This book offers a process-centered guide to natural resource, geotechnical, agrophysical and environmental investigations. There is a good blend of geophysical principles and modern industrial practice. It is intended as a self-contained textbook for students and professionals engaged in the evaluation, financing and development of natural resources, natural and built environment, and natural hazard investigations.
Traditional geophysical texts focus on the technical fundamentals with little attention to the geological basis of exploration and relationship to actual business needs in society and industry. The vast majority of explorers and financial investors that need to understand and use geophysical exploration methods in resource or environmental evaluations come from a less mathematical background and consequently find it difficult to understand classical treatments of geophysical principles. Geophysics thus remains unpopular with many geoscientists and environmentalists whose viewpoints are not well represented by these traditional texts which fail to exploit the link between geophysical principles and the traditional geological-driven resource and environmental exploration and development strategies. It is also known that those for whom these books were originally intended, quite often fail to make the connection between the genesis and exploration of the vast majority of natural resources since oil and gas prospecting typically dominate traditional treatments. The proposed book will address these issues. It will focus on how geophysics meets the needs of society and industry in a format that can be understood by various stakeholders in resource appraisal and development.
Table of Contents:
INTRODUCTION
Chap.1 Basic geophysical tools for subsurface evaluation
1.1 Basis of geophysical exploration:
geophysical processes, rock physical properties, required physical
property contrasts,classification of geophysical methods.
1.2 Common tools of geophysical exploration
1.2.1 Electrical and Electromagnetic methods
1.2.2 Magnetic method
1.2.3 Nuclear magnetic resonance method
1.2.4 Gravity method
1.2.5 Seismic refraction and reflection methods
1.2.6 Ground probing radar method
1.2.7 Radiometric method
1.2.8 Borehole methods
1.2.9 Airborne methods
1.3 Financial aspects of geophysical surveys
1.3.1 Estimated relative exploration costs
1.3.2 Project management and execution
PART 1: GEOFLUIDS AND GEOENERGY
Chap. 2. Groundwater resource evaluation
2.1 Habitat of groundwater:
sand aquifers, clay aquitards, fracture zones in hard rocks.
2.2 Geological models of groundwater systems
2.3 Geophysical characterisation of groundwater systems
2.4 Geophysical prospecting for groundwater
2.4.1 Mapping of sand and gravel aquifers
2.4.2 Mapping of carbonate aquifers
2.4.3 Mapping of saline intrusion in coastal freshwater aquifers
2.4.4 Mapping of aquifers in crystalline basement terrains
2.5 Problems and limitation of geoelectrical surveying for groundwater
2.6 Predictive modelling in groundwater survey design
2.7 Estimating aquifer characteristics from geophysical data
2.8 Selected case histories of exploration
2.8.1 Combined application of seismic reflection, VES and TEM methods in
aquifer mapping in the Netherlands
2.8.2 Integrated mapping of aquifer systems and complex bedrock in New
Jersey, U.S.A.
2.8.3 Regional aquifer mapping using combined VES, TEM, AMT methods in
Parnaiba basin, Brazil
2.8.4 Mapping of Sherwood Sandstone aquifer in England
2.8.5 Groundwater exploration in crystalline basement terrains in Africa
2.8.6 Groundwater exploration in crystalline basement terrains in Brazil
2.9 Exploration exercises
2.10 Selected references
Chap. 3. Geothermal energy resources
3.1 Occurrence of geothermal resources
3.2 Geological models of geothermal systems
3.3 Geophysical characterisation of geothermal systems
3.4 Exploration for concealed geothermal resources
3.5 Predictive modelling and implicationd for prospecting
3.6 Case histories of exploration
3.61 The Cove Fort-Sulphurdale Geothermal System, Utah,USA
3.6.2 Rehai Field of Tengchong area, China
3.6.3 Chyulu Hills volcanic area, Kenya
3.6.4 Milos geothermal field, Greece
Chap. 4. Hydrocarbon (fossil & unconventional) energy resources
4.1 Development of exploration models for petroleum systems
4.4.1 Plate tectonics and distribution of major oil and gas accumulations
4.1.2 Basin development, structural styles and depositionals systems
4.1.3 Formation, migration and accumulation of hydrocarbons
4.1.4 Mode of occurrence of oil ad gas: character and associated features
4.1.4.1 Favourable environments and clusterinng in petroleum provinces
4.1.4.2 Oil and gas seeps
4.1.4.3 Geochemical alterations over oil and gas fields
4.1.5 Effects of deep weathering and erosion
4.1.6 Petrophysical properties of productive reservoir systems
4.1.7 Generalised exploration models for oil and gas
4.2 Coal Deposits
4.2.1 Geophysical characterisation of coal deposits:
the nature of peat and coal seams, seismic reflectivity of coal seams, high
resolution seismic profiling for coal, ground radar profiling for coal, gravity
anomalies over coalfields, location of dykes in coalfield exploration,
detection of cavities and mining subsidence, downhole logging applications.
