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diff --git a/old/3772-h/files/contents.html b/old/3772-h/files/contents.html new file mode 100644 index 0000000..85d3d63 --- /dev/null +++ b/old/3772-h/files/contents.html @@ -0,0 +1,736 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> +<!-- saved from url=(0036)http://../Lyell/The Student's Elements of Geology --> +<html> +<head> +<meta name="generator" content="HTML Tidy, see www.w3.org"> +<title>The Student's Elements of Geology: Title</title> +<meta content="text/html; charset=iso-8859-1" http-equiv= +"Content-Type"> +<meta content="MSHTML 5.00.2919.6307" name="GENERATOR"> +<link rel="stylesheet" href="geology.css" type="text/css"> +</head> +<body> +<p><b>The Student's Elements of Geology</b></p> + +<hr> +<br> + + +<center> +<h2>CONTENTS</h2> + +—::— + +<p> </p> + +<a href="ch1.html"><b>Chapter I</b></a><br> +<br> +ON THE DIFFERENT CLASSES OF ROCKS.</center> + +<p>Geology defined. — Successive Formation of the Earth's +Crust. — Classification of Rocks according to their Origin +and Age. — Aqueous Rocks. — Their Stratification and +imbedded Fossils. — Volcanic Rocks, with and without Cones +and Craters. — Plutonic Rocks, and their Relation to the +Volcanic. — Metamorphic Rocks, and their probable Origin. +— The term Primitive, why erroneously applied to the +Crystalline Formations. — Leading Division of the Work.</p> + +<br> + + +<center><a href="ch2.html"><b>Chapter II</b></a><br> +<br> +AQUEOUS ROCKS—THEIR COMPOSITION AND FORMS OF +STRATIFICATION.</center> + +<p>Mineral Composition of Strata. — Siliceous Rocks. — +Argillaceous. — Calcareous. — Gypsum. — Forms of +Stratification. — Original Horizontality. — Thinning +out. — Diagonal Arrangement. — Ripple-mark.</p> + +<br> + + +<center><a href="ch3.html"><b>Chapter III</b></a><br> +<br> +ARRANGEMENT OF FOSSILS IN STRATA—FRESH-WATER AND +MARINE.</center> + +<p>Successive Deposition indicated by Fossils. — Limestones +formed of Corals and Shells. — Proofs of gradual Increase of +Strata derived from Fossils. — Serpula attached to Spatangus. +— Wood bored by Teredina. — Tripoli formed of +Infusoria. — Chalk derived principally from Organic Bodies. +— Distinction of Fresh-water from Marine Formations. — +Genera of Fresh-water and Land Shells. — Rules for +recognising Marine Testacea. — Gyrogonite and Chara. — +Fresh-water Fishes. — Alternation of Marine and Fresh-water +Deposits. — Lym-Fiord.</p> + +<br> + + +<center><a href="ch4.html"><b>Chapter IV</b></a><br> +<br> +CONSOLIDATION OF STRATA AND PETRIFACTION OF FOSSILS.</center> + +<p>Chemical and Mechanical Deposits. — Cementing together of +Particles. — Hardening by Exposure to Air. — +Concretionary Nodules. — Consolidating Effects of Pressure. +— Mineralization of Organic Remains. — Impressions and +Casts: how formed. — Fossil Wood. — Goppert's +Experiments. — Precipitation of Stony Matter most rapid where +Putrefaction is going on. — Sources of Lime and Silex in +Solution.</p> + +<br> + + +<center><a href="ch5.html"><b>Chapter V</b></a><br> +<br> +ELEVATION OF STRATA ABOVE THE SEA.—HORIZONTAL AND INCLINED +STRATIFICATION.