Electron paramagnetic resonance spectroscopy: A suggested approach to trace metal analysis in marine environments

Burgess, Bruce A.; Chasteen, N. Dennis; Gaudette, Henri E.

doi:10.1007/bf02428945

Cited by 13 publications

(1 citation statement)

References 19 publications

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“…Some applications of the EPR technique to earth sciences include trace metal analysis in different environments (Burguess et al, 1975;Boughriet et al, 1992) and dating of carbonate rocks (Jonas, 1997;Rink, 1997). In addition, the EPR technique has been applied to the study of clay minerals (Meads and Malden, 1975;Angel and Vincent, 1978;Hall, 1980); dolomites (Lumsden and Lloyd, 1988;Granwehr et al, 2004), volcanic ashes (Pawse et al, 1998), sedimentary organic matter (Aizaenshtat et al, 1986;Díaz et al, 2000;Gonzalez et al, 2002) and marine sediments (Otamendi et al, 2006).…”

Section: Sampling and Experimental Techniquesmentioning

confidence: 99%

Hydrocarbon-induced magnetic contrasts in some Venezuelan and Colombian oil wells

et al. 2006

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In this work we present a review of our current research on the subject of near-surface hydrocarbon-induced magnetic contrasts. Samples are drill cuttings from number of Venezuelan and Colombian oil fields, and some soils from an oil prospective area. Results from rock magnetic, electronic paramagnetic resonance (EPR), extractable organic matter (EOM) and scanning electron microscopy (SEM) are discussed in light of new experiments. Two types of magnetic susceptibility (MS) anomalies have been recognized in oil well samples (i.e. A and B-like). A-like anomalies are probably associated to a reducing environment caused by the underlying reservoirs, whereas B-like anomalies might reflect lithological contrasts. Samples from A-like anomalous levels reveal the restrictive presence of authigenic spherical aggregates of submicronic Fe-rich magnetic crystals. Peaks of organic matter free radical concentration (OMFRC) and EOM are also observed at depth levels that lie close to those with A-like anomalies. Hysteresis ratios J rs /J s and H cr /H c could be used as additional criteria to recognize A-like magnetic contrasts. In soil samples, MS and OMFRC anomalies coincide with peaks of ethane concentration and an area underneath where source rock has reached appropriate conditions of pressure and temperature to generate hydrocarbons (Cretaceous kitchen). Different types of crude oils and subsurface structures could have also a direct effect on the observed amplitude of A-like anomalies.

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