Insoluble organic matter residues are the remaining insoluble organic material after extreme acid digestion of the extraterrestrial material. They contain complex morphologies that exist as either: isolated spherical compounded shapes; hollow spherical objects or irregular (non spherical) shapes which internally often contain the same conglomeration of spherical features. Please see attached DF STEM images of some of these morphologies from two organic rich carbonaceous chondrites. As the residues are a product of the removal of surrounding mineralogy (i.e. context in situ is lost), connected features on the submicron to micron scale in the images, by approximation, should only be considered. Thanks!
I should add that by 'affinities' I mean to say morphological ones. So ideally electron microscope images of potential similar materials.
That makes the extraterrestrial IOM very unique then, morphologically speaking. Some people have actually made OM with some morphological affinities (e.g. Kebakawa et al., 2013; Saito and Kimura, 2009 - papers attached). However, I'm particularly interested in the morphologies that are clearly shown in the right images from the Bells meteorites, as this is what most of the IOM residues look like in the water rich meteorites. I guess I'm more likely trying to reach out to organic polymer specialists that may have synthesized similar polymer morphologies, as similar morphologies in terrestrial kerogen are not as common?
Article Origin of Organic Globules in Meteorites: Laboratory Simulat...
Article Exploring the Potential Formation of Organic Solids in Chond...
I guess that's the question. Are there any photos of terrestrial kerogen or synthetic polymers that have affinities to the ones attached? Thanks!
Hi,
I really don't know. Frances Westall has perhaps seen something similar in ancient rocks.
Cheers
Andre
Thank you Andre, I will contact him. It would be exciting to see similar material in ancient natural materials rather than synthetic ones! What we have been seeing is some compositional similarity between shale material and organic material in the more thermally altered meteorites. More thermal alteration of the OM the meteorite parent bodies leads to aromatic richer and perhaps bitumen-like OM. So we have already been seeing some affinities between the more processed OM and terrestrial kerogen, but not any as of yet really with OM from meteorites that have more extensive aqueous rather than thermal alteration in the carbonaceous chondrites - lesser energies.
No, I havn't - many thanks for this. The spherical particles in the Onverwacht chert are really interesting. Discrete spherical particles can be readily found in the carbonaceous chondrite matrices but are most abundantly submicron in size. These ones from the chert are much bigger. Most of the inclusions in the carbonaceous matrices are irregular in shape but contain internal morphologies that are reminiscent of conglomerates of the compounded and hollow spherical particles. Some of the irregular shaped inclusions also display vein-like textures suggesting that they filled spaces in the matrices.
It's always remarkable seeing links between biogenic material from Earth and the pre biotic material in the meteorites. I've seen some evidence of graphitization in the matrices of the unequilibrated ordinary chondrites that have recorded more elevated thermal histories than the carbonaceous chondrites. A consistent difference though between the natural carbonaceous material on Earth and IOM from carbonaceous chondrites seems to be the size distribution. It seems that you see variation at smaller scales in carbonaceous chondrite IOM, ranging from submicron to nanoscopic. Discrete globules are modally around 200 nm. What has controlled this smaller size distribution is unclear. Within the material from Earth, perhaps the sizes of the organisms and the pores in the rocks control it? Was pressure more of controlling factor than temperature in the degree of graphitization or maturation on Earth?
Dear Hitesh,
If you are interested in the theory of living-matter formation anywhere in Universe, I advise you the works on the LOH-Theory. The publications are available in my pages at the ResearchGate site.
Dear Hitesh,
As for the direct answer to your question, this is a case when I agree with Dr. Kenneth M. Towe.
If you are interested in the theory of living-matter formation anywhere in Universe, I advise you the works on the LOH-Theory. The publications are available in my pages at the ResearchGate site.
Dear Hitesh,
This insoluble organic matter is made of polycyclic aromatic hydrocarbons (PAHs) that belong to the family of kerogen. They are found in meteorites, but also in micrometeorites with size peaking between 100-200 µm, that deliver about 1000 times more extraterrestrial material to the Earth than meteorites. Also important in my previous work in exobiology, they have been recently observed in cometary dust grains during the recent Rosetta mission to a comet.
On the Earth they are the final degradation products of any kind of organic material. For example if you irradiate occidentally one of your finger in a beam of accelerated electron, its colour will turn to that observed at the surface of meat cooked in a barbecue.
And don't forget: on the Earth there are ''kerogen-rich-rocks'', which are also coined as ''petroleum-source-rocks'', when they contain more that 2% of kerogen. When they get sufficiently buried upon sedimentation , the high temperatures and pressures ''crack'' their kerogen into the huge variety of molecules that constitute petroleum, the richest source of organics on the Earth (about 100,000 molecules).
