DMD Excavations

A patch of Dark Mantle Deposits at western region of Sinus Aestuum. NAC M1103666930R. Image center is 4.591°N, 344.348°E, image width is 940 meters [NASA/GSFC/Arizona State University].

Dark Mantle Deposits (DMDs) are diffuse deposits with a very low albedo, which are the remnants of pyroclastic eruptions. Sinus Aestuum is a DMD near Copernicus crater. Today's Featured Image is a portion of one of the lowest-reflectance areas in this DMD (see next WAC context image), about 150 km southeast from Copernicus. 

In the opening image, the lowest-reflectance materials are located at the rims and the ejecta of the multiple small craters (< 20 m in diameter), indicating that these dark materials are in the shallow subsurface. On the other hand, the two craters near the middle of this image display relatively high reflectance materials and do not expose any dark deposits from beneath the surface. That means that the lateral extent of these low-reflectance pyroclastic materials is somewhat discontinuous.  Looking at the ejecta blankets of craters within lunar DMDs is one of the best ways to estimate the extent and thickness of lunar pyroclastic deposits.  In the case of regional DMDs like Sinus Aestuum, the pyroclastic glasses that comprise these deposits represent one of the most accessible lunar resources that could be used by future human explorers to enable extended lunar surface operations.

Context view of Sinus Aestuum and surrounding areas in WAC monochrome mosaic. Image center is 4.60°N, 344.38°E. The NAC footprint (blue box) and the location of opening image (yellow arrow) are indicated [NASA/GSFC/Arizona State University]. 

Explore the DMDs at Sinus Aestuum in full NAC frame yourself!

Related posts:

Pyroclastic TrailsPyroclastics and VentHyginus Crater and PyroclasticsPyroclastic ExcavationRima Bode: Constellation region of interest

Published by Hiroyuki Sato on 20 February 2013