Morphology, stratigraphy, and surface roughness properties of Venusian lava flow fields

Authors

  • Jeffrey M. Byrnes,

    1. Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
    2. at="now-at">Department of Space Studies, John D. Odegard School of Aerospace, University of North Dakota, Grand Forks, North Dakota, USA.
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  • David A. Crown

    1. Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
    2. Planetary Science Institute, Tucson, Arizona, USA
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Abstract

[1] Morphologic characteristics, flow stratigraphy, and radar backscatter properties of five lava flow fields on Venus (Turgmam Fluctus, Zipaltonal Fluctus, Tuli Mons/Uilata Fluctus, Var Mons, and Mylitta Fluctus) were examined to understand flow field emplacement mechanisms and relationships to other surface processes. These analyses indicate that the flow fields studied developed through emplacement of numerous, thin flow units, presumably over extended periods of time. Although the Venusian fields display flow morphologies similar to those observed within terrestrial flow fields, the Venusian flow units are significantly larger and have a larger range of radar backscatter coefficients. Both simple and compound flow emplacement appear to have occurred within the flow fields. A potential correlation between flow rheology and radar brightness is suggested by differences in planform morphology, apparent flow thickness, and apparent sensitivity to topography between bright and dark flows. Distributary flow morphologies may result from tube-fed flows, and postemplacement modification by processes such as flow inflation and crustal foundering is consistent with discrete zones of increased radar brightness within individual flow lobes. Mapping of these flow fields does not indicate any simple evolutionary trend in eruptive/resurfacing style within the flow fields, or any consistent temporal sequence relative to other tectonic and volcanic features.

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