The given coordinates will take you to an area in Harrods Creek Park where exposed bedrock has separated in mass sections do in part to the erosion that exposed it, and seasonal "frost Wedging" that broke the massive boulders that you will see here and displaced them. The photo above is an area of exposed bedrock that is the predominant bedrock of this area, limestone. Here you will notice several large boulders that have separated from the exposed limestone bedrock wall and found their way to a resting distance well away.
While erosion does play a part in the separated boulders here, by removing the soil and exposing the bedrock, a form of mechanical weathering called frost wedging is the primary reason for what you see here. Frost wedging is caused by the repeated freeze-thaw cycle of water in extreme climates.Most rocks have small cracks in them, called joints (or, tectonic joints). When it rains, rainwater seeps into these joints. As the day cools and temperatures at night drop below freezing, the water inside the joints freezes.
As water freezes into ice, it expands. The expanding ice places pressure on the joints in the rock. Finally, when the pressure is too much, the joint expands. In some cases, the rock will split, though this usually happens after repeated freeze and thaws. As new water is added during the warmer days, more ice is created at night, wedging the joints apart further. In the photo below, which is near the GZ you will see a very large "chunk" of rock that has been separated in mass fairly recently, and will eventually end up down the hill when erosion plays it's part along with a little help from gravity.
In the photo below is the area where the coordinates take you to. Notice the large displaced boulder and the tree that is growing in the middle of it, a somewhat rare but not uncommon anomaly. Not only did frost wedging remove the rock from the wall, but it probably assisted afterwards by splitting the rock allowing a young sapling to flourish.
In order to log this cache, please email me the answers to the following questions.
1. Explain briefly why frost wedging may have aided the tree in the middle of the rock at GZ.
2. Why do you think so many large rocks are now so far from the exposed wall of bedrock near the GZ?
3. Can you see any further frost wedging in the process near this area?
4. (Optional) Take a photo of yourself or your GPSR near the GZ.