4.2.2 Estimation of total anomalous mass from gravity data
4.3 Systematic structural prospecting for oil and gas
4.3.1 Remote sensing in hydrocarbon exploration
4.3.2 Magnetics and gravity in oil exploration
4.3.3 Seismic exploration for oil and gas
4.3.4 Electrical and electromagnetic exploration
4.3.4.1 Marine CSEM/MT acquisition, processing and interpretation
4.3.4.2 Induced Polarisation/Transient EM acquisition and analysis
4.4 Non-structural prospecting for oil and gas
4.4.1 Exploring for stratigraphic traps
4.4.2 Carbonate exploration
4.4.3 Mapping of alteration patterns in prospective regions
4.5 Predictive exploration modelling in survey design
4.6 Case histories of conventional petroleum exploration and development
4.6.1 Fossil fuel exploration in carbonate terrains (Cuba, Arab fields)
4.6.2 Fossil fuel exploration in volcanic-margins and volcanic-covered terrains
(North sea and Barrents Sea superprovince , Deccan Trap, Parana
basin, Columbia basalt)
4.6.3 Fossil fuel exploration in salt-tectonic or gravity-driven fold and thrust belts
4.6.3.1 Northwest Borneo thrust belts
4.6.3.2 West African transform margin (Niger Delta superprovince of Nigeria,
Sierra Leone-Cote d’Ivoire-Ghana sectors)
4.6.3.3 Southwest African transform margin (post- and pre-salt exploration in
Angola-Congo-Gabon sectors)
4.6.3.4 Brazilian passive margin (sub-salt exploration in Santos, Campos & Espiro
santos basins)
4.6.3.5 Gulf of Mexico (sub-salt exploration in USA & Mexico sectors – the
Wilcox trend)
4.6.4 Exploration in intracontinental basins (Sao Francisco basin, Brazil)
4.6.5 Time-lapse monitoring for enhanced oil recovery and alteration mapping
4.6.5.1 Monitoring changes in conductivity with temperature during combustion
enhanced oil recovery.
4.6.5.2 Monitoring changes in seismic velocity and electrical conductivity with
alternating water and gas injection during enhanced oil recovery.
4.6.5.3 Mapping of low resistivity-contrast and saline-water saturated reservoirs.
4.6.5.4 Hydrocarbon reserve estimation using integrated geophysical methods.
4.7 Evaluation of unconventional resources
4.7.1 Models of tight sandstones and carbonate reservoirs
4.7.1.1 Depositional systems, diagenesis, stratigraphy, correlation, reservoir quality
4.7.1.2 Discrete versus basin-centered accumulations
4.7.1.3 Resolving geo-bodies, fractures, poroperms with 3D seismic, VSP and
CSEM/CSAMT
4.7.1.4 Petrophysics: routne and special core analyses, log analyses
4.7.1.5 Identifying sweetspots: key data to acquire and analyse, success criteria
and exit ramps
4.7.2 Models of shale gas reservoirs
4.7.2.1 Depositional systems, diagenesis, stratigraphy, correlation, fractures,
reservoir quality, laboratory/log analyses
4.7.2.2 Identifying sweetspots: key data to acquire and analyse, appraisal and
development strategies, economics
4.7.3 Models of coal seam gas reservoirs
4.7.3.1 Depositional systems, coalification, fractures, hydrology, reservoir quality,
laboratory log analyses
4.7.3.2 Identifying sweetspots: key data to acquire and analyse, appraisal and
development strategies, economics
4.7.4 Tight sandstones and carbonate case histories
USA: Medina-Clinton (Appalachian basin), Spraberry (Permian Basin),
Bakken (Williston Basin), Jean Marie (British Columbia);
Indonesia: Baturaja.
