Applied Geophysics Geology 319 / 829 Professor: Gerhard Pratt pratt@geol.queensu.ca TA’s: Rie...

Applied GeophysicsApplied GeophysicsGeology 319 / 829Geology 319 / 829

Professor: Gerhard Pratt pratt@geol.queensu.ca

TA’s: Rie Kamei, Drew Brenders

Calendar Description:

Techniques of geophysics (including gravity, magnetic, electrical, and seismic) applied to engineering problems, including resource exploration and site investigation. Physical principles, instrumentation, field procedures, data interpretation, and design of field programs are covered for each of the major methods.

Web Page: geol.queensu.ca/people/pratt/geol319

Username: geol319

To find out the password, send me an email!

Course objectivesCourse objectives

To train you for your future careers as geoscientists, To train you for your future careers as geoscientists,

geological engineers and mineral explorationistsgeological engineers and mineral explorationists

To allow you to be informed enough to make use of To allow you to be informed enough to make use of

those geophysical techniques appropriate for your those geophysical techniques appropriate for your

applications applications

To allow you to be able to speak knowledgeably to both To allow you to be able to speak knowledgeably to both

your contractors and your managers, about geophysical your contractors and your managers, about geophysical

surveys surveys

To allow you to be innovative if there is a new problem To allow you to be innovative if there is a new problem

that might lend itself to geophysical methods. that might lend itself to geophysical methods.

Pre-requisitesPre-requisites

Geol 249 (Geophysical Geol 249 (Geophysical characterization)characterization)

Math 226, 227 (diff eqs, Math 226, 227 (diff eqs, vector calculus)vector calculus)

Other geophysics courses at Other geophysics courses at Queen’s Queen’s

Geol 249Geol 249: Geophysical characterization of the Earth. Winter : Geophysical characterization of the Earth. Winter term.term.

Geology 349Geology 349: Applications of quantitative analysis in geological : Applications of quantitative analysis in geological engineering. Winter term.engineering. Winter term.

Geology 409Geology 409: Applied geophysics laboratory: Fall term, : Applied geophysics laboratory: Fall term, alternate years.alternate years.

Geology 429Geology 429: Geophysical signal analysis. Winter term, : Geophysical signal analysis. Winter term, alternate years.alternate years.

Geology 479Geology 479: Potential field and electromagnetic methods. : Potential field and electromagnetic methods. Winter term, alternate years.Winter term, alternate years.

Geology 489Geology 489: Seismic methods: Winter term, alternate years.: Seismic methods: Winter term, alternate years.

Geology 409 Applied Geology 409 Applied Geophysics LabGeophysics Lab

Geology 409 Applied Geology 409 Applied Geophysics LabGeophysics Lab

Geology 409 Applied Geology 409 Applied Geophysics LabGeophysics Lab

Course structure Course structure

Gravity and magnetic field methods (4 Gravity and magnetic field methods (4 weeks)weeks)

Gravity:Gravity: Regional, basin studies, salt Regional, basin studies, salt diaperism, intrusives, sand and gravel diaperism, intrusives, sand and gravel deposits, depth to bedrockdeposits, depth to bedrock

Magnetics:Magnetics: Airborne mapping, intrusives, Airborne mapping, intrusives, sea floor spreading, mineral deposits, sea floor spreading, mineral deposits, environmental hazards, archeologyenvironmental hazards, archeology

1 out of 4

Course structureCourse structure Electrical methods (4 weeks)Electrical methods (4 weeks)

Resistivity:Resistivity: Mineral prospecting, Mineral prospecting, hydrogeology, contaminants, hydrogeology, contaminants, construction sites, groundwater mappingconstruction sites, groundwater mapping

Induced polarization:Induced polarization: Disseminated Disseminated minerals, aquifer mapping, contaminant minerals, aquifer mapping, contaminant mappingmapping

Self potential:Self potential: Mineral prospecting, Mineral prospecting, hydrogeology, geothermal studieshydrogeology, geothermal studies

2 out of 4

Course structureCourse structure Electromagnetic methods (4 weeks)Electromagnetic methods (4 weeks)

