THE PEAT ORIGIN OF COAL.

Timaru Herald, Volume LXXXIII, Issue 12901, 12 February 1906, Page 3

THE PEAT ORIGIN OF COAL.

(By Professor Arthur Lakes, iu Deuver " .Yiiiiiiig Keporier. ;

Peat is the original or primitive foim of coal, and was undoubtedly the suu-sianc-c iroiu which the g'icaier pan of our coai-beds, both lignitic, bituimuious, aL<i auturaciie, were formed. The several varieties oi coal axe merely tue results ol age, pressure, and a certain auw'ia.i ui heat upon wnat was once pe.it.

JL'eat is a vegetable niattei, v r lest ! decomposed ana chemically idieiea, ioui.d ] througnout temperate a., wed as uiom I ; uicic climates, la boggy .piutes \. ucit i ; marshy plants glow yaa uecay. The piiaj cipal plant loiiiuug pe.it i> .„ nn,s.> ......ed I ["sphagnum." which, growing on uiii-,.ups,! ; slopes, and valley-bottoms "as a wet, s r . jtibious mass; uies in .its" iower paiis ii^o.; scuds out new fibies ab-ve. Some peaty] I deposits have been formed in lakes, either | by the growth of aquatic plants on the j bottom or by the precipitation -cf decaying I vegetation lrom the layer of matted plantgrowth which creeps from the shore along i |ihe surface of the water. The surface | of the lake is gradually covered with a | i treacherous' gieen suiface. The decayed' vegetable -matter from the under-part* of this crust sinks tc the bottom of the water. I forming there a line, peaty mud which slowly grows upward. A layer of brown niuddy water lies between, the still grow- | ing vegetation, abov* and the niuddy de- | posit at the bottom. Heavy rains augmenting this intermediate wateiy layer mav make the centre swell up until* the" matted skin of moss bursts and a deluge of black mud pours into *he surrounding country. • The inundated ground is covered with a /black peaty earth. From the treacherous nature of their surface, peat swamps have frequently engulfed, men and animals venturing on them. Peat has a great antiseptic power, derived from lramic acid and hydrocarbons, which preserve organic tissues. In Ireland the re/ mains of the great extinct Irish elk, and! in -America those of the mastodon, have] been dug out of peat-bogs. In peat-bogs" in England the bodies of men and women! have been found, the former dressed in; course haircloth, the former retaining both! hair and teeth, with sandals on the feet, i 'TYees embedded in peat-bogs are sometkaes* turned into a'species of hard, ja-like sub-j stance, such as the "bog-oak" seld by Irish women to transatlantic passengers on] the steamers off Cork Harbour. Human! weapons, tools, and ornaments, dating* through Bitten, .B.oman. .and Saxon pei riods, • have . often been _fcund : ; also, in '■ lake.dwellings., and canoes. . , ! In some few cases marine peat-beds have •been - " formed'of. seaweeds. Some arevalsq buried urid-ei; Cbe to «ulf ■ sidences of. the Jand: '"rSonieyeirs ago Ba^jS' veiy low on "the* oorir oF the Channel Isles, between England and France, a peat-bed being dug up close to the retreating waves; the petrified trunks and branches of oak-trees still retained their form, together with that of acorgi attached to" them. . The same peat-bear' outcrop at low water on the Cornish coastj, on the oppose- gidespjf l $e x Ghajinel. v Wplyiug a subsidence of land feetween "these two points. "'These peat-beds, by accumulation of sands above them to great thickness, would change in time into lignite coal; and that, by still greater accumulation of sands compressed into sandstone, or by upheaval raised into dry land, would be changed to bituminous coal; and that, by great mechanical upturning, as in the Eastern States, or by the intrusion of rolcanic rocks, as in Colorado, be changed into anthracite. Still greater heat might change the anthracite to graphite. The cdal-seams of both the Eastern and Western States were formed in immense peat-swamps bordering on, or nearly on, a level with the sea... - In the Eastern States the aquatic plants forming the peat, swamps. were of gigantic size, consisting of enormous horse-tail reeds, club-messes, i and. tree-ferns. In the western-or Laramie | coalfields • the' swamp vegetation _was more ■ like that of uhe semi-tropical regions of .to-day, .such sw-Florida and the Southern States. We often find in the roofs of ccal-seems beautifully preserved impressions of palmettos, delicate ferns, water-lily leaves, imingled Vith a great variety of leaves of. semi-tropical trees, such as magnolia-, sassafras, cinnamon, cassia, gum platanus, buckthorn, oak, beech, and i poplar. These leaves were doubtless blown in'.o the peat-swamps horn forests i growing in the vicinity. i It was a not uncommon idea by those | I who recogcise the vegetable origin of coal, [that American coal-seams represent the .buried . remains of forests like those of Canada: but this is not the case.. The trunks of forest-trees occasionally found 'embedded in coal-seams' -were . drifted in'»oi the.swamps by rivers,..but- do] iiotJoiiii an huportanWlem^ehrin-'thVni^k-. jflg.. of,. thß^o^^aßo^.,. J .",SJtodinit Joreste. » on high gromid, ILka thote of Canada, decay.

nsd form soil, but no coaL It is the humbler swamp vegetation, such as mosses :m<l aquatic plants, that are mainly aesponsih'c for the existence of the c'»al-s*ams. (>c;:erntion after generation of these have been submerged, and formed jn;!t, and subsequently coal, with but little .issistonce from the forests that might grow in the Ticinity. The great Carboniferous coal j-o.<:tis of t3ie Kastern States w«re similarly f<rn:ed. not of trunks of forest-trees, but of remains of a gigantic and luxuriant swamp vegetation.