4.7.6 Shale gas case histories
4.7.6 Coals seam gas case histories
USA: Drunkard’s Wash, South Shale Ridge projects,
Australia: Surat Basin
4.8 Case histories of the use of geophysical methods in the coal industry.
4.8.1 Development of coalfields for extraction: geophysical constraints.
PART 2: METALLICS
Chap. 5. Volcanic-associated polymetallic massive sulphide deposits
5.1 Development of exploration models
5.1.1 Geological setting: features, concepts and models of VMS deposits
5.1.1.1 Age distribution and general features
5.1.1.2 Mechanism of formation
5.1.2 Mode of occurrence: character and associations
5.1.2.1 Mineral and hydrothermal alteration zoning
5.1.2.2 Clustering in favourable terrains
5.1.2.3 Textural and regional metamorphic features
5.1.2.4 Ore weathering and palaeodrainage features
5.1.3 Physical properties of massive sulphide ores and host rocks
5.1.4 Generalised exploration approach
5.2 Predictive modelling for exploration design
5.3 Geophysical prospecting for massive sulphides
5.3.1 Systematic or sequential exploration approach
5.3.1.1 Regional geophysical exploration
5.3.1.2 Local geophysical exploration
5.3.2 Prospecting in deeply-weathered terrains
5.3.3 Prospecting in glacial terrains
5.4 Approximate ore tonnage estimation using geophysical data
5.5 Case studies of exploration in different terrains
5.5.1 Deeply-weathered terrain: Elura orebody, Cobar, Australia
5.5.2 Glaciated terrain: Kerry Road deposit, Gairloch, Scotland
5.5.3 Unconsolidated volcanics: Klirou orebody,Troodos Ophiolite
Complex, Cyprus
5.5.4 Deep palaeoerosional surface: Lagoa Salgada deposit, Portugal
5.6 Modelling and exploration exercises
5.7 Selected references
Chap. 6. Vein and disseminated metallic sulphide (porphyry copper) deposits
6.1 Porphyry copper deposits
6.2 Model development for porphyry copper systems
6.2.1 Regional geological setting
6.2.2 Mode of occurrence
6.2.3 Geophysical characterisation of porphyry copper systems
6.3 Predictive modelling
6.4 Geophysical exploration
6.4.1 Regional reconnaissance surveys
6.4.2 Detailed follow-up investigation
6.5 Case histories of exploration
6.5.1 IP in Troodos Ophiolite Complex of Cyprus
6.5.2 IP in Philipines
6.5.3 Island Copper
6.6 Exploration design exercises
6.7 Selected references
Chap. 7. Vein and disseminated Gold deposits
7.1 Classification of deposit types, rock and magnetite associations and
structural controls,
7.2 Geophysical models of epithermal gold systems,
7.3 Prospecting in Archaen greenstone belts. The use of ground and
airborne magnetic and electromagnetic surveys.
