| 1. |
- Holmqvist, Anders, et al.
(författare)
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The Lycksele ring structure–still no proof of an impact origin
- 2020
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Ingår i: GFF. - : Taylor & Francis. - 1103-5897 .- 2000-0863. ; 142:2, s. 96-99
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Tidskriftsartikel (refereegranskat)abstract
- The origin of the more than 100 km wide Lycksele ring structure in Sweden has puzzled geoscientists for years. In this short note we present results from field analysis, detailed sampling and laboratory analysis executed in search for evidence of an impact, e.g. shatter cones and shock features in minerals. Both approaches gave negative results and consequently an impact origin could neither be confirmed nor rejected. The circular structure of the Lycksele ring and its central uplift are, however, typical features of large, complex impact structures.
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| 2. |
- Paige, David A., et al.
(författare)
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Ground penetrating radar observations of the contact between the western delta and the crater floor of Jezero crater, Mars
- 2024
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Ingår i: Science Advances. - 2375-2548. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- The delta deposits in Jezero crater contain sedimentary records of potentially habitable conditions on Mars. NASA's Perseverance rover is exploring the Jezero western delta with a suite of instruments that include the RIMFAX ground penetrating radar, which provides continuous subsurface images that probe up to 20 meters below the rover. As Perseverance traversed across the contact between the Jezero crater floor and the delta, RIMFAX detected a distinct discontinuity in the subsurface layer structure. Below the contact boundary are older crater floor units exhibiting discontinuous inclined layering. Above the contact boundary are younger basal delta units exhibiting regular horizontal layering. At one location, there is a clear unconformity between the crater floor and delta layers, which implies that the crater floor experienced a period of erosion before the deposition of the overlying delta strata. The regularity and horizontality of the basal delta sediments observed in the radar cross sections indicate that they were deposited in a low-energy lake environment.
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