Small Martian Shield Volcanoes and Terrestrial

Introduction: A number of terrestrial analog studies have focused on characterizing individual lava flows [e.g., 3, 6-7]. Morphometric and compositional information from these features can be used to infer the rheological properties of similar lava flows, the timing and duration of the eruptions episodes, the depth of the magma chambers [2, 12-14], and even the eruptive and emplacement history of the larger shield volcanoes found on Mars [e.g. 8]. Another common volcanic feature are small shield volcanoes, which are small constructional feature formed by the eruption of lava flows from a central vent [9]. Small shield volcanoes have been found on Mars [1-2], Ve-nus [3], the Moon [4], and possibly even Titan [5]. They represent important stages in the volcanic evolution of a planet's surface and can also provide clues regarding the composition and rheology of the magma, timing and duration of volcanism, and potentially the lithosphere conditions. Small shield volcanoes have been described as a relatively late volcanic feature formed during the waning stages of plains-style volcanism [e.g. 10]. On Mars, this type of vol-canism may result from a magmatic occurrence that occurs near larger plumes [1, 10]. Currently we are collecting field observations, Global Positioning System (GPS) measurements, and remote sensing data of small, parasitic shield volcanoes and their related lava flows located on the flanks of Kilauea Volcano, Hawaii, and on the rift zones on Iceland. These features provide us with the opportunity to characterize the textural and morphologic variability of flow field surfaces and provide a means to generate surface unit maps that represent local flow emplacement processes and constrain flow field development. Our analyses suggest that an understanding of the lithospheric characteristics and temperature fields in volcanic regions dominated by shield volcanoes is crucial to correctly interpret the development of these regions. Small Shield Volcanoes On Mars: Small shield volcanoes are found in a variety of places on Mars. Syria Planum shield volcanoes represent a late-stage volcanic episode that began with the formation of long lava flows [2]. This complex and multi-staged volcanic system is probably related to the formation of the main Tharsis volcanic province, which is generally younger than Syria Planum [e.g.11]. On Syria Planum, the volcanic eruptions may have ceased in the early Hesperian [2]. The formation of small shield volcanoes continued in the Tharsis region as these