Effect of an igneous intrusion on maturation of organic matter in Lower Jurassic shales from NW-Germany

1980 ◽  
Vol 12 ◽  
pp. 133-139 ◽  
Author(s):  
D. Leythaeuser ◽  
F.J. Altebäumer ◽  
R.G. Schaefer
Keyword(s):  
Organic Matter ◽  
Lower Jurassic ◽  
Nw Germany ◽  
Igneous Intrusion

Rapid heating of carbonaceous matter by igneous intrusions in carbon-rich shale, Isle of Skye, Scotland: an analogue for heating of carbon in impact craters?

2006 ◽  
Vol 5 (4) ◽  
pp. 343-351 ◽  
Author(s):  
Paula Lindgren ◽  
John Parnell
Keyword(s):  
Organic Matter ◽  
High Temperature ◽  
High Temperatures ◽  
Rapid Heating ◽  
Igneous Intrusion ◽  
High Temperature Process ◽  
Igneous Intrusions ◽  
Life Impact ◽  
Impact Events ◽  
Isle Of Skye

The response of organic matter to high-temperature events is important to astrobiology, as it governs the survival of carbon during several processes that may be critical to the origin and spread of life. Impact cratering is a widespread high-temperature process. The behaviour of carbon during impact events is not well understood. But there is the potential to examine other examples of the response of organic matter to high-temperature processes in the terrestrial geological record. In this study, we report on the interaction of Tertiary igneous intrusions (dolerite sills) and carbon-rich Jurassic mudrocks on the Isle of Skye, Scotland. Despite the high temperatures of the igneous intrusion, carbon has been preserved at the dolerite–shale contact and in shale enclaves where partial melting of the shale has occurred. Even though the temperatures achieved by igneous intrusion are much lower than during impact events, it is a valuable analogue, because it represents a rapid introduction of high temperatures to a carbon-rich rock.

scholarly journals Comparison of organic geochemical and palynofacies methods: Example from the Upper Triassic Gassum Formation in Denmark

1991 ◽  
Vol 38 ◽  
pp. 267-277
Author(s):  
Bjørn Buchardt ◽  
Marianne Vasard Nielsen
Keyword(s):  
Organic Matter ◽  
Carbon Isotope ◽  
Isotope Composition ◽  
Lower Jurassic ◽  
Upper Triassic ◽  
Carbon Isotope Composition ◽  
Preparation Methods ◽  
Rock Samples ◽  
Deep Well ◽  
Amorphous Organic Matter

Copenhagen, February 19th, 1991. Disseminated organic matter from the · Upper Triassic to Lower Jurassic Gassum Formation in the Gassum-1 deep well has been analyzed by palynological and organic geochemical methods. Tue paper compares the effects of the different preparation methods on the organic matter. The kerogen isolation process (demineralisation by HF) is found to cause major changes in the Rock-Eva! parameters, but not in carbon isotope composition of organic matter. Tm.,- and HI-values determined from kerogen concentrates are more consistent with the palynofacies data than those determined from whole rock samples. The differences are ascribed to analytical problems when dealing with low-TOC whole rock samples. Palynofa­cies data obtained from unfiltered and filtered kerogen concentrates demonstrate a variable loss of amorphous organic matter during filtration ( up to 1()()%). Other palynomorph distributions are not seriously affected by filtration. The loss in amorphous organic matter has no influence on the Rock-Eva! data and carbon isotope composition. Comparison of polynofacies and carbon isotope data identifies three organic matter sources with characteristic isotopic composition.

scholarly journals Effects of Igneous Intrusion on the Organic Content of Irati Formation, Paraná Basin, in Sapopema (PR)

2020 ◽  
Vol 43 (4) ◽  
Author(s):  
Werlem Holanda ◽  
Anderson Costa dos Santos ◽  
Camila Cardoso Nogueira ◽  
Sérgio Bergamaschi ◽  
René Rodrigues ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Organic Matter Content ◽  
Organic Content ◽  
Insoluble Residue ◽  
Sem Images ◽  
Igneous Intrusion ◽  
Irati Formation ◽  
Paraná Basin ◽  
Parana Basin

