Page:EB1911 - Volume 11.djvu/690

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670
GEOLOGY
[PHYSIOGRAPHICAL
The Geological Record or Order of Succession of the Stratified Formations of the Earth's Crust.
    Europe. North America.
Quaternary or Post-Tertiary Recent, Post-glacial or Human. Historic, up to the present time.

Prehistoric, comprising deposits of the Iron, Bronze and later Stone Ages.

Neolitic—alluvium, peat, lake-dwellings, loess, &c.

Palneolithic—river-gravels, cave-deposits, &c.

Similar to the European development, but with scantier traces of the presence of man.
Pleistocene or Glacial. Older Loess and valley-gravels; cave-deposits.

Strand-lines or raised beaches; youngest moraines.

Upper Boulder-clays; eskers; marine sands and clays.

Interglacial deposits.

Lower boulder-clay or Till, with striated rock-surfaces below.

As in Europe, it is hardly possible to assign a definite chronological place to each of the various deposits of this period, terrestrial and marine. They generally resemble the European series. The characteristic marine, fluviatile and lacustrine terraces, which overlie the older drifts, have been classed as the Champlain Group.
Cainozoic or Tertiary. Pliocene Newer:—English Forest-Bed Group; Red and Norwich Crag; Amstelian and Scaldesian groups of Belgium and Holland; Sicilian and Astian of France and Italy.

Older:—English Coralline Crag; Diestian of Belgium; Plaisancian of southand Italy.

On the Atlantic border represented by the marine Floridian series; in the interior by a subaerial and lacustrine series; and on the Pacific border by the thick marine series of San Francisco.
Miocene Wanting in Britain; well developed in France, S. E. Europe and Italy; divisible into the following groups in descending order: (1) Pontian; (2) Sarmatian; (3) Tortonian; (4) Helvetian; (5) Langhian (Burdigalian). Represented in the Eastern States by a marine (Yorktown or Chesapeake, Chipola and Chattahoochee groups) and in the interior by the lacustrine Loup Fork (Nebraska), Deep River, and John Day groups.
Oligocene In Britain the "fluvio-marine series" of the Isle of Wight; also the volcanic plateaux of Antrim and Inner Hebrides and those of the Faeroe Isles and Iceland. In continental Europe the following subdivisions have been established in descending order: (1) Aquitanian, (2) Stampian (Rupelian) (3) Tongrain (Sannosian) On the Atlantic border no equivalents have been satisfactorily recognised, but on the Pacific side there are marine deposits in N.W. Oregon, which may represent this division. In the interior the equivalent is believed to be the fresh-water White River series, including (1) Protoceras beds, (2) Oreodon beds, and (3) Titanothervum beds.
Eocene Barton sands and clays; Ludian series of France.

Bracklesham Beds; Lutetian (Calcaire grossier and Caillasses) of Paris basin.

London clay, Woolwich and Reading Beds; Thanet sands; Ypresian or Londinian of N. France and Belgium; Sparnacian and Thanetian groups.

Woodstock and Aquia Creek groups of Potomac River; Vicksburg, Jackson, Claiborne, Buhrstone; and Lignitic groups of Mississipi.

In the interior a thick series of fresh-water formations. comprising, in descending order, the Uinta, Bridger, Wind River, Wasatch, Torrejon, and Puerco groups.

On the Pacific side the marine Tejon series of Oregon and California.

Mesozoic or Secondary. Cretaceous. Upper. Danian—wanting in Britain; uppermost limestone of Denmark.

Senonian—Upper Chalk with Flints of England; Aturian and Emscherian stages on the European continent.

Turonian—Middle Chalk with few flints, and comprising the Angoumian and Ligerian stages.

Cenomanian—Lower Chalk and Chalk Marl.

Albian—Upper Greensand and Gault.

On the Atlantic border both marine strata and others containing a terrestrial flora represent the Cretaceous series of formations.

In the interior there is also a commingling of marine with lacustrine deposits. At the top lies the Laramie or Lignitic series with an abundant terrestrial flora, passing down into the lacustrine and brackish-water Montana series. Of older date, the Colorado series contains an abundant marine fauna, yet includes also some Niobrara marls and limestones are likewise of marine origin, but the lower members of the series (Benton and Dakota) show another great representation of fresh-water sedimentation with lignites and coals.

In California a vast succession of marine deposits (Shasta-Chico) represents the Cretaceous system; and in western British N. America coal-seams also occur.

Cretaceous. Lower. Aptian—Lower Greensand; Marls and limestones of Provence, &c.

Urgonian (Barremian)—Atherfield clay; massive Hippurite limestones of southern France.

Neocomian—Weald clay and Hastings sand; Hauterivian and Valanginian sub-stages of Switzerland and France.

Jurassic. Purbeckian—Purbeck beds; Münder Mergel; largely present in Westphalia.

Portlandian—Portland group of England, represented in S. France by the thick Tithonian limestones.

Kimmeridgian— Kimmeridge Clay of England; Virgulian and Pterocerian groups of N. France; represented by thick limestones in the Mediterranean basin.

Corallian—Coral Rag, Coralline Oolite; Sequanian stages of the Continent, comprising the sub-stages of Astartian and Rauracian.

