Global 3‐D Simulations of the Triple Oxygen Isotope Signature Δ
            17
            O in Atmospheric CO
            2

In the Miocene of the northern Apennines, a widespread carbonate precipitation was induced by the expulsion of methane-rich fluids. Numerous outcrops of carbonate masses share sedimentological, textural and geochemical features with present-day gas hydrate-associated carbonates. We hypothesize the contribution of paleo-gas hydrate destabilization on the base of the heavy oxygen isotope signature, the presence of distinctive sedimentary features (breccias, pervasive nonsystematic fractures, and soft sediment deformation), the close association between seep carbonates and sedimentary instability, and the huge dimensions of seep carbonates bearing brecciated structures.

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Oxygen isotope signature of Pi regeneration from organic compounds by phosphomonoesterases and photooxidation

Geochimica et Cosmochimica Acta ◽

10.1016/j.gca.2006.04.036 ◽

2006 ◽

Vol 70 (15) ◽

pp. 3957-3969 ◽

Cited By ~ 80

Author(s):

Y. Liang ◽

R.E. Blake

Keyword(s):

Oxygen Isotope ◽

Organic Compounds ◽

Isotope Signature ◽

Pi Regeneration

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Geochemical and Oxygen Isotope Signature of Sea-Floor Alteration Associated with a Polydeformed and Highly Metamorphosed Massive Sulfide Deposit, Ruostesuo, Central Finland

Economic Geology ◽

10.2113/98.3.535 ◽

2003 ◽

Vol 98 (3) ◽

pp. 535-556 ◽

Cited By ~ 3

Author(s):

M. D. Roberts

Keyword(s):

Oxygen Isotope ◽

Massive Sulfide ◽

Sulfide Deposit ◽

Massive Sulfide Deposit ◽

Sea Floor ◽

Isotope Signature

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The Benthonic foraminiferal response to changing substrate in Cenomanian (Cretaceous) rhythms induced by orbitally-forced surface water productivity

Journal of Micropalaeontology ◽

10.1144/jm.11.2.107 ◽

1992 ◽

Vol 11 (2) ◽

pp. 107-111 ◽

Cited By ~ 10

Author(s):

Paul N. Leary ◽

Malcolm B. Hart

Keyword(s):

Surface Water ◽

Oxygen Isotope ◽

Water Productivity ◽

Systematic Variation ◽

Orbital Forcing ◽

Foraminiferal Assemblage ◽

Isotope Signature ◽

Southern England ◽

The Mean ◽

Enhanced Surface

Abstract. The rhythmic sedimentation of Cenomanian age in Southern England is most likely the result of orbital forcing (precession). The oxygen isotope signature and the foraminiferal assemblage from detailed (5cms), continuous samples through three of these rhythms show systematic variation with lithology. The marls yield cooler surface water palaeotemepratures with high benthonic diversities, low planktonic:benthonic ratios and the planktonic assemblage contains around 5–10% rotaliporids. The chalks yield warmer surface water palaeotemperatures with low benthonic diversities, high planktonic:benthonic ratios and the planktonic assemblage contains 1–4% rotaliporids. This indicates that the chalks represent enhanced surface water productivity induced by increased surface water palaeotemperature. Three groups (Tritaxia pyramidata Reuss, Gavelinella spp. and Lenticulina spp.) together form over 90% of the benthonic assemblage. Each >250μm assemblage exhibits a systematic variation in size with lithology. The mean sizes are smallest and the maximum sizes of the moving populations decrease in the middle of the chalks. This may be a consequence of three different factors, (a) during intervals of increased productivity (chalks) the benthonic foraminifera may be achieving gametogenesis at an enhanced rate due to the increased availability of food supplies, or (b) the increased productivity may cause dwarfism within the micro-benthos, or (c) the effects of current winnowing prior to burial. The relative merits of each of these possibilities are discussed.

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