Show 1 4 t MYSTERIES OF NATURE I 1 by george frederick wright 1 A al LL D seas slowly fining filling up with sediment I 1 among ibe the active but often de ed a agencies asil assisting sting running 9 titer water in its work of down the continents angles orme have a prom 4 place this they do by material and making it w ipg the ac filble darwin haa has discussed their work ork la in a very interesting and con laglye manner according to his es estes tl there are on the average angleworms to the acre weigh bt to ITS pounds so active are animals in in working over the surface a SOIL that they annual annually lr eject to the surface about seven tone tons of solid tat erial which Is 1 in condition to be fully washed away by y the falling rains lat from thia this it can be learned ahat bat we should not despise the day of abill things nor forget when we on a worm that we are destroy ig tit important geological agency numerous other aide aids in preparing material for water transportation exist such uch as various other forma forms of kalmal and vegetable life and the action of the heat beat and cold in pulver wa liin the rocks and of ice in starting then them from their foundation but these deserve treatment by themselves and we till will tor for the present pass them by when the question arises what lecomet of all thia this sediment which la 13 transported into the sea the answer Is cot not difficult to find the wash of the hills Is 1 constantly being spread out over the bottom of the lakes the tay bays and the seas into which the rivers empty where are ad accumulating cumulating the beds of mud sand gravel and pebbles which under proper conditions ral be into slatestone sandstone siad stone and conglomerate rock ue the lime held in solution is furnishing material out of corals and shellfish of various kinds r will constrict colstr act their personal habata HOBS and leave them to form vast bed beds of rock toe the rapidity with which these ite c lations of sediment take place Is somewhat astonishing within historic times wo we know that many famous cities which were once sea pea porte ports are now far inland the city A c adria adds in northern nort bern italy which was it t the beginning of the christian era 10 famous a seaport that it gave ita its came to the adriatic sea la Is now IS 16 miles iliad the po and the abige baylog extended their deltas that distance since the city became famous naoto on oil the bellfo pel ho in china was on the shore of he be yellow sea D C it Is now 40 miles inland ae As late WO as A D the sea was 18 miles bearer nearer than it Is now all along the head of the yellow sea into which great chinese rivers are flow in hi the land Is gaining on the water it t the rate of about feet teet per an nun im in approaching shanghai across thi this tea sea one meets the turbid water long a clearly marked line forty or eltty miles out from the shore so sharp is 1 this line that in crossing it talf of the ship would still be in the blue ocean watce while the other halt 13 I 1 plunging gIng into water made turbid by the allt brought down by the hoang ha the euphrates and tigris have tiled lied up the head of the persian eull gulf alth their sediment until ur of the the former residence of 0 abraham Is now seventy or eighty ing atlle 11 inland nd the delta of the mia is more than miles long I 1 and nl on the average 60 miles wido wida overl ng square mile miles while uie tho deposits of the river are pushing it t out into the gulf at 0 mexico exIco 1 one bile tulle farther every 16 years toward be lower part of its course this tnt it Is known to be several hundred feet et la in depth the extensive plains et of eastern and an d southern china are all ts of at the ho ito and yingtse rang ang outside of at the glaciated re poa in the northern hemisphere all lake basins with few exceptions have teen filled to the brim with sediments into them by incoming stream tre ami it th glaciated region atre the lifetime of the lakes has been ea much shorter Bh orter they have been largely reely filled with sediment and so are e undergoing undergo lne a rapid process of ex traction tf Action tho the western halt of aake erie ie for converted example will be wo to solid land in a few thousand years bat la Is going on thus at the preat prest nt time helpa helps us to appreciate the last at extent of similar work which waa was during the long geolot le c agn in early geological time the 01 ol mississippi valley brors the blocky oclay mountains to the id the range of Archa ean rocks ex anding southward to north carolina lils a vast opa sea into which were airing rivers from the land oa on the tast t and the north bad nl III ady risen above 11 sea these rivers rs like thoe those already described at the e present timo were bearing into bea their burdena burdens of and al spread th it out over the bottom until all it beca me full the Is w but contin continuing aing this abl work in filling ad B the cult gulf of mexico blex ica all the rocks of the basin are of 1 centary origin their total thickness many thousand feet the different strata lie its one upon lother alother a like th leaves of at a book each esch containing some game fossil tive age mark 0 of life ito to indicate ita its rela according to the moat most moderate cal culat lons fons the crystalline mountains surrounding the mississippi basin on the north and east alch which constitute the oldest land in the world arid began their work of filling up the ippa basin about years ago an and d all that time has been necessary to prepare america for its present remarkable leaps in civilization it if in times past the same rate of erosion baa has been la in progress that Is going on now dow 1 1500 cubic miles of sediment has been handled in thia this work of at preparation this would make a mountain 20 miles wide and a mile high and miles long or enough to reach around the world three time times great as is the amount of sedimentary rocks in the world so industrious and efficient ein clent are the running streams stream ot of water that it Is calculated by alfred russell wallace that the entire work of its removal and deposition could easily have been in the limits set above to geological time copyright by joseph D howlee dowles |