Sandstone sample analysis and additional structural data from Jabal Rayah, a possible impact structure in Saudi Arabia

Autor: Mohammed A. Halawani, Beda A. Hofmann, Ayman Mahjub, Abdulaziz A. Al-Solami, Edwin Gnos, Siddiq N. Habibullah, Albert Matter, Khalid Al-Wagdani
Rok vydání: 2018
Předmět:
Zdroj: Meteoritics & Planetary Science. 53:2652-2660
ISSN: 1086-9379
Popis: The ~ 5.5 km sized Jabal Rayah ring structure located at 28° 390 N/37° 120 E in Saudi-Arabia has been classified as a possible complex impact structure located in flat-lying-Paleozoic clastic sediments. Previous, detailed mapping showed that erosional processes led-to a relief inversion, with displaced, folded, and faulted blocks of Silurian to Early-Devonian strata, interpreted to form a ring syncline, now forming a topographically-outstanding, 150 m high ring crest. The drainage toward the center of the structure seems-controlled by a set of radial faults. This central part is eroded to the level of the-surrounding plateau and partially covered with gravel. Analysis of 28 Qusaiba Formation-sandstones showed that at the present outcrop level, the sediments seem devoid of shock-features. Measurement of fold axes in the central part of the structure shows radially-outward plunging fold axes, becoming steeper toward the center, and also fold axes of other-orientation, and folded folds. This fold axis pattern is interpreted as an upward-pointing,-kilometer-sized sheath fold. Assuming an impact scenario and using the present size of the-structure, the minimum central structural uplift is estimated at ~ 500 m, which is consistent-with Qusaiba Formation occupying the center of the ring structure.
Databáze: OpenAIRE
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