Presentation on theme: "GEOLOGIC MAPPING IN SUPPORT OF LAND-USE PLANNING Central Mesabi Iron Range August 1, 2007 MINNESOTA GEOLOGICAL SURVEY Mark Jirsa and Gary Meyer Funded."— Presentation transcript:
GEOLOGIC MAPPING IN SUPPORT OF LAND-USE PLANNING Central Mesabi Iron Range August 1, 2007 MINNESOTA GEOLOGICAL SURVEY Mark Jirsa and Gary Meyer Funded in part by The Environmental Trust Fund administered by the Legislative Commission on Minnesota Resources (LCMR) Project Partners: Central Iron Range Initiative (CIRI), Minnesota Department of Natural Resources, and NortheastTechnical Services
RATIONALE RATIONALE Assist planning and development. Assist planning and development. Guide resource management. Guide resource management. Avoid flooding, slumping, and infrastructure damage. Avoid flooding, slumping, and infrastructure damage. Preserve water quality. Preserve water quality. PROVIDE FRAMEWORK GEOLOGIC MAPS AND TECHNICAL DATA TO:
Hill Annex State Park How high will the waters rise?How high will the waters rise? What lands can be developed?What lands can be developed? REQUIRES UNDERSTANDING: The water balance (Hydrology-DNR) Water in = rain, runoff, groundwater flow Water out = evaporation, groundwater flow, pumping The geologic “container” (Geology-MGS) Groundwater flow through sand and gravel / fractures in rock ULTIMATELY answer the questions:
SUMMARY OF MESABI PROJECTS ) HYDROGEOLOGIC BASE MAPS OF THE WESTERN AND EASTERN MESABI RANGE (LCMR) Bedrock Topography and Depth to Bedrock -Completed 2001 (W) and 2005 (E) -Completed 2001 (W) and 2005 (E) *DNR DIVISION OF WATERS: Site-specific hydrologic study of the CANISTEO PIT COMPLEX *DNR DIVISION OF WATERS: Site-specific hydrologic study of the CANISTEO PIT COMPLEX 2) BEDROCK AND QUATERNARY GEOLOGIC MAPS OF ENTIRE RANGE (MCC) Geologic maps and ancillary data; completed November 2005 (MCC) Geologic maps and ancillary data; completed November ) CENTRAL IRON RANGE INITIATIVE (CIRI) PROJECT (LCMR) Geologic maps and subsurface data (MGS) (LCMR) Geologic maps and subsurface data (MGS) *DNR DIVISION OF WATERS hydrologic study *DNR DIVISION OF WATERS hydrologic study -Completion: June, Completion: June, 2007
COLLABORATORS, COOPERATORS, AND FUNDERS Val Chandler Dale Setterholm Rich Lively Emily Bauer Bruce Bloomgren G.B. Morey Gary Meyer Lisa Dosch Bob Tipping Tim Wahl Carrie Jennings Wade Reynolds Lynn Swanson Lori Robinson MGS Staff: NRRI Staff: Julie Oreskovich Larry Zanko Mark Severson DNR Staff: Erika Herr John Adams Dan Steinbrink James Selner Tim Pastika (mine databases) Dave Dahl (geophysics) Mining and Fee Company Staff: Mike Orobona (Hibtac) Jeff Price (Keetac) Dan England (Eveleth Fee Office) David Meineke (Meriden) Peter Jongewaard (United) John Arola (ISPAT) Roger Johnson (GNIOP) Doug Halverson (NorthShore) Al Strandlie and Ron Graber (Cliffs) Frank Pezzutto, Bruce Kniivila, Jerry Dombek (Minntac) FUNDING: Legislative Commission on Minnesota Resources (LCMR) Minerals Diversification program of the Minnesota Legislature, recommended by Minerals Coordinating Committee (MCC) U.S. Geological Survey EDMAP program Minnesota Geological Survey—State Special funding
Canisteo Pit Complex, 1999 ~2004 waterline Mining altered the topography of watersheds WATER ISSUES Pump at Scranton Mine, HIBTAC, 2004
MAPPING the shape of the BEDROCK SURFACE ( ) 1) Compile database 2) Hand contouring 3) Scan and digitize
1899 MAP OF HIBBING AREA *Paper on linen maps, scanned and digitized Test Pits Inferred geologic contact
Hibbing Taconite Keewatin Taconite Modified from Lively, Morey, and Bauer, 2002; MGS M-118 Contrasts in land-surface topography, infrastructure, and surface hydrology Useful for issues of mine reclamation and watershed restoration
CHANGE IN LAND SURFACE TOPOGRAPHY Hibbing Area “Mounds” “Mines” Lively and others, 2002 estimate ~45% of the 1899 map area was modified by mining +240 feet -340 feet 0 feet
