Extensive volcanic plains units are one of the oldest known and best-documented features of the Martian surface [e.g.,Greeley and Spudis, 1981; Scott and Tanaka, 1986; Greeley and Guest, 1987]. These volcanic units are typically Late Noachian to Hesperian in age, and are thought to have resurfaced at least ∼30% of the Martian surface during this time period [Scott and Tanaka, 1986; Greeley and Guest, 1987; Head et al., 2002]. The emplacement of volcanic plains in the Hesperian directly follows a period earlier in Martian history when fluvial activity was common, recorded by distinct morphologies such as large valley networks and paleolake basins [e.g., Pieri, 1980; Goldspiel and Squyres, 1991; Cabrol and Grin, 1999, 2001; Howard et al., 2005; Irwin et al., 2005; Fassett and Head, 2008a, 2008b]. It is thought that much of the fluvial activity that created such features ended near the Noachian-Hesperian boundary [Irwin et al., 2005; Fassett and Head, 2008b; Hoke and Hynek, 2009; Mangold et al., 2012], and so preserved evidence of interaction between fluvial and volcanic activity at this critical junction in Martian history is an intriguing possibility.
 Paleolake basins provide a topographic depression that lava may have ponded in, and many paleolake basins are contained within ancient impact craters [e.g., Goldspiel and Squyres, 1991; Cabrol and Grin, 1999, 2001; Irwin et al., 2005; Fassett and Head, 2008a; Hauber et al., 2009]. Impact craters can enable surface volcanic eruptions through reductions in the crustal thickness, which may be further aided by deeply fractured zones under impact basins [e.g., Pike, 1971; Schultz, 1976, 1978; Head and Wilson, 1992]. Open-basin lakes, defined as hydrological basins with both an inlet valley and an outlet valley, require that water must have ponded in the basin to at least the topographic level of the outlet valley head before overflowing [e.g.,Cabrol and Grin, 1999; Fassett and Head, 2008a].
 In situ and orbital observations show that volcanic resurfacing has affected many open-basin lakes [Goldspiel and Squyres, 1991; Squyres et al., 2004; Fassett and Head, 2008a; Goudge et al., 2012]. A recent study of the morphology of a catalog of 226 open-basin lakes has shown that a variety of geologic resurfacing and modifying processes have played an important role in the post-lacustrine activity history of open-basin lakes on Mars [Goudge et al., 2012]. From this study, it was shown that the emplacement of volcanic plains units in particular was one of the dominant geologic processes responsible for post-lacustrine activity resurfacing, with 96 of the 226 (∼42%) open-basin lakes examined classified as volcanically resurfaced based on a distinctive morphology of the basin interiors [Goudge et al., 2012]. In this investigation, we present a detailed study of 30 open-basin lakes classified as volcanically resurfaced byGoudge et al. , to further assess their morphology, physical surface properties (e.g., thermal inertia), composition and age of emplacement. The 30 basins chosen for this analysis are broadly geographically distributed across the Martian surface (Figure 1 and Table 1), and have relatively large surface areas, allowing for improved crater counting statistics compared to open-basin lakes with smaller floor areas.
 The major goals in this study are: (1) to document evidence of volcanic resurfacing of these open-basin lakes using multiple remotely sensed data sets, (2) to help further understand the timing and emplacement of the resurfacing units within paleolake basins, and (3) to assess the possibility of lava-water interaction at these sites. These analyses are designed to provide further insight into the history of open-basin lakes on Mars, and help to illuminate aspects of the hydrological cycle during the Noachian and Hesperian periods.