Stratigraphy and structural evolution of southern Mare Serenitatis: A reinterpretation based on Apollo Lunar Sounder Experiment data
The Apollo Lunar Sounder Experiment (ALSE) detected two subsurface reflecting horizons in southern Mare Serenitatis. These horizons appear to be regolith layers, >2 m thick, which correlate with major stratigraphic boundaries in southeastern Mare Serenitatis. Our analysis differs from previous interpretations and implies that the lower horizon represents the interface between the earliest mare unit (unit I; approx.3.8 b.y.) and the modified Serenitatis basin material below. The upper horizon represents the regolith developed by sustained impact bombardment of the unit I surface prior to the emplacement of the intermediate basalts (unit II; approx.3.5 b.y.). The latest volcanic episode (unit III; approx.3.2 b.y.) resulted in a very thin infilling (<400 m deep) in the southern portion of the basin and was undetected by ALSE. Profiles of the stratigraphic surfaces represented by the ALSE reflecting horizons are reconstructed for three stages in the basin filling history. These reconstructions permit the timing and magnitude of various volcanic and tectonic events within the Serenitatis basin to be assessed. On the basis of comparison with Orientale ring topography, the large subsurface arch is interpreted to be the peak-ring-related topography of the Serenitatis basin. The thickness of mare basalts across the ALSE ground track is highly variable: basalts are <400 m thick above the peak ring, while they reach a maximum thickness of approx.2.5 km in the depression between the first and second basin rings. Comparison with Orientale topography suggests that a major increase in basalt thickness of approx.6 km may occur approx.50 km inside the peak ring.
- Research Organization:
- Department of Geological Sciences, Brown University, Providence, Rhode Island 02912
- OSTI ID:
- 5987852
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 87:B13
- Country of Publication:
- United States
- Language:
- English
Similar Records
Lu-Hf and Sm-Nd evolution in lunar mare basalts
Development of the mare regolith: some model considerations