Oxfordian—Oxford Clay; Axgovian and Neuvizyan stages.

Callovian—Kellaways Rock, Divesian sub-stage of N. France.

Bathonian—series of English strata from Cornbrash down to Fuller’s Earth.

Bajocian—Inferior Oolite of England.

Lassic—divisible into (1) Upper Lias or Toarcian, (2) Middle Lias, Marlstone or Charmouthian, (3) Lower Lias of Sinemurian and Hettangian.

Representatives of the Middle and lower Jurassic formations have been found in California and Oregon, and farther north among the Arctic islands.

Strata containing Lower Jurassic marine fossils appear in Wyoming and Dakota; and above them come the Atlantosaurus and Baptanodon beds, which have yielded so large a variety of deinosaurs and other vertebrates, and especially the remains of a number of genera of small mammals.

Triassic. In Germany and western Europe this division represents the deposits of inland seas or lagoons, and is divisible into the following stages in descending order: (1) Rhaetic, (2) Keuper, (3) Muschelkalk, (4) Bunter. In the eastern Alps and the Mediterranean basin the contemporaneous sedimentary formations are those of open clear sea, in which a thickness of many thousand feet of strata was accumulated. In New York, Connecticut, New Brunswick, and Nova Scotia a series of red sandstone (Newark series) contains land-plants and labyrinthodonts like the lagoon type of central and western Europe. On the Pacific slope, however, marine equivalents occur, representing the pelagic type of south-eastern Europe.
Paleozoic or Primary. Permian. Thuringian—Zechstein, Magnesian Limestone; named from its development in Thuringia; well represented also in Saxony, Bavaria and Bohemia.

Saxonian—Rothliegendes Group; Red Sandstones, &c.

Autunian—where the strata present the lagoon facies, well displayed at Autun in France; where the marine type is predominant, as in Russia, the group has been termed Artinskian.

To this division of the geological record the Upper Barren Measures of the coal-fields of Pennsylvania, Prince Edward Island, Nova Scotia and New Brunswick have been assigned.

Farther south in Kansas, Texas, and Nebraska the representatives of the division have an abundant marine fauna.

Carboniferous. Stephanian or Uralian—represented in Russia by marine formations, and in central and western Europe by numerous small basins containing a peculiar flora and in some places a great variety of insects.

Westphalian or Moscovian—Coal-measures, Millstone Grit.

Culm or Dinantian—Carboniferous Limestone and Calciferous Sandstone series.

Upper productive Coal-measures.

Lower Barren measures.

Lower productive Coal-measures.

Pottsville conglomerate.

Mauch Chunk shales; limestones of Chester, St Louis, &c.

Pocono series; Kinderhook limestone.

Devonian and Old Red Sandstone. Devonian type. Old Red Sandstone type.  
Upper Famennian.

Frasnian.

Yellow and red sandstone with Holoptychius, Bothriolepis, &c. Catskill red sandstone; Old Red Sandstone type: the strata below show the Devonian type.

Chemung Group.

Genesee Group.

Middle Givetian

Eifelian

Caithness Flagstones with Osteolepus, Dipterus, Homosteus, &c. Hamilton Group.

Marcellus Group.

Lower Coblentzian

Gedinnian

Red and purple sandstones and conglomerates with Cephalaspis, Pteraspis, &c. Corniferous Limestone.

Onondaga Limestone.

Upper Helderberg Group.
Oriskany Sandstone.
Silurian Upper Ludlow Group.

Wenlock Group.

Llandovery Group.

Lower Helderberg Group.

Water-Lime.

Niagara Shale and Limestone.

Clinton Group.

Medina Group.

Lower (Ordovician) Caradoc or Bala Group.

Llandeilo Group.

Arenig Group.

Cincinnati Group.

Utica Group.

Trenton Group.

Chazy Group.

Calciferous Group.

Cambrian Upper or Olenus series—Tremadoc slates and Lingula Flags.

Middle or Pardoxides series—Menevian Group.

Lower or Olenellus series—Llanberis and Harlech Group, and Olenellus-zone.

Upper or Potsdam series with Olenus and Dicelocephalus fauna.

Middle or Acadian series with Paradoxides fauna.

Lower or Georgian series with Olenellus fauna.

Archean, Pre-Cambrian Eozoic.   In Scotland, underneath the Cambrian Olenellus group, lies unconformably a mass of red sandstone and conglomerate (Torridonian) 8000 or 10,000 ft. thick, which rests with a strong gneisses and schists (Lewisian). A thick series of slates and phyllites lies below the oldest Palaeozoic rocks in central Europe, with coarse gneisses below. In Canada and the Lake Superior region of the United States a vast succession of rocks of Pre-Cambrian age has been grouped into the following subdivisions in descending order: (1) Keweenwan, lying unconformably on (2) Animikie, separated by a strong unconformability from (3) Upper Huronian, (4) Lower Huronian with an unconformable base, (5) Goutchiching, (6) Laurentian. In the eastern part of Canada, Newfoundland, &c., and also in Montana, sedimentary formations of great thickness below the lowest Cambrian zone have been found to contain some obscure organisms.