Giant's Causeway cases the horizontal fracture has resulted in a bottom face that is convex while the upper face of the lower segment is concave, producing what are called "ball and socket" joints. The size of the columns is primarily determined by the speed at which lava from a volcanic eruption cools. The extensive fracture network produced the distinctive columns seen today. The basalts were originally part of a great volcanic plateau called the Thulean Plateau which formed during the Paleocene. According to legend, the columns are the remains of a causeway built by a giant. The story goes that the Irish
Cave Cave A cave is a hollow place in the ground, specifically a natural space large enough for a human to enter. Caves form naturally by the weathering of rock and often extend deep underground. The word "cave" can also refer to much smaller openings such as sea caves, rock shelters, and grottos, though strictly speaking a cave is exogene, meaning it is deeper than its opening is wide, and a rock shelter is endogene. A cavern is a specific type of cave, naturally formed in soluble rock with the ability to grow speleothems. Speleology is the science of exploration and