Browsing by Author "Peterson, Dean M"

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Bedrock Geologic Map of a Portion of the South Kawishawi Intrusion, Lake County, Minnesota
(2014-08) Branham, Jesse; Dove, Andrea; Ferry, Carlos; Gorlick, Jacob; Hoeft, Erin; Pysher, Aaron; Mulcahy, Connor; Peterson, Dean M
This map is the result of a six day mapping project in the South Kawishiwi Intrusion, which took place from August 3rd through the 8th of 2014. This map was created on a 1:5000 scale by Precambrian Research Center field camp students at the University of Minnesota Duluth under the supervision of Dr. Dean Peterson. Data for this project was compiled from Peterson (2014) and Phinney (1966) and combined with the data that was collected over the mapping period. The purpose of this project was to create a more detailed and accurate geological map of this locality on the Duluth Complex, as well as a better understanding of possible glacial till deposits in the area. This project was also performed to test the conceptual model of this location, which inferred that the lineaments seen on LIDAR of the area consisted of mainly fault-like features and that the area was primarily covered by glacial water table through these fractures/faults due to mining operations and tailings processes. This capstone area was selected under the idea that the proposed conceptual model for the lineaments in the mapping area were incorrect. After six days of mapping and data collection on this location it is accurate to conclude that this area consists of almost entirely bedrock composed of large amounts of varying types of troctolite and anorthosite, with a sparse amount of localized till piles that consist of small pebbles to large boulders. The 1227 outcrops that were mapped in this area were not found to be fractured/faulted but instead broke apart due to frost wedging. This is the dominant type of mechanical weathering in the area. of this area was found to be false and the local water table and aquifers in this area would not be in jeapordy by consequence of mining operations.
Bedrock Geologic Map of the Disappointment and Ima Lakes Area, Lake County, Northeastern Minnesota
(2008-08) Stifter, Eric; Wartman, Jakob; Gibbons, Jack; Kane, Kevin; Murphy, Laura; Carlson, Anders; Mason, Tracey; Hudak, George J; Peterson, Dean M
This map is the result of seven days of field mapping by the authors in 2008, as well as a compilation of information gathered from Van Hise (1901), Gruner (1941), and Chandler (1991). This map was created by PRC Field Camp students under the supervision and guidance of Dr. Dean Peterson, NRRI Senior Research Associate, and Dr. George Hudak, professor at UW-Oshkosh. The purpose of this map is to aid in understanding the nature of the basal contact between the Duluth Complex and Wawa Subprovince Archean metavolcanic-metasedimentary rocks, which was last mapped in the early 1940's. Additionally, this map will serve as a basis for additional undergraduate honors theses studies. Access to the 663 outcrops mapped for this project was provided by extensive canoe shoreline mapping and traverses in the blown-down bush of the Dissapointment and Ima Lakes field area. This map was made at a 1:10,000 scale, and is the first detailed map done in an area previously mapped on a reconnaissance scale.
Bedrock Geologic Map of the Disappointment Lake Area, Lake County, Northeastern Minnesota
(2009-08) Mulvey, Lucy; Ross, Cabin; Zeitler, Joseph; Pendleton, Matthew; McCarthy, Andrew; Copp, Lee; Nowak, Robert; Hudak, George J; Peterson, Dean M
This map was created by PRC Field Camp students under the guidance of Dr. Dean Peterson, Duluth Metals Limited Senior Vice President of Exploration, and Dr. George Hudak, Associate Professor of Geology at the University of Wisconsin Oshkosh. The purpose of this map is to further understand the relationship between the Duluth Complex and the older Archean metasediment, volcanic and volcaniclastic rocks in the area which were last mapped in the early 1940's by Gruner. This map will also facilitate undergraduate research theses studies. This map is the result of seven days of field mapping by the authors in 2009. Access to the 955 outcrops included in this project was achieved through extensive mapping of shorelines within the Disappointment, Parent and Snowbank Lakes field area combined with multiple traverses through dense bush and swamp areas. This is the first detailed map of the area produced at a 1:10,000 scale.
