| Abstract: | Geologic mapping of the Kuiper quadrangle of Mercury and other geologic studies of the planet indicate that secondary craters are much better preserved than those on the moon around primary craters of similar size and morphology. Among the oldest recognized secondary craters on the moon associated with craters 100 km across or less are those of Posidonius, Atlas and Plato; these craters have been dated as middle to late Imbrian in age. Many craters on Mercury with dimensions, morphologies and superposed crater densities similar to these lunar craters have fields and clusters of fresher appearing secondary craters. The apparent differences between secondary-crater morphology and parent crater may be due in part to: (1) rapid isostatic adjustment of the parent crater; (2) different impact fluxes between the two planets; and (or) (3) to the greater concentration of Mercurian secondaries around impact areas, thereby accentuating crater forms. Another factor which may contribute to the better state of preservation of Mercurian secondaries relative to the moon is the difference in crater ejecta velocities on both bodies. These velocities have been calculated for fields of secondary craters at about equal ranges from lunar and Mercurian parent craters. Results show that ejection velocities of material producing most of the secondary craters are rather low (<1 km/s) but velocities on Mercury are about 50% greater than those on the moon for equivalent ranges. Higher velocities may produce morphologically enhanced secondary craters which may account for their better preservation with time. ?? 1977. |
| Genre: | Article |
| ProdID: | 70010404 |
| Citation Author: | Scott, D. H. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 178 |
| Citation Issue: | 2-3 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Physics of the Earth and Planetary Interiors |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 6 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | Elsevier |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Moon-Mercury: Relative preservation states of secondary craters; 1977; Article; Journal; Physics of the Earth and Planetary Interiors; Scott, D. H. |
| Citation Start Page: | 173 |
| Citation Volume: | 15 |
| Citation Year: | 1977 |
| Type: | citation/reference |
| Text: | Moon-Mercury: Relative preservation states of secondary craters; 1977; Article; Journal; Physics of the Earth and Planetary Interiors; Scott, D. H. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1016/0031-9201(77)90029-2 |
| Date Other: | Sat, 1 Jan 1977 00:00 -0600 |
| Publisher: | Elsevier |
