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Show 190 NEW LAKES IN LOUISLAND. . · 1 . but on t h e con t r al·y ' the ocean here swar.m s aquati.c amm·a t s' ral'l y d oes w1 1 ere the influx of a great river with hfe, as 1 g~ne 1 f organic and mineral matter. furnishes a copi~us su~~nyth~ behold the spoils of the land Yet many geologists, w t yand blended confusedly with · essive stra a heaped m succ . t' s ersed with broken shells and the remains of fishesh, or m ervi.PewinO' the signs of a turbulent, 1 · · that t ey are o cora s, Imagme .1 d ttled state of the planet. They instead of a tranqm an thse proof of chaotic disorder, and d · h henomena e rea m sue P . t d of indications of a surface reiterated catastro~hes, 1~sde~icious and fertile districts now as habitable as t eT~:s are e not content with disregarding the tenanted by man. Y f Nature when they speculate l f the present course o ' 1 ana ogy o l t · of past ti·m es, but they often draw cone u-on the revo L~ Ions t te of things directly the reverse sions concermn~ the ~o~m~r; ~tion from facts would infallibly of those to whiCh a lair m u lead them: h ."k' feature in the basin of the Missis- There IS anot er stn mg . h. h we . . . . f the changes now m progress, w IC Slppt, Illustrative o . the eormation by natural causes of t it to mentiOn- 11 • ll must no om d . f others These are espeCia y 1 1 d the ramage o · great a {es, an b . f tl e Red River in Louisiana, where the f t in the asm o 1 . 'l 1 requen f h m called Bistineau, is more than thtrty mt es ong, largest o t e d.' d th of from fifteen to twenty feet. In the and has a me mm ep ress-trees, of all sizes, now deepest p;rts a;:;e~~e:~~;~~~1~~ptops broken by the wi?d, dead, an mos t This tree resists the actlon yet standing erect under wa er. ther and if not submerged of air and water longer than ;~~e~ain iife f~r an extraordinary throughout the wh~l~ year, WI 11 Bl k Lake Cado Lake, . d * Lake Bistmeau, as we as ac ' b n perio · d thers have ee Spanish Lake, Natchitoches Lakeb an m;:~l oeleva;ion of the formed, accord~ng t~ Da~?~ ~Je ta1;u~~=l accumulations have bed of Red RIVer, m ~ Ic . h 1 and cause its waters, been so great as to raise Its c annie ' ths of many tribu· during the fl oo d season, t 0 flow up t. 1e mou • to lakes. In taries, and to convert parts of their courses m . f, t of ines standing erect under water "' Captains Clark and Lewls found a ores p . bich they supposed, froro in the body of the Columbia River in North A:enca~;abouttwentyyears.-Vol. the appearance of the trees, to have been only su merg ii., p. 241. EARTHQUAKES IN BASIN OF MISSISSIPPI. 191 the autumn, when the level of Red River is again depressed, the waters rush back again, and some lakes become grassy meadows, with streams meandering through them *. Thus, there is a periodical flux and reflux between Red River and some of these basins, which are mere1y reservoirs, alternately emptied and filled like our tide estuaries-with this difference, that in the one case the land is submerged for several months continuously, and, in the other, twice in every twentyfour hours. It has happened, in several cases, that a bar has been thrown by Red River across some of the openings of these channels, and then the lakes become, like Bistineau, constant repositories of water. But even in these cases, their level is liable to annual elevation and depression, because the flood when at its height passes over the bar; just as, where sand-hills close the entrance of an estuary on the Norfolk or Suffolk coast, the sea, during some high tide or storm, has often breached the barrier and inundated again the interior country. The frequent fluctuations in the direction of river-courses, and the activity exerted by running water in various parts of the basin of the Mississippi, are partly, perhaps, to be ascribed to the co-operation of subterranean movements, which alter from time to time the relative levels of various parts of the surface. So late as the year 181~, the whole valley, from the mouth of the Ohio to that of the St. Francis, including a front of three hundred miles, was convulsed to such a degree, as to create new islands in the river, and lakes in the alluvial plain, some of which were twenty miles in extent. We shall allude to this event when we treat of earthquakes, but may state here that they happened exactly at the same time as the fatal convulsions at Caraccas; and the district shaken was nearly five degrees of latitude farther removed from the great centre of volcanic disturbance, than the basin of the Red River, to which we before alluded t. When countries are liable to be so extensively and permanently affected by earthquakes, speculations concerning changes in their hydrographical features must not be made with- * Darby's Louisiana, p. 33. t Darby mentions beds of marine shells on the banks of Red River, which seem to indicate that Lower Louisiana is of recent formation: its elevation, perhap~, above the sea, may have been due to the same series of earthquakes which contmues to agitate equatorial America. |