Jackson

D=71 km
Center: 22¡N, 197¡E

Count Area: 136 km^2 (NAC used: M103209479 L and R)
Observed Density (@ 1km): not observed
Age: 0.07 ± 0.07 (+sec: none)
Stoffler epoch: Copernican
Fit Density (@ 1km): ?? ± ??
PF fit: good

Age calculation notes:
Fit has slight deviation below (well within error) at larger crater points from Melosh gravity only regime and NEO population. Incorporating strength regime (not used for age reported above) fits the large craters better, but is below the small craters - reports and older age (~0.4 Ga).

USGS geology: 
Copernican

Wilhelms: 
Copernican

Floor material: 
Best guess is original. Has hummocky and smooth areas, which are likely melt. Hummocky areas avoided for counts.

Geology Observations: 
Formed in highlands. Maybe observe some rays. Ejecta blanket visible and can see it's secondary field. Large, sharp central peak complex. Rim sharp. No obvious secondary chain in zoom out or close up. I have some craters labeled as "secondaries", which in this case represents craters of unusual morphology. These are typically fresher craters that have morphologies like "splash" or "concentric" or "mound" craters. These may actually be self secondaries instead of being formed in layered materials, because they are not surrounded by many similar sized craters that are much more degraded.

SFD Observations: 
Dominated by classes 3 and 4. Class 1 at much lower density. Class 4 shallower than the others. The "secondaries" have shallower distribution. Steeper distribution. Slope(Diff)= -4.1 ± 0.3. secondaries slope(diff)=-3.2 ± 0.5

Using ejecta data from Van Der Bogert et al. 2010
Area: 2.73 km^2
Density (@ 1km): 123
Age: 0.147 ± 0.023 Ga

Note they also counted a melt pool which has a younger age - attributed to differences in material. I decided on ejecta, because more likely crater age(?)


Last Edited by MRK 1/8/2014