PRELIMINARY ROCK GEOCHEMISTRY FROM THE NORTHEASTERN CRAIG A-1 QUADRANGLE, ALASKA

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1 Public-data File PRELIMINARY ROCK GEOCHEMISTRY FROM THE NORTHEASTERN CRAIG A-1 QUADRANGLE, ALASKA Karen H. Clautice, Thomas K. Bundtzen, and Shirley A. Liss Alaska Division of Geological and Geophysical Surveys April 1991 THIS REPORT HAS NOT BEEN REVIEWED FOR TECHNICAL CONTENT (EXCEPT AS NOTED IN TEXT) OR FOR CONFORMITY TO THE EDITORIAL STANDARDS OF DGGS. 794 University Avenue, Suite 200 Fairbanks, Alaska

2 INTRODUCTION This preliminary report lists the results from geochemical analyses of 49 rock samples collected September 6-10, 1990 north of the Dolomi Bay area, Prince of Wales Island, Southeast Alaska. The samples were collected as part of an initial reconnaissance for a geologic mapping project of the Craig A-1 Quadrangle. Analyses and rock descriptions are listed in Tables 1 and 2, sample locations are shown on Plate 1. This on-going study of the Craig A-1 quadrangle is being conducted as part of a cooperative agreement between the U. S. Bureau of Mines and the Alaska Division of Geological and Geophysical Surveys to investigate the geology and mineralization of the Ketchikan Mining District. SAMPLING AND ANALYTICAL METHODS Most rock samples represent individual grab samples of approximately 1 kg. Composite and chip samples are noted in the sample descriptions. Samples were analyzed by either Chemex Labs, Inc., North Vancouver, B.C. or Bondar Clegg & Company Ltd.., North Vancouver, B.C. as noted in Table 1. Sample preparation methods and analytical techniques, including detection and upper limits used by the two labs are listed in the appendix to this report. In addition, analytical techniques are abbreviated below each element in Table 1 as follows: FA+ AA 30g FA+ AA log FA - Grav. AAS ICP XRF Fire assay Atomic absorption, 30 g sample Fire assay + Atomic absorption, 10 g sample Fire assay, gravimetric Atomic absorption spectroscopy Inductively coupled arc-plasma X-ray fluorescence Results are listed in parts per million(ppm) unless otherwise indicated.

3 Table 1. Rock analyses from the Dolomi area, Prince of Wales Island, Southeast Alaska (Values listed in parts per million unless otherwise noted.) Map no. Field no. Ag AAS AlX I CP < ~ < < ~ < < < < < < < < < < < < ~ B = Bondar Clegg & Company Ltd., North Vancouver, B.C.; C = Chemex Labs, Inc., North Vancouver, B.C. 2- = Not analyzed

4 Table 1. Rock analyses from the Dolomi area, Prince of Wales Island, Southeast Alaska (cont.) Map no. Cu I CP

5 M z Cr 0,,,, c u o m u -,,,, I u -,,, u -, I I u -,,, V) IX v v v v I,,,, X an. a,,,, l l 0 l I C C- C- F '-2 v v v v v I,,,, - ~ n + m ~ ~ b a ms z - N M * ~ ~$~~~ - N M + ~ F r F - c N N N N N

6 Table 1. Rock analyses from the Dolomi area, Prince of Wales Island, Southeast Alaska (cont.) Map no. Field no. Lab.1 Au ppb FA+AA 309 Au ppb FA+AA 109 A9 AAS AL% I CP Ba Ba Be B i ICP XRF I CP I CP < < < < < ~ ~ B = Bondar Clegg & Company Ltd., North Vancouver, B.C.; C = Chemex Labs, Inc., North Vancouver, B.C. 2- = Not analyzed

7 Table 1. Rock analyses from the Dolomi area, Prince of Wales Island, Southeast Alaska (cont.) Map no

8 I a" Q) 5 a n t o o t I r---r r - v v v v v v v v v v v v v v F I a n m m ~ m m V): v v v v V V V V V v v v v m m m m m a m m a 0 m 8 m l t 1 I,,-,, v IA n v ~ * $ z 2 - V m ~ m b - S N ~ U I m t m t m I l o, l - V M r V N \0bCOOIO em \ 0 k a m 0 - N M * ~ \ ~ L D J ~ N N N N M Z M M M M M M M M * ***** ****

