This telescopic image shows the eastern margin of the multiringed
Imbrium Basin. The Apennine, Alpes, and Caucasus mountains are among the
tallest on the Moon and were formed by uplift during the Imbrium impact.
Smooth mare basalts fill much of the interior and periphery of the basin.
The Apollo 15 mission landed at the foot of the Apennine mountains and
returned 3.3 Ga-old mare basalts from the plains at the base of the mountains.
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Q1 (2 pts). Which of the four larger craters, Plato, Archimedes,
Eratosthenes, or Copernicus, is the youngest? How can you tell from
this image?
Q2 (2 pts). Which of these 4 larger craters is the oldest, and
how can you tell from this image?
The remaining questions are based on the next image, which is centered near the crater Autolycus in the southeast portion of the Imbrium Basin.
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Q3 (6 pts). Based on morphology and superposition, which of the
following craters formed before, and which after, the eruption of mare
basalts in Mare Imbrium and Palus Putridenis?
Aristillus- before or after?
Autolycus- before or after?
Archimedes- before or after?
Crater 1- before or after?
Crater 2- before or after?
Crater 3- before or after?
Q4 (2 pts). Based on morphology, superposition, and relative
crater density, did mare basalts in Palus Putridenis and the Apollo 15
landing site area form before, after, or roughly at the same time as plains
unit 4? Before, after, or roughly at the same time as mare basalts in Mare
Imbrium?
Q5 (2 pts). Based on morphology and superposition, which of the
large craters, Archimedes, Autolycus, or Aristllus, is youngest? How can
you tell from this image?
Q6 (2 pts). Which of the thee large craters in Q5 is the oldest,
and how can you tell?
Q7 (2 pts). Look carefully at the relationship between Crater
1 and Aristillus. Which of these craters formed last, and how can you tell?
Q8 (5 pts). Based on your answers to the questions above, construct
two stratigraphic columns showing older units below younger units for the
following: (a) crater ejecta for craters 1, 2, 3, Archimedes, Autolycus,
and Aristillus; and for (b) plains in Unit 4, Palus Putredinis, and Mare
Imbrium. If features formed at about the same time (or you can't tell whether
one is older than another), indicate this in each column by putting the
features at the same vertical position.
Column a: ejecta deposits
Column b: plains deposits
Q9 (2 pts). Assign absolute ages (either ~ 3.3 Ga, >3.3 Ga, or
<3.3 Ga) to each of the vertical positions in the stratigraphy columns
in Q8.