The thermal effects of an igneous intrusion on organic-rich sedimentary rocks can be considering an important source of maturation of organic matter. The Permian Irati Formation of Paraná Basin (Brazil) is a carbonatic and organic-rich shale sequence intruded by Jurassic-Cretaceous basic rocks. This study reports possible effects of igneous intrusion on the organic matter content of Irati Formation, in Sapopema region (Paraná State). Total organic carbon (TOC), total sulfur (S) and insoluble residue (IR) data were combined with scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The relatively low TOC values recorded in well where Irati Formation is in contact with 60 m of diabase sill (SP-58-PR) are residuals, associated with the depletion of organic carbon, caused by the thermal effect from the overlying intrusive rock. It was responsible to promote the cracking of the organic matter and reduced those values in relation to the original ones, observed in SP-32-PR (without thermal influence). When comparing the TOC peaks of the Assisting Member in both wells, it was observed that there was a decrease between 80.7 and 84% in the SP-58-PR. SEM images reveal that organic matter in Taquaral Member is sub-rounded and regular shape, while the organic matter in Assistência Member presents a characteristic pattern of thermally evolved organic matter.

scholarly journals Depositional environment and burial history of a Lower Cretaceous carbonaceous claystone, Bornholm, Denmark

1996 ◽  
Vol 43 ◽  
pp. 133-142
Author(s):  
H. I. Petersen ◽  
J. A. Bojesen Koefoed ◽  
H. P. Nytoft
Keyword(s):  
Organic Matter ◽  
Lower Cretaceous ◽  
Depositional Environment ◽  
Lower Jurassic ◽  
Plant Litter ◽  
Burial History ◽  
Transport Distance ◽  
Geochemical Parameters ◽  
Kerogen Type ◽  
History Of

A c. 1 m thick carbonaceous claystone from the type locality of the Lower Cretaceous Skyttegård Member (Rabekke Formation), Bornholm, has been investigated by organic pétrographie and organic geochemical methods in order to assess the depositional environment of the claystone and the thermal maturity of the organic matter. The claystone was deposited in a low-energy, anoxic lake which occasionally was marine influenced. The organic matter is terrestrial and can be classified as kerogen type III and lib. Detrital organic matter and cutinite are characteristic components. The organic matter is allochthonous but the transport distance was short, and the plant material was probably mainly derived from plants growing at the edge of, or nearto, the lake. Source-specific biomarkers such as norisopimarane suggest that the plant litter was derived from a gymnospermous, low-diversity vegetation. Evidence for early angiospermous plants cannot be demonstrated with any certainty. A huminite reflectance value of 0.24%Rm and several geochemical parameters indicate that the organic matter is highly immature. It has only experienced coalification corresponding to the peat stage. Estimates show that, prior to uplift, the claystone was buried to a maximum of approximately 260 m. Reflectance data further suggest that a maximum c. 550 m thick sediment package was removed by erosion prior to deposition of the ?uppermost Jurassic-Lower Cretaceous sediments on Lower Jurassic strata.

scholarly journals A source rock evaluation of the Mesozoic Sediments of the Well Hyllebjerg-1 Danish Subbasin

1988 ◽  
Vol 9 ◽  
pp. 1-105
Author(s):  
Birthe J Schmidt
Keyword(s):  
Organic Matter ◽  
Source Rock ◽  
Geothermal Gradient ◽  
Organic Content ◽  
Lower Jurassic ◽  
Source Rocks ◽  
Marginal Areas ◽  
Algal Material ◽  
Clay Formation ◽  
Promising Source

