Athabasca Valles

Athabasca Valles
}
The Athabasca Valles, showing the flow direction of what are interpreted by some researchers to be floodwater-related morphologies. Note streamlined islands which show direction of flow to southwest.
Coordinates8°36′N 205°00′W / 8.6°N 205.0°W / 8.6; -205.0
Length285.0 km (177.1 mi)
NamingRiver in Canada. (Changed from Athabasca Vallis.)

The Athabasca Valles are a late Amazonian-period outflow channel system in the central Elysium Planitia region of Mars, located to the south of the Elysium Rise. They are part of a network of outflow channels in this region that are understood to emanate from large fissures in the Martian surface rather than the chaos terrains that source the circum-Chryse outflow channels.[1] The Athabasca Valles in particular emanate from one of the Cerberus Fossae fissures and flow downstream to the southwest, constrained to the south by a wrinkle ridge for over 100 km, before debouching into the Cerberus Palus volcanic plain.[2] The Athabasca Valles are widely understood to be the youngest outflow channel system on the planet.[3][4][5]

Although researchers generally agree that the valley was formed by the catastrophic outpouring from the southernmost Cerberus Fossae fissure,[6][1] the scientific community has not reached a consensus on the precise formation mechanism behind the Athabasca Valles – both in the nature of the fluids that tracked through the valley, and in terms of later geologic events that have since resurfaced the region. Researchers concurrently propose a floodwater origin (akin to the Missoula Floods that formed the Channeled Scablands of Washington state), a low-viscosity lava origin (similar to the pāhoehoe flows of Hawaiʻi), a glacial origin, or some combination of the aforementioned mechanisms. The presence of pitted mounds on the valley floor has also been subject to debate and underpins the different hypotheses that have been proposed, and have variably been suggested to be pingoes[7] and rootless cones.[8] Polygonal terrains of varying scales observed in the Athabasca Valles and downstream in Cerberus Palus have been proposed to have both and/or either volcanic and periglacial features. Interpretations on these terrains differ strongly even with respect to in what order these features superpose other events in the valley.[9][10]

  1. ^ a b Cite error: The named reference jaeger2007 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference burr2002 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference mcewen2005 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference berman2002 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference cassanelli2018 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference page2009 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference burr2005 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference burr-diss was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference page2008resp was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference jaeger2008resp was invoked but never defined (see the help page).