Bedrock Geologic Map of the Duluth Complex in the Northern South Kawishiwi Intrusion and Surrounding Area, Lake and St. Louis Counties, Minnesota
(University of Minnesota Duluth, 2008-05) Peterson, Dean M
This map is the result of numerous investigations by the author and many others over the last 8 years of the South Kawishiwi intrusion (SKI) and it's contained Cu-Ni-PGE mineralization. Detailed geological mapping evolved from a study of the Nickel Lake Macrodike (NLM) into a comprehensive geologic mapping and compilation project (104,000 acres) to answer some of the fundamental questions on the origin of the extensive known and undiscovered Cu-Ni-PGE mineralization in the northern portion of the SKI. Such an increase in scope is needed due to the economic significance of the published resource estimates (>$146 billion in contained metal) from this area. To date, nearly 15,000 outcrops, 1,400 structural measurements, geology and geochemistry from 773 drill holes totaling over 845,000 feet of core, and 12,500,000 meters of elevated contour lines (see Digital Topography image below) have been integrated into the comprehensive GIS database. The map units of the SKI depicted on this map sheet differ from previous maps from the area, in that the author has consulted with numerous company geologists and defined map units based on what industry geologists use to define rock masses encountered in drill core. This new map includes geology from each of the major lithologic units in the area, namely the Late Archean Giants Range batholith, the Paleoproterozoic Biwabik Iron and Virginia Formations, and the Anorthositic Series, Bald Eagle Intrusion, SKI, and the NLM of the Mesoproterozoic Duluth Complex. There are only a few faults depicted on the map, and literally hundreds of kilometers of linear topographic features that remain to be investigated in detail (see Digital Topography image below). However, little obvious offset of rock units have been observed along these features where investigated in detail, thus the author has purposely not drawn many faults on the map. One main new insight of this recently completed compilation is the recognition that the northeastern extent of the SKI is not a shallowly dipping sill but rather a southwest trending, inclined funnel-like body. Such an interpretation leads to the conclusion that the eastern contact of the SKI, which previously was interpreted as the top of the intrusion, is a basal contact, and thus has great potential for hosting Cu-Ni-PGE mineralization at its base. Understanding the origin of mineralized zones is the goal of all economic geologists, and in magmatic ore systems like the SKI, one must try to imagine the magmatic processes that culminated in the formation of the ores and surrounding rocks, i.e. how did the SKI form? Did the magmas intrude as crystal-laden slurries? Are the "Open" and "Confined" styles of mineralization defined by Peterson (2001) true mappable units? Such thoughts are the basis upon which the author began the quest to complete this map sheet. The author has inserted a number of inset maps and figures for the reader to review and ponder about the possible types of magmatic prosesses that occurred in the area (now depicted on this map sheet) 1.1 billion years ago. It is hoped that careful review of the bedrock geologic map and inset figures will give the reader and user of the map new geologic insight and ideas for future mineral exploration programs and scientific study.
Bedrock Geologic Map of the Forest Center Area, Lake County Minnesota
(2012-08) Doane, Victoria T; Raines, Rachel A; Reely, William P; Rogers, Philip M; Wnukowski, Joseph D; Peterson, Dean M
The Anorthositic Series of the Duluth Complex has largely been mapped as a single undifferentiated unit. The 2011 Pagami Creek Fire burned away a great deal of organic material in the Forest Center area, south of Lake Isabella, exposing a great many outcrops of the Duluth Complex Anothositic Series. This map was created by students of the Precambrian Research Center under the guidance of Dean Peterson (Senior Vice President of Duluth Metals) from August 5th to August 16th using detailed field mapping techniques, ArcGIS 10, and Adobe Illustrator. It was done to try and further split up the Anorthositic Series and to make new inferences about the units formation within the Duluth Complex
Bedrock Geologic Map of the Gafvert Lake Area, St. Louis County, Northeastern Minnesota
(2013-08) Baumgardner, Mark; Brown, Nathan; Grotte, Matt; Jacobson, Alan; Kendall, Jamie; Ostwald, Claire; Schriner, Nathan; White, Justin; Peterson, Dean M
This project was carried out under the supervision of Dean Peterson, Vice President of Exploration at Duluth Metals with the goal of creating a higher-resolution bedrock map of the Gafvert Lake area. The area was last mapped in 2003 at the 1:100,000 scale by the Minnesota Geological Survey (Jirsa and Boerboom, 2003). Mapping was carried out over five days by eight students for the 2013 Precambrian Field Camp. Six hundred and seventeen outcrops were mapped by hiking and lakeshore canoe mapping. The final map incorporated over 1,500 outcrops from historical work in the area. Emphasis was placed on defining the structure of an Archean stratovolcano within the Vermilion Greenstone Belt.
