Layered Blocks on the Moon
Planetary Society Weblog Download time: Mar 29 2011 11:41 AM ET
Some recent high-resolution images from the Lunar Reconnaissance Orbiter Camera (LROC) have revealed large blocks on the lunar surface that show evidence of layers. The layered blocks were seen near the crater Aristarchus, which is a bright crater in the northeast quadrant of the nearside Moon. Aristarchus Crater is surrounded by the dark terrain of Oceanus Procellarum and can be easily identified with binoculars.
Layers are important because they are like pages in a geological story: each layer tells a chapter about how material was deposited on the surface. Put it all together in context and you can surmise the history of how that terrain came to be. Finding layered blocks in the ejecta of a large impact crater tells us that the pre-impact target terrain was layered. In the case of Aristarchus Crater, this layering was probably due to many flows of lava being emplaced one on top of another to make a layer stack of the different flood basalt events.…
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