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The Daily Volcano Quote: Charles Darwin and ‘the grandeur of the one motive power’ 18 February 2009

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Part of the Western Coast of South America

With these views, if we look at a map of America, and observe the continuity of the great chain of the Andes, and its lesser parallel ones, in which from lat. 55° 40′ South to 60° North, a space of little less than 7000 miles, the volcanic forces either now are, or recently have been, in action,—and likewise the symmetry of the whole,—we shall be deeply impressed with the grandeur of the one motive power, which, causing the elevation of the continent, has produced, as secondary effects, mountain-chains and volcanos. The same reasons which led me to the conviction, that the train of connected volcanos in Chile and the recently uplifted coast, together more than 800 geographical miles in length, rested on a sheet of fluid matter, are applicable with nearly equal force to the areas beneath the other trains. We see that these areas are connected by one uniform chain of mountains, from many distant points of which fluid rock is yearly ejected; and as there are proofs that nearly the whole west coast of South America has been elevated within a period geologically modern, and that this movement, in some parts at least, has extended across the continent,—keeping, also, in mind the probability, that during periods of increased subterranean action, such as those indicated in the foregoing tables, the whole western part of the continent has been almost simultaneously affected, it appears to me, that there is little hazard in assuming, that this large portion of the earth’s crust floats in a like manner on a sea of molten rock. Moreover,—when we think of the increasing temperature of the strata, as we penetrate downwards in all parts of the world, and of the certainty that every portion of the surface rests on rocks which have once been liquefied;—when we consider the multitude of points from which fluid rock is annually emitted, and the still greater number of points from which it has been emitted during the few last geological periods inclusive, which, as far as regards the cooling of the rock in the lowest abysses, may probably be considered as one, from the extreme slowness with which heat can escape from such depths;—when we reflect how many and wide areas in all parts of the world are certainly known, some to have been rising and others sinking during the recent æra, even to the present day, and do not forget the intimate connexion which has been shown to exist between these movements and the propulsion of liquified rock to the surface in the volcano;—we are urged to include the entire globe in the foregoing hypothesis.

Charles Darwin, it has been suggested, would be ‘thrilled and excited’ by the developments that have occurred in the study of biological evolution since his own time. Passages from his geological writings such as the above make it clear that he would have greeted subsequent developments in geology, and particularly perhaps the emergence of the theory of plate tectonics, with equal fascination and delight.

From Charles Darwin, ‘On the connexion of certain volcanic phenomena in South America; and on the formation of mountain chains and volcanos, as the effect of the same power by which continents are elevated’, Transactions of the Geological Society of London, series 2, vol. 5, no. 3 (1840), pp. 629-30. Available online at The Complete Work of Charles Darwin Online.

For one week from 12 February 2009, the 200th anniversary of Charles Darwin’s birth, The Volcanism Blog will feature a volcano-related quote from Darwin each day.

The Daily Volcano Quote: from Monday to Friday, a new eruption of volcanic verbiage each day.

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