{"id":10409,"date":"2016-12-16T12:18:23","date_gmt":"2016-12-16T20:18:23","guid":{"rendered":"https:\/\/www.darkenergybiosphere.org\/?post_type=project_data&#038;p=10409"},"modified":"2016-12-16T12:18:23","modified_gmt":"2016-12-16T20:18:23","slug":"phosphorus-cycling-in-ridge-flank-sediments","status":"publish","type":"data_project","link":"https:\/\/www.darkenergybiosphere.org\/data_project\/phosphorus-cycling-in-ridge-flank-sediments\/","title":{"rendered":"Phosphorus cycling in ridge-flank sediments"},"content":{"rendered":"<p>Phosphorus (P) plays a key role in fueling life, including microbial life in the deep subseafloor environment, which is estimated to contain up to 1% of Earth\u2019s total biomass. These microorganisms play a significant role in controlling the chemical composition of the deep-ocean and atmosphere on geological timescales by selectively degrading organic matter through metabolic respiration. Consequently, understanding P geochemistry in subseafloor sediments is important, since P bioavailability can impact microbial activity. This project focuses on characterizing and quantifying the main reservoirs of solid-phase P in open ocean sediments, and uses stable oxygen isotopes in phosphate as a proxy for studying P cycling in deep sea sediments. The sediment samples used in this study were collected during the International Ocean Discovery Program (IODP) Expedition 336 to North Pond, a sediment-filled depression in the oceanic crust located on the western flank of the Mid-Atlantic Ridge, and during IODP Expedition 327 to the Juan de Fuca Ridge flank.\u00a0 We characterized solid-phase P reservoirs in sediments using the SEDEX sequential extraction scheme. This method quantitatively separates five distinct sedimentary P reservoirs: (1) loosely-sorbed P; (2) ferric iron-bound P; (3) authigenic carbonate fluorapatite + biogenic apatite + CaCO3-associated P; (4) detrital apatite and (5) refractory organic P. The separation of these P-bearing phases is based on the reactivity of each targeted phase to a particular extractant solution. We then conducted stable phosphatic oxygen isotope ratio analyses on a subset of those samples from borehole U1382B at North Pond (X336) to further constrain the biotic and abiotic factors influencing P cycling at this site.<\/p>\n","protected":false},"template":"","_links":{"self":[{"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/data_projects\/10409"}],"collection":[{"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/data_projects"}],"about":[{"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/types\/data_project"}],"wp:attachment":[{"href":"https:\/\/www.darkenergybiosphere.org\/wp-json\/wp\/v2\/media?parent=10409"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}