Geochemical evolution of organic-rich shales with increasing maturity: A STXM and TEM study of the Posidonia Shale (Lower Toarcian, northern Germany)

Bernard, Sylvain; Horsfield, Brian; Schulz, Hans-Martin; Wirth, Richard; Schreiber, Anja; Sherwood, Neil

doi:10.1016/j.marpetgeo.2011.05.010

Cited by 435 publications

(257 citation statements)

References 152 publications

(267 reference statements)

Supporting

Mentioning

246

Contrasting

Order By: Relevance

“…Their spectral patterns of aromatic/ olefinic carbon, aromatic ketone, and carboxyl carbon are typical of those observed from terrestrial coal (Cody et al 1998;Bassim et al 2012) and kerogen (Bernard et al 2012) and even extraterrestrial organic solids from chondritic meteorites and IDPs (e.g., Flynn et al 2003;Cody et al 2011). This does not necessarily imply that our category 3 particles are coal or chondritic organics, but the findings do suggest the presence of some form of heterogeneous macromolecule formed through chemical processing in a natural environment.…”

Section: Approach To Identify Category 3 Carbonaceous Particlesmentioning

confidence: 78%

X-ray absorption near edge structure spectroscopic study of Hayabusa category 3 carbonaceous particles

et al. 2014

View full text Add to dashboard Cite

Analyses with a scanning transmission x-ray microscope (STXM) using x-ray absorption near edge structure (XANES) spectroscopy were applied for the molecular characterization of two kinds of carbonaceous particles of unknown origin, termed category 3, which were collected from the Hayabusa spacecraft sample catcher. Carbon-XANES spectra of the category 3 particles displayed typical spectral patterns of heterogeneous organic macromolecules; peaks corresponding to aromatic/olefinic carbon, heterocyclic nitrogen and/or nitrile, and carboxyl carbon were all detected. Nitrogen-XANES spectra of the particles showed the presence of N-functional groups such as imine, nitrile, aromatic nitrogen, amide, pyrrole, and amine. An oxygen-XANES spectrum of one of the particles showed a ketone group. Differences in carbon-and nitrogen-XANES spectra of the category 3 particles before and after transmission electron microscopic (TEM) observations were observed, which demonstrates that the carbonaceous materials are electron beam sensitive. Calcium-XANES spectroscopy and elemental contrast mapping identified a calcium carbonate grain from one of the category 3 particles. No fluorine-containing molecular species were detected in fluorine-XANES spectra of the particles. The organic macromolecular features of the category 3 particles were distinct from commercial and/or biological 'fresh (non-degraded)' polymers, but the category 3 molecular features could possibly reflect degradation of contaminant polymer materials or polymer materials used on the Hayabusa spacecraft. However, an extraterrestrial origin for these materials cannot currently be ruled out.

show abstract

Section: Approach To Identify Category 3 Carbonaceous Particlesmentioning

confidence: 78%

X-ray absorption near edge structure spectroscopic study of Hayabusa category 3 carbonaceous particles

et al. 2014

View full text Add to dashboard Cite

show abstract

“…This result may indicate the presence of micropores in the organic material. This finding is in accordance with that of Bernard et al (2012) who reported increasing micro-and mesoporosity with increasing degree of maturation of the Posidonia shale. On the other hand, the results are also in accordance with those of Mann (1987) who reported smaller surface areas for samples with intermediate vitrinite reflectance (within the oil window).…”

Section: Characterization Of the Samplessupporting

confidence: 93%

“…The Hilsmulde, in particular, was investigated with respect to evolution of hydrocarbons and porosity within the shale Rullkötter et al, 1988;Ropertz, 1994;Bernard et al, 2012;Kanitpanyacharoen et al, 2012;Klaver et al, 2012) because of the opportunity to study samples with different degrees of maturity. The geography and geology have been explained in detail, e.g.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Methods for the Determination of the Pore System of a Potential German Gas Shale

Kaufhold¹,

Grathoff²,

Halisch³

et al.

Filling the Gaps – From Microscopic Pore Structures to Transport Properties in Shales

View full text Add to dashboard Cite

“…By using these imaging methods, it is possible to receive a solid idea of a shale's internal (micro) structure and pore geometry (e.g., [6][7][8][9][10][11]). BIB milling in combination with SEM imaging delivers direct information about pore sizes, their morphology and spatial distribution, rock microstructure, and potential anisotropy as well as core damage due to sample handling (e.g., [3,[12][13][14][15][16][17][18][19][20][21][22][23][24][25]). Additionally, in combination with energy dispersive X-ray spectroscopy (EDX), BIB-SEM enables the identification of individual grains [26,27].…”

Section: Introductionmentioning

confidence: 99%

Using BIB-SEM Imaging for Permeability Prediction in Heterogeneous Shales

et al. 2017

View full text Add to dashboard Cite

Organic-rich shale samples from a lacustrine sedimentary sequence of the Newark Basin (New Jersey, USA) are investigated by combining Broad Ion Beam polishing with Scanning Electron Microscopy (BIB-SEM). We model permeability from this 2D data and compare our results with measured petrophysical properties. Three samples with total organic carbon (TOC) contents ranging from 0.7% to 2.9% and permeabilities ranging from 4 to 160 nD are selected. Pore space is imaged at high resolution (at 20,000x magnification) and segmented from representative BIB-SEM maps. Modeled permeabilities, derived using the capillary tube model (CTM) on segmented pores, range from 2.3 nD to 310 nD and are relatively close to measured intrinsic permeabilities. SEM-visible porosities range from 0.1% to 1.8% increasing with TOC, in agreement with our measurements. The CTM predicts permeability correctly within one order of magnitude. The results of this work demonstrate the potential of 2D BIB-SEM for calculating transport properties of heterogeneous shales.

show abstract

Geochemical evolution of organic-rich shales with increasing maturity: A STXM and TEM study of the Posidonia Shale (Lower Toarcian, northern Germany)

Cited by 435 publications

References 152 publications

X-ray absorption near edge structure spectroscopic study of Hayabusa category 3 carbonaceous particles

X-ray absorption near edge structure spectroscopic study of Hayabusa category 3 carbonaceous particles

Comparison of Methods for the Determination of the Pore System of a Potential German Gas Shale

Using BIB-SEM Imaging for Permeability Prediction in Heterogeneous Shales

Contact Info

Product

Resources

About