Electromagnetic:Electromagnetic: Deep mineral Deep mineral prospecting, airborne surveys, prospecting, airborne surveys, groundwater studies, subsurface pipes groundwater studies, subsurface pipes and cables, agricultural studiesand cables, agricultural studies

Radar:Radar: Shallow sedimentary structures, Shallow sedimentary structures, water table mapping, depth to bedrock, water table mapping, depth to bedrock, faulting, contaminant mappingfaulting, contaminant mapping

3 out of 4

Course structureCourse structure

Seismic methods (4 weeks)Seismic methods (4 weeks) Earthquakes, microseismics:Earthquakes, microseismics: Active Active

seismic zones, structural fabric, imagingseismic zones, structural fabric, imaging Refraction:Refraction: Mapping and imaging from Mapping and imaging from

crustal scales through to engineering scalescrustal scales through to engineering scales ReflectionReflection: High resolution imaging from : High resolution imaging from

crustal scales to engineering scales, primary crustal scales to engineering scales, primary method in oil and gas exploration, method in oil and gas exploration, increasingly used in mineral exploration and increasingly used in mineral exploration and productionproduction

3 out of 4

AssessmentAssessment

Geol 319Geol 319

AssignmentsAssignments 25%25%

Mid-term examMid-term exam 15%15%

Final examFinal exam 55%55%

Class participation, Class participation, quizzes etcquizzes etc

5%5%

Memo to all: come to Memo to all: come to class!class!

TextbooksTextbooks

1 out of 3

P.V. Sharma, Environmental and Engineering Geophysics. Cambridge University Press.

(Suitable for students specializing in Geo-environmental or Geotechnical Engineering. A new, very well written book, at the intermediate level. Examples are specific to environmental and engineering geophysics. This book is so well written that I would encourage all interested students to own a copy).

TextbooksTextbooks

2 out of 3

Kearey and Brooks, Introduction to Geophysical Exploration, Blackwells.

(Suitable for students specializing in Mineral Exploration. A less advanced book, but contains well written introductory material to most methods).

TextbooksTextbooks

3 out of 3

Telford, W.M., Geldart, L.P, and Sheriff, R.E. Applied Geophysics, Second Edition. Cambridge University Press, 1990.

(Suitable for students specializing in Geophysics. In the past this was considered a very complete reference textbook, but it is becoming somewhat dated. In sections it tends to be overly mathematical, but it does have many examples of geophysical data in a wide range of applications. For descriptions of the engineering principles of geophysical sensors it is unrivaled).

Definitions of GeophysicsDefinitions of Geophysics The study of the earth by quantitative physical method, especially The study of the earth by quantitative physical method, especially

by seismic reflection and refraction, gravity, magnetic, electrical, by seismic reflection and refraction, gravity, magnetic, electrical, electromagnetic, and radioactivity methods. electromagnetic, and radioactivity methods.

The application of physical principles to studies of the earth. The application of physical principles to studies of the earth. Includes the branches of (a) seismology … (b) geothermometry Includes the branches of (a) seismology … (b) geothermometry …); (c) hydrology … (d) physical oceanography; (e) meteorology; …); (c) hydrology … (d) physical oceanography; (e) meteorology; (f) gravity and geodesy … (g) atmospheric electricity and (f) gravity and geodesy … (g) atmospheric electricity and terrestrial magnetism … (h) tectonophysics … and (i) exploration terrestrial magnetism … (h) tectonophysics … and (i) exploration and engineering geophysics. and engineering geophysics.

Exploration geophysics is the use of seismic, gravity, magnetic, Exploration geophysics is the use of seismic, gravity, magnetic, electrical, electromagnetic, etc., methods in the search for oil, electrical, electromagnetic, etc., methods in the search for oil, gas, minerals, water, etc., with the objective of economic gas, minerals, water, etc., with the objective of economic exploitation.exploitation.

Source: Robert E. Sheriff (an explorationist!)

Definitions of GeophysicsDefinitions of Geophysics Geophysics is: The subsurface site characterization of the Geophysics is: The subsurface site characterization of the

geology, geological structure, groundwater, contamination, geology, geological structure, groundwater, contamination, and human artifacts beneath the Earth's surface, based on the and human artifacts beneath the Earth's surface, based on the lateral and vertical mapping of physical property variations lateral and vertical mapping of physical property variations that are remotely sensed using non-invasive technologies. that are remotely sensed using non-invasive technologies. Many of these technologies are traditionally used for Many of these technologies are traditionally used for exploration of economic materials such as groundwater, exploration of economic materials such as groundwater, metals, and hydrocarbons. metals, and hydrocarbons.

