Kilometers away some of these secondary impacts are

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kilometers away. Some of these secondary impacts are quite significant in their own right.The origin of rings is somewhat contested. The excavation models suggest the basins are shallowexcavations and the rings are features left behind. There is a model that suggests rings are createdseismically like a “tsunami.” As energy from the impact races outwards it lifts and displacesmaterial in a very familiar wave-like pattern which then settles or cools in the ring shape. Thismodel shows the outer ring as being the limit of excavation and the inner rings as shockwaveartifacts. The begin as central rebound peaks that spread outward concentrically. Another model,the floor uplift model, suggests upheaval of material essentially as a rebounding of impact energyfrom below.The material distribution in and around impact basins are direct artifacts of the impact formation.Primary ejecta fields, secondary ejecta, and impact melts all result from these catastrophicimpacts. Primary ejecta settles first along a lower trajectory. Secondary ejecta results from theinitial formation of rings as they radiate outward with high energy. This ejecta has a highertrajectory and secondary impact signature. When the event winds down, impact melts settle intothe lower terrain left behind in the excavations.

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Term
Spring
Professor
N/A
Tags
Impact crater, Orientale basin, Montes Rook Formation

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