At the posted coordinates you have a good view of the Pikeview Quarry. This cache is focused on the geological topic and not the engineering side. the logging tasks are:
1partA) Do you see any of the reasons of the 2008 landslide? If so what reason?
1partB) Does it look like this was the main reason of the rockslide?
1partC) Does it look like a landslide happen again due to this?
2) Using your observing skills, what color is the limestone?
3)Compare the circled limestone formations. Which spot looks like the rockslide happened at?
4) A picture of you or a personal item at the posted coords to prove you were there.
Pikeview Quarry
Pikeview Quarry is a limestone mine. Pikeview Quarry is a quarry located adjacent to Blodgett Peak Open Space and is in the final stage of reclamation currently.
Landslide
In 2008 Pikeview Quarry suffered a landslide. The geological reasons to this are extractions at base of the rock, rampart range fault zone, the underlying Pikes Peak Granite, and steep bedding planes. Pikes Peak Granite is formed with underground igneous intrusion, slow crystalization, and eventual tectonic lift. Millions of years ago, the upward thrust of the underlying Pikes Peak Granite tilted the younger sedimentary layers sitting on top of it. This geological process caused the limestone above to dip steeply. When mining operators cut away the stone at the bottom of the slope, gravity easily pulled the massive limestone blocks down along these tilted planes.
Pikes Peak Granite
Pikes peak granite is a 1.08 billion year old geological formation. Pikes Peak Granite is formed with underground igneous intrusion, slow crystalization, and eventual tectonic lift. It's color is red and pinkish caused by a high concentration of feldspar. It consists quartz, perthitic feldspar, and biotite.
Limestone
Limestone is a sedimentary rock composed primarily of calcium carbonate (CaCO₃), usually in the form of the mineral calcite or aragonite. It makes up about 10% of all sedimentary rocks on Earth. One well known type of limestone is chalk. The limestone at Pikeview Quarry was formed 300 to 500 million years ago when Colorado was located near the equator and covered by a warm, shallow tropical ocean.
weathering at the quarry
For billions of years the limestone has been weathering. It's main source is rain. Weathering is the process that breaks down, cracks, or dissolves solid rock right where it sits, without moving it anywhere. When normal rain falls through the atmosphere, it mixes with carbon dioxide to create a very weak, natural acid called carbonic acid. Over thousands of years, this slightly acidic rainwater has soaked into the cracks of the quarry, slowly dissolving the solid limestone from the inside out.
Erosion at the quarry
Once weathering has successfully cracked and dissolved the mountain into pieces, erosion takes over. Erosion is the actual movement of those broken rock pieces from one place to another by natural forces like water, wind, and gravity. A big source of erosion is water runoff. When thunderstorms hit the slopes of the quarry, there is not any obstacles to slow it down. As a result, flash floods rush down the mountain getting quicker every foot. The water picks up the loose limestone and carves deep, V-shaped channels called gullies into the dirt and rock. Another big source of erosion is gravity. This source is called mass wasting. Mass wasting is a specific type of erosion where gravity pulls massive amounts of rock and soil downhill all at once without needing water to carry it. When miners dug away the bottom of the hill, they removed the support holding up the top layers. Gravity took over, pulling millions of tons of fault-cracked, weathered limestone slabs straight down the slanted hillside in catastrophic landslides and rockfalls.
Sources:
https://coloradogeologicalsurvey.org/wp-content/uploads/woocommerce_uploads/OF-03-18.pdf
https://www.lecomptoirdespierres.com/gb/faq-burgundy-limestone/limestone-definition.html
https://coloradosprings.gov/news/city-council-accepts-donation-historic-pikeview-quarry-site-future-community-use
https://coloradosprings.gov/ReclaimedPikeviewQuarry