SQUIRES LAKE
There are two rock units in this area. One of these rock units is metamorphic, and was once buried maybe 10 kilometers within the crust during subduction, and the other is a terrestrial sedimentary formation -- that means that the contact between them is an unconformity(in this case it is not visible).
When you arrive at the given coordinates, located on the South Ridge Trail, you will come to an exposed cliff on the upper (east) hillside. Look carefully at the sandstone exposures and note the orientation of the beds. It is subtle, but worth the effort. These beds are tilted, and dip downward to the lake. 'Dip' is always 'downward', the steepest angle you can determine. It is the path a drop of water would take. 'Strike' is the direction that a level horizontal line points when drawn on a dip face. See image below.
In the photo, Doug Madsen demonstrates 'right hand rule' for determining direction of strike --- fingers of his right hand point down the direction of dip, and his right thumb would then point in the direction of strike. Strike is not always easy to see in these rocks, as smooth bed surfaces are few and far between; a little geo-intuition may be needed.
REQUIREMENTS:
Please log your find and then email answers to the questions below in a timely manner.
1. Which compass direction do the beds dip?
2. What angle is the dip?
3. How many distinct layers do you observe?
4. What is the color of these distinct layers?
5. What is the approximate measurement of the exposed dip/strike area?
REFERENCE:
Geology Field Trips: Geology of Squires Lake and the Alger Alp; Dave Tucker 24Mar11.