Figure 90

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This panoramic camera enlargement shows two small (2 km across volcanic cones (A and B) near the southeastern margin of Mare Serenitatis. They are intergradational with the surrounding mare basalt and probably are similar in age (about 3 billion years). The same cones can be seen in their regional context in  Figure 58  (lower right) and  Figure 60  (lower left). One cone (B) has an enclosed summit crater and the other (A) has a breached crater leading to a rillelike valley. Both conditions are common among volcanic cinder cones on Earth. The cones appear to be alined along the buried extension of a straight rille (C), suggesting a relationship between volcanism and tectonism that is common on Earth. In size, appearance, and geologic setting these lunar cones are remarkably similar to terrestrial cinder cones; by analogy they are probably composed of interlayered fragmental material and lava flows. The elongate depressions marked D, as well as the straight and arcuate rilles, are probably of structural origin resulting from faulting and collapse along fractures.   -D.H.S.

Report Source: NASA SP-362, Page 99, Figure 90

This web page was created by Francis Ridge for The Lunascan Project
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