GEOLOGY AND MINERAL DEPOSITS OF THE KEWEENAW PENINSULA, MICHIGAN William F. Cannon, Suzanne W. Nicholson - U.S. Geological Survey Michele E. McRae - U.S. Geological Survey, Oak Ridge Associated Universities ABSTRACT The area of this data set includes the classic geology and mineral deposits of the Keweenaw Peninsula, renowned for the occurrence of great volumes of Middle Proterozoic flood basalts and the world's largest concentration of native copper. Native copper was mined there continuously from the 1840's to the 1960's. For the earlier part of that period the Keweenawan native copper district was the principal source of copper for the United States. PURPOSE This database is intended to summarize and update a wealth of very detailed geologic maps of the region. The related hardcopy publication, Geologic Map of the Keweenaw Peninsula and Adjacent Area, Michigan (Cannon and Nicholson), is part of a set of maps portraying the regional geology of the Midcontinent rift on the south shore of Lake Superior. The geology and mineral deposits of the district have been painstakingly studied for many years. Milestones in the studies were the extensive report of Butler and Burbank (1929) and the detailed geologic maps produced by the USGS in the 1950's. The latter were aided greatly by the Calumet and Hecla Copper Company which provided USGS geologists with a wealth of exploration and production data that allowed construction of detailed 1:24,000 scale maps for the entire peninsula. Those maps are the principal source of information used to compile this data set. We have attempted to preserve as much detail as possible at 1:100,000 scale. For rocks northwest of the Keweenaw fault we have made few changes to previously mapped geology. New data is limited to deposits of chalcocite and native copper discovered since the previous mapping in the 1950's, to a more detailed study of rhyolite bodies, and to radiometric age determinations. For areas southeast of the Keweenaw fault, new geophysical data and drill holes allow some new inferences about the geology of volcanic rocks covered by a thin veneer of Jacobsville Sandstone. SPATIAL DATA DESCRIPTION The following is a list of data layers in this ArcView project and a brief description of the features contained in each. The list is followed by a detailed information on each coverage containing entity information, a brief description of attribute fields, and procedures used to develop individual data layers. All data were imported to ArcView 3.1 using the ARC/INFO .e00 interchange format. ATTITUDE - Orientation of bedding features (e.g., strike and dip) BURIED - Features concealed by Jacobsville Sandstone CGL - Interflow conglomerates CHALC - Chalcocite bodies COORD - A 15X15 minute geographic latitude/longitude locator grid FISSURE - Fissure veins GEOLOGY - Geologic units and faults LAKES - Lakes LODES - Native copper lodes MAG - Distinct aeromagnetic trends MINES - Mine shafts in the native copper district OUTCROPS - Locations of outcrops RIVERS - Rivers and streams ROADS - Roads STRUCTUR - Major structural features (other than faults) WETLANDS - Wetlands, marshes, bogs, etc. XSECTION - Cross section lines *****Description of DOUBLE precision coverage ATTITUDE***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- POINTS 195 78 ANNOTATIONS DIP 195 SECONDARY FEATURES Tics 12 TOLERANCES Fuzzy = 0.002 N Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -88.997 Xmax = -87.606 Ymin = 46.441 Ymax = 47.480 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Datum NAD27 Units DD Spheroid CLARKE1866 Parameters: Description of point attribute table attitude.pat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 AREA 8 18 F 5 - 9 PERIMETER 8 18 F 5 - 17 ATTITUDE# 4 5 B - - 21 ATTITUDE-ID 4 5 B - - 25 TYPE 40 40 C - - 65 STRIKE 7 7 I - P1 - 72 DIP 3 3 I - P2 - 75 ANGLE 3 3 I - - Description of author-defined items in attitude.pat: *TYPE - Specifies the type of feature described by symbol (i.e., stike and dip of bedding, strike and dip of cleavage, strike and dip of foliation, strike of vertical bed) *STRIKE - Strike (the alternate name P1 is the original field name assigned by GSMAP) *DIP - Dip angle (the alternate name P2 is the original field name assigned by GSMAP) *ANGLE - An rotation angle for use with ArcView which allows the user to correctly orient the symbols PROCEDURES: These point features represent orientation of bedding or bedding features. However, they are not the actual geographic location of measurements. Rather, symbols thought to adequately represent the trend of geologic units were selected and