BEDROCK AND QUATERNARY GEOLOGIC MAPS OF THE MESABI IRON RANGE ) Quaternary (glacial sediments) Geologic Map 2) Bedrock Geologic Map 3) Mine-scale Hydrogeologic Data (groundwater “connectivity”) Funded by the Minnesota Legislature on recommendation of the Minerals Coordinating Committee Published November, 2005 Dunka pit 2004
FIELD WORK in most of 400 mines WADE REYNOLDS Graduate student Quaternary geology CARRIE JENNINGS (MGS) Quaternary studies MARK JIRSA (MGS) Bedrock structure and stratigraphy GARY MEYER (MGS) Quaternary geology
BEDROCK GEOLOGIC MAP M-163 Mark Jirsa, Val Chandler, and Richard Lively Hibbing Grand Rapids Babbitt
Biwabik Iron Formation (~2 billion years old) Thomson Formation Jay Cooke State Park (~2 billion years old) Granite and greenstone (~3 billion years old) Duluth Complex Gabbro (~1 billion years old) BEDROCK TYPES Hibbing
QUATERNARY (glacial sediments) GEOLOGIC MAP M-164 Carrie Jennings and Wade Reynolds Hibbing Grand Rapids Babbitt
St. Louis sublobe till (red) Rainy Lobe till (gray) GLACIAL LAYERS Advancing lobes of ice
Sand and gravel (variably rounded, sorted) Formed as OUTWASH from the ice Photo source: Carrie Jennings, MGS
Sand and gravel (dome shape, poorly sorted) Formed in TUNNEL VALLEY Photo source: Carrie Jennings, MGS
Layered sand (rounded pebbles, graded beds) Formed by streams flowing into local lakes Photo source: Carrie Jennings, MGS
Canisteo pit lake at Bovey Ironworld pit lake
BEDROCK Folds, faults, and fractures m173e Susquehanna Blast deformation HIBTAC WR joints Chisholm Mine Role as hydrologic conduits Understand deformation history
GROUNDWATER m131b United S. pit m008g Hill Annex WR Canisteo m365a LTV 6
Mark Jirsa and Gary Meyer Minnesota Geological Survey University of Minnesota Funded by the Environmental Trust Fund administered by the Legislative Commission on Minnesota Resources (LCMR) Project Partners: Central Iron Range Initiative (CIRI), Minnesota Department of Natural Resources, and NE Technical Services SUMMARY OF FIELD WORK AND OTHER ACTIVITIES Central Mesabi Iron Range
CENTRAL IRON RANGE INITIATIVE (CIRI) PROJECT LCMR AREA: Keewatin to Virginia---focus on Chisholm lakes area COOPERATORS: DNR Waters, Lands and Minerals Minnesota Geological Survey NE Technical Services Architectural Resources Inc. Barr Engineering Natural Resources Research Institute Mining companies OBJECTIVES--ADDRESS FUTURE ECONOMIC DEVELOPMENT ISSUES: Plan present and future mine landscapes Create fish-friendly bathymetry Evaluate energy storage and production Address water resources issues HIBTAC Hibbing
CENTRAL IRON RANGE Focused study in the Chisholm lakes area Chisholm Lakes Area Digital Elevation Model Central Mesabi Iron Range DNR, 1999 Lake Minntac Lake Hibtac
HYDROLOGY OF THE CHISHOLM LAKES AREA Water level gauge Twin City N. Mine MINNESOTA DEPARTMENT OF NATURAL REOURCES DIVISION OF WATERS Erika Herr and John Adams
Grant Fraser Iron World pit complex Twin City Forster Sherman Hartley-Burt HIBTAC CHISHOLM LAKES AREA Iron World Grant Twin City Forster Sherman Hartley- Burt BEDROCK (1473’) (1343’) Vertical exaggeration ~50 X HIBTAC 100 feet 1 mile SEDIMENTS Fraser Longyear Lake (1486’) Underground mines MINE WASTE
MINNTAC KEETAC HIBTAC Chisholm Lakes Area
Sand and gravel-filled bedrock channels Fraser Iron World Grant Twin City Forster Sherman DIGITAL BEDROCK TOPOGRAPHY—Chisholm area
3-D DIGITAL MODELS Land surface elevation and pit lake bathymetry from Department of Natural Resources; Air photo from U.S. Farm Services Administration Imagery by Richard Lively, MGS
3-D MODEL OF CENTRAL IRON RANGE BEDROCK TOPOGRAPHY (color) from MGS and DNR Bathymetry LAND-SURFACE TOPOGRAPHY (fade-in, pale color overlay) Click image to start movie
