Al-Biruni

D=76 km
Center: 18°N, 93°E

Count Area: 1593 km^2
Observed Density (@ 1km): 13200 ± 2900
Age: 3.8 ± 0.1 (+sec: 3.8)
Stoffler epoch: Early Imbrian
Fit Density (@ 1km): 13500 ± 2300
PF fit: good, large craters are shallower, small craters in slight excess

Age calculation notes:
Bad fit. Good fit - use as is (SM).
Decent fit for small craters (although slightly steeper) - bad fit for large craters (this is a "right ear" crater) - perhaps exclude large craters from fit; adding OSs does not change fit or age (MRK).

USGS geology: 
Crater rim material mapped as Nectarian. Floor material mapped as mid-Imbrian plains.

Wilhelms: 
Crater is Nectarian. Floor is Late Imbrian mare.

Floor material: 
Best guess is not original. Smooth floor, surrounded by other filled craters and mare, and no peak visible. However, has softened appearance? Soft?

Geology Observations: 
Ejecta blanket eroded, little remaining. No central peak. Floor flat. Some collapses at the rim (avoided). Secondary clusters and chains observed primarily in crater center. Contain craters of various sizes (up to ~ 1.4 km). 

SFD Observations: 
Small craters (< 1.5 km) dominated by classes 3 & 4, large craters dominated by 1 & 2. Steeper distribution for small craters (D < 1.5 km), shallow for large. Shallow "right ear" (although only composed of one crater). Slope(Diff) = 5.1 ± 1.0.

Discussion notes: 
"v" feature not statistically significant, change MPF fit to "OK"

Last Edited by MRK 11/14/2012