Bedrock Geologic Map of the Gold Mine Camp Area, Quetico Subprovince, Northern Minnesota
(2011-08) Ryan, Patrick; Balogh, Taylor; Fischer, William; Lenane, Tim; Latson, Charles; Kroeninger, Adam; Radakovich, Amy; Peterson, Dean M
As part of the PRC 2011 Field Camp capstone project led by Dr. Dean Peterson, the authors mapped the Quetico Sub-Province of the Superior Province along the Vermillion River to the southwest of Vermillion Falls from August 8th 2011 through August 13th 2011. The goal of the project was to create a map of the structural relationships between the lithological units of the area. As part of the project, the mineral potential of sulfide-rich quartz veins in association with the historic gold prospect (1925-1933) mine was investigated. The study area was accessed by river using motor boats and a canoe, cars on forestry roads to accommodate long traverses, and traversed by foot both on and off trails. The geology of the area consists of a heterogeneous migmatite consisting of two major units, granitoid-rich migmatite and biotite schist-rich migmatite. The migmatite was derived from metamorphism and melting of passive margin sediments (greywacke and argillite) associated with the north directed collision of North America and the Wawa-Abitibi Sub-province during the Algoman Orogeny (2.68 Ga).
Bedrock Geology and Lode Gold Prospect Data Map of the Mud Creek Road Area, Northern St. Louis County, Minnesota
(University of Minnesota Duluth, 2004) Peterson, Dean M; Patelke, Richard L
Gold mineralization in northeastern Minnesota occurs in numerous prospects east of Lake Vermilion in rocks of the Bass Lake sequence (Peterson and Jirsa, 1999) of the Neoarchean Wawa Subprovince of the Canadian Shield. This zone of abundant gold mineralization is bounded to the south by the Mud Creek shear zone and to the north by the Vermilion fault (Fig. 1). The main access to these prospects is along the Mud Creek road (County Road 38). A brief period of mineral exploration for lode-gold deposits in this immediate area of the Vermilion district occurred in the mid 1980s to early 1990s. These programs typically consisted of grid-based geologic mapping, bedrock sampling, ground geophysics, and the completion of soil geochemical surveys. Personal conversations with many of the people involved in gold exploration programs in the area, and compilation of all exploration data from the district as a whole by Peterson (2001), has led to the conclusion that interpretation of linear structural elements exposed in outcrops were typically not used in designing exploratory drilling plans in the map area. Therefore, many of the prospects discovered on the surface as a result of these exploration programs remain untested by drilling. The goal of this project was to try to determine the downdip orientation of specific gold mineralized zones discovered in these previous exploration programs, and therefore, encourage new gold exploration in the area. Brief descriptions of the techniques used in the project are described below. Detailed geologic outcrop maps (at scales ranging from 1:1,000 to 1:3,000) were completed for a number of the gold prospects located in the field area. The mapping was focused on structural (shear zones, lineations, intersecting foliations and small-scale folds), geological (contact relationships, competence contrasts), geochemical (gold assays, trace element characteristics), and alteration (Fe-bearing carbonate, sericite, pyrite, silicification) features within and around areas of gold mineralized exposures.
