This an earthcache so there isn’t a container to find but instead you discover something about the geology of the area. To log this cache as a found, you will visit two locations and then provide me with answers to a few questions.
The earthcache will explore the differences among drumlins, eskers, and kames. All three involve glaciers and what is left behind when the glacier melted but there are structural differences among them based on how the sediment and glacier interacted over time. After reading the geology lesson below, you will use what you have learned to view the area at the two sets of coordinates to answer the questions in the “Logging Requirements” section.
The earthcache is located at Woodsom Farm. This area offers open and rolling meadows, sprawling wetlands, and stands of birch, beech, and oak. Acting primarily as conservation land for Amesbury's Powow River watershed, it is open to the public. Popular uses are dog walking, sledding, and hiking.
GEOLOGY LESSON
At the posted coordinates, view the higher of the two hills to view its shape from the side. The second set of coordinates will bring you to the top of the higher hill where you will view the front and backside of the hill. These two viewpoints along with the information found in this "Geology Lesson" will help you answer the "Logging Requirements" questions.
Drumlins
Drumlins are elongated egg-shaped hills. The hills are made up of sediment (generally a quarter of a mile or more in length) that have been streamlined by glacier flow. As a glacier advances, it encounters the harder bedrock and carves and grinds it as it moves around and over it. The glacier deposits the softer sediment in behind the bedrock which sculpts the landscape into the egg-like shape you see today.
The classic drumlin shapes is a hill that highest on its up-glacier end and tapers gently from there, like a half-buried egg. Because they have been streamlined by flowing ice, scientists often use them to understand past glacier flow directions.
Eskers
Eskers are long sinuous hills, snake shaped. They are different from drumlins because the esker was formed by meltwater from the receding glacier rather than from the ice carving and grinding the bedrock. Eskers are made up of ridges of sediment that formed in water channels beneath or within the glacier ice. When the glacier retreats, the stream of water stops flowing because the hydrostatic pressure from the glacier is lost. The sediment carried in the stream drops and builds small piles that take on the shape of the channels. The result is ridges that extend pretty much perpendicular to the past glacier edge, the way the water flows from within to the edge of the glacier.
Kames
A kame is an irregular pyramid shaped hill or mound composed of sand, gravel, and till. Kames are similiar to eskers in that they were formed by glacial melt water which deposited the material at irregular places in and along melting ice. The material came from rocks or sediment that have fallen on top of the glacier. The rocks or sediment then fall into the crevasses in the glacier. As the glacier melted, the crevasses moved down closer and closer to the base of the glacier. When they reach the valley bed once the glacier has almost melted, they are dumped onto the bed as a mound of sediment.
LOGGING REQUIREMENTS
To log this cache as a found, provide me with answers to the two questions below and post the requisite photo to your online log. The answers can be sent to me using the Geocaching message system.
- Is the hill you are standing on at the second waypoint a drumlin, esker or kame? Explain why.
- What direction do you think the glacier was moving? Explain why.
- Post a photo of yourself or your GPSr/phone at the second waypoint.