Page:Polar Exploration - Bruce - 1911.djvu/195

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PHYSICS OF POLAR SEAS
191

Antarctic and subantarctic Regions, and which does not occur in other parts of the world except to a quite insignificant extent in certain places. To the south of this belt or band of diatom ooze we have a continuous ring south of 60° S., which is a deep-sea deposit of blue mud. In the Weddell and Biscoe Seas we have a small patch in the blue mud region which seems to be a sort of mixture of blue mud and red clay, and which is associated with the area of deep water mapped out by the Valdivia and the Scotia. A special point of interest in this blue mud deposit is found on examining maps of deposits in different parts of the world, when it is found that this deposit is always associated with continental lands. It occurs round the whole of the coasts of South and North America; round the coasts of Europe, Asia, and Africa. There is, in fact, no continental coast which is not bounded by blue mud. The natural inference, therefore, is that when we find blue mud surrounding an area of land about the South Pole that it is there in association with a great mass of continental land. It may here be mentioned that this blue mud has one character which is not common to other regions where that deposit occurs, for during the cruise of the Scotia there were taken up with the trawl many tons of subangular rocks, some of them weighing fully