Click here to load reader

The Tellus Airborne Geophysical Survey and Results · PDF fileThe Tellus Airborne Geophysical Survey and Results Mike Young ... Dalradian – low conductivity ... PowerPoint Presentation

  • View
    214

  • Download
    2

Embed Size (px)

Text of The Tellus Airborne Geophysical Survey and Results · PDF fileThe Tellus Airborne Geophysical...

  • Natural Environment Research Council Natural Environment Research Council

    The Tellus Airborne Geophysical Survey

    and Results

    Mike Young

    The Tellus Conference, Belfast, 17/18 October 2007

  • Geophysical surveying measures:

    Natural magnetic field Shallow electrical conductivity variations Surface radioactivity

    MAP surface and near-surface physical characteristics

    MODEL subsurface geological structure

  • We use the results for:Exploration for Earth resources Shallow structural mapping Basin interpretation Geothermal sources

    Environment management Natural baselines Anthropogenic effects Hydrogeology Soil carbon and peat Radon

  • Geological Survey of Finland

    British Geological Survey

    Joint Airborne-geoscience Capability

  • Natural Environment Research Council Natural Environment Research Council

    MagnetometerGamma-ray detector

    Electromagnetic coil

    BGS-GTK geophysical survey aircraft

  • Aircraft systems Aircraft De Havilland Twin Otter Crew Pilot, co-pilot, navigator, engineer Navigation Visual + real-time differential GPS Position recovery DGPS + digital video Altimetry Radar and laser altimeter

    Natural Environment Research Council Natural Environment Research Council

  • Specification

    Distance flown 81,000 km

    Flying speed ~ 210 km/h

    Flight direction 345 degrees

    Flying height 56 m rural250 m urban

    Line spacing 200 m

    Sampling: - Magnetic 6 - 7 m- EM 15 - 17 m- Radiometric 60 - 70 m

  • Airborne Geophysical Survey

  • Magnetics

    Electrical conductivity

    Gamma radiation

    New imagery

  • Magnetic field

    Geological mapping

    Structural mapping

    Regional geology and tectonics

    Basin studies

  • Igneous rocks

  • Magnetic intensity

  • Improving quality of mapping

  • Magnetics

  • Platinum in Soils Magnetics

  • Nickel Magnetics

  • Total magnetic field

  • Lower Lough Erne

    Upper Lough Erne

    Total magnetic field & soil nickel

  • Dykes outcrop scale

  • Cavanacaw

    Curraghinalt

  • Magnetic field

    Geological mapping

    Structural mapping

    Regional geology and tectonics

    Basin studies

  • Electrical conductivity

    Geological mapping

    Characterising soils and glacial material

    Salinity

    Pollution plumes

  • Embayment different lithology

    Omagh Thrust

    Dalradian low conductivity

    Lack Inlier (Dalradian)

    Carboniferous

    Inlier Bounding FaultNEW CONDUCTOR

  • Electrical conductivity and gold occurrences in Co. Tyrone

    Cavanacaw

    Curraghinalt

  • Coastal salinity Magilligan strand

  • Electrical conductivity west of Strabane

  • Possible plume?

  • Gamma radiation

    Geological mapping

    Soil characterisation

    Radioactivity baseline

    Radon

    Hot rock geothermal

  • Magnetics

    Electromagnetics

  • Uranium gamma-ray

  • Uranium soil geochemistry Gamma radiation - Ternary

    0

    151 ppm

  • Magnetic and gamma-ray anomaliesSlieve Gullion

    Magnetic Gamma-ray: Potassium-40

    Camlough Fault

    Newry Fault

    Gabbro

    Felsic Ring Dyke

  • Slieve Gullion from the southeast

  • 5 Km grid in-house records

    In-house radon estimation

    Multi-variate analysis

  • Peat extent and thickness

    ESTIMATE OF PEAT THICKNESS

    y = 30.459x-0.5255

    R2 = 0.8972

    0

    10

    20

    30

    40

    50

    60

    70

    80

    90

    100

    0.00 1.00 2.00 3.00 4.00 5.00 6.00

    Peat Thickness in m

    Cou

    ntra

    te -

    Han

    d Sp

    ectr

    omet

    er

    All remaining data after deletion of bogs and editing of outliers (345 data points)

    R2 = 0.6143

    0

    200

    400

    600

    800

    1000

    1200

    1400

    1600

    1800

    2000

    0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00

    Peat Thickness in m

    Tellu

    s To

    tal C

    PS

    Sperrins Type Section:Airborne TC vs Peat Thickness

    y = 1202.1e-1.3661x

    R2 = 0.8631

    0

    200

    400

    600

    800

    1000

    1200

    1400

    0.00 0.50 1.00 1.50 2.00 2.50 3.00

    Peat Thickness in m

    Airb

    orne

    Tot

    al c

    ps

  • Magnetics

    Electrical conductivity

    Gamma radiation

  • Natural Environment Research Council Natural Environment Research Council

    With acknowledgements to: BGS and GTK survey and processing teams led by David

    Beamish and Maija Kurimo

    Interpretation by Chris van Dam, Baz Chacksfield, Adrian Walker, Don Appleton, David Jones, Barry Rawlins and Cathy Scheib

    Geophysical surveying measures:We use the results for: Aircraft systemsAirborne Geophysical SurveyElectrical conductivity and gold occurrences in Co. TyronePeat extent and thickness

Search related