</center> + +<p>Why the Position of Marine Strata, above the Level of the Sea, +should be referred to the rising up of the Land, not to the going +down of the Sea. — Strata of Deep-sea and Shallow-water +Origin alternate. — Also Marine and Fresh-water Beds and old +Land Surfaces. — Vertical, inclined, and folded Strata. +— Anticlinal and Synclinal Curves. — Theories to +explain Lateral Movements. — Creeps in Coal-mines. — +Dip and Strike. — Structure of the Jura. — Various +Forms of Outcrop. — Synclinal Strata forming Ridges. — +Connection of Fracture and Flexure of Rocks. — Inverted +Strata. — Faults described. — Superficial Signs of the +same obliterated by Denudation. — Great Faults the Result of +repeated Movements. — Arrangement and Direction of parallel +Folds of Strata. — Unconformability. — Overlapping +Strata.</p> + +<br> + + +<center><a href="ch6.html"><b>Chapter VI</b></a><br> +<br> +DENUDATION.</center> + +<p>Denudation defined. — Its Amount more than equal to the +entire Mass of Stratified Deposits in the Earth's Crust. — +subaërial Denudation. — Action of the Wind. — Action of +Running Water. — Alluvium defined. — Different Ages of +Alluvium. — Denuding Power of Rivers affected by Rise or Fall +of Land. — Littoral Denudation. — Inland Sea-Cliffs. +— Escarpments. — Submarine Denudation. — +Dogger-bank. — Newfoundland Bank. — Denuding Power of +the Ocean during Emergence of Land.</p> + +<br> + + +<center><a href="ch7.html"><b>Chapter VII</b></a><br> +<br> +JOINT ACTION OF DENUDATION, UPHEAVAL, AND SUBSIDENCE IN +REMODELLING THE EARTH'S CRUST.</center> + +<p>How we obtain an Insight at the Surface, of the Arrangement of +Rocks at great Depths. — Why the Height of the successive +Strata in a given Region is so disproportionate to their Thickness. +— Computation of the average annual Amount of subaërial +Denudation. — Antagonism of Volcanic Force to the Levelling +Power of running Water. — How far the Transfer of Sediment +from the Land to a neighbouring Sea-bottom may affect Subterranean +Movements. — Permanence of Continental and Oceanic Areas.</p> + +<br> + + +<center><a href="ch8.html"><b>Chapter VIII</b></a><br> +<br> +CHRONOLOGICAL CLASSIFICATION OF ROCKS.</center> + +<p>Aqueous, Plutonic, volcanic, and metamorphic Rocks considered +chronologically. — Terms Primary, Secondary, and Tertiary; +Palæozoic, Mesozoic, and Cainozoic explained. — On the +different Ages of the aqueous Rocks. — Three principal Tests +of relative Age: Superposition, Mineral Character, and Fossils. +— Change of Mineral Character and Fossils in the same +continuous Formation. — Proofs that distinct Species of +Animals and Plants have lived at successive Periods. — +Distinct Provinces of indigenous Species. — Great Extent of +single Provinces. — Similar Laws prevailed at successive +Geological Periods. — Relative Importance of mineral and +palæontological Characters. — Test of Age by included +Fragments. — Frequent Absence of Strata of intervening +Periods. — Tabular Views of fossiliferous Strata.</p> + +<br> + + +<center><a href="ch9.html"><b>Chapter IX</b></a><br> +<br> +CLASSIFICATION OF TERTIARY FORMATIONS.</center> + +<p>Order of Succession of Sedimentary Formations. — Frequent +Unconformability of Strata. — Imperfection of the Record. +— Defectiveness of the Monuments greater in Proportion to +their Antiquity. — Reasons for studying the newer Groups +first. — Nomenclature of Formations. — Detached +Tertiary Formations scattered over Europe. — Value of the +Shell-bearing Mollusca in Classification. — Classification of +Tertiary Strata. — Eocene, Miocene, and Pliocene Terms +explained.</p> + +<br> + + +<center><a href="ch10.html"><b>Chapter X</b></a><br> +<br> +RECENT AND POST-PLIOCENE PERIODS.