Genesis of oil and hydrocarbon gases within Mars and carbonaceous chondrites from our solar system: organic origin (source rocks or direct biogenic sink?)

2011 ◽  
Author(s):  
Prasanta K. Mukhopadhyay
Author(s):  
Niels Hemmingsen Schovsbo ◽  
Arne Thorshøj Nielsen

The Lower Palaeozoic succession in Scandinavia includes several excellent marine source rocks notably the Alum Shale, the Dicellograptus shale and the Rastrites Shale that have been targets for shale gas exploration since 2008. We here report on samples of these source rocks from cored shallow scientific wells in southern Sweden. The samples contain both free and sorbed hydrocarbon gases with concentrations significantly above the background gas level. The gases consist of a mixture of thermogenic and bacterially derived gas. The latter likely derives from both carbonate reduction and methyl fermentation processes. The presence of both thermogenic and biogenic gas in the Lower Palaeozoic shales is in agreement with results from past and present exploration activities; thermogenic gas is a target in deeply buried, gas-mature shales in southernmost Sweden, Denmark and northern Poland, whereas biogenic gas is a target in shallow, immature-marginally mature shales in south central Sweden. We here document that biogenic gas signatures are present also in gas-mature shallow buried shales in Skåne in southernmost Sweden.


2009 ◽  
Vol 106 (17) ◽  
pp. 6904-6909 ◽  
Author(s):  
Matthieu Gounelle ◽  
Marc Chaussidon ◽  
Alessandro Morbidelli ◽  
Jean-Alix Barrat ◽  
Cécile Engrand ◽  
...  

Micrometeorites with diameter ≈100–200 μm dominate the flux of extraterrestrial matter on Earth. The vast majority of micrometeorites are chemically, mineralogically, and isotopically related to carbonaceous chondrites, which amount to only 2.5% of meteorite falls. Here, we report the discovery of the first basaltic micrometeorite (MM40). This micrometeorite is unlike any other basalt known in the solar system as revealed by isotopic data, mineral chemistry, and trace element abundances. The discovery of a new basaltic asteroidal surface expands the solar system inventory of planetary crusts and underlines the importance of micrometeorites for sampling the asteroids' surfaces in a way complementary to meteorites, mainly because they do not suffer dynamical biases as meteorites do. The parent asteroid of MM40 has undergone extensive metamorphism, which ended no earlier than 7.9 Myr after solar system formation. Numerical simulations of dust transport dynamics suggest that MM40 might originate from one of the recently discovered basaltic asteroids that are not members of the Vesta family. The ability to retrieve such a wealth of information from this tiny (a few micrograms) sample is auspicious some years before the launch of a Mars sample return mission.


2016 ◽  
Vol 113 (8) ◽  
pp. 2011-2016 ◽  
Author(s):  
Elishevah M. M. E. Van Kooten ◽  
Daniel Wielandt ◽  
Martin Schiller ◽  
Kazuhide Nagashima ◽  
Aurélien Thomen ◽  
...  

The short-lived 26Al radionuclide is thought to have been admixed into the initially 26Al-poor protosolar molecular cloud before or contemporaneously with its collapse. Bulk inner Solar System reservoirs record positively correlated variability in mass-independent 54Cr and 26Mg*, the decay product of 26Al. This correlation is interpreted as reflecting progressive thermal processing of in-falling 26Al-rich molecular cloud material in the inner Solar System. The thermally unprocessed molecular cloud matter reflecting the nucleosynthetic makeup of the molecular cloud before the last addition of stellar-derived 26Al has not been identified yet but may be preserved in planetesimals that accreted in the outer Solar System. We show that metal-rich carbonaceous chondrites and their components have a unique isotopic signature extending from an inner Solar System composition toward a 26Mg*-depleted and 54Cr-enriched component. This composition is consistent with that expected for thermally unprocessed primordial molecular cloud material before its pollution by stellar-derived 26Al. The 26Mg* and 54Cr compositions of bulk metal-rich chondrites require significant amounts (25–50%) of primordial molecular cloud matter in their precursor material. Given that such high fractions of primordial molecular cloud material are expected to survive only in the outer Solar System, we infer that, similarly to cometary bodies, metal-rich carbonaceous chondrites are samples of planetesimals that accreted beyond the orbits of the gas giants. The lack of evidence for this material in other chondrite groups requires isolation from the outer Solar System, possibly by the opening of disk gaps from the early formation of gas giants.