Bedrock Geology Map and Cu-Ni Mineralization Data for the Basal Contact of the Duluth Complex West of Birch Lake, St. Louis and Lake Countiues, Northeastern Minnesota
(University of Minnesota Duluth, 2004) Peterson, Dean M; Patelke, Richard L; Severson, Mark J
This map is the outcome of eight days of field mapping by Dean M. Peterson in 2001 (Peterson, 2002e), and 6 days of mapping by the authors in 2002. The discovery of large (hundreds of meters long) gossanous expanses of Cu-Ni mineralized rock in the basal zone of the South Kawishiwi intrusion (SKI) in 2001 (in a historically under-mapped area) lead to the acquisition of funds to complete the subsequent detailed geological mapping that resulted in the publication of this map sheet. The mapping was completed at a scale of 1:3,000 and was concentrated within the Cu-Ni-PGE mineralized horizon immediately east of the basal contact of the Duluth Complex. Three mapping traverses were completed to the west into the footwall Neoarchean Giants Range batholith, and to the east into the unmineralized rocks of the SKI stratigraphically overlying the mineralized zone. The information generated from the detailed geological mapping was integrated with previous work by Phinney (1967), Miller et al. (2001), and Miller et al. (2002c), outside of the corridors of detailed mapping during the final compilation of this geologic map (see Fig. 1). In addition, geologic units intersected in the scattered drill holes in the area (see Severson, 1994) have been projected updip to the surface. The faults depicted on the map are interpreted from analysis of aeromagnetic data, steepening of the dip of the basal contact of the Duluth Complex (Figs. 2 and 3), and topographic lineaments. Digital data will be available online at http://www.nrri.umn.edu/egg/ in the fall of 2004.
Bedrock Geology Map of the Crocodile Lake Intrusion: Cook County, Northeastern Minnesota
(2015-08) Church, Andrew; Curry, Zach; Dim, Jules; Lawyer, Luke; Reale, Peter; Slachter, Mitchell; Fix, Paul J; Peterson, Dean M
This map includes new bedrock geologic mapping by the authors combined with compilation of previous work (see references) under the direction of Dr. Dean Peterson for the 2015 Precambrian Research Center’s field course. The intent of this work was to improve upon previous mapping and to investigate potential economic mineralization near the base of the Crocodile Lake intrusion in Cook county Minnesota. Bedrock outcrop mapping at a scale of 1:20,000 was conducted in the Boundary Waters Canoe Area Wilderness (BWCAW) focusing on the areas immediately surrounding Crocodile Lake. During a period of five days, 233 outcrops were mapped along >130 miles of both land and canoe raverses. In addition, over 45 rock samples were collected from the field to aid the USGS in a regional assessment of mineralization potential. Early reconnaissance mapping was done by Dr. Dean Peterson and Dr. Phil Larson along Shoe Lake Road to the southeast of the map area. Using work done by F.F. Grout from 1925-1927 as a starting point, our intent was to discriminate units initially mapped by Grout as undifferentiated gabbro. After collecting data we were able to discern six units of gabbro, one of which has trace sulfides. Comparisons were made to the Poplar Lake intrusion, a similar Early Gabbro series of the Duluth Complex to the west of the map area. While the Poplar Lake and Crocodile Lake intrusions may be a correlative, a comparison of the lithologies suggests a distinction between the two. However, further mapping of the contact is needed for a definite conclusion. The authors acknowledge and appreciated the support of the University of Minnesota-Duluth, and to the staff of the Precambrian Research Center.
Bedrock Geology Map of the Nickel Lake Macrodike and Adjacent Areas: Lake County, Northeastern Minnesota
(University of Minnesota Duluth, 2006-11) Peterson, Dean M; Albers, Paul B; White, Chris R
This map is the first of what is hoped (contingent on funding) to be a series of new detailed bedrock geology maps of the marginal zone of the South Kawishiwi Intrusion by the University of Minnesota Duluth's Natural Resources Research Institute (see Peterson, 2006). Such mapping will form the basis for continued exploration for Cu-Ni-PGE mineralization as well create the geologic base upon which environmental review associated with exploitation of such mineralization can be built. Recent detailed mapping at a scale of 1:5,000 by the authors was conducted west and south of the Boundary Waters Canoe Area Wilderness (BWCAW). Nearly 1,000 outcrops along approximately 100 kilometers of field traverses were examined to identify and confirm the internal lithologic variability, contact relationships, and structure of the Nickel Lake Macrodike between the BWCAW and Omaday Lake. The authors wish to acknowledge Dr. Paul Weiblen (emeritus professor of geology at the University of Minnesota) for his keen insight of the geology of the area and Dr. George Hudak and undergraduate student Jeremiah Gowey of the University of Wisconsin Oshkosh for assistance in mapping outcrops around and south