This work analyzes geomorphological devolatilization features on the atmosphereless asteroid Vesta. In particular, it predominantly analyzes the features associated with the crater Marcia, as those add up to more than 96% on the whole body and are the only ones occurring within the ejecta of a crater. These features are called Pitted Impact Deposits, or short PIDs, and they have been previously identified on Mars, Vesta and the dwarf planet Ceres. PIDs are characterized by closely spaced pits

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... at occur as locally confined clusters of several kilometers length. The individual pits can overlap and often share boundaries. They lack raised rims as would be typical of an impact crater and are polygonal to circular in shape. Furthermore, they show distinct spectral characteristics like higher reflectance at 750 nm and more intense pyroxene absorptions near 0.9 and 1.9 µm. It is evident through previous studies that PIDs formed via degassing or devolatilization of parts of the ejecta, yet the detailed mechanism behind remained debated. Additionally to the previously known dominance of pyroxene-rich HED-like material on Vesta (HED: howardite, eucrite, diogenite meteorites), many studies have reported on the existence of OH-bearing material and the so-called 'dark material' which has been proposed to originate from influx of carbonaceous chondrite material. The identified OH is likely bound within the crystal structure of phyllosilicates (that are commonly found in carbonaceous chondrites) and is able to leave the crystal structure when heated. All remote observations shown here were obtained by NASA's Dawn mission. The presented analysis show that the formation of PIDs is controlled by the proportion of an ejecta deposit's volume to surface area, or depth. Many PIDs are located in small craters or at steep topographic slopes that existed prior to the Marcia impact or to the time of PID formation. This enables the estimation of the pre-existing topography and therefore of the shape and extent of the post-impact ejecta de [...]