generalized from larger scale geologic maps (1:24,000 and 1:62,500) and compiled on 1:100,000 scale mylar overlay. These were digitized using GSMAP software and converted to ARC/INFO format. Line features and duplicate points were deleted, the names of P1 and P2 changed to STRIKE and DIP, respectively, and the field ANGLE added and populated. *****Description of DOUBLE precision coverage BURIED***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 43 48 NODES 58 ANNOTATIONS LABEL 8 SECONDARY FEATURES Tics 8 Arc Segments 758 TOLERANCES Fuzzy = 0.000 N Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -88.994 Xmax = -88.159 Ymin = 46.447 Ymax = 47.350 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Units DD Spheroid CLARKE1866 Parameters: Description of arc attribute table buried.aat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 FNODE# 4 5 B - - 5 TNODE# 4 5 B - - 9 LPOLY# 4 5 B - - 13 RPOLY# 4 5 B - - 17 LENGTH 8 18 F 5 - 25 BURIED# 4 5 B - - 29 BURIED-ID 4 5 B - - 33 TYPE 15 15 C - - Description of author-defined items in buried.aat: *TYPE - The type of feature (concealed contact or concealed thrust) buried beneath the Jacobsville Sandstone. PROCEDURES: These previously unpublished features are covered by the Jacobsville Sandstone. They were mapped as a result of new interpretations of aeromagnetic and gravity data and compiled on 1:100,000 scale mylar overlays. They were digitized using GSMAP software and converted to ARC/INFO format. Line topology was constructed and the more descriptive attribute TYPE added. *****Description of DOUBLE precision coverage CGL***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 161 56 NODES 1850 ANNOTATIONS SYMBOL 30 SECONDARY FEATURES Tics 4 Arc Segments 3175 TOLERANCES Fuzzy = 0.002 N Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -89.034 Xmax = -87.491 Ymin = 46.527 Ymax = 47.487 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Units DD Spheroid CLARKE1866 Parameters: Description of arc attribute table cgl.aat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 FNODE# 4 5 B - - 5 TNODE# 4 5 B - - 9 LPOLY# 4 5 B - - 13 RPOLY# 4 5 B - - 17 LENGTH 8 18 F 5 - 25 CGL# 4 5 B - - 29 CGL-ID 4 5 B - - 33 NAME 20 20 C - - 53 SYMBOL 4 4 C - - Description of author-defined items in cgl.aat: *NAME - Name of interflow conglomerate *SYMBOL - Abbreviation for named conglomerate that corresponds to the symbol used on the USGS 1:100,000 scale Geologic Map of the Keweenaw Peninsula, Michigan PROCEDURES: These arcs represent conglomerates interbedded with flows of the Portage Lake Volcanics. They were digitized from 1:24,000 scale geologic maps using GSMAP software. GSMAP files were converted to ARC/INFO format for editing, building topology, and populating attribute tables. *****Description of DOUBLE precision coverage CHALC***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 5 32 POLYGONS 6 56 Yes NODES 5 SECONDARY FEATURES Tics 4 Arc Segments 72 Polygon Labels 5 TOLERANCES Fuzzy = 0.002 V Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -88.208 Xmax = -88.012 Ymin = 47.353 Ymax = 47.395 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Units DD Spheroid CLARKE1866 Parameters: Description of polygon attribute table chalc.pat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 AREA 8 18 F 5 - 9 PERIMETER 8 18 F 5 - 17 CHALC# 4 5 B - - 21 CHALC-ID 4 5 B - - 25 NAME 20 20 C - - 45 RESOURCE_TONNAGE 7 7 I - - 52 GRADE 4 4 F 2 - Description of items in chalc.pat: *NAME - Name of chalcocite body *RESOURCE_TONNAGE - Size of economic portion of body in tons *GRADE - Grade of economic portion of body in %Cu PROCEDURES: These polygons represent known chalcocite bodies. They were compiled on 1:100,000 scale mylar base from detailed unpublished maps from the Michcan Copper Company, Ltd. and then digitized in GSMAP. GSMAP files were converted to ARC/INFO for editing, building topology, and populating attribute tables. *****Description of DOUBLE precision coverage COORD***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 44 32 NODES 1875 ANNOTATIONS COORD 48 SECONDARY FEATURES Tics 4 Arc Segments 47 TOLERANCES Fuzzy = 0.002 N Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -89.000 Xmax = -87.500 Ymin = 46.000 Ymax = 47.500 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Units DD Spheroid CLARKE1866 Parameters: Note: There are no author-defined attributes for this coverage. PROCEDURES: This coverage is a 15 minute by 15 minute geographic coordinate grid which was created using the option of the command in ARC/INFO. It was then projected to the UTM coordinate system and clipped to match the extent