The Formation of Glacial Till: As the ice sheet moved across this region, it encountered the limestone bedrock below. The interaction between the ice and the limestone produced what we call a “glacial till.” A glacial till is a mixture of various sediments, including large rocks, erratics carried by the ice, and local rocks and sediments, all blended together.
Observing the Ice Bedrock Interface: At Seaham, we have a remarkable example of processes acting at the ice bedrock interface. If you look closely in places you’ll notice a clear line separating the limestone bedrock from the glacial till above. The glacial till comprises clay, silt, sand, and rocks of different sizes, all mixed with the local limestone.
Dynamic Ice Movement: The ice sheet’s movement along the Durham coast was dynamic and oscillatory, causing the deposition of multiple till layers, forming a sequence up to 10 to 12 meters thick. This oscillation of the ice sheet created a complex glacial landscape.
Glaciotectonic Features: Keen observers can spot “stringers” in the limestone, evidence of glaciotectonic features formed as the limestone was deformed by the ice above. These structures provide insights into the forces at play during the ice sheet’s movement.
Imagine the Ancient Ice: As you explore Seaham, envision a tremendous ice sheet, up to 500 meters thick, slowly shaping the landscape through its interaction with the limestone bedrock below. Transport yourself back in time to experience this awe-inspiring geological process.