9 Table 2. Rock sample descriptions Map no. Field no. Description Pyritic, light-colored phase(?) (possibly dike) in syenite quarry Brick red-colored med. grained hornblende(?) syenite, carbonate veinlets with pyrite, mafic minerals very altered Chalcopyrite/pyrite pod in quartz-carbonate zone Pods to 5 cm in diam. of massive pyrite and chalcopyrite in 5 m wide zone of quartz-carbonate breccia Black phyllitic shale Quartz-carbonate zone with pods of pyrite and chalcopyrite, chip-channel over 1 m Disseminated sulfides in muscovite-rich schist and dolomite; two zones each about 10 m thick sarrpled Limonite encrusted outcrop of actinolite schist Pale green schist with pyritic quartz veins. Pyrite-chalcopyrite bearing quartz-carbonate breccia Massive pyrite/chalcopyrite pods to 10 cm diam. in quartz-carbonate breccia Pyrite pods in quartz carbonate zone 2-3 m thick, chip-channel across 2 m Chalcopyrite-bearing quartz vein, 10 cm wide Quartz chlorite schist interlaminated with siliceous pyrite-rich layers, sample from 15 cm wide pyritic zone Pyrite pods in quartz carbonate Quartz-carbonate breccia zone with trace pyrite, abundant quartz veining Quartz-carbonate breccia with chalcopyrite Pyrite-rich quartz sericite schist zone, 6 m thick, part of Larger felsic meta-tuff horizon Numerous small cross-cutting barite(?) veinlets in Light green calcareous quartz sericite schist Massive pyrite from 20 x 60 cm vug at margin of fine grained mafic dike Iron-stained quartz chlorite schist with minor pyrite and chalcopyrite in 10 cm wide quartz vein Calcareous quartz muscovite schist, pyrite along foliations Light gray-green, siliceous aphanitic dike about 1 m wide, finely disseminated sulfides Dark gray calcareous graphitic quartz muscovite schist, finely disseminated sulfides along foliations Iron stained, gray, calcareous graphitic actinolite schist, most of outcrop is gray-green quartzite

10 Table 2. Rock sample descriptions (cont.) Map no. Field no. Description 1.2 m thick quartz vein uith ferricrete vug fillings and calcite breccia Pyrite-rich quartz sericite schist horizon; 1 m chip channel Iron-stained quartz muscovite schist associated with minor quartz veining Chalcopyrite, pyrite, and magnetite in folded Layers within greenschist; sampled over 1 m interval Pyrite-rich quartz-sericite schist; part of Larger felsic metatuff section; 2 m thick chip-channel Gossanous quartz sericite schist horizon in marble/schist unit Gossanous, tuffaceous semischist uith ferricrete fracture fillngs; 2 m chip-channel Pyrite-rich quartz sericite schist horizon, 3 meters thick; believed to be stratigraphically equivalent to no. 34 Pyrite-rich quartz sericite schist Layer 1 m thick; part of Larger meta-tuff package; believed to be stratigraphically equivalent to no. 35 Pyrite-rich quartz sericite schist zone; 2.5 m chip channel Sulfide-magnetite-garnet zone in metasomatic(?) zone within chlorite actinolite schist Sulfide-magnetite-garnet zone in amphibole-rich metasomatic(?) zone within chlorite actinolite schist, sampled over 2 m Pyrite-rich quartz sericite schist, 2 m chip channel Quartz sericite schist, pyrite and chalcopyrite along foliations Quartz sericite schist, sulfides along foliations Mineralized sericite-sulfide metakeratophyre tuff; grab sample over 3 meters Pyritic, gossanous material Sulfide-bearing meta-andesite or basalt Dolomite and mica schist with green stain, some dendritic pyrite Pyritic, calcareous mica schist; mica mineral is green Limestone with green malachite(?) stain and pods of micaceous schist (about 1% of rock) FeO-stained, quartz carbonate altered zone (igneous origin?) 10 m wide, cutting gray marble Malachite-stained calcite veins in bleached marble Pyritic marble