of the rest of the Keweenaw data set. *****Description of DOUBLE precision coverage FISSURE***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 49 104 NODES 126 SECONDARY FEATURES Tics 4 Arc Segments 105 TOLERANCES Fuzzy = 0.002 N Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -89.034 Xmax = -87.491 Ymin = 46.527 Ymax = 47.487 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Units DD Spheroid CLARKE1866 Parameters: Description of arc attribute table fissure.aat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 FNODE# 4 5 B - - 5 TNODE# 4 5 B - - 9 LPOLY# 4 5 B - - 13 RPOLY# 4 5 B - - 17 LENGTH 8 18 F 5 - 25 FISSURE# 4 5 B - - 29 FISSURE-ID 4 5 B - - 33 NAME 15 15 C - - 48 OWNER 30 30 C - - 78 TOTAL_PRODUCTION 16 16 N 0 - 94 YEARS_PRODUCTION 10 10 C - - Description of author-defined items in fissure.aat: *NAME - Name of fissure vein *OWNER - Owner of fissure vein *TOTAL_PRODUCTION - Total production of fissure in pounds *YEARS_PRODUCTION - Years in production Note: A value of -9999 in the TOTAL_PRODUCTION field indicates no data. PROCEDURES: These arcs represent fissure veins. They were digitized from 1:24,000 scale geologic maps using GSMAP software and converted to ARC/INFO format. In ARC/INFO, topology was built, and attribute fields added and populated. *****Description of DOUBLE precision coverage GEOLOGY***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 856 32 POLYGONS 178 576 Yes NODES 719 ANNOTATIONS SYMBOL 117 FAULT 16 ROUTES/SECTIONS THRUST 7/85 28/58 FAULT 71/298 34/32 SECONDARY FEATURES Tics 8 Arc Segments 11807 Polygon Labels 177 TOLERANCES Fuzzy = 0.002 V Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -89.000 Xmax = -87.498 Ymin = 46.421 Ymax = 47.480 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Datum NAD27 Units DD Spheroid CLARKE1866 Parameters: Description of items in polygon attribute table geology.pat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 AREA 8 18 F 5 - 9 PERIMETER 8 18 F 5 - 17 GEOLOGY# 4 5 B - - 21 GEOLOGY-ID 4 5 B - - 25 CODE 3 3 I - - 28 SYMBOL 5 5 C - - 33 ERA 12 12 C - - 45 PERIOD 22 22 C - - 67 SUBPERIOD 28 28 C - - 95 SUPERGROUP 15 15 C - - 110 GROUP 20 20 C - - 130 UNIT_NAME 38 50 C - - 168 SUBUNIT_NAME 20 20 C - - 188 AGE 9 9 C - - 197 RK_TYPE 11 11 C - - 208 MAJOR_SUBTYPE 15 15 C - - 223 MAJOR_LITHOLOGY 21 21 C - - 244 MINOR1_RKTYPE 12 12 C - - 256 MINOR1_SUBTYPE 15 15 C - - 271 MINOR1_LITHOLOGY 25 25 C - - 296 MINOR2_RKTYPE 12 12 C - - 308 MINOR2_SUBTYPE 15 15 C - - 323 MINOR2_LITHOLOGY 20 20 C - - 343 PROVINCE_ORIGIN 28 28 C - - 371 SUBPROV/TERRANE 40 40 C - - 411 PROVINCE_AGE 18 18 C - - 429 REWORKING_PROV 8 8 C - - 437 REWORKING_SUBPRO 20 20 C - - 457 REWORKING_AGE 18 18 C - - 475 ENV_OF_FORMATION 26 26 C - - 501 TECTONIC_SETTING 24 24 C - - 525 LITH_ASSEMBLAGE 52 52 C - - Description of author-defined items in geology.pat: *CODE - Code used to join polygon to attributes *SYMBOL - Abbreviation of named unit *ERA - Era *PERIOD - Period *SUBPERIOD - Subperiod *SUPERGROUP - Supergroup *GROUP - Group *UNIT_NAME - Name of geologic unit *SUBUNIT_NAME - Subdivision within geologic unit *AGE - Age of geologic unit millions of years *RK_TYPE - Primary rock type of named unit *MAJOR_SUBTYPE - Further subdivision of RK_TYPE *MAJOR_LITHOLOGY - Predominant lithology of RK_TYPE *MINOR1_RKTYPE - Other rock type within named unit (note: designations minor1 and minor2 do not indicate abundance) *MINOR1_SUBTYPE - Further subdivision of MINOR1_RKTYPE *MINOR1_LITHOLOGY - Predominant lithology of MINOR1_RKTYPE *MINOR2_RKTYPE - Other rock type within named unit *MINOR2_SUBTYPE - Further subdivision of MINOR2_RKTYPE *MINOR2_LITHOLOGY - Predominant lithology of MINOR2_RKTYPE *PROVINCE_ORIGIN - Province of origin *SUBPROV/TERRANE - Subprovince/terrane of origin *PROVINCE_AGE - Age of province of origin *REWORKING_PROV - Province of reworking (if applicable) *REWORKING_SUBPROV - Subprovince of reworking *REWORKING_AGE - Age of reworking *ENV_OF_FORMATION - Environment of formation *TECTONIC_SETTING - Tectonic setting *LITH_ASSEMBLAGE - Lithologic assemblage Description of route attribute table geology.ratfault: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 FAULT# 4 5 B - - 5 FAULT-ID 4 5 B - - 9 NAME 25 25 C - - Description of author-defined items in geology.ratfault: *NAME - Name of unclassified fault Description of route attribute table geology.ratthrust: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 THRUST# 4 5 B - - 5 THRUST-ID 4 5 B - - 9 NAME 20 20 C - - Description of author-defined items in geology.ratthrust: *NAME - Name of thrust fault PROCEDURES: Geology and faults