Geochemical evidence

Geochemical evidence from precipitated cal cite should be supplemented with study of the present-day processes in the vadose system above the location of the sample. 

Boyle EA, Keigwin LD (1982) Deep Circulation of the North Atlantic over the last 200,000 years geochemical evidence. Science 218 784-787... 

Bodinier, J. L., Vasseur, G., Vernieres, J., Dupuy., C. Fabries, J. (1990). Mechanisms of mantle metasomatism Geochemical evidence from the Lherz orogenic peridotite. J. 

Ravizza G, Norris RN, Blusztajn J, Aubry MP (2001) An osmium isotope excursion associated with the late Paleocene thermal maximum Evidence of intensified chemical weathering. Paleoceanogr 16 155-163 Raymo ME (1991) Geochemical evidence supporting Chamberlain, T. C., theory of glaciation. Geology 19 ... 

Selandian Rb-Sr ages of 59.6 2.8 Ma and 60.3 0.8 Ma were determined for the K1A and K19 bodies, respectively these bodies occur in the southwestern part of the field and are either barren of diamond or have the poorest diamond results within this field (Hood McCandless 2004 Fig 1). Mineralogical (e.g., amphibole, sanidine) and geochemical evidence (e.g., flatter chondrite-normalized REE pattern versus the steep profile of typical kimberlite) enticed Eccles et al. (2008) to conclude that these rocks are better referred to as hybrid kimberlite-ultrabasic rocks. 

Perez del Villar, L., Pelayo, M. etal. 1997. Miner-alogical and geochemical evidence of the migration/retention processes of U and Th in fracture fillings from the El Berrocal granitic site (Spain). Journal of Contaminant Hydrology, 26, 45 - 60. 

McSween, H. Y., Grove, T. L., Lentz, R. C. F. et al. (2001) Geochemical evidence for magmatic water within Mars from pyroxenes in the Shergotty meteorite. Nature, 409, 487-490. 

Presser, T.S. and Swain, W.C. (1990) Geochemical evidence for Se mobilization by the weathering of pyritic shale, San Joaquin Valley, California, USA. Applied Geochemistry, 5(5-6), 703-17. 

Stiiben, D Berner, Z Chandrasekharam, D. and Karmakar, J. (2003) Arsenic enrichment in groundwater of West Bengal, India geochemical evidence for mobilization of As under reducing conditions. Applied Geochemistry, 18(9), 1417-34. 

Prehistoric alteration of soil in the Lower Rhine Basin, Northwest Germany— archaeological 14C and geochemical evidence. Geoderma 136,38-50. 

Venkatesan, M. I., and Dahl, J. (1989). Organic geochemical evidence for global fires at the Cretaceous/Tertiary boundary. Nature 338,57-60. 

Downes H (2001) Formation and modification of the shallow sub-continental lithospheric mantle a review of geochemical evidence from ultramafic xenolith suites and tectonically emplaced ultramafic massifs of Western and Central Europe. J Petrol 42 233-250... 

Zachos J.C., Arthur M.A. and Dean W.E. (1989) Geochemical evidence for suppression of pelagic marine productivity at the Cretaceous/Tertiary boundary. Nature 337, 61-64. 

Hayes, J.M. (1983) Geochemical evidence bearing on the origin of aerobiosis, a speculative interpretation. In The Earth s Earliest Biosphere Its Origin and Evolution (Schopf, J.W., ed.), pp. 291-301, Princeton University Press, Princeton, NJ. 

Geochemical evidence for the origin pf australites. Geochim. cosmo-... 

Trimmer, M., NichoUs, J. C., and Deflandre, B. (2003). Anaerobic ammonium oxidation measured in sediments along the Thames Estuary, United Kingdom. Appl. Environ. Microbiol. 69, 6447—6454. Tyrrell, T., and Lucas, M. I. (2002). Geochemical evidence of denitrification in the Benguela upweUing system. Continent. Shelf Res. 22(17), 2497—2511. 

Higginson, M. J., Altabet, M. A., Murray, D. W., Murray, R. W., and Herbert, T. D. (2004). Geochemical evidence for abrupt changes in relative strength of the Arabian monsoons during a stadial/interstadial climate transition. Geochim. Cosmochim. Acta 68(19), 3807-3826. 

Geochemical evidence suggests that there were delays of several hundred million years between the rise of oxygenic photosynthesis, the oxygenation of the atmosphere, and the oxygenation of the deep ocean. Photosynthesis (evidenced by cyanobacterial microfossils and biomarkers) rose as early as 3.5 Ga (billion years before present (Schopf, 1993)) and had been sofidly established by 2.7—2.5 Ga (Brocks et al, 1999 KnoU, 1996 Schopf, 1993 Summons et al, 1999). Data from red beds, detrital mineral deposits, and sulfur isotopes indicate the rise of atmospheric oxygen around 2.4 Ga (Bekker et al, 2004 Chandler, 1980 Des Marais et al, 1992 ... 

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