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norcholestane

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Journal Article
Journal: Geology
Published: 01 September 1998
Geology (1998) 26 (9): 783-786.
.... We demonstrate here that 24-norcholestane biomarkers, i.e., C26 steranes (saturated hydrocarbons having a steroid skeleton), can be useful to constrain the age and paleolatitude of geologic samples. The biological precursors of 24-norcholestanes remain unclear, but samples from more than 100 basins...
Journal Article
Journal: Geology
Published: 01 May 2007
Geology (2007) 35 (5): 419-422.
...Sebastiaan W. Rampen; Stefan Schouten; Ben Abbas; F. Elda Panoto; Gerard Muyzer; Christine N. Campbell; Johanna Fehling; Jaap S. Sinninghe Damsté Abstract 24-norcholestanes have been shown to be useful biomarkers to assess the age of sediments and petroleum, but until now, the biological sources...
FIGURES
Journal Article
Journal: AAPG Bulletin
Published: 01 November 2005
AAPG Bulletin (2005) 89 (11): 1519-1545.
... relative amounts of oleanane in each oil sample indicate a notable input of terrestrial organic matter deposited in a mixed marine and terrestrial environment (probably deltaic). The high ratio of 24-norcholestanes to 27-norcholestanes and C 25 highly branched isoprenoid (HBI) alkanes suggests...
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Image
Cross-plot showing the <b>norcholestane</b> ratio (NCR) against the nordiacholesta...
Published: 07 October 2016
Fig. 6. Cross-plot showing the norcholestane ratio (NCR) against the nordiacholestane ratio (NDR). Age classification was carried out according to Holba et al . (1998 a , b ).
Image
Assessment of source age applying <b>norcholestane</b> (NCR) and nordiacholestane ...
Published: 01 June 2010
Figure 16 Assessment of source age applying norcholestane (NCR) and nordiacholestane ratios (NDR) according to Holba et al. (1998a , b ). The NCR values indicate mostly Cretaceous ages, and Tertiary age is suggested for sample 120.611. The NDR suggests Cretaceous and Upper Jurassic ages
Image
Figure 1. Comparison of the 24-<b>norcholestane</b> ratio with the diversity of di...
in > Geology
Published: 01 May 2007
Figure 1. Comparison of the 24-norcholestane ratio with the diversity of dinoflagellates and diatoms over geologic time. The shaded area (a) is the typical range of 24-norcholestane concentration for petroleum with age from Holba et al. (1998b) . The solid line (b) shows the number of described
Image
Comparative diagram showing (A) 24-<b>norcholestane</b> (NCR) vs. geologic age wit...
Published: 01 November 2005
Figure 12 Comparative diagram showing (A) 24-norcholestane (NCR) vs. geologic age with white field indicating the variation of NCR with geologic age (modified from Holba et al., 1998a , b ). (B) δ 13 C variation through geologic time with fields being defined by diagonal lines (modified from
Journal Article
Journal: AAPG Bulletin
Published: 01 June 2010
AAPG Bulletin (2010) 94 (6): 791-817.
...Figure 16 Assessment of source age applying norcholestane (NCR) and nordiacholestane ratios (NDR) according to Holba et al. (1998a , b ). The NCR values indicate mostly Cretaceous ages, and Tertiary age is suggested for sample 120.611. The NDR suggests Cretaceous and Upper Jurassic ages...
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Journal Article
Journal: Geology
Published: 01 March 2000
Geology (2000) 28 (3): 251-254.
... marine or coal-forming depositional environments. A TPP ratio, constructed from the gas chromatography–tandem mass spectrometry peak areas of a C 30 tetracyclic polyprenoid divided by the sum of the peak areas of the C 26 27-norcholestanes, revealed great specificity in identifying freshwater or brackish...
FIGURES
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—Representative metastable reaction monitoring m/z 358 to 217 mass chromato...
Published: 11 December 1999
Figure 11 —Representative metastable reaction monitoring m/z 358 to 217 mass chromatogram for hypersaline lacustrine oils indicates high 24-norcholestane ratios (inset table).