</center> + +<p>Recent and Post-pliocene Periods. — Terms defined. — +Formations of the Recent Period. — Modern littoral Deposits +containing Works of Art near Naples. — Danish Peat and +Shell-mounds. — Swiss Lake-dwellings. — Periods of +Stone, Bronze, and Iron. — Post-pliocene Formations. — +Coexistence of Man with extinct Mammalia. — Reindeer Period +of South of France. — Alluvial Deposits of Paleolithic Age. +— Higher and Lower-level Valley-gravels. — Loess or +Inundation-mud of the Nile, Rhine, etc. — Origin of Caverns. +— Remains of Man and extinct Quadrupeds in Cavern Deposits. +— Cave of Kirkdale. — Australian Cave-breccias. — +Geographical Relationship of the Provinces of living Vertebrata and +those of extinct Post-pliocene Species. — Extinct struthious +Birds of New Zealand. — Climate of the Post-pliocene Period. +— Comparative Longevity of Species in the Mammalia and +Testacea. — Teeth of Recent and Post-pliocene Mammalia.</p> + +<br> + + +<center><a href="ch11.html"><b>Chapter XI</b></a><br> +<br> +POST-PLIOCENE PERIOD, continued.—GLACIAL +CONDITIONS.</center> + +<p>Geographical Distribution, Form, and Characters of Glacial +Drift. — Fundamental Rocks, polished, grooved, and scratched. +— Abrading and striating Action of Glaciers. — +Moraines, Erratic Blocks, and "Roches Moutonnees". — Alpine +Blocks on the Jura. — Continental Ice of Greenland. — +Ancient Centres of the Dispersion of Erratics. — +Transportation of Drift by floating Icebergs. — Bed of the +Sea furrowed and polished by the running aground of floating +Ice-islands.</p> + +<br> + + +<center><a href="ch12.html"><b>Chapter XII</b></a><br> +<br> +POST-PLIOCENE PERIOD, continued.—GLACIAL CONDITIONS, +concluded.</center> + +<p>Glaciation of Scandinavia and Russia. — Glaciation of +Scotland. — Mammoth in Scotch Till. — Marine Shells in +Scotch Glacial Drift. — Their Arctic Character. — +Rarity of Organic Remains in Glacial Deposits. — Contorted +Strata in Drift. — Glaciation of Wales, England, and Ireland. +— Marine Shells of Moel Tryfaen. — Erratics near +Chichester. — Glacial Formations of North America. — +Many Species of Testacea and Quadrupeds survived the Glacial Cold. +— Connection of the Predominance of Lakes with Glacial +Action. — Action of Ice in preventing the silting up of +Lake-basins. — Absence of Lakes in the Caucasus. — +Equatorial Lakes of Africa.</p> + +<br> + + +<center><a href="ch13.html"><b>Chapter XIII</b></a><br> +<br> +PLIOCENE PERIOD.</center> + +<p>Glacial Formations of Pliocene Age. — Bridlington Beds. +— Glacial Drifts of Ireland. — Drift of Norfolk Cliffs. +— Cromer Forest-bed. — Aldeby and Chillesford Beds. +— Norwich Crag. — Older Pliocene Strata. — Red +Crag of Suffolk. — Coprolitic Bed of Red Crag. — White +or Coralline Crag. — Relative Age, Origin, and Climate of the +Crag Deposits. — Antwerp Crag. — Newer Pliocene Strata +of Sicily. — Newer Pliocene Strata of the Upper Val d'Arno. +— Older Pliocene of Italy. — Subapennine Strata. +— Older Pliocene Flora of Italy.</p> + +<br> + + +<center><a href="ch14.html"><b>Chapter XIV</b></a><br> +<br> +MIOCENE PERIOD.—UPPER MIOCENE.</center> + +<p>Upper Miocene Strata of France. — Faluns of Touraine. +— Tropical Climate implied by Testacea. — Proportion of +recent Species of Shells. — faluns more ancient than the +Suffolk Crag. — Upper Miocene of Bordeaux and the South of +France. — Upper Miocene of Oeningen, in Switzerland. — +Plants of the Upper Fresh-water Molasse. — Fossil Fruit and +Flowers as well as Leaves. — Insects of the Upper Molasse. +— Middle or Marine Molasse of Switzerland. — Upper +Miocene Beds of the Bolderberg, in Belgium. — Vienna Basin. +— Upper Miocene of Italy and Greece. — Upper Miocene of +India; Siwalik Hills. — Older Pliocene and Miocene of the +United States.