11 APPENDIX SAMPLE PREPARATION AND ANALYTICAL PROCEDURES

12 Bondar-Clegg & Company Ltd. 130 Pemberton Ave. North Vancouver, B.C. V7P 2R5 SAMPLE PREPARATION AND ANALYTICAL PROCEDURES LOWER ORDER ELEYEF~: [:ETECTION LIMIT EXTRACTION METHOD 1 Au 10s Gold - Fire Assay 5 PPB Fire-Assay Fire Assay AA 2 Aq Silve~, 0-2 PPM HN03-HC1 Pot Extr. Ind, Couple6 Piasma 3 Cu Copper 1 PPM HNOj-YC1 Hot Extr, Ind. Coupled Plasm 1 Pb cead 2 PPN Hi-U3-+CI Hot Extr. IAo, Couoled P:asna 5 2t1 Zinc 1 PPF HN03-HCl Hot Extr. Ind. Coupled Plas~a 6 Mo Molybdenum ; FPM HFiO?-I(Il Hot Ext,., Ird, Coupled Piasna 7 Ni Nickel 1 PPP HN03-HCI Hot Extr. Ind. Coup'efi "aasra 8 Co Cobalt 1?PY MG3-rfl Hot Extr. lnd, Coupled Plasna 9 Cd Cadmium A P?F HN33-HCl hot ixtr, it~i;, Coupied Plasria 10 As Arsenic 5 PPM HN03-~CI kst Ext~, Ind, Co~pied Piasna 11 Sb Antimony 5 P?b HFirlS-hz Hot Extr, Irid, Coupled P'asma 12 Fe Iron 0.01 P-T Hrd03-PC1 hot Extr. Ind. Coupied Plasma 13 Hn Manganese 0,Ol PC1 HN03-HC1 Hot Extr, Ind. Coupled Plasria 14 Te Tellurium 10 PPM HM3-HCl Hot Extr, Ind. Coupled Plasma 15 0a Barium 5 PPM HN03-HC1 Hot Extr, Ind, Coupled Plasma 16 Cr Chromium 1 PPM HN03-dC1 Hot Extr, Ind, Coupled Plasma 17 V Vanadi urn 1 PPM HN03-HC1 Hot Extr. Indo Coupled Plasma 18 W Tungsten 10 PPM HNO3-HC1 Hot Extr, Ind, Coupled Plasma 19 La Lanthanum 1 PPM HN03-HCl Hot Extr. Ind, Coupled Plasna 20 A1 Aluminum 0,02 PC1 HN03-HC1 Hot Extr, Ind, Coupled Plasma 21 Hg Magnesium 0.05 PC1 HN03-HC1 Hot Extr. Ind. Coupled Plasma 22 Ca Calcium 0,05 PC1 Hh03-HCl Hot Extr, Ind, Coupled Plasma 23 Na Sodium 0.05 PC7 HN03-HCl Hot Extr. Ind, Coupled Plasma 24 K Potassium 0.05 PC1 HN03-HCl Hot Extr, Ind, Coupled Plasma 25 Sr Strontium 1 PPM HN03-HC1 Hot Extr, Ind, Coupled Plasma 26 Y Yttrium 1 PPM HN03-HCI Hot Extr. Ind, Coupled Plasma 27 Bi Bismuth 1 PPM HN03-HC1 Hot Extr. Atomic Absorption 28 Hg Mercury PPM HN03-HCl -SnSO4 Cold Vapour AA 29 Ba Barium 20 PPM X-Ray Fluorescence 30 Sn Tin 5 PPM %-Ray Fl uorescence

13 Chemex Labs Ltd. 994 West Glendale Ave., Suite 7 Sparks, Nevada, I SAMPLE PREPARATION DESCRIPTION mapno. 3, 4, 11, 13, 17, 20, 36, Assay ring to approx 150 mesh Crush and split (0-10 pounds) Aesay total ICP digestion charge I IMMPLE~ CHEMEX CODE SAMPLE PREPARATION NUMBER DESCRIPTION Geochem ring to approx 150 msh Crush and split (0-10 pounds) PERCHLORIC-NITRIC-HYDROFLUORIC D ANALYTICAL PROCEDURES DESCRIPTION DETECTION LlMll UPPER LIMIT Au ppb: Fuse 30 g sample Ag ppm: 24 element, rock L core A1 %: 24 element, rock L core Ba ppm: 24 element, rock L core Be ppm: 24 element, rock L core Bi ppm: 24 element, rock L core Ca %: 24 element, rock L core Cd ppm: 24 element, rock L core Co ppm: 24 element, rock L core Cr ppm: 24 element, rock L core Cu ppm: 24 element, rock L core Fe %: 24 element, rock & core K %: 24 element, rock 5 core Mg %: 24 element, rock & core Mn ppm: 24 element, rock L core Mo ppm: 24 element, rock L core Na 8: 24 element, rock L core Ni ppm: 24 element, rock L core P ppm: 24 element, rock L core Pb ppm: 24 element, rock L core Sr ppm: 24 element, rock L core Ti %: 24 element, rock L core V ppm: 24 element, rock & core W ppm: 24 element, rock & core Zn ppm: 24 elemant, rock L core Au oz/t: 1/2 as#ay ton I FA-AAS AAS ICP -AES ICP -AES ICP-ABS ICP -AES ICP-ms FA-GRAVImTRIC