Direct measurement of riverine particulate organic carbon age structure
Rosenheim, Brad E.
MetadataShow full item record
Carbon cycling studies focusing on transport and transformation of terrigenous carbon sources toward marine sedimentary sinks necessitate separation of particulate organic carbon (OC) derived from many different sources and integrated by river systems. Much progress has been made on isolating and characterizing young biologically-formed OC that is still chemically intact, however quantification and characterization of old, refractory rock-bound OC has remained troublesome. Quantification of both endmembers of riverine OC is important to constrain exchanges linking biologic and geologic carbon cycles and regulating atmospheric CO2 and O2. Here, we constrain petrogenic OC proportions in suspended sediment from the headwaters of the Ganges River in Nepal through direct measurement using ramped pyrolysis radiocarbon analysis. The unique results apportion the biospheric and petrogenic fractions of bulk particulate OC and characterize biospheric OC residence time. Compared to the same treatment of POC from the lower Mississippi-Atchafalaya River system, contrast in age spectra of the Ganges tributary samples illustrates the difference between small mountainous river systems and large integrative ones in terms of the global carbon cycle.
Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 39 (2012): L19703, doi:10.1029/2012GL052883.
Showing items related by title, author, creator and subject.
Dilling, Lisa; Doney, Scott C.; Edmonds, Jae; Gurney, Kevin R.; Harriss, Robert; Schimel, David S.; Stephens, Britton B.; Stokes, Gerald (Annual Reviews, 2003-08-14)Agriculture and industrial development have led to inadvertent changes in the natural carbon cycle. As a consequence, concentrations of carbon dioxide and other greenhouse gases have increased in the atmosphere and may ...
Carbon isotope (δ13Ccarb) heterogeneity in deep-water Cambro-Ordovician carbonates, western Newfoundland Pruss, Sara; Castagno, Katherine; FIke, David; Hurtgen, Matthew (2015-10-09)Carbonates of western Newfoundland span the Cambro-Ordovician interval and preserve a record of slope-basinal deposition in the Cow Head Group near Cow Head. This unit consists of conglomerates and ribbon and laminated ...
Schefuß, Enno; Eglinton, Timothy I.; Spencer-Jones, Charlotte L.; Rullkötter, Jürgen; De Pol-Holz, Ricardo; Talbot, Helen M.; Grootes, Pieter; Schneider, Ralph R. (2016-07)The age of organic material discharged by rivers provides information about its sources and carbon cycling processes within watersheds. While elevated ages in fluvially-transported organic matter are usually explained ...