</p> + +<br> + + +<center><a href="ch15.html"><b>Chapter XV</b></a><br> +<br> +LOWER MIOCENE.</center> + +<p>Lower Miocene Strata of France. — Line between Miocene and +Eocene. — Lacustrine Strata of Auvergne. — Fossil +Mammalia of the Limagne d'Auvergne. — Lower Molasse of +Switzerland. — Dense Conglomerates and Proofs of Subsidence. +— Flora of the Lower Molasse. — American Character of +the Flora. — Theory of a Miocene Atlantis. — Lower +Miocene of Belgium. — Rupelian Clay of Hermsdorf near Berlin. +— Mayence Basin. — Lower Miocene of Croatia. — +Oligocene Strata of Beyrich. — Lower Miocene of Italy. +— Lower Miocene of England. — Hempstead Beds. — +Bovey Tracey Lignites in Devonshire. — Isle of Mull +Leaf-Beds. — Arctic Miocene Flora. — Disco Island. +— Lower Miocene of United States. — Fossils of +Nebraska.</p> + +<br> + + +<center><a href="ch16.html"><b>Chapter XVI</b></a><br> +<br> +EOCENE FORMATIONS.</center> + +<p>Eocene Areas of North of Europe. — Table of English and +French Eocene Strata. — Upper Eocene of England. — +Bembridge Beds. — Osborne or St. Helen's Beds. — Headon +Series. — Fossils of the Barton Sands and Clays. — +Middle Eocene of England. — Shells, Nummulites, Fish and +Reptiles of the Bracklesham Beds and Bagshot Sands. — Plants +of Alum Bay and Bournemouth. — Lower Eocene of England. +— London Clay Fossils. — Woolwich and Reading Beds +formerly called "Plastic Clay". — Fluviatile Beds underlying +Deep-sea Strata. — Thanet Sands. — Upper Eocene Strata +of France. — Gypseous Series of Montmartre and Extinct +Quadrupeds. — Fossil Footprints in Paris Gypsum. — +Imperfection of the Record. — Calcaire Silicieux. — +Gres de Beauchamp. — Calcaire Grossier. — Miliolite +Limestone. — Soissonnais Sands. — Lower Eocene of +France. — Nummulitic Formations of Europe, Africa, and Asia. +— Eocene Strata in the United States. — Gigantic +Cetacean.</p> + +<br> + + +<center><a href="ch17.html"><b>Chapter XVII</b></a><br> +<br> +UPPER CRETACEOUS GROUP.</center> + +<p>Lapse of Time between Cretaceous and Eocene Periods. — +Table of successive Cretaceous Formations. — Maestricht Beds. +— Pisolitic Limestone of France. — Chalk of Faxoe. +— Geographical Extent and Origin of the White Chalk. — +Chalky Matter now forming in the Bed of the Atlantic. — +Marked Difference between the Cretaceous and existing Fauna. +— Chalk-flints. — Pot-stones of Horstead. — +Vitreous Sponges in the Chalk. — Isolated Blocks of Foreign +Rocks in the White Chalk supposed to be ice-borne. — +Distinctness of Mineral Character in contemporaneous Rocks of the +Cretaceous Epoch. — Fossils of the White Chalk. — Lower +White Chalk without Flints. — Chalk Marl and its Fossils. +— Chloritic Series or Upper Greensand. — Coprolite Bed +near Cambridge. — Fossils of the Chloritic Series. — +Gault. — Connection between Upper and Lower Cretaceous +Strata. — Blackdown Beds. — Flora of the Upper +Cretaceous Period. — Hippurite Limestone. — Cretaceous +Rocks in the United States.</p> + +<br> + + +<center><a href="ch18.html"><b>Chapter XVIII</b></a><br> +<br> +LOWER CRETACEOUS OR NEOCOMIAN FORMATION.