<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">McCarthy, M. D.</style></author><author><style face="normal" font="default" size="100%">Beaupre, S. R.</style></author><author><style face="normal" font="default" size="100%">Walker, B. D.</style></author><author><style face="normal" font="default" size="100%">Voparil, I.</style></author><author><style face="normal" font="default" size="100%">Guilderson, T. P.</style></author><author><style face="normal" font="default" size="100%">Druffel, E. R. M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Chemosynthetic origin of C-14-depleted dissolved organic matter in a ridge-flank hydrothermal system</style></title><secondary-title><style face="normal" font="default" size="100%">Nature Geoscience</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Nat. Geosci.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">abundance</style></keyword><keyword><style  face="normal" font="default" size="100%">c-13</style></keyword><keyword><style  face="normal" font="default" size="100%">Content Type: Biblio</style></keyword><keyword><style  face="normal" font="default" size="100%">crust</style></keyword><keyword><style  face="normal" font="default" size="100%">deep subseafloor sediments</style></keyword><keyword><style  face="normal" font="default" size="100%">environments</style></keyword><keyword><style  face="normal" font="default" size="100%">fluids</style></keyword><keyword><style  face="normal" font="default" size="100%">isotopic fractionation</style></keyword><keyword><style  face="normal" font="default" size="100%">microbial life</style></keyword><keyword><style  face="normal" font="default" size="100%">north pacific-ocean</style></keyword><keyword><style  face="normal" font="default" size="100%">stable carbon</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Jan</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://000285498600014</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1</style></number><volume><style face="normal" font="default" size="100%">4</style></volume><pages><style face="normal" font="default" size="100%">32-36</style></pages><isbn><style face="normal" font="default" size="100%">1752-0894</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Hydrothermal fluids circulate through extensive areas of the upper oceanic crust. Most hydrothermal circulation occurs on ridge flanks(1,2), where low-temperature fluids flow through porous basalts. These fluids contain variable levels of dissolved organic carbon, but the source and composition of this carbon are uncertain. Here, we report Delta C-14 and delta C-13 measurements of dissolved organic carbon in ridge-flank and on-axis hydrothermal fluids sampled from the Juan de Fuca Ridge. Dissolved organic carbon from two independent ridge-flank sites was characterized by low delta C-13 and Delta C-14 values. The delta C-13 values ranged from -26 to -35 parts per thousand, and were consistent with a chemoautotrophic origin. The C-14 ages of the dissolved organic carbon ranged from 11,800 to 14,400 years before present, revealing that the carbon was around three times older than dissolved organics in the deep ocean. The Delta C-14 values of the ridge-flank dissolved organic matter also corresponded closely to those of dissolved inorganic carbon in the same fluid samples. Taken together, the data suggest that chemosynthetic crustal microbial communities synthesize dissolved organic carbon from inorganic carbon in ridge-flank fluids. We suggest that ridge-flank circulation may support an indigenous biosphere extensive enough to export substantial fixed carbon, with distinct isotopic and probably compositional character, to the overlying ocean.&lt;/p&gt;</style></abstract><accession-num><style face="normal" font="default" size="100%">ISI:000285498600014</style></accession-num><notes><style face="normal" font="default" size="100%">&lt;p&gt;ISI Document Delivery No.: 697FSCited References:      BACH W, 2003, GEOCHIM COSMOCHIM AC, V67, P3871, DOI     10.1016/S0016-7037(03)00304-1     BEAUPRE SR, 2007, LIMNOL OCEANOGR-METH, V5, P174     BENNER R, 1997, MAR CHEM, V57, P243     COMITA PB, 1984, NATURE, V307, P450     COWEN JP, 2003, SCIENCE, V299, P120     DHONDT S, 2004, SCIENCE, V306, P2216, DOI 10.1126/science.1101155     DRUFFEL ERM, 1992, J GEOPHYS RES, V97, P639, DOI 10.1029/92JC01511     FISHER AT, 2003, NATURE, V421, P618, DOI 10.1038/nature01352     GUO LD, 1996, LIMNOL OCEANOGR, V41, P1242     HAYES JM, 1999, CHEM GEOL, V161, P103     HEDGES JI, 1992, GLOBAL BIOGEOCHEMICA, V39, P67     HERNES PJ, 2002, DEEP-SEA RES PT I, V49, P2119     HERNES PJ, 2003, J GEOPHYS RES-OCEANS, V108, ARTN 3291     HEUER VB, 2009, GEOCHIM COSMOCHIM AC, V73, P3323, DOI     10.1016/j.gca.2009.03.001     HOUSE CH, 2003, ORG GEOCHEM, V34, P345     HUBER JA, 2006, ENVIRON MICROBIOL, V8, P88, DOI     10.1111/j.1462-2920.2005.00872.x     JOHNSON HP, 2003, EARTH PLANET SC LETT, V216, P565, DOI     10.1016/S0012-821X(03)00545-4     JOHNSON HP, 2003, EOS T AM GEOPHYS UN, V84, P109     KEIL RG, 1994, GEOCHIM COSMOCHIM AC, V58, P879     LANG SQ, 2006, GEOCHIM COSMOCHIM AC, V70, P3830, DOI     10.1016/j.gca.2006.04.031     LANG SQ, 2010, GEOCHIM COSMOCHIM AC, V74, P941, DOI     10.1016/j.gca.2009.10.045     LILLEY MD, 1993, NATURE, V364, P45     LOH AN, 2004, NATURE, V430, P877, DOI 10.1038/nature02780     MCCOLLOM TM, 2007, CHEM REV, V107, P382, DOI 10.1021/cr0503660     MOTTL MJ, 2003, ENERGY MASS TRANSFER, P271     PROSKUROWSKIA G, 2004, A, V225, P53     SANTELLI CM, 2008, NATURE, V453, P653, DOI 10.1038/nature06899     TAYLOR GT, 2001, LIMNOL OCEANOGR, V46, P148     WALKER BD, 2008, MAR CHEM, V108, P123, DOI 10.1016/j.marchem.2007.11.002     WILLIAMS PM, 1987, NATURE, V330, P246McCarthy, Matthew D. Beaupre, Steven R. Walker, Brett D. Voparil, Ian Guilderson, Thomas P. Druffel, Ellen R. M.Nature publishing groupNew york&lt;/p&gt;</style></notes><auth-address><style face="normal" font="default" size="100%">&lt;p&gt;[McCarthy, Matthew D.; Walker, Brett D.] Univ Calif Santa Cruz, Dept Ocean Sci, Santa Cruz, CA 95064 USA. [Beaupre, Steven R.] Woods Hole Oceanog Inst, Dept Geol &amp;amp; Geophys, Woods Hole, MA 02543 USA. [Voparil, Ian] Shell Int Explorat &amp;amp; Prod, NL-2596 The Hague, Netherlands. [Guilderson, Thomas P.] Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Santa Cruz, CA 95064 USA. [Guilderson, Thomas P.] Univ Calif Santa Cruz, Dept Ocean Sci, Santa Cruz, CA 95064 USA. [Guilderson, Thomas P.] Univ Calif Santa Cruz, Inst Marine Sci, Santa Cruz, CA 95064 USA. [Druffel, Ellen R. M.] Univ Calif Irvine, Dept EarthSyst Sci, Irvine, CA 92697 USA.McCarthy, MD, Univ Calif Santa Cruz, Dept Ocean Sci, 1156 High St, Santa Cruz, CA 95064 USA.mccarthy@pmc.ucsc.edu&lt;/p&gt;</style></auth-address></record></records></xml>