Direct measurement of riverine particulate organic carbon age structure

摘要: [1] Carbon cycling studies focusing on transport and transformation of terrigenous carbon sources toward marine sedimentary sinks necessitate separation particulate organic (OC) derived from many different integrated by river systems. Much progress has been made isolating characterizing young biologically-formed OC that is still chemically intact, however quantification characterization old, refractory rock-bound remained troublesome. Quantification both endmembers riverine important to constrain exchanges linking biologic geologic cycles regulating atmospheric CO2 O2. Here, we petrogenic proportions in suspended sediment the headwaters Ganges River Nepal through direct measurement using ramped pyrolysis radiocarbon analysis. The unique results apportion biospheric fractions bulk characterize residence time. Compared same treatment POC lower Mississippi-Atchafalaya system, contrast age spectra tributary samples illustrates difference between small mountainous systems large integrative ones terms global cycle.