Caves, Arches , Stacks & Stumps COASTAL FEATURES Caves, Arches , Stacks & Stumps

CAVES & ARCHES Weaknesses in rock are exposed to erosion through processes of abrasion, solution and hydraulic action. These processes widen these weaknesses into cracks, which slowly become larger and develop into small caves. As the cave continues to erode, the back wall becomes thinner until eventually it is completely eroded away leaving an arch.

CAVES The rocks along the coast may contain joints, fissures or other weaknesses. These can be enlarged by wave action, eventually forming a cave.

At the southwestern end of Las Cuevas beach, you’ll find the caves for which the beach is named.

ARCHES, STACKS & STUMPS If a cave is formed in an exposed headland, it may be enlarged until it runs right through this headland. The resulting feature is called an arch. Subsequent erosion under the arch eventually leads to widening and weakening of the structure until the roof of the arch collapses and leaves a feature called a stack. The piece of rock which is left stranded away from the headland is called a stack. Over time the stack will continue to erode and finally collapse into a stump.

CAVES, ARCHES, STACKS & STUMPS

Paria Bay ,Blanchisseuse, North Coast Cathedral Rock/Paria Arch

LAS CUEVAS BAY This stack is found on Las Cuevas Bay

GALERA POINT These stumps are seen along the Toco main road, Northeast Coast

MT. IRVINE ,TOBAGO

GROUP ACTIVITY Label the diagram showing erosion of the headland Create a 3D Model of the coastal features formed by erosion of a headland

GROUP ACTIVITY #1

INDIVIDUAL ASSESSMENT With the aid of a diagram, explain the features formed by the erosion of a headland. 10mks