of Omaday Lake. Additional reconnaissance mapping in early November by the senior author was conducted to field check compiled outcrop locations depicted on the 1957 INCO map of the Spruce Road Deposit and the 1968 Hanna Mining map of the South Filson Creek Deposit (both of which are publically available in the DNR archive at Hibbing, Minnesota). The reconnaissance mapping confirmed the location of gossaneous Cu-Ni bearing INCO outcrops and reconfirmed the outstanding field mapping of all types of Duluth Complex rocks by Hanna Mining Company geologists of the late 1960s (see figure of "Sources of Information"). This map has been built upon (in the areas surrounding depicted outcrops and historic drill holes) the 1966 map of the Gabbro Lake 15' quadrangle by Green et al. (Minnesota Geological Survey Miscellaneous Map M-2), which because of its quality has been the geologic foundation for this area for 40 years. The reader of this map should compare the author's interpretation of the bedrock geology to that depicted on M-2, which will undoubtedly highlight the need for continued detailed mapping of the marginal zone of the South Kawishiwi Intrusion (which was not the purpose of map M-2), especially in light of the greatly increased interest in the potential for exploiting the vast resources of Cu-Ni-PGE mineralization enclosed within these rocks. The Nickel Lake Macrodike is lithologically and structurally related to the South Kawishiwi Intrusion and the known Cu-Ni-PGE deposits of Birch Lake, Maturi, Maturi Extension, Spruce Road, and South Filson Creek. The citation for this map includes the caveat "Version 1", which points out the fact that the authors believe that more detailed geologic mapping and analytical studies (no petrography or geochemical analyses of recently collected samples has been completed) are needed to truly understand what the bedrock geology enclosed within the boundaries of this map sheet (and the area to the west-southwest) really is (ie. we've only begun to scratch the surface). This map and all associated GIS data (in ArcView 3.2 format) can be obtained online at http://www.nrri.umn.edu/egg/publicationlist.html.
Bedrock Geology of Lake Vermilion/Soudan Underground Mine State Park
(University of Minnesota Duluth, 2016-06) Radakovich, Amy; Pignotta, Geoff; Schwierske, Kelly; Students from the 2010-2013 Precambrian Research Center Geology Field Camp; Hudak, George J; Peterson, Dean M
Lake Vermilion/Soudan Underground Mine State Park possesses a rich cultural and natural history that is directly related to the bedrock geology in this part of Minnesota’s Vermilion District. The bedrock geology comprises a complex record of Neoarchean-age (>2.5 billion years old) volcanic, sedimentary, hydrothermal, structural, and tectonic events associated with the Wawa-Abitibi Terrane within the southwestern part of the Superior Craton (Stott et al., 2007; Stott and Mueller, 2009; Lodge et al., 2013, 2015). Considerable geological research has been conducted since the late 1990s to study the stratigraphy, hydrothermal alteration, structural geology, and economic geology in the Vermilion District (Lawler and Riihilouma, 1997; Hudak and Morton, 1999; Peterson and Jirsa, 1999; Hovis, 2001; Jirsa et al., 2001; Newkirk et al., 2001; Odette et al., 2001; Peterson, 2001, 2005; Peterson et al., 2001; Hudak et al., 2002a, 2002b, 2006, 2007, 2012; Hocker et al., 2003; Peterson and Patelke, 2003; Hoffman, 2007; Jansen et al., 2009; Lodge et al. 2013, 2015). As well, numerous geological field trips have been conducted in this region since the mid-2000s (Hudak et al., 2004, 2014; Jirsa et al., 2004, 2016; Larson and Mooers, 2009; Peterson and Patelke, 2004; Peterson et al., 2009a, 2009b). Although several regional scale geologic maps exist for regions encompassing, and in close proximity to, Lake Vermilion/Soudan Underground Mine State Park (Ojakangas et al., 1978; Sims and Southwick, 1980, 1985; Sims, 1985; Southwick, 1993; Peterson and Jirsa, 1999; Jirsa et al., 2001; Peterson and Patelke, 2003; Hudak et al., 2002b; Hoffman, 2007), no coherent, detailed (1:10,000 scale) geologic map exists for the region comprising Minnesota’s newest state park. Minnesota Department of Natural Resources Parks and Trails staff have partnered with the Precambrian Research Center (PRC) at the Natural Resources Research Institute (NRRI) at the University of Minnesota Duluth to conduct geologic mapping in Lake Vermilion/Soudan Underground Mine State Park since 2010. This partnership had two primary goals: 1) to offer a collaborative opportunity to train upper-level undergraduate and graduate university geology students effective and efficient methods to conduct geologic mapping in Precambrian terranes; and 2) through geologic mapping, gain a deeper understanding of the geological processes and events associated with the development of the Vermilion District within the context of the larger Wawa-Abitibi Terrane. This partnership has led to the development of a new geologic map for Lake Vermilion/Soudan Underground Mine State Park (Peterson et al., 2016) which this report describes.
