A Pyroclastic Flow Deposit on Venus
File(s)
Author(s)
Ghail, RC
Wilson, L
Type
Journal Article
Abstract
Explosive volcanism on Venus is severely inhibited by its high atmospheric pressure and lack of water. This paper shows that a deposit located near 16°S, 144°E, here referred to as Scathach Fluctus, displays a number of morphological characteristics consistent with a pyroclastic flow deposit. These characteristics, particularly its lack of channelisation and evidence for momentum rather than cooling limited flow length, contrast with fissure-fed lava flow deposits. The total erupted volume is estimated to have been between 225 km³ and 875 km³ but this may have been emplaced in more than one event. Interaction between Scathach Fluctus and a small volcanic cone constrain the flow velocity to 48 m s⁻¹ and plausible volatile concentrations to at least 1·8 wt% H₂O, 4·3 wt% CO₂ or 6·1 wt% SO₂, the latter two implying magma sourced directly from the mantle. The deposit has radar characteristics, particularly an exponential backscatter function, that are similar to those of nearly half the planetary surface, implying that pyroclastic deposits may be much more common on Venus than has been recognised to date, and suggesting both a relatively volatile-rich mantle and a volcanic source for atmospheric SO₂.
Editor(s)
Platz, T
Massironi, M
Byrne, PK
Hiesinger, H
Date Issued
2013-11-19
Citation
Special Publications (Geological Society London), 2013, 401
Journal / Book Title
Special Publications (Geological Society London)
Volume
401
Copyright Statement
Special Publication - Geological Society of London, vol. 401, 2013. http://sp.lyellcollection.org/content/early/2013/11/18/SP401.1 © Geological Society of London 2013
Publication Status
Published