image 4189 from Lunar Orbiter IV viaUSGS Lunar Orbiter Digitization Project and Clementine (inset)
At 81°W the 70 km wide crater Lavoisier seems to be imaged far less than Humboldt at 81°E on the opposite limb. And that is a shame for the crater named for the French chemist is perhaps even more fascinating that the larger one christened for the German savant. This Lunar Orbiter IV image reveals a wide wreath of rilles and churned up rocks that is more intense than others of the lunar nearside. The nearby crater Lavoisier F (bottom right) is somewhat similar (and has a domed floor and a string of secondary craters that don’t seem to come from Orientale). Lavoisier and a number of other rille-cut craters along this marshy western margin of Oceanus Procellarum are floor-fractured craters. Remember that FFC are normal impact craters deformed by the rise of magma under them, leading to uplifted floors, rilles, and various other aspects of volcanism. And like the opposite limb FFC Humboldt, Lavoisier has dark pyroclastic deposits (see high Sun Clementine inset) and a concentric crater. The pyroclastic (ashy) material must have erupted from the rilles but there are no conspicuous dark halo craters as at the FFC Atlas and Alphonsus. Notice the very narrow mare ridge-like feature along the southwest (bottom left) edge of Lavoisier F and in some places in Lavoisier. In the case of F this ridge was probably produced by the thrusting of one peice of the crater’s floor over an adjacent piece due to the uplift of the crater center. Who will capture the first high resolution image of Lavoisier from Earth?
This Lunar Orbiter image was tweaked by Stefan Lammel and posted on the LPOD Photo Gallery which now has 992 images!
Rükl charts 8 & VIII
Yesterday's LPOD: Two Dead Map-Makers
Tomorrow's LPOD: The Bottom of the World, Upside Down