MAPPING OF A VOLCANIC VENT FIELD EAST OF PAVONIS MONS VOLCANO IN THE THARSIS PROVINCE, MARS

The Tharsis Montes are a chain of three large volcanoes (Pavonis, Ascraeus, and Arsia Montes) located in the western hemisphere of Mars in what is known as the Tharsis province. The genetic relationship between neighboring small vent fields and the Tharsis Montes remains unclear, and as such the number, sequence and style of additional magma production events related to these fields are not clearly understood. To address this issue the goal of this project is to characterize small vents east of Pavonis Mons in order to understand the number of vent fields, and postulate how these magma production events contributed to the development of the Tharsis region. Mapping of volcanic vents east of Pavonis Mons reveals a variety of small-vents (tens of km in diameter) that may be genetically similar to those belonging to neighboring vent fields. This study uses image data from the Thermal Emission Imaging System (THEMIS), and Context Camera (CTX), as well as topographic information from the Mars Orbiter Laser Altimeter (MOLA). Small-vents were primarily identified based on the presence of radiating lava flow textures from a common topographically distinguishable point or linear fissure. Often a vent forms a topographic high from the accumulation of lava flows and explosive deposits. As such, a local topographic high and/or collapse features with or without rims at the summit were also used as indicators of volcanic vents. Each vent was assigned a two dimensional data point at the center of the inferred eruptive activity to represent the pathway through the crust that the source magma body traveled. Some vents are located in close proximity to one another and appear to be related to one shallow magma chamber. These vents construct a larger volcanic feature that we define as a vent complex. 61 of the total 109 vents are isolated and the remaining 48 vents form a total of 13 vent complexes. In other words, of the total population of 109 vents, there are 74 individual vents and vent complexes. The total number of vents recorded in this study likely represents a minimum of the entire population of volcanic features that exist in our mapping area.