DETECTION OF ANISTOPHY IN THE SPATIAL DISTRIBUTION OF TERRESTRIAL VOLCANIC FIELDS: EVIDENCE OF TECTONIC CONTROL

Tectonic setting is known to play a critical role in the emplacement of basaltic volcanic fields. Studies of the spatial pattern of vent distributions have revealed that vent alignments are ubiquitous, including local clustering of a few vents or cinder cones on short spatial scales (less than a few km) as well as alignments on larger, more regional scales (more than tens of km). We have previously investigated the spatial pattern of volcanic constructs in shield fields on Venus [Thomson and Lang, 2016; Nypaver et al., in review]. Here, we apply these methods to some terrestrial basaltic fields to test for correlations between the spatial distribution of edifices and local tectonic structures, including faults and fractures. Examined fields include the Lunar Crater volcanic field in Nevada and the Springerville volcanic field in Arizona.

Our hope is that examining fields for which we have better temporal constraints on Earth will enable us to make more informed interpretations of the relative timing of emplacement of shield fields on Venus.

References:

Thomson, B. J., and N. P. Lang (2016), Volcanic edifice alignment detection software in MATLAB: Test data and preliminary results for shield fields on Venus, Computers & Geosciences, 93, 1-11, doi:10.1016/j.cageo.2016.04.012.

Nypaver, C., N. P. Lang, and B. J. Thomson (2017 submitted), Constraints on geologic processes recorded in venusian shield fields: Implications for field formation and evolution, GSA Special Paper.