7.4 Exploration case histories.
PART 3: NON-METALLICS AND PLACERS
Chap. 8. Diamondiferous Kimberlites
8.1 Occurrence of diamond
8.2 Developing a model for kimberlite pipes
8.2.1 Geological constraints
8.2.2 Weathering characteristics
8.2.3 Geophysical characterisation
8.3 Predictive modelling of exploration targets
8.4 Exploration for kimberlite pipes
8.4.1 Regional prospect selection
8.4.2 Ground exploration strategy
8.5 Case histories of exploration
Chap. 9. Weathering, Residual and Unconformity-related Deposits
9.1 Model development
9.1.1 Weathering profiles
9.1.2 Weathering products
9.1.2.1 Bauxites
9.1.2.2 Lateritic nickel
9.1.2.3 Unconformity-related uranium deposits
9.1.2.4 Iron formations (BIF)
9.2 Exploration for bauxites
9.3 Prospecting for iron formations
9.4 Prospecting for unconformity-related uranium deposits
9.5 Case histories of exploration
9.5.1 Exploration and evaluation of the Cigar Lake Uranium deposit.
Chap. 10. Industrial Minerals and Bulk Materials
10.1 Model development
10.1.1 Igneous rocks
10.1.2 Sand and gravel deposits
10.1.2.1 Geomorphological constraints on distribution of deposits
10.1.2.2 Exploration model for sand and gravel
10.1.3 Barite and fluorite deposits
10.1.3.1 Physical characteristics of barite
10.1.3.2 Development of exploration models
10.2 Prospecting for sand and gravel deposits
10.3 The use of gravity and resistivity surveys in barite exploration
10.4 Prospecting for fluorite deposits
10.5 Predictive modelling in bulk material exploration
10.6 Case studies
Chap. 11. Placers
11.1 Model development
11.1.1 Geomorphological controls on the distribution of placers
11.1.2 Geophysical constraints
11.2 Exploration model for alluvial placers
11.3 Exploration model for marine placers
11.4 Predictive modelling of ideal targets
11.4.1 Detectability of magnetite concentrations
11.5 Exploration for alluvial placers
11.5.1 Magnetic method
11.5.2 Electrical and electromagnetic methods
11.5.3 Ground probing radar methods
11.5.4 Shallow seismic exploration methods
11.6 Predictive modelling
PART 4. NATURAL AND BUILT NEAR-SURFACE ENVIRONMENT
Chap. 12. Contaminated land and groundwater
12.1 Bye-products of natural resources exploitation: Hazardous Wastes and
other contaminants.
- Industrial, agricultural and domestic practices. High
level nuclear wastes, spent unreprocessed fuels, toxic chemical wastes,
saline groundwater, mine tailings.
- Waste disposal sites (landfills, tailings ponds, leaching operations),
suitability of earth materials, geological controls.
- Groundwater contamination: groundwater motion, dissolution and migration of hazardous wastes, sea-water intrusions, migration of brines from evaporation pits and ponds, the form of groundwater contamination plumes and implications for geophysical detection.
12.2 Hazardous waste minimization and remediation:
geophysical location of safe repositories, selection of optimum
survey methods, quality assurance and quality control.
systematic assessment of hazardous waste sites, detection of buried
metal pipes, drums and storage tanks; mapping of fluid migration
pathways and underground cavities; mapping of leachate plumes and
groundwater contamination. monitoring of waste sites and nuclear tests.
12.3 Natural hazards: earthquakes and volcanoes, mass movement of slopes,
environmental impact, geophysical detection and monitoring.
12.4 Landfill site investigation: Models and Case histories
12.4.1 Characteristics of landfill sites and anthropogenic deposits
12.4.2 Leachate formation and dispersal:Mechanical decomposition, physico-
chemical and microbial weathering.
12.4.3 Conceptual resistivity model: relationship between geoelectrically
important hydrochemical parameters. Age of saturated fill versus
hydrochemistry.
12.4.4 Development of a consistent investigative approach.
12.4.5 Case histories of landfill site investigation.
12.5 Case histories of geophysical mapping sea-water intrusion into fresh-water
aquifers.
12.6 Case histories of geophysical investigations of active fault systems and
volcanoes.
Chap. 13. Engineered and archaeological structures
13.1 Aspects of engineering geology
13.1.1 Major engineering structures: tunnelling and excavations, foundations,
dams, roads and HVDC grounding of power-stations.
13.1.2 Geological constraints on engineering design:
structural features, ground stability and strength of earth materials,
earthquakes and other geological hazards.
13.1.3 Geotechnical considerations in safe engineering design:
the need for reliable subsurface data.
13.2 Archaeological targets: size, shape and nature of targets.
13.3 Geophysical imaging of the near-surface:
scaling considerations for measurement systems. High resolution
shallow seismic reflection profiling, ground penetrating radar surveys,
dc resistivity and shallow electromagnetic surveys, high sensitivity
magnetometry and microgravimetry, cross-hole seismic tomographic
measurements of dynamic modulus.
13.4 Understanding the engineering geophysical data:
13.4.1 Velocity as a guide to rock strength
13.4.2 Indicators of structural discontinuities
13.4.3 Bedrock topography and overburden thickness determinations
13.4.4 Limitations of geophysical measurements.
13.5 Exploration case histories:
dam site investigations, mapping granite bodies at quarry sites
