Organic Geochemical Studies. I. Molecular Criteria for Hydrocarbon Genesis

McCarthy, E.D.; Calvin, Kevin

doi:10.1038/216642a0

Cited by 38 publications

(18 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Conversion of aspartate to asparagine in certain microorganisms has been shown to require ammonia and adenosine 5'-triphosphate (ATP) and to be associated with cleavage of ATP to inorganic pyrophosphate and adenosine 5'-monophosphate (11). The amide nitrogen atom of glutamine rather than the nitrogen of ammonia is utilized for asparagine synthesis in HeLa cells (12), and subsequent work (13,14) has confirmed the participation of glutamine in the synthesis in vitro of asparagine in mammalian systems. Synthesis of asparagine by preparations of Jensen sarcoma and from nutritional 533 Asparagine Synthetase Activity of Mouse Leukemias Abstract.…”

mentioning

confidence: 92%

“…The possibility of migration of organic molecules after sediment deposition and compaction has brought up in previous discussions the question whether these molecules are indeed indigenous. McCarthy and Calvin (12) have discussed the significance of the molecular structures of hydrocarbons with respect to their possible diagenetic transformations and biological or nonbiological origin. The isolation and identification of any particular molecular species is of debatable significance without the assurance that the species was laid down at the time of deposition and compaction of the sediment.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Isoprenoid Fatty Acids Isolated from the Kerogen Matrix of the Green River Formation (Eocene)

Burlingame

Simoneit

1968

Science

View full text Add to dashboard Cite

Demineralized oil shale was oxidized with chromic acid, and C(14) to C(22) isoprenoid fatty acids were isolated and identified. The major components of the branched-chain acid fraction after successive 3-, 6-, and 15-hour oxidations are C(15) and C(16) branched-chain acids; C(17), C(19) (norphytanic acid), and C(20) (phytanic acid) were obtained in lower concentration; no C(18) product was obtained. Separations were effected by column and gas-liquid chromatography, and the structures of individual components were determined by high- and low-resolution mass spectrometry.

show abstract

mentioning

confidence: 92%

mentioning

confidence: 99%

Isoprenoid Fatty Acids Isolated from the Kerogen Matrix of the Green River Formation (Eocene)

Burlingame

Simoneit

1968

Science

View full text Add to dashboard Cite

show abstract

“…The three most abundant biomarkers, loliolide, cholesterol, and phytol, are all derived from phytoplankton and represent broad phytoplankton groups [51][52][53] . Composition of the diatom assemblages and cyanobacteria in this bay are further described in Johnson et al 43 All become increasingly enriched in 13 C over the transect from high CO 2 concentrations near the seep to the control Mediterranean values.…”

Section: Discussionmentioning

confidence: 99%

“…8‰ from the seep to the control. Phytol, derived from chlorophyll-a, is found in all oxygenic photoautotrophs 53 . Terrestrial input may affect the signal of phytol but, as discussed above, there is no evidence for this here.…”

Section: Discussionmentioning

confidence: 99%

Testing algal-based pCO2 proxies at a modern CO2 seep (Vulcano, Italy)

Witkowski

Meer

Smit

et al. 2020

Sci Rep

View full text Add to dashboard Cite

Understanding long-term trends in atmospheric concentrations of carbon dioxide (pco 2) has become increasingly relevant as modern concentrations surpass recent historic trends. one method for estimating past pco 2 , the stable carbon isotopic fractionation associated with photosynthesis (Ɛ p) has shown promise over the past several decades, in particular using species-specific biomarker lipids such as alkenones. Recently, the Ɛ p of more general biomarker lipids, organic compounds derived from a multitude of species, have been applied to generate longer-spanning, more ubiquitous records than those of alkenones but the sensitivity of this proxy to changes in pco 2 has not been constrained in modern settings. Here, we test Ɛ p using a variety of general biomarkers along a transect taken from a naturally occurring marine co 2 seep in Levante Bay of the Aeolian island of Vulcano in italy. the studied general biomarkers, loliolide, cholesterol, and phytol, all show increasing depletion in 13 c over the transect from the control site towards the seep, suggesting that co 2 exerts a strong control on isotopic fractionation in natural phytoplankton communities. the strongest shift in fractionation was seen in phytol, and pco 2 estimates derived from phytol confirm the utility of this biomarker as a proxy for pco 2 reconstruction. The concentration of atmospheric carbon dioxide (pCO 2 , expressed in partial pressure µatm), as directly measured from air trapped in ice cores, has had a major influence on climate over the past 800 thousand years (ka) 1. During this period, pCO 2 and temperature oscillated together between stable bounds every 100 ka 2. In the past two centuries, the rise of pCO 2 has broken those bounds from the pre-industrial values, previously only ranging between ca. 180 to 280 µatm, to the 410 µatm of today 3. This rapid rise in pCO 2 causes concern that climate, particularly temperature, will accordingly change. In order to better understand how changes may occur, reconstructing longer trends in pCO 2 over the geologic record could offer context for evaluating the direction and magnitude of climate change. Many proxies have been developed for reconstructing past pCO 2 and applied with mixed success over the past several decades 4. One method for studying past pCO 2 makes use of the stable carbon isotopic fractionation due to CO 2-fixation (Ɛ p), where biomass of photoautotrophs becomes increasingly depleted in 13 C as pCO 2 increases due to kinetic discrimination by the CO 2-fixing enzyme Rubisco 5-7. Ɛ p can be derived from the δ 13 C of photoautotrophic biomass, recorded in sedimentary organic matter, and the δ 13 C of inorganic CO 2 derived from the carbonate in the shells of planktonic foraminifera 8. Although pCO 2 has been shown to be one of the dominant physiological control on the δ 13 C of photoautotrophic biomass 9 , studies on Ɛ p in algae have shown that other factors may influence this value, primarily growth rate 10 and cell size and shape 11 , as well as minor influences such as light, and ...

show abstract

“…Isoprenoid alkanes are compounds of particular geochemical interest belonging to this class, since they are usually taken as fairly conclusive evidence of the biological origin of the hydrocarbon material extracted from an ancient sediment [109,113,114]. An unambiguous identification is thus of great importance, especially in the case of very old rocks.…”

Section: Normal Hydrocarbonsmentioning

confidence: 99%