were digitized from 1:24,000 and 1:62,500 scale maps using GSMAP software and converted to ARC/INFO format. Imported geologic and fault lines were adjusted to match shorelines from the USGS 1:100,000 scale Digital Line Graphs (DLG's). Any unclosed polygons or dangling arcs were then cleaned manually before building polygon topology. Route systems representing faults (route.fault_thrust and route.fault_unclass) were created and attributed. *****Description of DOUBLE precision coverage LAKES***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 457 32 POLYGONS 362 26 Yes NODES 454 ANNOTATIONS NAME 16 SECONDARY FEATURES Tics 8 Arc Segments 10995 Polygon Labels 361 TOLERANCES Fuzzy = 0.002 V Dangle = 0.000 N Continue? | COVERAGE BOUNDARY Xmin = -88.999 Xmax = -87.608 Ymin = 46.423 Ymax = 47.477 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Datum NAD27 Units DD Spheroid CLARKE1866 Parameters: Description of polygon attribute table lakes.pat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 AREA 8 18 F 5 - 9 PERIMETER 8 18 F 5 - 17 LAKES# 4 5 B - - 21 LAKES-ID 4 5 B - - 25 LAKE 1 1 C - - Description of author-defined items in lakes.pat: *LAKE - Indicates whether specified polygon is a lake or land mass, either 'y' or 'n' PROCEDURES: This coverage was extracted from the USGS 1:100,000 scale DLG hydrographic data. DLG data for the quadrangles of the study area were downloaded from the EROS Data Center and converted to ARC/INFO format. Features representing lakes, wetland areas, and rivers were placed in separate coverages. Finally, coverages from each quadrangle representing these features were appended and clipped to the extent of the project area. *****Description of DOUBLE precision coverage LODES***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 67 32 POLYGONS 33 24 Yes NODES 55 REGIONS IROQUOIS 1 120 Yes KEARSARG 4 440 Yes HOUGHTON 1 120 Yes OSCEOLA 2 180 Yes CANDH 3 220 Yes ALLOUEZ 2 200 Yes ISLEROY 1 180 Yes BALTIC 5 200 Yes ASHBED 3 260 Yes PEWABIC 2 200 Yes KINGSTON 1 120 Yes SECONDARY FEATURES Tics 4 Arc Segments 1056 Polygon Labels 33 TOLERANCES Fuzzy = 0.002 V Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -88.698 Xmax = -88.192 Ymin = 47.010 Ymax = 47.429 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Units DD Spheroid CLARKE1866 Description of region attribute table lode.patkearsarg (NOTE: Only the description of this region attribute table is included. The items in all other region attribute tables (lode.patiroquois, lode.pathoughton, lode.patosceola, lode.patcandh, lode.patallouez, lode.patisleroy, lode.patbaltic, lode.patashbed, lode.patpewabic, and lode.patkingston) are identical except that there are fewer fields for mines. COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 AREA 8 18 F 5 - 9 PERIMETER 8 18 F 5 - 17 KEARSARG# 4 5 B - - 21 KEARSARG-ID 4 5 B - - 25 LODE_NAME 30 30 C - - 55 MINE_1 20 20 C - - 75 MINE_2 20 20 C - - 95 MINE_3 20 20 C - - 115 MINE_4 20 20 C - - 135 MINE_5 20 20 C - - 155 MINE_6 20 20 C - - 175 MINE_7 20 20 C - - 195 MINE_8 20 20 C - - 215 MINE_9 20 20 C - - 235 MINE_10 20 20 C - - 255 MINE_11 20 20 C - - 275 MINE_12 20 20 C - - 295 MINE_13 20 20 C - - 315 MINE_14 20 20 C - - 335 MINE_15 20 20 C - - 355 MINE_16 20 20 C - - 375 MINE_17 20 20 C - - 395 TOTAL_PRODUCTION 16 16 N 2 - 411 YEARS_PRODUCTION 10 10 C - - 421 IDED_RESERVES 16 16 N 2 - 437 RESERVE_GRADE 4 4 N 2 - Description of user-defined items in lode.patkearsarg and other region attribute tables: *LODE_NAME - Name of native copper lode *MINE_1 through MINE_17 - Names of mines that worked the lode *TOTAL_PRODUCTION - Total native copper production of lode in pounds *YEARS_PRODUCTION - Years lode was in production *IDED_RESERVES - Estimate of ore remaining in lode in units of thousands of tonnes *RESERVE_GRADE - Grade of identified reserves Note: Values of 0.00 in the IDED_RESERVES field indicate that no data is available. PROCEDURES: Region features in this coverage represent native copper lodes of the Keweenaw Peninsula. They were digitized from 1:24,000 scale geologic maps using GSMAP software and converted to ARC/INFO format. In ARC/INFO, polygon and region topology were constructed, and attribute tables added and populated. *****Description of DOUBLE precision coverage MAG***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 8 32 ANNOTATIONS LABEL 9 SECONDARY FEATURES Tics 4 Arc Segments 159 TOLERANCES Fuzzy = 0.002 N Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -89.034 Xmax = -87.491 Ymin = 46.527 Ymax = 47.487 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Units DD Spheroid CLARKE1866 Parameters: Note: There are no author-defined items in this coverage. PROCEDURES: These arc features represent distinct magnetic trends in the study area. They were digitized in GSMAP from a 1:250,000 scale hand-contoured magnetic compilation and converted to ARC/INFO format. *****Description of DOUBLE precision coverage MINES***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- POINTS 363 114 SECONDARY FEATURES Tics 4 TOLERANCES Fuzzy = 0.000 N Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -88.683 Xmax = -87.801 Ymin = 47.022 Ymax = 47.467 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Units DD Spheroid CLARKE1866 Parameters: Description of point attribute table mines.pat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 AREA 8 18 F 5 - 9 PERIMETER 8 18 F 5 - 17 MINES# 4 5 B - - 21 MINES-ID 4 5 B - - 25 MINE_NAME 50 50 C - - 75 SHAFT_NAME 10 10 C - - 85 LODE_NAME 30 30 C - - Description of author-defined items in mines.pat: *MINE_NAME - Name of mine owning shaft *SHAFT_NAME - Name of mine shaft *LODE_NAME - Name of primary lode being worked by shaft (in some cases, a shaft may have penetrated more than one lode) PROCEDURES: These points represent the location of mine shafts. They were digitized from 1:24,000 scale geologic maps using GSMAP software and converted to ARC/INFO format. In ARC/INFO topology was built, and attribute fields added and populated. *****Description of DOUBLE precision coverage OUTCROPS***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 1217 32 POLYGONS 1168 24 Yes NODES 1205 SECONDARY FEATURES Tics 12 Arc Segments 54887 Polygon Labels 1168 TOLERANCES Fuzzy = 0.002 V Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -88.999 Xmax = -87.587 Ymin = 46.434 Ymax = 47.480 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Datum NAD27 Units DD Spheroid CLARKE1866 Parameters: Note: No author-defined attributes in this coverage PROCEDURES: Outcrop data were generalized from 1:24,000 and 1:62,500 scale maps to 1:100,000 scale mylar base maps. These sheets were scanned as TIFF's and converted to ARC/INFO using the command. The grids created were registered using the and commands and then converted to vector coverages using the command. Finally, the individual coverages were appended and polygon topology built. *****Description of SINGLE precision coverage RIVERS***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 2163 76 NODES 6219 SECONDARY FEATURES Tics 16 Arc Segments 52411 TOLERANCES Fuzzy = 0.000 N Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -89.000 Xmax = -87.500 Ymin = 46.421 Ymax = 47.500 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Datum NAD27 Units DD Spheroid CLARKE1866 Parameters: Description of arc attribute table rivers.aat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 FNODE# 4 5 B - - 5 TNODE# 4 5 B - - 9 LPOLY# 4 5 B - - 13 RPOLY# 4 5 B - - 17 LENGTH 4 12 F 3 - 21 RIVERS# 4 5 B - - 25 RIVERS-ID 4 5 B - - 29 MAJOR1 6 6 I - - 35 MINOR1 6 6 I - - 41 MAJOR2 6 6 I - - 47 MINOR2 6 6 I - - 53 MAJOR3 6 6 I - - 59 MINOR3 6 6 I - - 65 MAJOR4 6 6 I - - 71 MINOR4 6 6 I - - Description of items in rivers.aat: *MAJOR1 - DLG code *MINOR1 - DLG code *MAJOR2 - DLG code *MINOR2 - DLG code *MAJOR3 - DLG code *MINOR3 - DLG code *MAJOR4 - DLG code *MINOR4 - DLG code PROCEDURES: This coverage was extracted from the USGS 1:100,000 scale DLG hydrographic data and converted to ARC/INFO format. Features representing lakes, wetland areas, and rivers were placed in separate coverages. Finally, coverages from each quadrangle representing these feature types were appended and clipped to the extent of the project area. *****Description of DOUBLE precision coverage ROADS***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 9122 52 SECONDARY FEATURES Tics 20 Arc Segments 55434 TOLERANCES Fuzzy = 0.002 N Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -89.000 Xmax = -87.714 Ymin = 46.421 Ymax = 47.500 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Datum NAD27 Units DD Spheroid CLARKE1866 Parameters: Description of arc attribute table roads.aat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 FNODE# 4 5 B - - 5 TNODE# 4 5 B - - 9 LPOLY# 4 5 B - - 13 RPOLY# 4 5 B - - 17 LENGTH 8 18 F 5 - 25 ROADS# 4 5 B - - 29 ROADS-ID 4 5 B - - 33 TYPE 20 20 C - - Description of author-defined items in roads.aat: *TYPE - Designates road type following conventions of USGS 1:100,000 scale topographic maps. PROCEDURES: This coverage was extracted from the USGS 1:100,000 scale SDTS transportation data. SDTS data for the study area were downloaded from the EROS Data Center and converted to ARC/INFO format. Coverages of