Dorsum Guettard is a named lunar wrinkle ridge— a low, elongated ridge formed by compressional forces in the mare basalt—situated on the near‑side of the Moon. It lies within the Mare Imbrium region and has been officially recognized by the International Astronomical Union (IAU). The feature is named after the French naturalist and geologist Jean‑Étienne Guettard (1715–1786), honoring his contributions to early geological science.
Physical characteristics
- Type: Wrinkle ridge (dorsum)
- Location: Mare Imbrium, near‑side of the Moon; approximate selenographic coordinates 28° N latitude, 33° W longitude.
- Length: Approximately 90 km (≈ 55 mi).
- Morphology: The ridge appears as a low, sinuous uplift of the mare surface, typically a few hundred meters in height and tens of meters in width, consistent with other lunar wrinkle ridges formed by tectonic contraction of basaltic lava plains.
Geological context
Wrinkle ridges such as Dorsum Guettard are interpreted as the surface expression of thrust faults that developed as the lunar mare basalts cooled and contracted. Their presence indicates regional compressive stresses related to the thermal evolution of the Moon’s interior and the loading of the mare basins.
Discovery and naming
The ridge was first imaged in detail by lunar orbiters, including the Lunar Orbiter and later the Lunar Reconnaissance Orbiter (LRO). The IAU approved the name “Dorsum Guettard” in 1976, following the convention of naming lunar dorsae after notable deceased scientists who contributed to Earth and planetary sciences.
Observational notes
- The ridge is visible in moderate‑resolution telescopic observations under favorable lighting conditions, appearing as a faint, elongated shadow.
- High‑resolution LRO images reveal its fine structural details, illustrating the typical deformational features of lunar wrinkle ridges such as lineated crests and occasional small fault scarps.
References
- International Astronomical Union (IAU) Working Group for Planetary System Nomenclature. Gazetteer of Planetary Nomenclature.
- Wilhelms, D. E. (1987). The Geologic History of the Moon. U.S. Geological Survey Professional Paper 1348.
- LRO Camera Team (Various years). LROC Image Catalog.
No further reliable encyclopedic information is currently available beyond the data summarized above.