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Large Igneous Provinces

Plume heads and LIPs
The main manifestations of plume heads on the earth's surface are a number of so-called Large Igneous Provinces or LIPs. These consist of very large areas of basalt, either as plateau basults on land (e.g. the Deccan Traps of India) or large submarine plateaus (e.g. Kerguelen Plateau) or smaller submarine edifices entirely below the present surface of the oceans. Often these features are accompanied by dyke swarms and/or igneous intrusions. When dated, these features usually cluster around a rather short time interval, indicating a brief but intense period of magmatic activity at the time of the plume head first 'struck'. Later plume activity is often less intense but, nevertheless, long-lived. Trails of plume activity are found across the ocean floors (e.g. the Walvis Ridge off southwest Africa) and minor oceanic islands, still with occasional volcanic activity, can me found (e.g. Bouvet island) associated with mantle plumes that broke out more than 180 million years ago. A number of hotspots show similar trails (e.g. Cameroon volcanic line) but lack the large areas of extrusion.
The animation shows the development of the LIP record over time. Areas of basalt are shown in red-brown, appearing at a time that rfeflects the dates measured, where available. Some of the known dyke swarms are shown as purple lines (e.g. the okavango dyke swarm in southern Africa) and a few large intrusion are purple with a red outline (e.g. Dufek in Antarctica). Most are too small to see at this scale. It should be remembered that erosion has probably removed much of the volcanic sequences on land and it is only the present-day outlines of plateaus that are shown.