 Uzboi Vallis based onTHEMIS day-time image | |
| Coordinates | 29°48′S37°06′W / 29.8°S 37.1°W /-29.8; -37.1 |
|---|---|
| Length | 366.0 |
| Naming | Dry riverbed in Turkmenistan. |
Uzboi Vallis is avalley lying situated within theMargaritifer Sinus quadrangle (MC-19) region onMars. It is named after theUzboy dry channel,[1] now inTurkmenistan, which repeatedly served as the main channel of theAmu Darya river. Thevalley begins on the northern rim of theArgyre basin, and cuts through severalcraters, before ending atHolden crater.
Uzboi Vallis is believed to have been formed by running water. It is believed that layers were formed on the floor of Uzboi Vallis (as shown in theHiRISE image below) when drainage was blocked by the impact that formedHolden Crater to the north. Eventually the lake in the area of Uzboi Vallis went high enough to overtop the rim of Holden.[2] The water then eroded the deposits to expose the layers as they are today. The sediments that make up the layers appear to be coarse in size, suggesting they were probably formed by a rapid flow.[3][4][5][6] The more narrow and sinuousNirgal Vallis ends at Uzboi Vallis and emptied into it.
It has been suggested that Uzboi,Ladon, Margaritifer andAres Valles, although now separated by large craters, once comprised a singleoutflow channel flowing north intoChryse Planitia.[7][8] The source of this outflow has been suggested as overflow from theArgyre crater, formerly filled to the brim as alake by channels (Surius, Dzigai, and Palacopus Valles) draining down from the south pole. If real, the full length of this drainage system would be over 8000 km, the longest known drainage path in the Solar System. This system has been called theUzboi-Landon-Morava (ULM) system.
