Published In

Geophysical Research Letters

Document Type

Article

Publication Date

2-19-1993

Subjects

Volcanology -- Research, Lava flows, Geologic formations, Venus (Planet) -- Geology

Abstract

The main evidence available for constraining the composition of the large circular "pancake" domes on Venus is their gross morphology. Laboratory simulations using polyethylene glycol show that the height to diameter (aspect) ratios of domes given total volume depend critically on whether their extrusion was continuous or episodic, with more episodes leading to greater cooling and taller domes. Thus without observations of their emplacement, the compositions of venusian domes cannot be uniquely constrained by their morphology. However, by considering a population of 51 venusian domes to sent a sampling of many stages during the growth of domes with comparable histories, and by plotting aspect ratio versus total volume, we find that the shapes of the domes are most consistent with episodic emplacement. On Earth this mode of me growth is found almost exclusively in lavas of dacite to rhlyolite composition, strengthening earlier inferences about the presence of evolved magmas on Venus.

Description

This is the publisher's final PDF. Originally published in Geophysical Research Letters (http://agupubs.onlinelibrary.wiley.com/agu/journal/10.1002/%28ISSN%291944-8007/).

This work was authored as part of the Contributor's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law

*At the time of publication, Jonathan Fink was affiliated with Arizona State University.

Persistent Identifier

http://archives.pdx.edu/ds/psu/13267

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