Annual report of the United States Geological Survey to the Secretary of the Interior . PLATE XLVII. 1 PLATE XLVII. A. Poikilitic gabbro, No. 985 S. N., showing the broken and corroded anorthites inclosed in later brown hornblende. The feldspars lie at all angles in thehornblende plate, which has the same optical orientation throughout. Thisis an illustration of the typical poikilitic structure as characterized by H. Williams. With the analyzer, X 20. B. Gabbro, No. 535 S. N., showing the gabbro or typical granular structure in which both the main constituents, pyroxene and plagioclase
Annual report of the United States Geological Survey to the Secretary of the Interior . PLATE XLVII. 1 PLATE XLVII. A. Poikilitic gabbro, No. 985 S. N., showing the broken and corroded anorthites inclosed in later brown hornblende. The feldspars lie at all angles in thehornblende plate, which has the same optical orientation throughout. Thisis an illustration of the typical poikilitic structure as characterized by H. Williams. With the analyzer, X 20. B. Gabbro, No. 535 S. N., showing the gabbro or typical granular structure in which both the main constituents, pyroxene and plagioclase, appear to have crystal-lized at about the same time, the anhedrons of each mutually interfering, sothat none of the grains attained their proper crystalline forms. With the ana-lyzer, X 40. C— plagioclase; A = hornblende; P = augite; H = hypersthene;F = iron GEOLOGICAL SURVEY SEVENTEENTH ANNUAL REPORT PART I PL. XLVII. A. POIKILITIC GABBRO, NO. 985 S N. B GABBRO. NO 535 S N , SHOWING THE GABBRO OR TYPICAL GRANULAR STRUCTURE. REPORT ON COAL AND LIGNITE OF ALASKA. BY WILLIAM HEALEY DALL. 763 CONTENTS. Pag?. Introduction 771 Localities of the coal-bearing Kenai formation 772 Alexander Archipelago 772 St. John Baptist Bay 772 Point Gardner 773 Port Camden 774 Whale Bay, Baranoff Island 774 Kuiu Island 774 Kootznahoo Inlet, Admiralty Island 776 Sepphagen inine 778 Keef 779 Point Sullivan 780 Mitchell Bay 780 Meade and Mitchell seam 780 Briglitmau and De Groff seam 781 McCluskey location 782 Localities west of the Alexander Archipelago, between Cape Spencer and Cook Inlet 783 Lituya Bay 783 Yakutat Bay 784 Localities in Cook Inlet 784 Port Graham 785 The Kenai pla teau 787 Kachemak Bay 788 Bradley seam 791 Curtis seam 792 McNeil Canyon 792 Eastland Canyon 793 Localities west of Cook Inlet 797 Cape Douglas 798 Amalik Harbor 799 Katmai 799 Kadiak Islands 800 Red River 800 Sitkinak Island 800 Yantarnie Bay 8
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