Bedrock Geology, Sample Location, and Property Position Maps of the West Birch Lake Area, South Kawishiwi Intrusion, Duluth Complex, Lake and St. Louis Counties, Northeastern Minnesota
(University of Minnesota Duluth, 2002-04) Peterson, Dean M; Marma, John; Brown, Philip
This map (NRRI/MAP-2002/02) is the outcome of eight field days mapping and sampling in the area by the senior author. The initial impetus for this mapping was to try to define Duluth Complex induced contact-metamorphic zonation in the footwall Giants Range batholith, and to relate this to Cu-rich mineralization in these rocks. Research into footwall Cu-rich mineralization continues, and will be published in the future. However, the discovery of large expanses of Cu-Ni mineralized rock in the basal zone of the South Kawishiwi, in an essentially unmapped area, lead to this preliminary map (Figure 1). The geologic map represents the initial interpretaton of the bedrock geology of the basal zone of the South Kawishiwi Intrusion, based on mapped outcrops, subcrops, and glacial materials (float). In addition, geologic units intersected in drill holes have been projected updip to the surface. The faults depicted on the map are interpreted from aeromagnetic data, steepening of the dip of the basal contact of the Duluth Complex, and topographic lineaments. The location and simplified regional geology encompassing the map area is depicted in Figure 4. The lithologic legend of the geology map is simplified into the intrusive stratigraphy of the South Kawishiwi Intrusion first defined by Severson (1994). Readers interested in detailed descriptions of the regional South Kawishiwi Intrusion stratigraphy are referred to that work. Cu-Ni-PGE mineralization is largely confined to the basal stratigraphic units of the intrusion (units BAN, BH, and U3), and on the ground is largely represented by knob-like outcrops, and large expanses of rusty, gossaneous boulder fields (subcrops). Old test pit dumps (circa 1890 ?) into the Biwabik Iron Formation are common in the southern portion of the map, and occur in areas of anomalous magnetic field properties. Seventy-five rock samples (Figure 2) were collected in the area (described in Table 1), and Dr. Philip Brown and John Marma (Department of Geology, University of Wisconsin - Madison) provided the funding for the base- and precious-metal analyses of twenty of these samples (presented in Table 2). Check assays for anomalous samples were analyzed by ALS Chemex labs from the original pulps and rejects (Table 2). Assay data for the majority of the drill holes in the map area have been compiled by Peterson (1997), which includes > 60,000 geochemical analyses for drill holes throughout the Duluth Complex. The smaller-scale property position map (Figure 3) depicts the current mineral lease holders in the area, and should only be viewed as a "snapshot" of the mineral land positions at the date of this map. Detailed geologic mapping in the area, including additional geochemical analyses, has been approved from the Permanent University Trust Fund, and will be completed during the 2002 field season.
C-51, Geologic Atlas of St. Louis County, Minnesota
(Minnesota Geological Survey, 2022) Bauer, Emily J; Jirsa, Mark A; Block, Amy R; Boerboom, Terrence J; Chandler, V.W.; Peterson, Dean M; Wagner, Kaleb G; McDonald, Jennifer M; Dengler, Elizabeth L; Meyer, Gary N; Hamilton, Jacqueline D
A County Geologic Atlas project is a study of a county's geology, and its mineral and ground-water resources. The information collected during the project is used to develop maps, data-base files, and reports. This same information is also produced as digital files for use with computers. The map information is formatted as geographic information system (GIS) files with associated data bases. The maps and reports are also reproduced as portable document files (PDFs) that can be opened on virtually any computer using the free Acrobat Reader from Adobe.com.
