Recent Advances and Current Research Issues in Lunar Stratigraphy
Emplacement scenarios for Vallis Schröteri, Aristarchus Plateau, the Moon
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Published:March 01, 2011
The volcanic processes that formed Vallis Schröteri are not well understood. Vallis Schröteri, located on the Aristarchus Plateau, is the largest rille on the Moon, and it displays three key morphologic components: the Cobra Head, the 155-km-long primary rille, and the 240-km-long inner rille. Observations of terrestrial eruptions are applied here to help explain the morphologic relationships observed for Vallis Schröteri. The Cobra Head, a 10-km-wide source vent surrounded by a 35-km-diameter and 900-m-high low shield, might have been constructed from flows, spatter, and pyroclastic deposits erupted during lava fountain events, similar to the early stages of the vent at Pu‘u ‘Ō‘ō in Hawaii and the final morphology of Bandera crater, a cinder cone in New Mexico. The vent fed an initial sheet flow controlled by pre-eruption topography. A channel formed within this sheet flow was the foundation for the primary rille, which deepened through construction and thermomechanical erosion by lava. The inner rille is confined to the flat floor of the primary rille and is characterized by tight gooseneck meanders. This rille crosscuts the distal scarp of the primary rille and extends toward Oceanus Procellarum. This enigmatic relationship can be explained through backup, overflow, and diversion of the lava into a new rille that eroded into the margin of the primary rille. Similar backup, overflow, and redirection of the lava flow were observed during the 1984 Mauna Loa eruption in Hawaii. Analysis of the final morphology of lunar rilles provides key information about lunar volcanic processes and insight into the local stratigraphy.
- Aristarchus
- East Pacific Ocean Islands
- emplacement
- eruptions
- geomorphology
- Hawaii
- igneous rocks
- lava
- lithostratigraphy
- Moon
- New Mexico
- Oceania
- Oceanus Procellarum
- Polynesia
- rilles
- surface features
- terrestrial comparison
- topography
- United States
- vents
- volcanic rocks
- volcanism
- Schroteri Vallis
- Cobra Head Rille