Then on the early Earth, I proposed that a fraction of this oil might have leaked up to the surface of the early oceans, as to form giant black tides, which contributed to the formation of prebiotic soups. In brief kerogen is one of the most insoluble material, that you had to transform first into soluble materials to form a prebiotic soup.
I fully agree with your statement. This will be a long answer that might be cut, in this case send me your E-mail address for my full answer.
I stopped worrying about this problem after the publication of my book in 2006 (Micrometeorites and the mysteries of our origins, Springer-Verlag), and you just reactivated this interest. My major objectives were to assess the role of micrometeorite accretion in both the formation of the atmospheres of the terrestrial planets and that of the prebiotic soup that gave birth to life on the Earth.
In Part VI (Micrometeorites in comparative Planetology), I list 4 chapters: 18 Micrometeoritic iridium in the Earth's mantle; 19 Micrometeoritic Neon on the Earth; 20 the Micrometeoritic purity of the Earth's atmosphere and early Earth's processes, and for you: 21 Extrapolation of EMMA to the Moon and Mars with 3 chapters (read several times the last one: 21-3); 21-1 The lunar iridium puzzle; 21-2 EMMA with Spirit and Opportunity on Mars, and most important; 21.3 A Hard time for EMMA on the Moon and Mars.
But we have many new important informations from astronomers, dealing with the origin of the zodiacal cloud of interplanetary dust particles in the ecliptic plane (mostly dust from Jupiter family comets ''similar to carbonaceous Antarctic micrometeorites), in which the terrestrial planets describe their orbits while capturing the same dust dust. I'll discuss them if you receive this mail.
Kenneth:....brough in living organism? Panspermia?
Unfortunately meteorites travel in space where they are irradiated by galactic cosmic rays . This irradiation generate cosmogenic nuclides that allow first to estimate the flight times of meteorites in space (exposure ages). They are too long to allow ''bugs'' to survive, in particular those of.... Martian meteorites. In fact, remember my first comment: they will just increase the concentration of....kerogen in the meteorites.
I knew about the results of experiments conducted by colleagues with beam of heavy ions (accelerator Ganil in France) on various types of carbonaceous materials, while using fluencies that correspond to the cosmic rays exposure ages of meteorites. We concluded that we are well protected from panspermia, because all bugs end up as kerogen. But what's about the fate of the carbon of...kerogen??
Optimistic conclusions were inferred from the irradiation of various forms of life that survived after being exposed on board of the space station. But these exposures were much smaller than those suffered by a chunk of Martian meteorite. So they are irrelevant.
About Carbon on Mars, I just increased the difficulty of answering your question, when I realized that I have to know about the date of the impact of the last planetary embryo that accreted the planet.
Remember that English is not my native language, and my text is not corrected.
Hi and thanks for reigniting this conversation. :)
Chondrites, having experienced various thermal and aqueous histories, record modified kerogen-like IOM in ways similar to the modification of kerogen buried on Earth (e.g. thermal maturation). I'm still perplexed by the formation of this IOM in chondrites. Parent body modification of IOM is at least very convincing.
Just by landing a rover on the surface of Mars, you can find meteorites on the martian surface. Therefore, the surface of Mars should have been delivered a lot of this abiotic kerogen-like material from early planetesimals such as carbonaceous chondrites and unequilibrated ordinary chondrites...
It's a challenge to me understanding the abundances of different types of organic material that contributed to the surface of Mars from an extraterrestrial origin rather than e.g. a volcanic one. If Mars' carbonaceous inventory on it's surface is abiotic in origin, considering it's peppered surface by impacts, it seems important to try and think about the exogenous delivery of carbonaceous material by early planetesimals as well as the more homogenous sprinkle of micro meteorites, IDPs etc to its surface. It would be interesting to gain a sense of whether organic abundances vary systematically in certain parts of the freshest craters on Mars, e.g the centre Vs it's edges. If they are not in the state that they were in the impactors (e.g. chondrites), we have to consider other processes on Mars that altered the delivered organic material. The kerogen-like IOM far outweighs the soluble stuff in chondrites. Where is this stuff as well?
It does seem to be an easier challenge deciphering the history of something that we have discovered or know to exist, although there are plenty of things that we havn't/hadn't discovered but still wonder/wondered about. Take the discovery of Neptune for instance or currently, dark matter. So there's a major point for understanding things that we have yet to discover, and from a scientific perspective, making testable hypotheses about them. Furthermore, hasn't SAM detected organic material? There's a few papers out there. Where did this organic carbon come from? There is organic material in some martian meteorites. Where did this organic material come from?
I guess that's what makes it so wonderful. :)
Even if we found some shale like material on Mars, how would we differentiate it from Kerogen-like material in chondrites i.e. IOM? This also needs to be ironed out.
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