A Summary of Progress in Petrography. in 1887-1896 |
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Page 1
... dykes on the island of Mull that contain the glassy selvages known as tachylite . It has been observed that the thickness of this glass band is always greatest in that portian of the dyke in contact with the most compact rock . A new ...
... dykes on the island of Mull that contain the glassy selvages known as tachylite . It has been observed that the thickness of this glass band is always greatest in that portian of the dyke in contact with the most compact rock . A new ...
Page 7
... dykes of porphyrite . Separated from this by a great fault is Sepulchre Mountain , made up in large part of surface flows of the magma that was extruded through the orifice at Electric Peak . This magma under the conditions surrounding ...
... dykes of porphyrite . Separated from this by a great fault is Sepulchre Mountain , made up in large part of surface flows of the magma that was extruded through the orifice at Electric Peak . This magma under the conditions surrounding ...
Page 9
... dykes cutting the slates and granite in the neighborhood of Kennebunkport , Maine , are men- tioned by Mr. Kemp . 10 The rocks forming the dykes are granites , diabases , camptonites , and diabase porphyrites . - - New Minerals ...
... dykes cutting the slates and granite in the neighborhood of Kennebunkport , Maine , are men- tioned by Mr. Kemp . 10 The rocks forming the dykes are granites , diabases , camptonites , and diabase porphyrites . - - New Minerals ...
Page 11
... dykes in the vicinity of the Langesunds- fiord , in Southern Norway . The first mineral is found in radial groups composed of monoclinic fibres with cleavages parallel to oP , ∞ P∞ and 2P . The axial ratio is a : b : c = 1.1687 : 1 ...
... dykes in the vicinity of the Langesunds- fiord , in Southern Norway . The first mineral is found in radial groups composed of monoclinic fibres with cleavages parallel to oP , ∞ P∞ and 2P . The axial ratio is a : b : c = 1.1687 : 1 ...
Page 5
... dykes cutting gneiss and crystalline schists in the Vorspessart in Germany . The crystalline schists consist of dioritic and " augen " gneisses , produced by pressure from eruptive rocks , and other gneisses , the history of whose ...
... dykes cutting gneiss and crystalline schists in the Vorspessart in Germany . The crystalline schists consist of dioritic and " augen " gneisses , produced by pressure from eruptive rocks , and other gneisses , the history of whose ...
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Common terms and phrases
acute bisectrix Al,O Amer AMERICAN NATURALIST amphibole analysis andesites apatite augite axial ratio basalt biotite bisectrix brown Bull calcite Colby University color colorless composition containing cordierite corresponding described diabase diorites double refraction dykes Edited by Dr epidote eruptive Fe,O feldspar FeO CaO MgO FeO MnO Förh formula gabbro garnet Geol gneiss grains granite green ground-mass H₂O hardness hexagonal hornblende inclusions isomorphous Jour Kryst Lacroix lamellæ lithophysæ lustre magma magnetite MAKERS SYRACUSE manganese mica microlites mineral occurs MINERALOGY AND PETROGRAPHY.¹ molecule monoclinic Na,O Na₂O nepheline Neues Jahrb olivine optical angle optical axes original orthoclase orthorhombic Petrog PETROGRAPHY.¹ Petrographical phenocrysts plagioclase pleochroic porphyritic porphyritic crystals pressure prismatic produced pyroxene quartz regarded resembles rhombohedral rocks scapolite schists silica small crystals specific gravity spherulites structure substance symmetry thin section tion twinning plane variety W. S. Bayley Waterville yellow yielded Zeits
Popular passages
Page 5 - The olivine is surrounded by a reactionary rim consisting of an inner zone of hypersthene and an outer one of actinolite.