This is an Earthcache, there is no real container hidden anywhere. You must visit the posted coordinates and will have to send me your answers to the following questions to get credit for your find.
You do NOT have to wait for me to tell you if your answers are correct to log this cache, log right away if you want.
To begin explaining the landforms in the Stillwater and St. Croix Valley area we will go back roughly 500 million years to the formation of the sedimentary rock layers found in this area.
North America was situated on the equator during the Paleozoic period, Minnesota was a low-lying, mostly flat area with no land plants which made the area quite barren. The sea level rose to a much higher elevation than it is today, and eventually, most of North America was covered by the ocean. Minnesota, Wisconsin, and Iowa became a shallow sea as a result, about 500 million years ago. Over the next 130 million years, sediments of quartz, feldspar, and other rocks accumulated as more and more sediments from the rising sea were moved and deposited into new areas. These sediments were later buried and cemented, eventually forming layers of rock.
As the Paleozoic Era continued sea level would rise and fall many times, covering and uncovering current day Minnesota. Leading to the deposition of many different layers of sedimentary rocks.
Around 100,000 years ago, a glacier covered much of Minnesota. A glacier called the Laurentian Glacier scraped into the Minnesota landscape and at times released meltwater. Depositing sediments into new areas and letting them cement and compact into sedimentary rock at the bottom of the St. Croix River river bed.
14,000 years ago, as the climate began to warm, the glacier retreated and melted. Much of the meltwater was carried downstream, due to gravity. The flowing meltwater carved into the soft sandstone and formed the St. Croix River Valley that we know today. Other water settled into a depression and formed what was called Glacier Lake Duluth. Continuing downstream, the water in Glacial Lake Duluth contributed to the formation of the St. Croix River Valley.
QUESTIONS
Use the information above to help you answer the questions and do the following. Send your answers to me via the message center and include your photo.
1. What initially caused the valley to begin forming?
2. What geological process brought the sediments that turned into sedimentary rocks to their current spot?
3. What is the name of the glacier that covered Minnesota 100,000 years ago?
4. What time period did the sea level begin to rise, bringing Minnesota under the ocean with other states in the area?
5. The sediments that were brought to the St.Croix area may have come from a lot of different places. They went through cementation and compaction to turn into sedimentary rocks, what would those sedimentary rocks have to go through to become metamorphic rocks?
At the posted coordinates, you must...
6. Take a photo of yourself next to the sedimentary rocks (the non-man-made ones) if you don't want to show yourself in the photo, a thumbs up or hand is fine. Please include this photo in your log.
7. Explain why you may think that the rocks on the side of the hill (Non-man-made ones) have layers in them.
8. Describe the current state of the sedimentary rocks at the posted coordinates. (What does it look like)