individual quadrangles were then appended and attributed. *****Description of DOUBLE precision coverage STRUCTUR***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 2 64 ANNOTATIONS LABEL 2 SECONDARY FEATURES Tics 8 Arc Segments 42 TOLERANCES Fuzzy = 0.002 N Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -89.034 Xmax = -87.491 Ymin = 46.442 Ymax = 47.487 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Units DD Spheroid CLARKE1866 Parameters: Description of arc attribute table structur.aat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 FNODE# 4 5 B - - 5 TNODE# 4 5 B - - 9 LPOLY# 4 5 B - - 13 RPOLY# 4 5 B - - 17 LENGTH 8 18 F 5 - 25 STRUCTUR# 4 5 B - - 29 STRUCTUR-ID 4 5 B - - 33 TYPE 32 32 C - - Description of author-defined items in structur.aat: *TYPE - The structural feature type. In this case either 'syncline' or 'Limestone Mtn. Structural Zone' PROCEDURES: These arcs represent significant miscellaneous structural features in the project area. The syncline was digitized in GSMAP from a 1:62,500 scale geologic map. The Limestone Mountain Structural Zone is a newly published feature. It has been interpreted from aeromagnetic and gravity data. Its location and extent are supported by outcrop data. The zone was compiled on a 1:100,000 scale mylar base, digitized in GSMAP, and converted to ARC/INFO. *****Description of SINGLE precision coverage WETLANDS***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 478 76 POLYGONS 148 16 Yes NODES 473 SECONDARY FEATURES Tics 16 Arc Segments 14185 Polygon Labels 147 TOLERANCES Fuzzy = 0.000 V Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -89.000 Xmax = -87.733 Ymin = 46.422 Ymax = 47.459 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Datum NAD27 Units DD Spheroid CLARKE1866 Parameters: Description of arc attribute table wetlands.aat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 FNODE# 4 5 B - - 5 TNODE# 4 5 B - - 9 LPOLY# 4 5 B - - 13 RPOLY# 4 5 B - - 17 LENGTH 4 12 F 3 - 21 WETLANDS# 4 5 B - - 25 WETLANDS-ID 4 5 B - - 29 MAJOR1 6 6 I - - 35 MINOR1 6 6 I - - 41 MAJOR2 6 6 I - - 47 MINOR2 6 6 I - - 53 MAJOR3 6 6 I - - 59 MINOR3 6 6 I - - 65 MAJOR4 6 6 I - - 71 MINOR4 6 6 I - - Description of items in wetlands.aat: *MAJOR1 - DLG code *MINOR1 - DLG code *MAJOR2 - DLG code *MINOR2 - DLG code *MAJOR3 - DLG code *MINOR3 - DLG code *MAJOR4 - DLG code *MINOR4 - DLG code PROCEDURES: The polygon features in this coverage were extracted from 1:100,000 scale DLG hydrographic data. These DLG's were downloaded from the EROS Data Center and converted to ARC/INFO format. Features representing lakes, wetland areas, and rivers were placed in separate coverages. Finally, coverages from each quadrangle were appended and clipped to the extent of the project area. *****Description of DOUBLE precision coverage XSECTION***** FEATURE CLASSES Number of Attribute Spatial Feature Class Subclass Features data (bytes) Index? Topology? ------------- -------- --------- ------------ ------- --------- ARCS 3 70 ANNOTATIONS LABEL 7 SECONDARY FEATURES Tics 8 Arc Segments 3 TOLERANCES Fuzzy = 0.002 N Dangle = 0.000 N COVERAGE BOUNDARY Xmin = -89.000 Xmax = -87.500 Ymin = 46.500 Ymax = 47.500 STATUS The coverage has not been Edited since the last BUILD or CLEAN. COORDINATE SYSTEM DESCRIPTION Projection GEOGRAPHIC Units DD Spheroid CLARKE1866 Parameters: Description of arc attribute table xsection.aat: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED? 1 FNODE# 4 5 B - - 5 TNODE# 4 5 B - - 9 LPOLY# 4 5 B - - 13 RPOLY# 4 5 B - - 17 LENGTH 8 18 F 5 - 25 XSECTION# 4 5 B - - 29 XSECTION-ID 4 5 B - - 33 ID 2 2 C - - Description of author-defined items in xsection.aat: *ID - Identifies cross section PROCEDURES: These lines were drawn by the authors. They indicate where detailed cross sections were constructed. They were drawn on the 1:100,000 scale mylar base, digitized in GSMAP, and converted to ARC/INFO. OTHER DIGITAL DATA In addition to the above named layers, this project contains cross sections which are also structured as ARC/INFO coverages. Although, these data layers contain attributes and georeferencing information, they are not true geographic data. Rather, they were structured as coverages to allow correct scaling and positioning with respect to map view data. There are two copies of each cross section. The first set of cross sections was oriented horizontally and placed in individual views labeled Cross Section A-A', Cross Section B-B', and Cross Section C-C'. The other set has been rotated to align with the cross section lines in the map view. This allows the user to view the cross sections in relation