1. Geomorphology of Eastern Meridiani Planum
Kevin Lewis
California Institute of Technology
Image Credit : Cornell/JPL/NASA

2. Regional Geology of Meridiani
Region of Interest
Etched Terrain
Hematite Unit
(Hynek, et al., 2002)

3. Region of Interest Layered Blanket Dozens of layers Linear features
1 km

4. Data:

5. Data: Moc vs. MOLA ~100x vertical exaggeration
Overall, Stereo and MOLA DEMs show similar profiles.
Baseline for Stereo has NOT been adjusted to MOLA
~100x vertical exaggeration

6. Notable observations
This depression has an anomalously low depth/diameter ratio (~1/60)
The basin seems to tilt to the North
Several layers inside form distinct benches
The inferred stratigraphy implies regional folding
A fresh impact crater, which punches through the etched layers, aids in reconstructing the stratigraphy

7. Geologic Model

8. Formation Mechanisms:

9. 1: Impact Crater with Fluidized Ejecta
Evidence for:
Looks like a crater
Craters are common!
Explains blanket around circular feature
Evidence Against:
Layers appear undisturbed
Fails to explain uniqueness of feature
Ejecta blankets do not normally have as many layers

10. 2: Circular Anticline Evidence for: Evidence Against: Complex layering
Shallow depth
Evidence of folding
Evidence Against:
Requires a very localized uplift
Does not explain lithification
Model requires 2x thickness of layered unit
sgeo/sgeo_S13.gif

11. 3: Hydrologic Feature Evidence for: Evidence Against:
Provides an explanation for complex erosion patterns
Could create layering and lithification
Evidence of water at Opportunity site
Evidence Against:
No other clear signs of hydrologic activity in this unit
Likely too large to be a hydrothermal basin (geyser) [see Hynek et al, 2002]

12. Conclusions and Unresolved Questions
An anticline or a hydrologic origin are most likely from this research – however, all the scenarios tested have problems, which do not fit the data
Are there possible formation mechanisms which have not been addressed?
How does this area tie into the regional geology?
What is the mineralogical composition of this unit?

13. Another possibility...?
Image Credit: easyweb.easynet.co.uk/~aburnham/ eng/arborhi2.htm