For purposes of logging this cache you must answer the following three questions. You also must take a picture of you or a personal item near the falls without giving away any answers at the posted coordinates
1) At the posted coordinates you will be able to observe the bedrock of the eastern side of the Olympic Peninsula. What is its name and what does it look like?
2) Approximately how many feet of carving down would you say that it took the creek to expose this bedrock? Hint: look how high the opposite side of the hill is to help you make this guesstimate.
3) Long after the subduction process an ice sheet sculpted the land. Do you see any evidence nearby that would support glacial activity in this area? (The nearby sign should help with this question.)
4) Please take a Mandatory photo of yourself or a personal item near GZ and either send it to me when you message the answers or attach it to your found log.
This earthcache is located on private property and placed with permission..
Note: An earthcache is the magical combination of geocaching and geological discovery. They vary greatly from traditional geocaches in that there is NO PHYSICAL CONTAINER! Once at the Earth Cache site, take in the scenery, the geological marvels or oddities, and read the cache description. You will likely be asked to answer some questions about the site and take a picture. You can email the cache owner or use the Message Center to send answers to the required questions. Please don’t be intimidated about answering the questions. They are not graded and were meant to enrich your visit, open your eyes and provide you with new knowledge and insights about the location. Most importantly have fun!
This is a short, (.75), pretty little loop walk through the woods into a small canyon where Ludlow Creek tumbles down. There are interpretive signs along the way describing the trees, plants,the geology and of course a fine little waterfall. There is also an Adventure Lab and a traditional cache located along the loop.
The Olympic Mountains are extraordinary. They are an anomaly, both in their height, and in their geography. On the map they look like a gigantic horseshoe. A geologic sketch map reveals the basic structure of the range. The "horseshoe" of basalt and sedimentary rocks (the Peripheral Rocks, or Crescent Formation) partially surrounds the "Core Rocks", an assemblage of slightly altered sandstone and shale layers. The Core Rocks accumulated from underwater landslides ("turbidity currents") within the trench and accretionary wedge of the subduction zone. The fact that these rocks are now thousands of feet above sea level is the interesting puzzle. This happened because bits and pieces of continents and island arcs randomly arrived at the subduction zone, mucking up the subduction process the way too many sheets of paper at once can muck up a paper-shredder. In the case of the Olympics, there was a mass of land north (Vancouver Island) and an accreted terrane to the south (the North Cascades), and a bend in the subduction zone itself. In essence, too much material was being stuffed into the subduction zone, so the excess material went the only way it could.
Here is my illustration demonstrating the process: The creamy filling is the layers of sediment and basalt on the ocean floor. As the Juan de Fuca Plate (lower cookie) subducts beneath the North American Plate (upper cookie), the layers are scraped off the ocean floor and pile up as the Coast Range.
The alpine glaciers that nest year round high in the Olympic Mountains are relicts of the recent ice age. During the last ice advance a large sheet of ice, called the Cordilleran Ice Sheet, moved down from western Canada and into Washington. The ice sheet crept southward into the northern Puget Sound region and bumped up against the Olympics, where it split into two lobes. One lobe went out into the Strait of Juan de Fuca toward the Pacific Ocean, and the Puget Lobe moved south and filled what is now the Puget Lowland. This and previous ice sheets carved and changed the landscape drastically.
While many glaciers have melted, we can still see evidence of their influence across the landscape today:
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Glacial erratics are large boulders and rocks that were not formed where they rest today, but instead were moved to that location by a glacier. Sediment can fall on a glacier and move with it or be picked up as a freeze happens. Areas were carved out by glaciers' weight and friction, but the sediment moved doesn’t disappear. Instead, it is pushed aside or picked up and moved to other places. As they melt, glaciers drop sediment, sometimes carried for thousands of miles. The cycle of melting, moving, and refreezing has helping to track the former paths of these glacier.
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Scree fields can be created in the moraines, shaping basins and sediment.
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Basins formed by sediment buildup often leave behind glacial lakes.
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When the glaciers were much larger, they would extend down into the rainforest valleys of today. These valleys are U-shaped with wide, flat bottoms and tall cliff sides as the glacier moved across the entire valley, spreading its weight and grinding action evenly across. This is distinctly different to V-shaped, river carved valleys, where the water is fluid and concentrated as it takes the smallest path of least resistance.
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As a glacier melts, the water flows through these valley watersheds.
In order to substantiate your visit and comply with the educational requirement for Earth Caches you will need to submit your answers to the following questions to the cache developers via their profile using the message option. For purposes of logging this cache you must take a picture of you or a personal item near the falls without giving away any answers at the posted coordinates and answer the following questions. If you can't submit your answers at the same time that you log it simply use the write note option until you can do. that.
For purposes of logging this cache you must answer the following three questions. You also must take a picture of you or a personal item near the falls without giving away any answers at the posted coordinates
1) At the posted coordinates you will be able to observe the bedrock of the eastern side of the Olympic Peninsula. What is its name and what does it look like?
2) Approximately how many feet of carving down would you say that it took the creek to expose this bedrock? Hint: look how high the opposite side of the hill is to help you make this guesstimate.
3) Long after the subduction process an ice sheet sculpted the land. Do you see any evidence nearby that would support glacial activity in this area? (The nearby sign should help with this question.)
4) Please take a Mandatory photo of yourself or a personal item near GZ and either send it to me when you message the answers or attach it to your found log.
Resources:
https://wa100.dnr.wa.gov/olympic-peninsula/how-olympics-formed
https://www.nps.gov/olym/planyourvisit/upload/geology_printer-friendly.pdf/
https://olympicnationalparkvisitor.info/mountains/geology/
http://www.cokesmithphototravel.com/geology-of-the-olympic-peninsula.html