Image
The  m / z  358 →  m / z  217 parent-daughter mass chromatograms of two sam...
Published: 01 June 2010
Figure 15 The m / z 358 → m / z 217 parent-daughter mass chromatograms of two samples from Matochkin Strait with norcholestane (NCR) and nordiacholestane (NDR) values ( Table 6 ). Peak identifications are from Holba et al. (1998a) .
Image
Figure 1. Gas chromatography–tandem mass spectrometry (GC/MS/MS) mass chrom...
in > Geology
Published: 01 March 2000
Figure 1. Gas chromatography–tandem mass spectrometry (GC/MS/MS) mass chromatograms. A: 414 → 259 lacustrine source-rock extract from Triassic Cacheuta Shale, Cuyo basin, Argentina. B: 414 → 259 from Jurassic marine oil, Ekofisk field, North Sea, Norway. C: 358 → 217 norcholestanes from
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MRM chromatograms (M +  ⟶ m/z 217) showing the C21-C29 sterane distribution...
in > GeoArabia
Published: 01 October 2009
predominance. 21-norcholestane is only detected in silicilyte samples.
Image
Tetracyclic polyprenoid (TPP) ratio versus content of C 30  24- n -propyldi...
Published: 01 March 2016
+ → mass-to-charge ratio (m/z) 217 and 259. TPP = 2(TPPa)/(2(TPPa) + 27-nor-C 26 ); TPP a = 21S isomer of tetracyclic polyprenoid measured by m/z 414 → 259; 27-nor-C 26 = ∑27-norcholestanes. Circle, triangle, rhombus, and star represent samples of families I, II, III-a, and III-b respectively.
Series: AAPG Memoir
Published: 01 January 2000
DOI: 10.1306/M73705C4
EISBN: 9781629810706
... evolved), especially those containing abundant achritarchs, led Moldowan and Talyzina (1998) to suggest a genetic dinoflagellate– achritarch link. The absence of triaromatic dino-steroids in marine-derived oils indicates a Triassic or older source ( Moldowan et al., 1996 ). 24-Norcholestanes and 24...
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Journal Article
Journal: AAPG Bulletin
Published: 01 April 2001
AAPG Bulletin (2001) 85 (4): 601-619.
.... Calculated 24-norcholestane ratios [24/(24 + 27)-norcholestane] from MRM-GC-MS (metastable reaction monitoring-gas chromatograph-mass spectrometer) for this group of oils are between 0.37 and 0.40. Holba et al. (1998) have documented that norcholestane ratios in excess of 0.6 indicate an Oligocene...
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Journal Article
Journal: AAPG Bulletin
Published: 11 December 1999
AAPG Bulletin (1999) 83 (12): 1980-2005.
...Figure 11 —Representative metastable reaction monitoring m/z 358 to 217 mass chromatogram for hypersaline lacustrine oils indicates high 24-norcholestane ratios (inset table). ...
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Journal Article
Journal: GeoArabia
Publisher: Gulf Petrolink
Published: 01 October 2009
GeoArabia (2009) 14 (4): 53-86.
... predominance. 21-norcholestane is only detected in silicilyte samples. ...
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Journal Article
Journal: AAPG Bulletin
Published: 01 August 2000
AAPG Bulletin (2000) 84 (8): 1109-1128.
..., there are exceptions to this rule, most notably the 3YM2 sample (from Tabei area), which has 0.85% sulfur, the highest sulfur content of any of the samples for which there are data. Source-rock extracts that are the best match for group 1 oils based upon Pr/Ph, percent steranes, Ts/(Ts + Tm), norcholestanes...
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Journal Article
Published: 05 April 2017
Petroleum Geoscience (2018) 24 (1): 92-101.
.... & Dzou , L.I.P. 1998 . 24-Norcholestanes as age-sensitive molecular fossils . Geology , 26 , 783 – 786 . Holba , A.G. , Ellis , L. , Dzou , I.L. , Hallam , A. , Masterson , W.E. , Francu , J. & Fincannon , A.L. 2001 . Extended tricyclic terpanes...
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