Geology and the
Aggregate Industry:
The Role of Geologists
Donald G. Mikulic
Illinois State Geological Survey
Prairie Research Institute
University of Illinois at Urbana-Champaign
Outline
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Importance of geology in the aggregate industry
History of the crushed stone industry in Illinois
Historical role of geologists in the industry
Geologists for the producer
A company program for geologic education
Why is geology important to the
aggregates industry?
• Aggregates are geological resources
• Geology controls the availability and quality of
these resources
Geology determines the character
and availability of aggregates
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Determines source
Determines type of products
Determines quality
Determines quantity
Determines methods of extraction
Determines methods of processing
Determines investment
Expensive Geologic Mistakes
• No long term plan based on geology
• Non-avoidance of geological problems
• Burial of reserves with stripping, waste rock,
trash, etc.
• Placement of buildings, haul roads, tunnels,
sumps, etc. in wrong areas
• Wrong purchase of property
• Zoning of unsuitable areas
• Investment without proving reserves
Changes in the Stone Industry 18002016
• Major change in products around 1900
• Everything made of stone before 1900 is
now made of concrete
• Extraction rates and methods
• Processing rates and methods
• Transportation systems
• Quality standards
• Population growth: needs and limitations
Midwestern Use of Stone—1800s
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Building design: load bearing walls
Construction using wood, brick, or stone
No Portland Cement, steel, etc.
Crushed stone was a minor product, used mostly
macadamizing roads
• Limited transportation: water, road, rail
• Quality was less important than proximity to market
Midwestern Use of Crushed Stone —
1900s
• Portland Cement and concrete replaced lime and
building stone
• Concrete created a larger market for crushed stone
• Quality becomes more important
• Improving transportation network
• Urban growth expands market and covers reserves
Limited Importance of Geology to
Early Producers
• “Limitless” reserves because of slow production
and open lands
• Extensive room for expansion at shallow depths
• Quality issues were minimal
• Regulation was minimal
Changing Northeastern Illinois Quarry
Locations 1830-2000
Aggregate Production
Geology Limiting Access
to Crushed Stone Resources
Urban Expansion Limiting Access
to Stone Resources
How have stone resources
been discovered?
Historically, most were found by accident
Outcrops and Excavations
1800s
Research and Exploration
1900s
Geologist in the Aggregate Industry
• Early operators and quarrymen developed
knowledge through experience
• Few professional company geologist before 1970s
• Problems:
• Limited plans for utilization
• Non geologic tasks
• Decline in employment
Company Geologist
• Rock Products 1926
• “This is said to be the first time that a geologist
has been permanently employed by a crushedstone producer, although other companies have
employed them to do prospecting work and to
solve special problems.”
• “The biggest part of his time is spent in the field
either where core drilling is going on or in the
quarries, noting new developments at the face.”
Local Understanding
Regional Understanding
Geologist and the Modern Aggregate
Industry
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Company Geologist
Private Consultants
University Geologist
Government Geologist
“Need a specialist and
expert”
Who is not a geologist?
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Mining Engineer
Environmental Scientist
Quality Control Testing Specialist
Surveyors
Engineering
Geology
Company Geologist
• Determine and revise geology through operations
and study of regional geology = research
• Should be the expert on the geology of company
properties
• Advantage: on-site and long term connection
• Disadvantage: limited regional access
What is not a geologic task?
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Stock pile inventory
Permitting
Reclamation
Public relations
Private consultant
• Address certain geologic questions and quality
issues through specific short-term studies
• Advantages: Have testing equipment and facilities
not available to producers
• Experience in testing
• Special training, and manpower
• Disadvantage: Applied geology
• Limited site-specific expertise and absence of
long-term regional or general research
University Geologist
• Basic research on geology and regional
relationships
• Geologic framework
• Advantages: Regional research and experience
• Disadvantages: Very few available, lack of time
and funding
Government Geologist
• Basic research on geology and regional
relationships
• Develop and update geologic framework
• Advantages: Comprehensive regional research and
experience
• Disadvantages: Few available, limited time,
limited funding
Illinois State Geological Survey
ISGS objectives and duties by 1905 legislation:
•“A study of geological formations of the state with
special references to its products, ores, clays,
building stone, cement materials for construction.”
•“prepare reports which include general and detailed
descriptions of the geological and material resources
of the State”.
Illinois State Geological Survey
• Assisting the aggregate industry since 1905
• Basic geologic research
• Maintains large collection of samples, field notes,
unpublished reports, and records of sample
analysis
• Only organization that conducts long term, broadbased, basic research on Illinois geology
• Does not do quality testing but research on how
geology effects quality
ISGS Sample
Collections
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Records on over 900,000 wells and sites
Cutting sets for 70,000 wells
Samples from 15,000 cores
Over 200,000 feet of core from NE Illinois
Large collections of rock and mineral samples
150,000 fossils
Basic knowledge for a company
Geologist
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How were rocks formed?
How were rocks altered through time?
How might rocks change in area?
How do these to factors effect site-specific
aggregate production?
What kind of geologist does a
company need?
• Focus of training on general geology
• “Field and specimen geologist”
• Understanding of the geologic history of the area
• Site-specific knowledge
• Regional knowledge
Education for the Aggregate Geologist
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Basic Geology
Mineralogy
Petrology
Stratigraphy
Structural Geology
Regional geology
Field Geology
• Geochemistry
• Hydrogeology
• Environmental
Geology
• Geophysics
• Local geology
• Remote sensing
Company Geology Program
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Management and general staff
Half-day course
General geology pertinent to region
If a producer can’t afford a staff
geologist it should have one person
that has some knowledge of geology