T77 Best Practices and Exciting Discoveries in Identifying, Mapping, and Analyzing Planetary Landforms and Terrestrial Analogues

Monday, 11 October 2021
8:00 AM - 12:00 PM
D139/D140

VENT DEVELOPMENT AT THE HOLUHRAUN LAVA FLOW (NORTHERN ICELAND) AND SMALL MARTIAN VOLCANOES

Paper number: T77-2
Program: Technical Sessions
Time: 8:05 AM – 8:25 AM

Authors

Abstract

Elongate volcanic vents are a common feature in volcanic fields on the Moon, Mars, and Earth and are generally the source for basaltic lava flows. On Mars, hundreds of these elongate fissure vents have constructed the current landscape within the Tharsis Volcanic Province. The fissure vent system of the 2014-2015 Holuhraun lava flow in central Iceland has an analogous morphology to the fissure vents in Tharsis. In addition to a large lava flow field, the main phase of this eruption constructed several pyroclastic cones, the largest of which is Baugur, a 500-m long, 50-m deep spatter rampart. The exterior of Baugur exhibits multiple lava channels that fed the Holuhraun lava flow, and its main flanks are built by basalt pyroclasts that are variably welded. The interior of Baugur hosts cliff faces that expose welded spatter and sub-horizontal ledges made of basalt lava.

We produced topographic models at <1 - 20 cm ground sample distance (GSD) and orthoimages at 2.5–4 cm/px from our terrestrial lidar and uncrewed aerial system (UAS) stereophotogrammetric surveys conducted by our team during field expeditions to Holuhraun from 2015–2019. We have generated high resolution (1–6 m GSD) topographic models of vents in Tharsis to enable geomorphological comparisons to Baugur, and to enable applications of terrestrial vent construction models.

Martian fissure vents bear many similarities to the Baugur vent. The presence of small channels at volcanic vents in Tharsis is similar to the early period of construction at Baugur when isolated fire fountains along the fissure each produced channels. The presence of a main channel and buried channels suggests a sustained eruption, evolving over weeks or more. Morphologic differences between Baugur and martian vents may indicate different eruption dynamics on Mars. The ratio of the thickness of raised rims to the vent widths in Tharsis is much lower than that observed at Baugur, indicating that lava fountaining may not be contributing as much to vent construction as is observed in terrestrial fissure eruptions.

Geological Society of America Abstracts with Programs. Vol. 53, No. 6

doi: 10.1130/abs/2021AM-370494

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