</center> + +<p>Classification of marine and fresh-water Strata. — Upper +Neocomian. — Folkestone and Hythe Beds. — Atherfield +Clay. — Similarity of Conditions causing Reappearance of +Species after short Intervals. — Upper Speeton Clay. — +Middle Neocomian. — Tealby Series. — Middle Speeton +Clay. — Lower Neocomian. — Lower Speeton Clay. — +Wealden Formation. — Fresh-water Character of the Wealden. +— Weald Clay. — Hastings Sands. — Punfield Beds +of Purbeck, Dorsetshire. — Fossil Shells and Fish of the +Wealden. — Area of the Wealden. — Flora of the +Wealden.</p> + +<br> + + +<center><a href="ch19.html"><b>Chapter XIX</b></a><br> +<br> +JURASSIC GROUP.—PURBECK BEDS AND OOLITE.</center> + +<p>The Purbeck Beds a Member of the Jurassic Group. — +Subdivisions of that Group. — Physical Geography of the +Oolite in England and France. — Upper Oolite. — Purbeck +Beds. — New Genera of fossil Mammalia in the Middle Purbeck +of Dorsetshire. — Dirt-bed or ancient Soil. — Fossils +of the Purbeck Beds. — Portland Stone and Fossils. — +Kimmeridge Clay. — Lithographic Stone of Solenhofen. — +Archæopteryx. — Middle Oolite. — Coral Rag. +— Nerinæa Limestone. — Oxford Clay, Ammonites and +Belemnites. — Kelloway Rock. — Lower, or Bath, Oolite. +— Great Plants of the Oolite. — Oolite and Bradford +Clay. — Stonesfield Slate. — Fossil Mammalia. — +Fuller's Earth. — Inferior Oolite and Fossils. — +Northamptonshire Slates. — Yorkshire Oolitic Coal-field. +— Brora Coal. — Palæontological Relations of the +several Subdivisions of the Oolitic group.</p> + +<br> + + +<center><a href="ch20.html"><b>Chapter XX</b></a><br> +<br> +JURASSIC GROUP, CONTINUED.—LIAS.</center> + +<p>Mineral Character of Lias. — Numerous successive Zones in +the Lias, marked by distinct Fossils, without Unconformity in the +Stratification, or Change in the Mineral Character of the Deposits. +— Gryphite Limestone. — Shells of the Lias. — +Fish of the Lias. — Reptiles of the Lias. — Ichthyosaur +and Plesiosaur. — Marine Reptile of the Galapagos Islands. +— Sudden Destruction and Burial of Fossil Animals in Lias. +— Fluvio-marine Beds in Gloucestershire, and Insect +Limestone. — Fossil Plants. — The origin of the Oolite +and Lias, and of alternating Calcareous and Argillaceous +Formations.</p> + +<br> + + +<center><a href="ch21.html"><b>Chapter XXI</b></a><br> +<br> +TRIAS, OR NEW RED SANDSTONE GROUP.</center> + +<p>Beds of Passage between the Lias and Trias, Rhætic Beds. +— Triassic Mammifer. — Triple Division of the Trias. +— Keuper, or Upper Trias of England. — Reptiles of the +Upper Trias. — Foot-prints in the Bunter formation in +England. — Dolomitic Conglomerate of Bristol. — Origin +of Red Sandstone and Rock-salt. — Precipitation of Salt from +inland Lakes and Lagoons. — Trias of Germany. — Keuper. +— St. Cassian and Hallstadt Beds. — Peculiarity of +their Fauna. — Muschelkalk and its Fossils. — Trias of +the United States. — Fossil Foot-prints of Birds and Reptiles +in the Valley of the Connecticut. — Triassic Mammifer of +North Carolina. — Triassic Coal-field of Richmond, Virginia. +— Low Grade of early Mammals favourable to the Theory of +Progressive Development.</p> + +<br> + + +<center><a href="ch22.html"><b>Chapter XXII</b></a><br> +<br> +PERMIAN OR MAGNESIAN LIMESTONE GROUP.</center> + +<p>Line of Separation between Mesozoic and Palæozoic Rocks. +— Distinctness of Triassic and Permian Fossils. — Term +Permian. — Thickness of calcareous and sedimentary Rocks in +North of England. — Upper, Middle, and Lower Permian. — +Marine Shells and Corals of the English Magnesian Limestone. +— Reptiles and Fish of Permian Marl-slate. — +Foot-prints of Reptiles. — Angular Breccias in Lower Permian. +— Permian Rocks of the Continent. — Zechstein and +Rothliegendes of Thuringia. — Permian Flora. — Its +generic Affinity to the Carboniferous.