Tartarus Colles are a group of knobby hills in the northern plains ofMars.
Tartarus Colles runs from 8° to 33° north latitude and 170° to 200° west longitude. They were named after aclassic albedo feature. The name was officially approved by the IAU in 1985.[1] The term "Colles" is used for small hills or knobs.[2]
There are over 40,000 knobs associated with Tartarus Colles.[3]
This landform is located within theDiacria quadrangle ofMars.
Some researchers have proposed that the knobs of western Tartarus Colles are consistent with concurrent interpretations of knobs inCerberus Palus (downstream ofAthabasca Valles), which would suggest that they formed as the result of interactions between lava and water to form what has been termed by some authors asvolcanic rootless constructs (VRC). This class of lava-water interactions includesrootless cones, but have fewer genetic implications in their definition, as are not necessarilyphreatomagmatic (resulting from the explosion of steam from the sudden evaporation of fluids on contact with lava). The water source is not required to have been addeden masse in the form of some aqueous flood - instead possibly being available in the form of an extremely thin and shallow ground ice reservoir whose presence and extent is controlled byobliquity as anorbital forcer.[3]
In 2008, Mark A. Bishop of thePlanetary Science Institute and theUniversity of South Australia reported on his results using higher-order neighbor analysis to attempt to discern any kind of pattern in the distribution of Tartarus Colles' knobs. The purpose of the study was to reconcile competing hypotheses as to the origin of these knobby landforms, which had been analogized by other authors to putativepingoes androotless cones inAthabasca Valles and elsewhere inElysium Planitia. Bishop found the cones of Tartarus Colles to exhibit acomplete spatial randomness except wheresolifluction or magmatic effects were readily apparent.[4]
In 2011, Christopher W. Hamilton and Sarah A. Fagents of theUniversity of Hawaiʻi at Mānoa inHonolulu,Hawaii, and Thorvaldur Thordarson of theUniversity of Edinburgh inScotland reported on the results of their geomorphic mapping, lava thickness estimations, and statistical analyses (nearest neighbor modeling) to investigate the hypotheses that the cones of Tartarus Colles are what the authors have termed "volcanic rootless constructs" - a more generalized variation of the term "rootless cone" that does not explicitly require a phreatomagmatic origin, or any clear explosive expression such as a pseudocrater. The authors criticize the tendency to generalize Martian pseudocrater analogies againstMývatn, the Icelandic lake, which has been used as a type example of structures arising on Mars from water-lava interactions in a way that ignores the variability of such structures even across Iceland.[3]
