Rockin' it on Conanicut Island
This Earthcache will bring you to the trails in Conanicut Battery Historic Park located in Jamestown, RI.
A little history of the area -
The original fort, built it 1776 was probably a simple, crescent-shaped earthwork designed to house and protect six to eight heavy cannon and their men. The British captured the fort in December 1776 and occupied it until October 1779. They rebuilt the battery in the shape seen today. A ditch surrounds the earthen barricades on all sides. The fort could house heavy cannon to defend the West Passage, and the bastions on the north and south protected it from land attack. Check out the plaque and information provided along the way. You will pass this area on the way to the earthcache.
A brief history of the formation of Conanicut Island -
120,000 years ago a glacier formed Conanicut Island off the coast of Rhode Island. This glacier brought boulders and sediment from the north of what is now known as Narragansett Bay. This island formation is called a moraine.
A glacial erratic is a piece of rock that differs in size and type native to an area that were carried by the glacier over distances of many hundreds of miles and dropped in place as the glacier retreated. Erratics can range in size from pebbles to large boulders.
A fracture is any separation in a geologic formation, such as a joint or a fault that divides the rock into two or more pieces. A fracture will sometimes form a deep fissure or crevice in the rock.
A Large Rock -
Take the main trail to the battery area. When you reach the battery take the trail to the left toward the Large Rock. There is a sign pointing the way. At the end of this short trail you will find ground zero.
Once you arrive at the posted coordinates, you will notice the large boulder.
Resources:
1) Bedrock Geology of Rhode Island GEOLOGICAL SURVEY BULLETIN 1295 Prepared in cooperation with the State of Rhode Island Development Council
2) Rocks, stones and erratics: the 'bedrock' of life. By Kim Gaffett, Mon, 04/11/2011
3) Rhode Island Geology for the Non Geologist Paperback – 1973 by Alonzo W. Quinn
The Geocache -
Please answer the following. Do not include the answers in your log - send them separately to me. After sending your answers to me, log your find. I will only contact you if I have questions about the responses. Rock on!
1. In the field of geology, what does the term ‘erratic’ commonly refer to?
2. At the listed coordinates you will find a large boulder.
A. Describe its size, color and shape.
B. Do you see any other rock formations where this boulder could have come from?
C. Using the above information and what you observe at the site, where do you think this boulder came from and how did it get to this spot.
3. Are there any fractures or fissures on the boulder? Have any pieces broken off?
4. Based on what you’ve learned about erratics and what you’ve read on this page, would you consider this rock to be an erratic and why/why not?
5. OPTIONAL: Post a picture of yourself at the boulder.
6. Favorite Points always enjoyed.
A big Thank You to Groopsoop for helping me out!
Congrats to schwandt for FTF!