</p> + +<br> + + +<center><a href="ch23.html"><b>Chapter XXIII</b></a><br> +<br> +THE COAL OR CARBONIFEROUS GROUP.</center> + +<p>Principal Subdivisions of the Carboniferous Group. — +Different Thickness of the sedimentary and calcareous Members in +Scotland and the South of England. — Coal-measures. — +Terrestrial Nature of the Growth of Coal. — Erect fossil +Trees. — Uniting of many Coal-seams into one thick Bed. +— Purity of the Coal explained. — Conversion of Coal +into Anthracite. — Origin of Clay-ironstone. — Marine +and brackish-water Strata in Coal. — Fossil Insects. — +Batrachian Reptiles. — Labyrinthodont Foot-prints in +Coal-measures. — Nova Scotia Coal-measures with successive +Growths of erect fossil Trees. — Similarity of American and +European Coal. — Air-breathers of the American Coal. — +Changes of Condition of Land and Sea indicated by the Carboniferous +Strata of Nova Scotia.</p> + +<br> + + +<center><a href="ch24.html"><b>Chapter XXIV</b></a><br> +<br> +FLORA AND FAUNA OF THE CARBONIFEROUS PERIOD.</center> + +<p>Vegetation of the Coal Period. — Ferns, +Lycopodiaceæ, Equisetaceæ, Sigillariæ, +Stigmariæ, Coniferæ. — Angiosperms. — +Climate of the Coal Period. — Mountain Limestone. — +Marine Fauna of the Carboniferous Period. — Corals. — +Bryozoa, Crinoidea. — Mollusca. — Great Number of +fossil Fish. — Foraminifera.</p> + +<br> + + +<center><a href="ch25.html"><b>Chapter XXV</b></a><br> +<br> +DEVONIAN OR OLD RED SANDSTONE GROUP.</center> + +<p>Classification of the Old Red Sandstone in Scotland and in +Devonshire. — Upper Old Red Sandstone in Scotland, with Fish +and Plants. — Middle Old Red Sandstone. — +Classification of the Ichthyolites of the Old Red, and their +Relation to Living Types. — Lower Old Red Sandstone, with +Cephalaspis and Pterygotus. — Marine or Devonian Type of Old +Red Sandstone. — Table of Devonian Series. — Upper +Devonian Rocks and Fossils. — Middle. — Lower. — +Eifel Limestone of Germany. — Devonian of Russia. — +Devonian Strata of the United States and Canada. — Devonian +Plants and Insects of Canada.</p> + +<br> + + +<center><a href="ch26.html"><b>Chapter XXVI</b></a><br> +<br> +SILURIAN GROUP.</center> + +<p>Classification of the Silurian Rocks. — Ludlow Formation +and Fossils. — Bone-bed of the Upper Ludlow. — Lower +Ludlow Shales with Pentamerus. — Oldest known Remains of +fossil Fish. — Table of the progressive Discovery of +Vertebrata in older Rocks. — Wenlock Formation, Corals, +Cystideans and Trilobites. — Llandovery Group or Beds of +Passage. — Lower Silurian Rocks. — Caradoc and Bala +Beds. — Brachiopoda. — Trilobites. — +Cystideæ. — Graptolites. — Llandeilo Flags. +— Arenig or Stiper-stones Group. — Foreign Silurian +Equivalents in Europe. — Silurian Strata of the United +States. — Canadian Equivalents. — Amount of specific +Agreement of Fossils with those of Europe.</p> + +<br> + + +<center><a href="ch27.html"><b>Chapter XXVII</b></a><br> +<br> +CAMBRIAN AND LAURENTIAN GROUPS.