is characterized as a rift-chain feature (g3/k22/d1 in Sëngor and Natalin’s classification), composed of ten linear rift segments along with their associated damage zones.  The linked tectonic elements are approximately 2300 km long and average about 150 km in width. They surround and define a Colorado Plateau Microplate (CPM) that is larger than the physiographic province. Clockwise-rotation of the microplate creates rifting of the craton on the east and north. Regional elevation is caused by mantle buoyancy in response to extension and thinning of the lithosphere, as seen at oceanic spreading centers and the East African Rift. The late Cenozoic taphrogen is coeval with, and kinematically related to, the regional extension caused by changing plate interactions along the west coast. This extensional tectonic belt is superimposed on a regional erosion surface that greatly subdued the topography of the Late Cretaceous/Early Paleogene structures of the Laramide orogeny.

A variety of 21st century databases provide documentation of the Neogene/Quaternary taphrogen. Distribution and orientation of stress (SHmax) and strain (faults and dikes) within the 150-km-wide taphrogen are parallel to the principal rift segments. Kilometer-scale displacement of Neogene/Quaternary fault blocks is supported by thermochronological transects and creates ultra-high topography (more than 900 peaks >3962 meters AMSL).  GPS vectors are normal to the rift segments and indicate that the taphrogeny is ongoing at present.  Most of the taphrogen correlates with high crustal attenuation (Q0) and high heat flow (mW/m2).

Igneous activity with mantle signatures is widespread throughout the taphrogen. Multiple grabens contain thick syntectonic strata. Rivers emanating from mountains formed by the taphrogeny have deeply incised the CPM and Great Plains as well as transported substantial volumes of sediment to both the Gulf Coast and the Gulf of California.

Three types of physical modeling in the laboratory help in understanding the distribution of stress and strain that is observed within the taphrogen.  The Sangre Taphrogen model is a synthesis of old ideas and 21st century datasets and tools.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6

doi: 10.1130/abs/2025AM-412922

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