C-54, Geologic Atlas of Lake County, Minnesota
(Minnesota Geological Survey, 2022) Bauer, Emily J; Jirsa, Mark A; Block, Amy R; Boerboom, Terrence J; Chandler, V.W.; Peterson, Dean M; Wagner, Kaleb G; McDonald, Jennifer M; Dengler, Elizabeth L; Meyer, Gary N; Hamilton, Jacqueline D
A County Geologic Atlas project is a study of a county's geology, and its mineral and ground-water resources. The information collected during the project is used to develop maps, data-base files, and reports. This same information is also produced as digital files for use with computers. The map information is formatted as geographic information system (GIS) files with associated data bases. The maps and reports are also reproduced as portable document files (PDFs) that can be opened on virtually any computer using the free Acrobat Reader from Adobe.com.
Continuous Pilot-Scale Demonstration of Ilmenite Processing Technology
(University of Minnesota Duluth, 2021-05) Hudak, George J; Rao, Shashi; Peterson, Dean M; Chen, Jonathan; Lakshmanan, V.I.; Sridhar, Ram; Gluck, Eugen
Copper-Nickel Grade Maps for the Spruce Road Deposit, South Kawishiwi Intrusion, Duluth Complex
(University of Minnesota Duluth, 2002-02) Peterson, Dean M
This report describes the Cu-Ni mineralization of the Spruce Road area in the northern portion of the South Kawishiwi intrusion. The mineralization in the area is defined by > 9,500 assays from approximately 140,000 feet of core from 232 exploration holes drilled by INCO (220 holes), Bear Creek (6 holes), U.S. Bureau of Mines (3 holes), Hanna Mining (2 holes), and Wallbridge Mining (1 hole). Drilling in the Spruce Road area largely occurred during two time periods: the middle 1950s, following the original discovery of Cu-Ni mineralization, and from 1966 to 1973. Assay data from all of the drill holes within the South Kawishiwi intrusion have been compiled by the author into a comprehensive geological and geochemical database. Drill hole assays for the Spruce Road area have been exported out of this database and form the geochemical basis for this report. Preliminary analysis of the drill hole assay data for all of the deposits of the South Kawishiwi intrusion has led to the identification of two main styles of mineralization associated with the base of the intrusion. These mineralization types include: 1) “Open” – vertically extensive (> 450 meters) mineralization with moderate Cu-Ni grade and low Au+PGE grades. Examples of this open style include the Spruce Road, Serpentine, and Dunka Pit deposits. 2) “Confined” – vertically restricted (< 150 meters) mineralization with high Cu-Ni grades and moderate to very high (locally) Au+PGE grades. Examples of the confined style include the Maturi, Maturi Extension, and the Birch Lake deposits. Regional crosscutting relationships indicate that the “Open” style mineralization preceded the “Confined” style. Moreover, the curvilinear nature of the contact between the styles of mineralization is similar to the regional contacts of most of the intrusions of the Duluth Complex and adds further support to this theory.
Development of Archean Lode-Gold and Massive Sulfide Deposit Exploration Models using Geographic Information System Applications: Targeting Mineral Exploration in Northeastern Minnesota from Analysis of Analog Canadian Mining Camps (Volumes I-III)
(2001-12) Peterson, Dean M
Detailed lode-gold (LG) and volcanogenic massive sulfide (VMS) deposit mineral potential maps have been developed from new mapping and compilation of a 2270 mi2 area of the Late Archean Wawa Subprovince of the Superior Province in northern Minnesota. The mineral potential maps have been developed by the integration of ore deposit models for lode-gold and volcanogenic massive sulfide deposits into an exhaustive geological, geochemical, and geophysical Geographical Information System (GIS) data compilation of the study area. In addition, detailed GIS geological compilations from the three largest lodegold mining camps of the Superior Province of Canada (the Hemlo, Timmins, and Kirkland Lake mining camps) have been completed, and are incorporated in the lode-gold mineral potential model. Methods used to predict mineral potential include both knowledge-driven (LG and VMS models) and data-driven (LG only) analysis of information derived from the new GIS geologic map compilations, and from databases of geochemical and geophysical data for the Minnesota study area. The mineral potential analysis includes the use of fuzzy logic techniques in ranking the importance of specific types of information derived from the ore deposit models. In addition, fuzzy logic techniques have been used in the digital overlay of hundreds of maps portraying specific geologic data, into the final LG and VMS maps showing base- and precious-metal mineral potential of the Minnesota study area.