</center> + +<p>Classification of the Cambrian Group, and its Equivalent in +Bohemia. — Upper Cambrian Rocks. — Tremadoc Slates and +their Fossils. — Lingula Flags. — Lower Cambrian Rocks. +— Menevian Beds. — Longmynd Group. — Harlech +Grits with large Trilobites. — Llanberis Slates. — +Cambrian Rocks of Bohemia. — Primordial Zone of Barrande. +— Metamorphosis of Trilobites. — Cambrian Rocks of +Sweden and Norway. — Cambrian Rocks of the United States and +Canada. — Potsdam Sandstone. — Huronian Series. — +Laurentian Group, upper and lower. — Eozoon Canadense, oldest +known Fossil. — Fundamental Gneiss of Scotland.</p> + +<br> + + +<center><a href="ch28.html"><b>Chapter XXVIII</b></a><br> +<br> +VOLCANIC ROCKS.</center> + +<p>External Form, Structure, and Origin of Volcanic Mountains. +— Cones and Craters. — Hypothesis of "Elevation +Craters" considered. — Trap Rocks. — Name whence +derived. — Minerals most abundant in Volcanic Rocks. — +Table of the Analysis of Minerals in the Volcanic and Hypogene +Rocks. — Similar Minerals in Meteorites. — Theory of +Isomorphism. — Basaltic Rocks. — Trachytic Rocks. +— Special Forms of Structure. — The columnar and +globular Forms. — Trap Dikes and Veins. — Alteration of +Rocks by volcanic Dikes. — Conversion of Chalk into Marble. +— Intrusion of Trap between Strata. — Relation of +trappean Rocks to the Products of active Volcanoes.</p> + +<br> + + +<center><a href="ch29.html"><b>Chapter XXIX</b></a><br> +<br> +ON THE AGES OF VOLCANIC ROCKS.</center> + +<p>Tests of relative Age of Volcanic Rocks. — Why ancient and +modern Rocks can not be identical. — Tests by Superposition +and intrusion. — Test by Alteration of Rocks in Contact. +— Test by Organic Remains. — Test of Age by Mineral +Character. — Test by Included Fragments. — Recent and +Post-pliocene volcanic Rocks. — Vesuvius, Auvergne, Puy de +Come, and Puy de Pariou. — Newer Pliocene volcanic Rocks. +— Cyclopean Isles, Etna, Dikes of Palagonia, Madeira. — +Older Pliocene volcanic Rocks. — Italy. — Pliocene +Volcanoes of the Eifel. — Trass.</p> + +<br> + + +<center><a href="ch30.html"><b>Chapter XXX</b></a><br> +<br> +AGE OF VOLCANIC ROCKS—CONTINUED.</center> + +<p>Volcanic Rocks of the Upper Miocene Period. — Madeira. +— Grand Canary. — Azores. — Lower Miocene +Volcanic Rocks. — Isle of Mull. — Staffa and Antrim. +— The Eifel. — Upper and Lower Miocene Volcanic Rocks +of Auvergne. — Hill of Gergovia. — Eocene Volcanic +Rocks of Monte Bolca. — Trap of Cretaceous Period. — +Oolitic Period. — Triassic Period. — Permian Period. +— Carboniferous Period. — Erect Trees buried in +Volcanic Ash in the Island of Arran. — Old Red Sandstone +Period. — Silurian Period. — Cambrian Period. — +Laurentian Volcanic Rocks.</p> + +<center><a href="ch31.html"><b>Chapter XXXI</b></a><br> +<br> +PLUTONIC ROCKS.</center> + +<p>General Aspect of Plutonic Rocks. — Granite and its +Varieties. — Decomposing into Spherical Masses. — Rude +columnar Structure. — Graphic Granite. — Mutual +Penetration of Crystals of Quartz and Feldspar. — Glass +Cavities in Quartz of Granite. — Porphyritic, talcose, and +syenitic Granite. — Schorlrock and Eurite. — Syenite. +— Connection of the Granites and Syenites with the Volcanic +Rocks. — Analogy in Composition of Trachyte and Granite. +— Granite Veins in Glen Tilt, Cape of Good Hope, and +Cornwall. — Metalliferous Veins in Strata near their Junction +with Granite. — Quartz Veins. — Exposure of Plutonic +Rocks at the surface due to Denudation.</p> + +<br> + + +<center><a href="ch32.html"><b>Chapter XXXII</b></a><br> +<br> +ON THE DIFFERENT AGES OF THE PLUTONIC ROCKS.