The source rock potential of Mesozoic sediments (cuttings) from the Hyllebjerg 1 well, Danish Subbasin, has been assessed using a number of different petrographical and organochemical methods. Upper Jurassic sediments (Bream Formation) equivalent to the principal source rocks of the North Sea graben structures (Kimmeridge Clay Formation and lateral equivalents) do not show similar prominent source rock characteristics in this well, although a higher proportion of algal material is observed. Sediments with the most promising source rock characteristics for liquid hydrocarbons were· detected mainly in the lower- Jurassic sequences of the upper Fjerritslev Format ion (F-4 and upper F-3 Member) and in one horizon in the Upper Cretaceous Vedsted Formation which showed a good quality composition and a relatively high content of organic matter. But these sediments may be excluded as actual source rocks in this well as maturity (assuming the threshold value near 0. 60 % R ) is first reached at approximately 8500' 0 depth i.e. at the top of the Gassum Formation (Upper Triassic/ Lower Jurassic). The conditions may only by slightly different off - structure is this area, as the F-4 and F-3 Member sequence according to seismic sections is found at approximately the same depth. But the depth to ( and the thickness of) the Fjerritslev Formation is increasing towards the SE into the rimsynclines of the saltdomes nearby. While sufficient maturity is reached in the deeper part of the well, no commercial accumulations of hydrocarbons were encountered. This is attributed to the mainly reworked, unfavourable type of organic matter and the generally decreasing organic content downwards in the well, approaching the lower 1 imi t for potential source rocks ( set at O, 5% TOC). However, generation and migration of small amounts of gaseous hydrocarbons from Gassum Formation sediments containing more humic-influenced organic matter with only minor reworking cannot generally be excluded either here or elsewhere in the basin. Some more attention should also be paid to the Vinding Formation sediments which contain some algae- ri eh ( Botryocous-type) oil-prone horizons of more favourable source rock conditions. Mature sediments are found at shallower depths ( 8500 ') in this well in the central part of the basin compared to the more marginal areas (8900') where a slightly higher geothermal gradient in Jiyllebjerg 1 ( 28°C/km uncorrected) is seen compared with the marginal areas (23.5°C/km uncorrected) away from the basinal depocenter. The basinal depocenter also has a higher heat flow.

scholarly journals The Hydrocarbon Genesis of pre-Jurassic Complex of Khanty-Mansiyskoe Oil Field

2020 ◽  
Vol 6 (10) ◽  
pp. 95-110
Author(s):  
Yu. Korzhov ◽  
G. Lobova ◽  
A. Starikov ◽  
M. Kuzina
Keyword(s):  
Organic Matter ◽  
Molecular Mass Distribution ◽  
Lower Jurassic ◽  
Oil Field ◽  
Tectonic Block ◽  
The Core ◽  
Complex Source ◽  
Parent Rocks ◽  
Paleozoic Rocks ◽  
Hydrocarbon Deposits

The origin of hydrocarbon deposits in Jurassic and pre-Jurassic complexes of the Khanty-Mansiysk area, located within the Frolov depression, in the local compression zone of the West Siberian plate — the suture zone, is established. The core and crude oil of Jurassic and pre-Jurassic complexes from prospecting wells of the Khanty-Mansiyskoe field is studied. The content and molecular mass distribution of hydrocarbons, including n-alkanes, n-alkylbenzenes, naphthalene’s and phenanthrenes, is determined in bitumen of rocks and oils by chromatography-mass spectrometry. Lithological and petrographic characteristics of rocks is determined by optical microscopy. For oil deposits of the pre-Jurassic complex “source of hydrocarbons” is not reliably established, the parent rocks were not clearly identified in this research. In the lower horizons of the Jurassic section, there is a layer of highly permeable gritstone of the Gorely formation, in which organic matter is localized, presumably making the main contribution to the hydrocarbon deposits of the lower Jurassic and pre-Jurassic complexes. As a possible “source of Paleozoic oil”, it is proposed to collect hydrocarbons from scattered organic matter of Paleozoic rocks at a significant depth (not covered by core drilling) in the areas of tectonic block crushing of foundation.

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