The Students Elements of Geology | Page 7

Condition of Land and Sea indicated by the Carboniferous Strata of Nova Scotia.



CHAPTER XXIV.
FLORA AND FAUNA OF THE CARBONIFEROUS PERIOD.
Vegetation of the Coal Period. Ferns, Lycopodiaceae, Equisetaceae, Sigillariae, Stigmariae, Coniferae. Angiosperms. Climate of the Coal Period. Mountain Limestone. Marine Fauna of the Carboniferous Period. Corals. Bryozoa, Crinoidea. Mollusca. Great Number of fossil Fish. Foraminifera.



CHAPTER XXV.
DEVONIAN OR OLD RED SANDSTONE GROUP.
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.



CHAPTER XXVI.
SILURIAN GROUP.
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. Cystideae. 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.



CHAPTER XXVII.
CAMBRIAN AND LAURENTIAN GROUPS.
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.



CHAPTER XXVIII.
VOLCANIC ROCKS.
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.



CHAPTER XXIX.
ON THE AGES OF VOLCANIC ROCKS.
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.



CHAPTER XXX.
AGE OF VOLCANIC ROCKS-- CONTINUED.
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.



CHAPTER XXXI.
PLUTONIC ROCKS.
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.



CHAPTER XXXII.
ON THE DIFFERENT AGES OF THE PLUTONIC ROCKS.
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.



CHAPTER XXXIII.
METAMORPHIC ROCKS.
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.