This Earthcache will bring you to the Peter Russell Rock Garden located on the University of Waterloo campus and hosted by the University's Earth Sciences Museum. Public access to the area is free and encouraged, however there will be a fee for parking in one of the university lots. So if you're a local, why not bike or take public transit. While you are here you may also want to visit the Earth Sciences Museum which is just next door.
Let the lesson begin and remember, Geology rocks!
What is bedrock?
Bedrock is simply the consolidated "solid" rock that lies beneath layers of unconsolidated weathered rock, till, sand, clay, and soil. Bedrocks located in Ontario fall within one of four geological eons spanning from millions of years ago to billions of years ago.
- Paleozoic Sedimentary Rocks - 248 - 545 million years old
- Grenville Province Rocks - one billion years old
- Huronian Supergroup Rocks - 2.2 - 2.45 billion years old
- Superior Province Rocks - older than 2.6 billion years old
Local Bedrock
In May 1976, a hole was drilled by the Department of Earth Sciences close to the posted coordinates. The solid bedrocks encountered 45 metres below the surface were formed from sediments deposited in a warm shallow sea many millions of years ago. The deposits overlying the bedrock are mainly derived from glaciation creating layers of till laid down by ice that covered all of Ontario. The glaciers retreated about 15,000 years ago depositing sand and gravel overtop the till. Your task today will be to identify if the bedrock lying deep beneath you is geologically young or old?
Task
The posted coordinates will take you to a 3-sided information sign explaining the interesting geology underneath the Waterloo campus. You'll need to read information on the local bedrock, find it's estimated age, and then find the geological eon the bedrock falls in. Once you have found which eon it falls in then you'll have to hunt around the garden to find another rock from the same eon. It will be easy if you follow these steps.
Directions:
- 1. Locate the side of the sign titled "Geology of the University of Waterloo Campus".
- 2. Read the section about the UW campus borehole for the answers to questions #1 and #2.
- 3. Walk around to the other side of the sign titled "Ontario Rocks".
- 4. Match up the age of the local bedrock to one of the 4 geological Eons shown to answer question #3.
- 5. Compare the age of the local bedrock's Eon to the age of the other Eons to answer question #4.
- 6. Choose any one of the 4 examples of rocks shown on the sign within same Eon as the local bedrock you found in direction step #4 and locate it within the garden.
- 7. Read the plaque attached to the rock for answer to question #6.
You may log your "find" right away but please follow with the answers within a few days. To log this cache please send me the answers to the following questions through my Geocaching.com profile.
Questions:
- 1. What two types of rock make up the bedrock below you?
- 2. How old is the bedrock below this spot?
- 3. What Eon do these bedrocks fall under?
- 4. In geological terms, is the local bedrock young or old compared to other Ontario bedrock?
- 5. What is the name of 1 other example of rock from the same EON?
- 6. What area of Ontario is your specimen from? It will state on the plaque glued to the rock.
- Optional - Take a picture of you or your GPSr ontop of your favourite rock specimen from the garden.