to the geologic units. The following are cross section coverage names: XA_MAPVIEW XB_MAPVIEW XC_MAPVIEW XA_HORIZ XB_HORIZ XC_HORIZ Several images have been included for reference. Each was placed in a separate view. These images include: INDEXMAP.TIF - Index of geologic quadrangle maps used in compilation CORDIAG.TIF - Correlation Diagram, Eagle Harbor to South Range STRATSEC.TIF - Correlation of Map Units REFERENCES (asterisk indicates sources used for map compilation) Barovich, K.M., Patchett, P.J., Peterman, Z.E., and Sims, P.K., 1989, Nd Isotopes and the Origin of the 1.9-1.7 Ga Penokean Continental Crust in the Lake Superior Region: Geological Society of America Bulletin, v. 101, p. 333-338. Bornhorst, T.J., Paces, J.B., Grant, N.K., Obradovich, J.D., and Huber, N.K., 1988, Age of Native Copper Mineralization Keweenaw Peninsula, Michigan: Economic Geology, v. 83, p. 619-625. Brojanigo, A., 1984, Keweenaw Fault: Structures and Sedimentology: Houghton, Michigan, Michigan Technological University, M.S. thesis, 124 p. Bodwell, W.A., 1972, Geologic Compilation and Nonferrous Metal Potential, Precambrian Section, Northern Michigan: Houghton Michigan, Michigan Technological University, M.S. thesis, 106 p. Butler, B.S., and Burbank, W.S., 1929, The Copper Deposits of Michigan: U.S. Geological Survey Professional Paper 144, 238 p. *Cannon, W.F., 1986, Bedrock Geologic Map of the Iron River 1x2 degree Quadrangle, Michigan and Wisconsin: U.S. Geological Survey Miscellaneous Investigations Series Map I-1360-B, scale 1:250,000. Cannon, W.F., Green, A.G., Hutchinson, D.R., Lee, M., Milkereit, B., Behrendt J.C., Halls, H.C., Green, J.C., Dickas, A.B., Morey, G.B., Sutcliffe, R., and Spencer, C., 1989, The North American Midcontinent Rift beneath Lake Superior from GLIMPCE seismic reflection profiling: Tectonics, v. 8, p. 305-332. *Cannon, W.F., and Klasner, J.S., 1980, Bedrock Geologic Map of the Kenton- Perch Lake Area, Northern Michigan: U.S. Geological Survey Miscellaneous Investigations Series Map I-1290, scale 1:62,500. Cannon, W.F., Nicholson, S.W., Zartman, R.E., Peterman, Z.E., and Davis, D.W., 1993a, The Kallander Creek Volcanics -- a Remnant of a Keweenawan Central Volcano Centered near Mellen, Wisconsin: 39th Annual Institute on Lake Superior Geology Proceedings, p. 20-21. Cannon, W.F., Peterman, Z.E., and Sims, P.K., 1993b, Crustal Scale Thrusting and Origin of the Montreal River Monocline -- a 35km Thick Cross Section of the Midcontinent Rift in Northern Michigan and Wisconsin: Tectonics, v. 12, p. 728-744. Cannon, W.F., Nicholson, S.W., Woodruff, L.G., Hedgman, C.A., and Schulz, K.J., 1995, Geologic Map of the Ontonagon and part of the Wakefiled 30'x60' Quadrangles, Michigan: U.S. Geological Survey Miscellaneous Investigations Map I-2499, scale 1:100,000. Cannon, W.F., Woodruff, L.G., Nicholson, S.W., and Hedgman, C.A., 1996, Bedrock Geologic Map of the Ashland and Northern Part of the Ironwood 30'x60' Quadrangles, Wisconsin and Michigan: U.S. Geological Survey Miscellaneous Investigations Map I-2566, scale 1:100,000. Case, E.C., and Robinson, W.I., 1915, The Geology of Limestone Mountain and Sherman Hill in Houghton County, Michigan: Michigan Geological and Biological Survey, Publication 18, p. 165-181. *Cornwall, H.R., 1954a, Bedrock Geology of the Delaware Quadrangle, Michigan: U.S. Geological Survey Quadrangle Map GQ-51, scale 1:24,000. *Cornwall, H.R., 1954b, Bedrock Geology of the lake Medora Quadrangle, Michigan: U.S. Geological Survey Geological Quadrangle Mpa GQ-52, scale 1:24,000. *Cornwall, H.R., 1954c, Bedrock Geology of the Phoenix Quadrangle, Michigan: U.S. Geological Survey Geological Quadrangle Map GQ-34, scale 1:24,000. *Cornwall, H.R., 1955, Bedrock Geology of the Fort Wilkins Quadrangle, Michigan: U.S. Geological Survey Geological Quadrangle Map GQ-74, scale 1:24,000. *Cornwall, H.R., and White, W.S., 1955, Bedrock Geology of the Manitou Island Quadrangle, Michigan: U.S. Geological Survey Geological Quadrangle Map GQ-73, scale 1:24,000. *Cornwall, H.R., and Wright, J.C., 1954, Bedrock Geology of the Eagle Harbor Quadrangle, Michigan: U.S. Geological Survey Geological Quadrangle Map GQ-36, scale 1:24,000. *Cornwall, H.R., and Wright, J.C., 1956a, Geologic Map of the Hancock Quadrangle, Michigan: U.S. Geological Survey Mineral Investigations Field Studies Map MF-46, scale 1:24,000. *Cornwall, H.R., and Wright, J.C., 1956b, Geologic Map of the Laurium Quadrangle, Michigan: U.S. Geological survey Mineral Investigations Field Studies Map MF-47, scale 1:24,000. Daniels, P.A., Jr., 1982, Upper Precambrian Sedimentary Rocks: Oronto