| Title | Resolution and uncertainty in lithospheric 3-D geological models |
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| Author | Snyder, D B ;
Schetselaar, E; Pilkington, M; Schaeffer, A J |
| Source | Mineralogy and Petrology vol. 112, issue S1, 2018 p. S133-S147, https://doi.org/10.1007/s00710-018-0619-2 |
| Image |  |
| Year | 2018 |
| Alt Series | Earth Sciences Sector, Contribution Series 20150488 |
| Publisher | Springer Nature |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Program | GEM2: Geo-mapping for Energy and Minerals Geological Map Flow |
| Released | 2018 08 15 |
| Abstract | As three-dimensional (3-D) modelling of the subcontinental mantle lithosphere is increasingly performed with ever more data and better methods, the robustness of such models is increasingly questioned.
Resolution thresholds and uncertainty within deep multidisciplinary 3-D models based on geophysical observations exist at a minimum of three levels. Seismic waves and potential field measurements have inherent limitations in resolution related to
their dominant wavelengths. Formal uncertainties can be assigned to grid-search type forward or inverse models of observable parameter sets. Both of these uncertainties are typicallyminor when compared to resolution limitations related to the density
and shape of a specific observation array used in seismological or potential field surveys. Seismic wave source distribution additionally applies in seismology. A fourth, more complex level of uncertainty relates to joint inversions of multiple data
sets. Using independent seismic wave phases or combining diverse methods provides another measure of uncertainty of particular physical properties. Extremely sparse xenolith suites provide the only direct correlation of rock type with observed
ormodelled physical properties at depths greater than a few kilometers. Here we present one case study of the Canadian Mohorovi?i? (Moho) discontinuity using only two data sets. Refracted and converted seismic waves formthe primary determinations of
the Moho depth, gravity fieldmodeling provide a secondary constraint on lateral variations, the slope of the Moho, between the sparse seismic estimates. Although statistically marginal, the resulting co-kriged Moho surface correlates better with
surface geology and is thus deemed superior. |
| Summary | (Plain Language Summary, not published)
The Open Geoscience program has embarked on a 2-year pilot study to assess the practicality of building a digital 3-D geological map of Canada. The deep
layers of this model will depend almost entirely on geophysical observations. This paper discusses uncertainties associated with these observations as well as estimating the resolution possible with geophysical models today. Discussion also includes
uncertainties associated with mapping geophysical properties into geological models. This all underpins the reliability and confidence users can have in a 3-D model of Canada. |
| GEOSCAN ID | 297847 |
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