RED CLAY TILL St. Louis sublobe (sources from NW and S), small percentage of rock clasts MESABI TILL Rainy lobe (NE source) bouldery till; locally white, red, yellow, brown, or gray. Yellow stain inferred to represent paleo - water level. Commonly contains thin sand lenses and layers Localized older, variegated clay till, sand and gravel “TYPICAL” QUATERNARY SECTION Twin City south mine, north shore 2005 Gary Meyer ~100 feet
MINNTAC Red clay till Sand and gravel Gray “Mesabi” bouldery, sandy till Minntac West Pit, 2006
South Agnew Mine, 2006 Thick, layered Sand and gravel Gray “Mesabi” bouldery, sandy till
DRILLING Funded by LCMR contract to DNR Drilled by TRAUT WELL COMPANY Materials logged by MGS
Distribution of subsurface materials (sand vs. clay) Test material properties Understand hydrologic connections Evaluate and quantify hydrologic properties DRILLING Example of cross-section, based in part on drilling
Hibbing photo by David A. Witt, P.G., Aero-Environmental Consulting 2005 HIBTAC-Albany Mine HIBBING EXAMPLE OF BEDROCK OBSERVATIONS AND INFERENCES From the ALBANY MINE
Outflow beneath talus feeds waterfall. Algae growth implies warmer water source; possibly derived from Albany mine through bedrock fracture system.
METEORIC (surface) WATER SOURCE: Short residence time (if any) in “aquifer”
GROUND WATER SOURCE Long residence time(?) in aquifer; may explain common mineral coatings
FINAL PRODUCTS Available as Minnesota Geological Survey Open-File Report #07-02: “Bedrock and Quaternary geology of the Central Mesabi Iron Range, northeastern Minnesota” by Mark A. Jirsa and Gary N. Meyer Printable pdf maps (shown on the following slides) 1. Bedrock Geology map 2A. Bedrock topography map 2B. Bedrock topography-Chisholm area 3. Depth to bedrock map 4A. Surficial geologic map 4B. Sand and gravel units (shows cross-section line) 5. Lineaments map 6. Geologic cross-section 7. Locations of field observations Other digital files: Abstract and Readme documents Shapefiles of all covers incorporated into pdf maps (above); station locations (correspond to photographs) Tables of textural analyses of representative Quaternary materials Digital photographs (keyed to stations) This PowerPoint presentation All products in digital format only.
1. BEDROCK GEOLOGIC MAP Shows distribution of bedrock geologic units beneath unconsolidated sediments and exposed in natural rock outcrops and mines.
2A. BEDROCK TOPOGRAPHIC MAP Shows elevation of top of the bedrock surface beneath unconsolidated materials; areas of active and previous mining shown in pink. White=high topography Black=low
2B. BEDROCK TOPOGRAPHY- CHISHOLM AREA Shows detail of bedrock surface in area of focused study. CHISHOLM White=high topography Black=low
3.DEPTH TO BEDROCK MAP Shows thicknesses of unconsolidated materials. Bedrock outcrops shown in red and mining areas shown in black represent zero thickness. White=thick sediment cover Black=thin
4A. SURFICIAL GEOLOGIC MAP Shows surface distribution of unconsolidated glacial sediments. White areas represent surface materials disturbed by mining.
4B. SAND AND GRAVEL UNITS Shows distribution of known sand and gravel units near-surface (green) and at depth (tan).
5. LINEAMENTS AND BEDROCK STRUCTURE Shows orientation of faults, folds, joints, veins, diabase dikes, bedding, and planar foliation in bedrock; at map and outcrop scales.
6. GEOLOGIC CROSS-SECTION Shows distribution of unconsolidated glacial and man-made materials at and beneath the land surface. WE BEDROCK Red clayey till Sand Gray clayey till Tailings Tan, rocky and sandy till Overburden dump Waste dump Elevation (ft.) Note: “till” is a mixed sediment containing various proportions of rocks, sand, silt, and clay 35 MILE SECTION: Along a line from Nashwauk to Virginia Example of detail in a cross-section
7. MAP OF FIELD OBSERVATION POINTS Shows locations of observations, including material descriptions, samples, measurements, and photographs. Red points are primarily related to bedrock observations; green to observations of unconsolidated materials.