TO LOG A FIND ON THIS CACHE YOU MUST ANSWER ALL OF THE QUESTIONS BELOW. You can contact me through the geocaching message center or email to submit your answers. Any incorrect answers may result in a clarification response.
1. "Angels Point Unconformity" on the first line of your message AND list all geocaching names of your party so I can match your answers to them. If you all want to learn something, I would prefer each cacher send me individual emails in the spirit of earthcaching.
2. Take close up photo of the rock outcrop using some sort of scale. Geologists often use coins, GPS', pens, shoes, notebooks, etc. You might want to be creative in what you use for your scale, however, the scale that you choose is entirely up to you. This photo must be uploaded to your log.
3. Based on the diagram, what type of unconformity is this? How can you tell?
4. Why do you think this unconformity is here and how do you think it was formed?
Elysian Park is home to some interesting geologic features. As you drive up the long, windy Angles Point road, you will come across an unconformity: or a gap missing in geologic time. An unconformity is when there are units of geologic rock that are not in sequential order. There are four types of unconformities and they are best shown in the diagram below
Disconformity - Weathering has occurred to existing rock, which has eroded away an uneven surface. Then, sediments began to be deposited on top of this rough and uneven surface. This makes the unit non-continuous in time.
Paraconformity - Weathering has occurred to existing rock, which has eroded away an even surface. Then, sediments began to be deposited on top of this smooth and even surface. This makes the unit non-continuous in time. These are quite difficult to see in the field and are often not even noticed.
Nonconformity - Igneous rock has protruded up from the depths below but did not make it to the surface. This makes the unit younger on the bottom and older on top. In geology, typically, units form from bottom to top so oldest should be on the bottom. Instead, this igneous rock is younger than the sediments above it.
Angular Unconformity - Sediments have been tilted due to tectonic forces. Then sediments have been horizontally deposited on top of that, creating a gap in time between older sedimentary units.
Works Cited
https://www.eoas.ubc.ca/courses/eosc326/resources/Stratigraphy/unconformities-v2.htm
Super special thank you to bluesnote for creating this earthcache
for the Spring Fling III Mega-event!