Clast sizes in terrestrial and Martian ignimbrite lag deposits

Wilson, L. and Heslop, Sally (1990) Clast sizes in terrestrial and Martian ignimbrite lag deposits. Journal of Geophysical Research, 95 (B11). pp. 17309-17314. ISSN 0148-0227

Full text not available from this repository.

Abstract

Large-scale pyroclastic flows (ignimbrites) are produced when a dense mixture of volcanic gas and pyroclasts is erupted into an atmosphere and forms a collapsed, fountain-like structure over a vent. A physical model of the resulting fluid flow field can be devised for any planetary environment which allows the pressure and velocity of the "dusty gas' mixture emerging from the vent to be deduced. Calculation of the drag forces exerted by the dusty gas on relatively large clasts allows us to deduce the sizes of the largest clasts of a given density which can just be transported through the vent to contribute to a proximal lag breccia deposit. We find that ignimbrites on Earth are potentially capable of transporting out of the vent significantly larger clasts than those commonly found in lag deposits. Martian ignimbrite lag breccia deposits should contain near-vent clasts at least twice as large as those in terrestrial deposits produced in eruptions with the same volatile contents. Such clasts should be detectable from future Mars orbiting spacecraft. -from Authors

Item Type: Journal Article
Journal or Publication Title: Journal of Geophysical Research
Uncontrolled Keywords: /dk/atira/pure/subjectarea/asjc/1900/1902
Subjects:
Departments: Faculty of Science and Technology > Lancaster Environment Centre
ID Code: 134664
Deposited By: ep_importer_pure
Deposited On: 22 Jun 2019 09:16
Refereed?: Yes
Published?: Published
Last Modified: 22 Jun 2019 09:16
URI: https://eprints.lancs.ac.uk/id/eprint/134664

Actions (login required)

View Item View Item