Table of Contents
Field studies of conductivity anomalies in the lithospheric mantle that may be related to carbon
Anomalies ?
Conduction mechanisms likely in the SCLM
EM methods (1)...
EM methods (2)...
Parameter measured: electrical conductivity (1/resistivity) Range...
Fundamenal EM Phenomenon: Skin Depth
MT 1D response: 2-layers
2D Earth response: Graben
Magnetotelluric method: uniqueness theorems
Mantle studies
Lithosphere….?
Laboratory studies of olivine
Isotropic olivine r-T curve
olivine, opx & cpx
Mantle geotherm
Mantle olivine resistivity
Lithospheric thermal model
Lithospheric resistivity model
Lithospheric resistivity response
Best-fitting smooth model to 1% data
Best-fitting layered model to 1% data
Best-fitting layered models to 1% data
Electronic conduction - sulphides: THO (NACP)
Mantle electrical anisotropy
Mantle electrical anisotropy
SCLM resistivity resolution
Depth to ELAS (electrical asthenosphere)
Variation in depth to ELAS?
Seismic asthenosphere below Baltic Shield
Electrical asthenosphere below NW Baltic Shield
Resistivity of sub-Moho SCLM (depths of 40-100 km)
Western Churchill Province
Western Churchill - MT model
WCH007/8
WCH007/8
WCH007 1D model to AV data
SNORCLE: Slave NORthern Cordilleran Lithospheric Evolution
Lithospheric MT anisotropy
Site 106 decomposed data
Site 106 1D models: both smooth (Occam) & layered (Minim)
Site 106 1D Models with discontinuity in Occam at 36 km
Superior craton
Correlation of EM & seismic anisotropy
Kapuskasing Uplift - anisotropy
Kapuskasing Uplift - anomaly
Alberta: MT site locations
Southern Alberta: MT model
Slave craton
Significant industry interest
Why use electromagnetism?
Slave craton: EM studies
Winter road:
Slave Lakes:
Walmsley Lake TGI project:
Slave location map
MT response comparison
Winter road MT phases
PPT Slide
Slave Lakes prelim. results
Anomalous region
Other anomalous mantle responses
Anomalous ultra-depleted mantle
Griffin’s interpretation
Anomalous geophysical and geochemical regions
PPT Slide
Conduction mechanisms in the mantle
Interpretation in terms of carbon
Observations
Conclusions: Canadian SCLM
Conclusions: general
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