Digital Base for Geological Mapping within the Northern South Kawishiwi Intrusion: Lake and St. Louis Counties, Northeastern Minnesota
(University of Minnesota Duluth, 2006-07) Peterson, Dean M
This map depicts the outcome of several hundred hours of digitizing contour lines and associated topographic map data (lakes, streams, roads, trails) as well as updating a three-dimensional database of drill hole information and scattered surface sample geochemical analyses for the northern portion of the South Kawishiwi Intrusion. The data was digitized in three-dimensions, and was used to generate the 3D image of the surface topography that forms the background of the map sheet. As well, all of the data has been incorporated into a detailed GIS basemap of the area. The purpose of this work is two-fold: (1) to visually comprehend the geomorphology of this area (which is in the scoured bedrock terrane of northeastern Minnesota) as a tool in understanding the bedrock and surficial geology, and (2) to provide a visual impetus for funding a large geological mapping project in this economically significant (Cu-Ni-PGE mineral potential) and environmentally sensitive (BWCAW) area. Such a project would need financial support from both the University of Minnesota Duluth's Natural Resources Research Institute and from companies in the Minerals Industry that have active Cu-Ni-PGE mineral exploration programs situated within the boundaries of this map sheet (Duluth Metals Limited, Franconia Minerals, Encampment Resources). These active mineral exploration activities are being driven by greatly increased metal prices as a result of global economic expansion. Previous mineral exploration programs within the boundaries of this map sheet has included approximately 607 exploration holes totaling over 90 miles of core (296 kilometers) that was drilled between the years 1951 - 2006. Integration of geologic data from these historic exploration programs into a conservative geological resource estimate of contained copper, nickel, platinum, palladium, and gold indicates that at today's metal prices, over $500 billion dollars of these metals (which includes an estimated 50 million ounces of palladium, 25 million ounces of platinum, and 10 million ounces of gold) is hosted by the South Kawishiwi Intrusion within this map sheet (Peterson, unpublished data). The economic significance of these geological resources, along with the possible extraction of these metals in the future, is driving the author's desire to complete a new geological map of a large portion of this area. Published geological maps of portions of this sheet are given in the "INDEX TO MAPPING". Review of this figure highlights the need for a new mapping campaign, namely that the bulk of this area has only been mapped at small scales (1:31,680 and 1:48,000 scales) thirty to forty years ago, prior to the great advances in our knowledge of the geology, geophysical characteristics (Fig. 1), and mineralization in the Duluth Complex over the past twenty years.
Examination of Non-Lithium Battery Storage Concepts
(University of Minnesota Duluth, 2021-06) Fosnacht, Donald R; Peterson, Dean M; Myers, Evan
This study was undertaken to inform State of Minnesota Energy Policy and is funded by the Legislative-Citizens Commission on Minnesota Resources (LCCMR). It is focused on identifying alternative energy storage opportunities for the state. Various battery storage techniques for renewable energy are under active development by various parties, and many of these technologies are geared for energy storage for 2- to 4-hour duration. Other non-battery technologies are also under active development. These do not involve electrochemical storage concepts. This report summarizes non-lithium ion battery approaches that take advantage of physical principles involving gravity, compressing air and/or carbon dioxide, using hot carbon dioxide or molten salts or flywheel systems to capture energy that can be converted into electricity when renewable energy sources are unable to provide what is required. The use of these concepts can lead to long-duration storage that can facilitate better capture of available renewable energy and potentially eliminate the need for natural gas-based peaking plants to provide a more stable electrical supply when intermittent (e.g., solar or wind) resources cannot supply the necessary electricity. Additionally, the future impact of hydrogen as a means for long-duration energy storage is considered, especially using ammonia as a storage media. It is also apparent that redox flow batteries may also be useful in supporting storage needs beyond 2- to 4-hour duration. The techniques noted do not require nickel, cobalt, or lithium resources, have improved environmental characteristics, and in most cases reduced fire hazards compared to lithium ion-based battery systems. Finally, geographic information system (GIS) analysis is applied to better understand where the technologies can be potentially adopted at specific locations in the state of Minnesota. Some technologies need very specific geologic features for ready site selection; others can be placed if suitable near-grid locations are available.

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