2020 ◽  
Vol 6 (42) ◽  
pp. eaay2724
Author(s):  
Alexander N. Krot ◽  
Kazuhide Nagashima ◽  
James R. Lyons ◽  
Jeong-Eun Lee ◽  
Martin Bizzarro

The Sun is 16O-enriched (Δ17O = −28.4 ± 3.6‰) relative to the terrestrial planets, asteroids, and chondrules (−7‰ < Δ17O < 3‰). Ca,Al-rich inclusions (CAIs), the oldest Solar System solids, approach the Sun’s Δ17O. Ultraviolet CO self-shielding resulting in formation of 16O-rich CO and 17,18O-enriched water is the currently favored mechanism invoked to explain the observed range of Δ17O. However, the location of CO self-shielding (molecular cloud or protoplanetary disk) remains unknown. Here we show that CAIs with predominantly low (26Al/27Al)0, <5 × 10−6, exhibit a large inter-CAI range of Δ17O, from −40‰ to −5‰. In contrast, CAIs with the canonical (26Al/27Al)0 of ~5 × 10−5 from unmetamorphosed carbonaceous chondrites have a limited range of Δ17O, −24 ± 2‰. Because CAIs with low (26Al/27Al)0 are thought to have predated the canonical CAIs and formed within first 10,000–20,000 years of the Solar System evolution, these observations suggest oxygen isotopic heterogeneity in the early solar system was inherited from the protosolar molecular cloud.


2020 ◽  
Vol 6 (7) ◽  
pp. eaay7604 ◽  
Author(s):  
Martin Schiller ◽  
Martin Bizzarro ◽  
Julien Siebert

Nucleosynthetic isotope variability among solar system objects provides insights into the accretion history of terrestrial planets. We report on the nucleosynthetic Fe isotope composition (μ54Fe) of various meteorites and show that the only material matching the terrestrial composition is CI (Ivuna-type) carbonaceous chondrites, which represent the bulk solar system composition. All other meteorites, including carbonaceous, ordinary, and enstatite chondrites, record excesses in μ54Fe. This observation is inconsistent with protracted growth of Earth by stochastic collisional accretion, which predicts a μ54Fe value reflecting a mixture of the various meteorite parent bodies. Instead, our results suggest a rapid accretion and differentiation of Earth during the ~5–million year disk lifetime, when the volatile-rich CI-like material is accreted to the proto-Sun via the inner disk.


2010 ◽  
Vol 291 (1-4) ◽  
pp. 39-47 ◽  
Author(s):  
R.G.A. Baker ◽  
M. Schönbächler ◽  
M. Rehkämper ◽  
H.M. Williams ◽  
A.N. Halliday

1989 ◽  
Vol 29 (1) ◽  
pp. 96 ◽  
Author(s):  
G.W. O'Brien ◽  
D.T. Heggie

During April- May 1988, the BMR research vessel Rig Seismic carried out a 21- day geochemical and sedimento- logical research program in the Otway (17 days) and Gippsland (4 days) Basins. The concentrations and molecular compositions of light hydrocarbon gases (C1- C4) were measured in sediments at 203 locations on the continental shelf and upper continental slope: the presence of thermogenic hydrocarbons was inferred from the molecular compositions of the gas mixtures. Thermogenic hydrocarbons were identified in near- surface sediments at 32 locations in the Otway Basin; 6 of these locations were on the Crayfish Platform, 7 were on the Mussel Platform and 17 were in the Voluta Trough. Thermogenic hydrocarbons were identified at 10 locations in the Gippsland Basin. Data from the Otway Basin indicated that total C1- C4 gas concentrations were higher in the Voluta Trough than on the basin margins, probably because intense faulting in the trough facilitates gas migration from deeply buried source rocks and/or reservoirs to the seafloor. However, anomalies were detected where the Tertiary sequence was thick and relatively unfaulted. The wet gas contents of the anomalies were highest on the basin margins, lower in the Voluta Trough and co- varied with the depth of burial of the basal Early Cretaceous sedimentary sequence. These data, when integrated with geohistory, thermal maturation modelling and well data, suggest that the areas with the best potential for liquid hydrocarbon entrapment and preservation are the Crayfish Platform and the inshore part of the Mussel Platform. In contrast, the Late Cretaceous Sherbrook Group and much of the Voluta Trough appear to be gas prone.Thermogenic anomalies in the Gippsland Basin were concentrated within and along the margins of the Central Deep where mature Latrobe Group source rocks are present. The wet gas content of these anomalies was variable, which is consistent with the spatial heterogeneity of hydrocarbon accumulations in the Gippsland Basin.


2007 ◽  
Vol 260 (3-4) ◽  
pp. 582-596 ◽  
Author(s):  
Hans-Michael Seitz ◽  
Gerhard P. Brey ◽  
Jutta Zipfel ◽  
Ulrich Ott ◽  
Stefan Weyer ◽  
...  

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