here for larger NASA image of Figure 185
Click here for larger NASA image of Figure 186
Click here for lunar chart showing location
Schroter's Valley in the Aristarchus plateau is one of the largest lunar sinuous rilles (width in picture is about 5 km). The valley consists of an arcuate rille (1) that contains a meandering sinuous rille (2). The valley here traverses what appears to be a lava plain embaying low hills in the southern part of the picture. The blocky outcrop ledges, probably lava layers, near the rim (3) and the blocks at the inside base of the slopes (4) are of interest as is the downslope movement of material in the walls, which results in partial burial of the inside rille (5) and shows that the valley is laterally enlarged by mass wasting processes.
The sinuous shape, uniform width, presence of low levees, irregular depressions at the head of this and other rilles (outside the picture), and uniform cratering of floor and surrounding terrain suggest that the feature originated as lava flow channels, or collapsed lava tubes (Greeley, 1971). The rilles in the picture probably formed by the draining of a large lava flow channel and a smaller channel in a somewhat later flow that was confined within the boundaries of the larger channel. Incision by thermal erosion of lava streams with turbulent flow is an alternative explanation for the formation of sinuous rilles such as Schroter's Valley (Hulme, 1973).
Other conspicuous features in the pictures are secondary crater clusters
from the young crater Aristarchus (6). The secondary clusters cross the
rille at (7), and show that the crater Aristarchus is younger than the
Report Source: NASA SP-362, Page 180, Figure 186
This web page was created by Francis Ridge
for The Lunascan Project
Section Directory 18