Wrinkle ridge

Unnamed wrinkle ridges north of the lunar crater Flamsteed, Oceanus Procellarum, from Apollo 12

Lunar crater Krieger and vicinity, showing wrinkle ridges in the surrounding mare and sinuous rilles along the left edge, from Apollo 15

A wrinkle ridge is a type of feature commonly found on lunar maria. These features are low, sinuous ridges formed on the mare surface that can extend for up to several hundred kilometers. Wrinkle ridges are tectonic features created when the basaltic lava cooled and contracted. They frequently outline ring structures buried within the mare, follow circular patterns outlining the mare, or intersect protruding peaks. They are sometimes called veins due to their resemblance to the veins that protrude from beneath the skin. These are found near craters.

Wrinkle ridges are named with the Latin designation dorsum (plural dorsa). The standard IAU nomenclature uses the names of people to identify wrinkle ridges on the Moon. Thus the Dorsa Burnet are named for Thomas Burnet, and the Dorsum Owen is named after George Owen of Henllys.

Floor and eroded south wall of the crater Flaugergues on Mars. Arrows point to wrinkle ridges.

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  Wrinkle ridges in Hesperia Planum, as seen by Viking The wrinkle ridges go in different directions so compressional forces may have changed direction over time.

Wrinkle ridges can also be found on Mars, for example in Chryse Planitia, as well as on several of the asteroids that have been visited by spacecraft, as well as Mercury, and a couple of moons of Jupiter and Saturn. Although several hypotheses have been advanced as causes of Martian wrinkle ridges, today they are generally considered to be of tectonic origin. They involve folding and faulting.^[1] They are evidence of compressional stresses in Mars’ crust. The stress created a crack (fault) where one side was pushed on top of the other side, also known as a thrust fault.^[2]

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  Map of tectonic stresses Normal faults are shown in yellow. Normal faults occur when the crust undergoes spreading forces. Thin red lines show the location of wrinkle ridges which result from compressional forces. Thick red lines show thrust faults; dykes are in green.

See also

• List of features on the Moon
• Planetary nomenclature

References

Wikimedia Commons has media related to Wrinkle ridges.

Notes

• Golombek, M. P., F. S. Anderson, and M. T. Zuber (2001), Martian wrinkle ridge topography: Evidence for subsurface faults from MOLA, J. Geophys. Res., 106, 23,811–23,821, doi:10.1029/2000JE001308.
• Montési, L. G. J., and M. T. Zuber (2003), Clues to the lithospheric structure of Mars from wrinkle ridge sets and localization instability, J. Geophys. Res., 108(E6), 5048, doi:10.1029/2002JE001974.
• Watters, T. R. (1988), Wrinkle Ridge Assemblages on the Terrestrial Planets, J. Geophys. Res., 93(B9), 10,236–10,254, doi:10.1029/JB093iB09p10236.
• Watters, et al., Evidence of Recent Thrust Faulting on the Moon Revealed by the Lunar Reconnaissance Orbiter Camera. Science 20 August 2010: 936-940. doi:10.1126/science.1189590