Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431662
Title: Corona-related volcanism on Venus
Author: Grindrod, Peter Martin
Awarding Body: UCL (University College London)
Current Institution: University College London (University of London)
Date of Award: 2006
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Please try the link below.
Access from Institution:
Abstract:
This thesis reports the results of a study of volcanic processes at coronae on Venus. The Aglaonice F-Map region has been mapped, and its geological history interpreted, at the full-resolution of Magellan SAR data. Volcanism at coronae is shown to have occurred repeatedly over a protracted period of time, supporting a non-directional style of resurfacing in the F-Map region, and suggesting that corona-related flows may be an important resurfacing mechanism on Venus. It is likely that the magma storage system varies between each corona, with eruption dependent on local conditions such as location of magma body and local stress regime. Numerous flows which can be sourced to coronae, and were previously mapped as plains units, have also been identified. A global survey has revealed 29 volcano/corona 'hybrids', features which resemble both coronae and large volcanoes. Age, magma supply, stress state, thermal gradient and eruption duration are all important factors in determining gross hybrid morphology. It is likely that not all hybrids follow a similar evolutionary path. A detailed study of four selected hybrids is presented and suggests that processes typical of both large volcanoes and coronae have occurred throughout their history, and does not imply evolution from one type of feature into another. The presence of large central depressions and/or topographic rims at the hybrids support the theory that some large volcanoes undergo a sagging process similar to coronae. Study of the depth and extension at large radial graben at four centres of radial fractures is also reported. The inferred levels of hoop strain are too large to be explained by previous models of plume uplift, and a newly applied magma chamber inflation model concludes that dike formation is responsible for the strain at the large radial graben, and that intrusion is an important process at early-phase coronae.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.431662  DOI: Not available
Share: