Coolrox Limited po box 14591 Gainesville, Florida 32604-2591 USA Andrew Romeo, Owner andrew@coolrox.com (352) 378-6026 (888)-COOL-ROX
Slickensides!?
I went to Alaska to study something, something outside, something on an icefield, I didn't know what. After some good solitude and clean air I remebered inspiration from a Sedimentary Geology class field trip to West Virginina - Slickensides!
When an earthquake occurs, our ground moves and shifts, rivers offset, highways shift, terrible things can happen. While all this is going on, rock masses shear or break apart and move past one another. This motion in the rock is what is really happening when an earthquake occurs. (see animation below)
This animation shows the faulting process. The different fill patterns represent horizontal rock units. Can you see how one rock mass moves past another as they are faulted? It is along this fault line that the slickensides occur.
As the broken rock layers move past one-another, their faces scrape/scratch/polish each other. These faces comprise the 'fault plane.' The linear scratches from the friction during movement of the earthquake are called slickenlines. These lines all point in the direction of rock movement. Any rock face that has features of this shifting movement are called slickensides.
So anyway...I went skiing around Alaska looking for faults in the rocks of the Coast Mountain range. I found some - 225 to be exact. I determined the fault's direction of motion by resting a bamboo staff parallel to the slickenlines and used my compass to find the orientation of the fault.
With many notes and pounds of rock, I flew back to Florida, put all my facts and figures into a Macintosh and out popped two fault planes. Surprise, surprise! Since no one had paid them this much attention in the past (I 'discovered' them), so I named one The Seratine Displacement and the other the MuCowe Fault.
All of this faulting, stratching, scraping, 'quaking and shifting took place about 50 Million Years Ago.
Here is a beautiful picture of one of my study areas: The Gilkey Trench. You can go on this expedition yourself, surf to FGER.
Here is my abstract. You can meet the staff. Or get more information...
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