Geophysics is: The non-invasive investigation of subsurface Geophysics is: The non-invasive investigation of subsurface conditions in the Earth through measuring, analyzing and conditions in the Earth through measuring, analyzing and interpreting physical fields at the surface. Some studies are interpreting physical fields at the surface. Some studies are used to determine what is directly below the surface (the used to determine what is directly below the surface (the upper meter or so); other investigations extend to depths of upper meter or so); other investigations extend to depths of 10's of meters or more. 10's of meters or more.

Source: Environmental and Engineering Geophysical Society (not explorationists!)

Definitions of GeophysicsDefinitions of Geophysics

“… “… the application of physical the application of physical theories and measurements to theories and measurements to discover the properties of the earth.” discover the properties of the earth.” (Society of Exploration Geophysics)(Society of Exploration Geophysics)

Is this Geophysics?Is this Geophysics?

“… “… the application of physical theories and the application of physical theories and measurements to discover the properties measurements to discover the properties of the earth.”of the earth.”

Gravity field central Gravity field central BritainBritain

• Gravity data respond largely to areas of uplift, low gravity over sedimentary basins

Magnetic field central Magnetic field central BritainBritain

• Magnetic field data respond to tectonic fabric, due to the redistribution of magnetite rich rocks near major fault zones

Landfill siting by electrical Landfill siting by electrical conductivityconductivity

• High conductivity glacial clays have been scoured, resulting in a decrease in conductivity.

Sedimentary structuresSedimentary structures

Sedimentary structures: Sedimentary structures: Seismic reflection imagesSeismic reflection images

Three dimensional seismic Three dimensional seismic surveys in oil and gas surveys in oil and gas

explorationexploration

• Gulf of Mexico survey, showing a salt dome with associated “rim syncline”

Seismic “time slices” in oil Seismic “time slices” in oil and gas explorationand gas exploration

• Seismic time slice from a 3-D survey in the Gulf of Thailand, showing a meandering stream channel.

Interpretation and Interpretation and identification of drilling identification of drilling

targets in oil and gas targets in oil and gas explorationexploration

• Prograding delta system within the Gulf of Thailand, based on interpretation of seismic time slices

Sedimentary structures: Sedimentary structures: Seismic reflection imagesSeismic reflection images

Gravity imaging of impact Gravity imaging of impact craterscraters

• The impact crater on the right is buried below 1 km of sedimentary cover

Gravity imaging of Gravity imaging of sedimentary basinssedimentary basins

• The Weald basin in Southern England (courtesy Black Rock Petroleum Co)

Gravity imaging of mineral Gravity imaging of mineral depositsdeposits

• The Darnley Bay anomaly, Northwest Territories, thought to be caused by an intrusive ultramafic body, hosting a major Nickel / Copper deposit

Magnetic field imaging of mineral Magnetic field imaging of mineral depositsdeposits

• The Darnley Bay anomaly, Northwest Territories, thought to be caused by an intrusive ultramafic body, hosting a major Nickel / Copper deposit

Magnetic field imaging of Magnetic field imaging of mineral depositsmineral deposits

• The Sudbury basin is now thought to have been caused by a meteorite impact more than 2 billion years ago.

Gravity imaging at an abandoned Gravity imaging at an abandoned building sitebuilding site

• An example of the location of a suspected building foundation

Applied GeophysicsApplied GeophysicsGeology 319 / 829Geology 319 / 829

Professor: Gerhard Pratt pratt@geol.queensu.ca

TA’s: Rie Kamei, Drew Brenders

Calendar Description:

Techniques of geophysics (including gravity, magnetic, electrical, and seismic) applied to engineering problems, including resource exploration and site investigation. Physical principles, instrumentation, field procedures, data interpretation, and design of field programs are covered for each of the major methods.

Web Page: geol.queensu.ca/people/pratt/geol319

Username: geol319

To find out the password, send me an email!