Group, Michigan-Wisconsin, in Wold. R.J. and W.J. Hinze, eds., Geology and Tectonics of the Lake Superior Basin: Geological Society of America Memoir 156, p. 107-133. *Davidson, E.S., Espenshade, G.H., White, W.S., and Wright, J.C., 1955, Bedrock Geology of the Mohawk Quadrangle, Michigan: U.S. Geological Survey Geological Survey Quadrangle Map GQ-54, scale 1:24,000. Davis, D.W., and Sutcliffe, R.H., 1985, U-Pb Ages from the Nipigon Plate and Northern Lake Superior: Geological Society of America Bulletin, v. 96, p. 1572-1579. Davis, D.W., Paces, J.B., 1990, Time Resolution of Geologic Events on the Keweenaw Peninsula and implications for development of the Midcontinent Rift: Earth and Planetary Science Letters, v. 97, p. 54-64. *Gregg, W.J., 1993, Structural Geology of Parautochthonous and Allocthonous Terranes of the Penokean Orogeny in Upper Michigan -- Comparisons with Northern Appalachian Tectonics: U.S. Geological Survey Bulletin, 1904-Q, p. Q1-Q28. Hedgman, C.A., 1992, Petrology and Provenance of a Conglomerate Facies of the Jacobsville Sandstone: Ironwood to Bergland, Michigan: [abst.] 38th Annual Institute on Lake Superior Geology Proceedings, v. 38, p.32-33. James, H.L., 1955, Zones of Regional Metamorphism in the Precambrian of Northern Michigan: Geological Society of America Bulletin, v. 66, p. 1455-1488. Kalliokoski, J., 1982, Jacobsville Sandstone, in Wold, R.J. and Hinze, W.J., eds., Geology and Tectonics of the Lake Superior Basin: Geological Society of America Memoir 156, p. 147-155. Mauk, J.L., Kelly, W.C., van der Pluijm, B.A., and Seasor, R.W., 1992, Relations between Deformation and Sediment-hosted Copper Mineralizations: Evidence from the White Pine Portion of the Midcontinent Rift System: Geology, v. 20, p. 427-430. Michcan Copper Company Ltd., 1982, Michigan Copper Sulfide Project, Keweenaw Peninsula: unpublished company document, 21 p. Nicholson, S.W., 1992, Geochemistry, Petrography and Volcanology of Rhyolites of the Portage Lake Volcanics, Keweenaw Peninsula, Michigan: U.S. Geological Survey Bulletin 1970-B, p. B1-B57. Ojakangas, R.W., 1994, Sedimentology and Provenance of the Early Proterozoic Michigamme Formation and Goodrich Quartzite, Northern Michigan - Regional Stratigraphic Implications and Suggested Correlations: U.S. Geological Survey Bulletin 1904-R, p. R1-R31. Robertson, J.M., 1975, Geology and Mineralogy of some Copper Sulfide Deposits near Mount Bohemia, Keweenaw County, Michigan: Economic Geology, v. 70, p. 1202-1224. Waggoner, T.D., 1994, Echo Lake Gabbro, Houghton County, Michigan [abs.]: 40th Annual Institute on Lake Superior Geology, Proceedings, Part 1 - Program and abstracts, p. 70. *White, W.S., 1956, Geologic Map of the Chassell Quadrangle, Michigan: U.S. Geological Survey Minerals Investigations Field Studies Map MF-43, scale 1:24,000. *White, W.S., 1968, The Native Copper Deposits of Northern Michigan, in Ridge, J.D., ed., Ore Deposits of the United States of 1933-1967 (Graton-Sales volume): New York, American Institute of Mining, Metallurgy and Petroleum Engineers, v. 1, p. 303-325. *White, W.S., Cornwall, H.R., and Swanson, R.W., 1953, Bedrock Geology of the Ahmeek Quadrangle, Michigan: U.S. Geological Survey Geological Quadrangle Map GQ-27, scale 1:24,000. *White, W.S., and Wright, J.C., 1956, Geologic Map of the South Range Quadrangle, Michigan: U.G. Geological Survey Minerals Investigations Field Studies Map MF-48, scale 1:24,000. White, W.S., and Wright, J.C., 1966, Sulfide Mineral Zoning in the Basal Nonesuch Shale, Northern Michigan: Economic Geology, v. 61, p. 1171-1190. Wilband, J.T., 1978, The Copper Resources of Northern Michigan: Final Report under U.S. Bureau of Mines contract J0366067, 61 p. *Wright, J.C., and Cornwall, H.R., 1954, Bedrock Geology of the Bruneau Creek Quadrangle, Michigan: U.S. Geological Survey Geologic Quadrangle Map GQ-35, scale 1:24,000. Young, C.T., and Repasky, T.R., 1986, A Magnetotelluric Transect of the Jacobsville Sandstone in Northern Michigan: Geological Society of America Bulletin, v. 97, p. 711-716. REVIEWS A paper copy of this data set was printed and reviewed for content and accuracy. The paper copy was then submitted to the USGS publications group for publication of the traditional geologic map. For the review of tabular data, coverages were converted to ArcView. A variety of queries and searches were performed to check for typographic and content errors. STATUS Complete MAINTENANCE AND UPDATE FREQUENCY None planned ACCESS CONSTRAINTS None USE CONSTRAINTS None POINT OF CONTACT Bill Cannon MS 954, USGS Reston, VA 20192 (703) 648-7345 wcannon@usgs.gov