A GEOLOGIC ANALYSIS OF THE ARISTARCHUS PLATEAU REGION ON THE MOON

In spite of recently acquired lunar data sets (such as Clementine and Lunar Prospector), there has not been a systematic global geologic investigation of the lunar surface since the Apollo era. A new lunar geologic mapping program, funded through NASA Planetary Geology and Geophysics and supported through the USGS Astrogeology Science Center, provides a mechanism through which planetary scientists can generate new geologic maps of the lunar surface that incorporate all currently available data. As part of this program, we are mapping a roughly 10° by 10° region centered at 25°N, 30°E, that includes Aristarchus plateau, an ~ 34,000 km² elevated block with volcanic and possibly crustal components. The area including and surrounding Aristarchus plateau is one of the most geologically diverse regions on the Moon. Surface features include primary and secondary impact craters; the highest concentration of sinuous rilles on the Moon (probably lava channels and/or collapsed lava tubes); volcanic depressions and domes; lava flows, including a candidate for the youngest lunar flow; and a blanket of dark mantling material believed to be composed of pyroclastic deposits. The purpose of this map is to facilitate the assessment of timing and emplacement mechanisms for these distinct volcanic products.

We are currently in the process of generating the regional map of Aristarchus plateau. Using ArcGIS, we began with a map template and geodatabase provided by the USGS. We are customizing this template for Aristarchus plateau by adding new features and datasets as necessary. Mapping and interpretation techniques focus on stratigraphic and cross-cutting relationships between observed volcanic features with the goal of inferring subsurface changes in magma properties and behaviors from observed morphology and composition. These interpretations of the local volcanic evolution near Aristarchus plateau have implications for the history of near-side lunar volcanism.