Amazonian (Mars)

This article is about the Mars geologic system and time period. For other senses, see Amazonia.
Amazonian
2000 – 0 Ma (lower bound uncertain – between about 3200 and 2000 million years ago)
MOLA colorized relief map of Amazonis Planitia, the type area for the Amazonian System. Amazonis Planitia is characterized by low rates of meteorite and asteroid impacts. Colors indicate elevation, with red highest, yellow intermediate, and green/blue lowest.
Usage information
Celestial bodyMars
Time scale(s) usedMartian Geologic Timescale
Definition
Chronological unitPeriod
Stratigraphic unitSystem
Type sectionAmazonis Planitia

The Amazonian is a geologic system and time period on the planet Mars characterized by low rates of meteorite and asteroid impacts and by cold, hyperarid conditions broadly similar to those on Mars today.[1][2] The transition from the preceding Hesperian period is somewhat poorly defined. The Amazonian is thought to have begun around 3 billion years ago, although error bars on this date are extremely large (~500 million years).[3] The period is sometimes subdivided into the Early, Middle, and Late Amazonian. The Amazonian continues to the present day.

The Amazonian period has been dominated by impact crater formation and Aeolian processes with ongoing isolated volcanism occurring in the Tharsis region and Cerberus Fossae, including signs of activity as recently as a tens of thousands of years ago in the latter[4] and within the past few million years on Olympus Mons, implying they may still be active but dormant in the present.[5]

  1. ^ Tanaka, K.L. (1986). The Stratigraphy of Mars. J. Geophys. Res., Seventeenth Lunar and Planetary Science Conference Part 1, 91(B13), E139–E158.
  2. ^ Carr, M.H. (2006), The Surface of Mars. Cambridge Planetary Science Series, Cambridge University Press.
  3. ^ Werner, S. C., and K. L. Tanaka (2011), Redefinition of the crater-density and absolute-age boundaries for the chronostratigraphic system of Mars, Icarus, 215(2), 603–607, doi:10.1016/j.icarus.2011.07.024.
  4. ^ Horvath, David G.; et al. (2021). "Evidence for geologically recent explosive volcanism in Elysium Planitia, Mars". Icarus. 365: 114499. arXiv:2011.05956v1. Bibcode:2021Icar..36514499H. doi:10.1016/j.icarus.2021.114499. S2CID 226299879.
  5. ^ Martel, Linda M. V. (January 31, 2005). "Recent Activity on Mars: Fire and Ice". Planetary Science Research Discoveries. Retrieved July 11, 2006.