T386 Challenges in Tectonics: Beyond Steady State: New Developments in Understanding Strain Localization Processes and the Rheology of the Lithosphere (Posters)

Wednesday, 25 October 2017
9:00 AM - 6:30 PM
Halls 4EF

STATISTICS OF ELLIPSOIDAL DATA FROM RIDGE-TRANSFORM SYSTEMS

Paper number: T386-16
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Abstract

Our understanding of ridge-transform systems, shear zones, and faults is informed by various types of data. Among the richest data types to mine are ellipsoids, such as stress, strain, shape preferred orientation (SPO), and anisotropy of magnetic susceptibility (AMS). However, it is not obvious how one should perform statistical analysis on a given data set of ellipsoids. For example, if the ellipsoids represent a single population, then what is the mean of that population? Or how do the ellipsoids vary over space and by rock type? Geologic studies rarely address such questions statistically, even when the answers may affect their conclusions.

In this presentation we describe a coherent framework for statistics of ellipsoidal data. The theory is based on a natural vector space structure on the set of ellipsoids. Within this vector space, many techniques of multivariate statistics are safely and easily applied: principal component analysis, regression, spatial statistics, inference about the mean, etc. The results can be transferred back to more familiar forms, such as Hsu-Nadai and equal-area plots, for interpretation.

We demonstrate this methodology on AMS, SPO, and X-ray computed tomography data sets from fossil ridge-transform systems preserved in Cyprus and New Caledonia. In the latter setting, we use a non-steady, heterogeneous deformation model to predict the formation of spinel fabrics at the ridge and how they are affected by progressive deformation along the transform.

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-301627

© Copyright 2017 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.