Exploring the relative contribution of mineralogy and CPO to the seismic velocity anisotropy of evaporites

Liliana Vargas Meleza, David Healy, G Ian Alsop, Nicholas E Timms

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


We present the influence of mineralogy and microstructure on the seismic velocity anisotropy of evaporites. Bulk elastic properties and seismic velocities are calculated for a suite of 20 natural evaporite samples, which consist mainly of halite, anhydrite, and gypsum. They exhibit strong fabrics as a result of tectonic and diagenetic processes. Sample mineralogy and crystallographic preferred orientation (CPO) were obtained with the electron backscatter diffraction (EBSD) technique and the data used for seismic velocity calculations. Bulk seismic properties for polymineralic evaporites were evaluated with a rock recipe approach. Ultrasonic velocity measurements were also taken on cube shaped samples to assess the contribution of grain-scale shape preferred orientation (SPO) to the total seismic anisotropy. The sample results suggest that CPO is responsible for a significant fraction of the bulk seismic properties, in agreement with observations from previous studies. Results from the rock recipe indicate that increasing modal proportion of anhydrite grains can lead to a greater seismic anisotropy of a halite-dominated rock. Conversely, it can lead to a smaller seismic anisotropy degree of a gypsum-dominated rock until an estimated threshold proportion after which anisotropy increases again. The difference between the predicted anisotropy due to CPO and the anisotropy measured with ultrasonic velocities is attributed to the SPO and grain boundary effects in these evaporites.
Original languageEnglish
Pages (from-to)39-55
Number of pages17
JournalJournal of Structural Geology
Early online date18 Nov 2014
Publication statusPublished - Jan 2015

Bibliographical note

We thank Stewart Mac Swain from the Canadian Salt Co. Ltd., Pugwash Mine, for access to the underground workings and facilitate the collection of samples. This study was funded by the National Council for Science and Technology of Mexico (CONACYT) and the Mexican Petroleum Institute (IMP).


  • elastic properties
  • seismic velocity anisotropy
  • CPO
  • fabric
  • evaporite


Dive into the research topics of 'Exploring the relative contribution of mineralogy and CPO to the seismic velocity anisotropy of evaporites'. Together they form a unique fingerprint.

Cite this