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
Geological Survey of Canada conduct fieldwork in the early 1950's . Dr. Alice Wilson, the first of these women, lobbied for the inclusion of paleontologist Frances Wagner shortly afterward. Around this same time, the GSC employed a third woman Dr. Helen Belyea. The Canadian National Seismograph Network is monitored by the Geological Survey of Canada. The Geological Survey Canada operates a network of 14 magnetic observatories throughout Canada, located as follows: Notes Bibliography Geological Survey of Canada The Geological Survey of Canada (GSC; ) is a Canadian federal government agency responsible for performing geological surveys of the country, developing Canada's natural resources and protecting