</center> + +<p>Difficulty in ascertaining the precise Age of a Plutonic Rock. +— Test of Age by Relative Position. — Test by Intrusion +and Alteration. — Test by Mineral Composition. — Test +by included Fragments. — Recent and Pliocene Plutonic Rocks, +why invisible. — Miocene Syenite of the Isle of Skye. — +Eocene Plutonic Rocks in the Andes. — Granite altering +Cretaceous Rocks. — Granite altering Lias in the Alps and in +Skye. — Granite of Dartmoor altering Carboniferous Strata. +— Granite of the Old Red Sandstone Period. — Syenite +altering Silurian Strata in Norway. — Blending of the same +with Gneiss. — Most ancient Plutonic Rocks. — Granite +protruded in a solid Form.</p> + +<br> + + +<center><a href="ch33.html"><b>Chapter XXXIII</b></a><br> +<br> +METAMORPHIC ROCKS.</center> + +<p>General Character of Metamorphic Rocks. — Gneiss. — +Hornblende-schist. — Serpentine. — Mica-schist. — +Clay-slate. — Quartzite. — Chlorite-schist. — +Metamorphic Limestone. — Origin of the metamorphic Strata. +— Their Stratification. — Fossiliferous Strata near +intrusive Masses of Granite converted into Rocks identical with +different Members of the metamorphic Series. — Arguments +hence derived as to the Nature of Plutonic Action. — +Hydrothermal Action, or the Influence of Steam and Gases in +producing Metamorphism. — Objections to the metamorphic +Theory considered.</p> + +<br> + + +<center><a href="ch34.html"><b>Chapter XXXIV</b></a><br> +<br> +METAMORPHIC ROCKS—continued.</center> + +<p>Definition of slaty Cleavage and Joints. — Supposed Causes +of these Structures. — Crystalline Theory of Cleavage. +— Mechanical Theory of Cleavage. — Condensation and +Elongation of slate Rocks by lateral Pressure. — Lamination +of some volcanic Rocks due to Motion. — Whether the Foliation +of the crystalline Schists be usually parallel with the original +Planes of Stratification. — Examples in Norway and Scotland. +— Causes of Irregularity in the Planes of Foliation.</p> + +<br> + + +<center><a href="ch35.html"><b>Chapter XXXV</b></a><br> +<br> +ON THE DIFFERENT AGES OF THE METAMORPHIC ROCKS.</center> + +<p>Difficulty of ascertaining the Age of metamorphic Strata. +— Metamorphic Strata of Eocene date in the Alps of +Switzerland and Savoy. — Limestone and Shale of Carrara. +— Metamorphic Strata of older date than the Silurian and +Cambrian Rocks. — Order of Succession in metamorphic Rocks. +— Uniformity of mineral Character. — Supposed Azoic +Period. — Connection between the Absence of Organic Remains +and the Scarcity of calcareous Matter in metamorphic Rocks.</p> + +<br> + + +<center><a href="ch36.html"><b>Chapter XXXVI</b></a><br> +<br> +MINERAL VEINS.</center> + +<p>Different Kinds of mineral Veins. — Ordinary metalliferous +Veins or Lodes. — Their frequent Coincidence with Faults. +— Proofs that they originated in Fissures in solid Rock. +— Veins shifting other Veins. — Polishing of their +Walls or "Slicken sides". — Shells and Pebbles in Lodes. +— Evidence of the successive Enlargement and Reopening of +veins. — Examples in Cornwall and in Auvergne. — +Dimensions of Veins. — Why some alternately swell out and +contract. — Filling of Lodes by Sublimation from below. +— Supposed relative Age of the precious Metals. — +Copper and lead Veins in Ireland older than Cornish Tin. — +Lead Vein in Lias, Glamorganshire. — Gold in Russia, +California, and Australia. — Connection of hot Springs and +mineral Veins.</p> + +<br> + + +<center><a href="geolind.html"><b>INDEX</b></a><br> +<br> +</center> + +<hr> +<small><a href="Title.html">Title</a><br> +<a href="ch1.html">Chapter I</a></small> +</body> +</html> + |