Academic Journal
Pyroclastic flow deposits on Venus as indicators of renewed magmatic activity
| العنوان: | Pyroclastic flow deposits on Venus as indicators of renewed magmatic activity |
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| المؤلفون: | Campbell, Bruce A., Morgan, Gareth A., Whitten, Jennifer L., Carter, Lynn M., Glaze, Lori S., Campbell, Donald B. |
| Thesis Advisors: | Univ Arizona, Lunar & Planetary Lab, Center for Earth and Planetary Studies; Smithsonian Institution; Washington District of Columbia USA, Lunar and Planetary Laboratory; University of Arizona; Tucson Arizona USA, NASA Goddard Space Flight Center; Greenbelt Maryland USA, Department of Astronomy; Cornell University; Ithaca New York USA |
| بيانات النشر: | AMER GEOPHYSICAL UNION, 2017. |
| سنة النشر: | 2017 |
| المجموعة: | University of Arizona |
| Original Material: | Pyroclastic flow deposits on Venus as indicators of renewed magmatic activity 2017, 122 (7):1580 Journal of Geophysical Research: Planets Journal of Geophysical Research: Planets |
| الوصف: | Radar bright deposits on Venus that have diffuse margins suggest eruptions that distribute debris over large areas due to ground-hugging flows from plume collapse. We examine deposits in eastern Eistla, western Eistla, Phoebe, and Dione Regiones using Magellan data and Earth-based radar maps. The radar bright units have no marginal lobes or other features consistent with viscous flow. Their morphology, radar echo strength, polarization properties, and microwave emissivity are consistent with mantling deposits composed of few centimeters or larger clasts. This debris traveled downhill up to similar to 100km on modest slopes and blanketed lava flows and tectonic features to depths of tens of centimeters to a few meters over areas up to 40x10(3)km(2). There is evidence for ongoing removal and exhumation of previously buried terrain. A newly identified occurrence is associated with a ridge belt south of Ushas Mons. We also note radar bright streaks of coarse material west of Rona Chasma that reflect the last traces of a deposit mobilized by winds from the formation of Mirabeau crater. If the radar bright units originate by the collapse of eruption columns, with coarse fragmental material entrained and fluidized by hot gases, then their extent suggests large erupted volatile (CO2 or H2O) amounts. We propose that these deposits reflect the early stage of renewed magmatic activity, with volatile-rich, disrupted magma escaping through vents in fractured regions of the upper crust. Rapidly eroding under Venus surface conditions or buried by subsequent eruptions, these markers of recently renewed activity have disappeared from older regions. |
| Original Identifier: | oai:arizona.openrepository.com:10150/625517 |
| نوع الوثيقة: | Article |
| اللغة: | English |
| تدمد: | 21699097 |
| DOI: | 10.1002/2017JE005299 |
| الاتاحة: | http://hdl.handle.net/10150/625517 http://arizona.openrepository.com/arizona/handle/10150/625517 |
| Rights: | ©2017. American Geophysical Union. All Rights Reserved. |
| رقم الانضمام: | edsndl.arizona.edu.oai.arizona.openrepository.com.10150.625517 |
| قاعدة البيانات: | Networked Digital Library of Theses & Dissertations |
| تدمد: | 21699097 |
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| DOI: | 10.1002/2017JE005299 |