Planetary Geology Lecture Outline - Mercury
- strong magnetic field despite small size.
- have not been able to detect any Fe in surface materials
(yet large iron core?).
- has O2 in thin atmosphere.
- spins slowly (59 days vs. 88 days orbit around sun).
- ice at the poles?
- 3500 km diameter core and 4880 km diameter total, greater
density. How do we know size of core?
- strong magnetic field source?
- evidence of isostatic response - implications? Rheid
or fluid interior.
- densely cratered terrane with intercrater plains (oldest
- Caloris basin: about 3.6 billion years old, focusing
on other side creating hilly & lineated terrane, polygonal fractures
part of basin.
- contractional wrinkle ridges: character? origin?
- smooth plains: youngest, similar to maria.
- accretion and differentiation, development of anorthositic
crust (magma ocean)?
- intense bombardment and formation of intercrater plains
- formation of Caloris basin
- continued cooling and contraction
- minor bombardment and atmosphere development
Some images to play with (see what features discussed
in lecture you can identify):
half globe imageCaloris basinBach quadrangle
Next time: Venus
Reading: text chapter on Venus
Discussion questions for next time:
Venus has surface temperatures in the realm of metamorphic
conditions on earth where rocks flow ductilely. Yet brittle structures (faults)
abound. Why? There is the standard answer, and another somewhat neglected
How does the distribution of volcanism on Venus differ
from that on earth, and what does that suggest about the tectonic style?
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