The Red Pine Shale (RPS; ~1120m), uppermost formation of the Neoproterozoic Uinta Mountain Group, Utah, is an organic-rich sedimentary succession that represents marine deltaic systems delivering mature sediment from the east and immature sediment from the north. Multiple data sets suggest regional climate and sea-level changes associated with changing organic carbon burial rates. Six facies identified represent wave-, tidal-, and river-influenced parts of the distal prodelta to delta front. The shale facies is interpreted as distal prodeltaic deposition in a marine environment. The concretion facies is interpreted as prodeltaic deposition to distal prodelta. The shale-sandstone facies represents suspension settling with dilute density currents in a proximal prodelta to delta front environment. The slump fold facies was deposited on the proximal prodelta or delta front. The sandstone facies represents deposition on the delta front and shows marine- and river- influences. The pebbly sandstone facies is representative of a delta front environment. C-isotope values from this shale range from -29.46 / to -16.91 / PDB and TOC from 0.04% to 5.91%. Combined H/C, TOC, and local-regional isotopic correlations suggest that these values are representative of C-isotope composition of Neoproterozoic seawater. The composite C-isotope curve for the RPS is less negative values near the base, followed by a long decline to a thick interval of homogeneous lower values. Petrographic analyses reveal immature arkosic sandstone and mature quartz arenite populations. Detrital zircon data show an Archean population from the Wyoming Craton to the north and a mixed Proterozoic/Archean population from the east-southeast. Measured sections show north to south delta progradation with a proximal source to the north and a mature sediment source to the east. The composite section shows one low-order regressive cycle and ~11 high-order cycles. There is a relationship between C-isotope values, shale geochemistry, and lithostratigraphy. Less negative C-isotope values correspond with increased kaolinite and facies indicating higher sea-level. These relationships are seen in the correlative Chuar Group, Arizona, and a similar model is suggested for their origin: humid climate, high organic carbon burial rates, and high sea-level. This paper meets the requirements to revise the RPS as a formalized unit in accordance with the Stratigraphic Code guidelines.

Agriculture contributes significantly to national and global greenhouse gas (GHG) inventories but there is considerable control over management decisions and changes in production methods could lead to a significant reduction and possible mitigation of emissions from the sector. For example, conservation tillage practices have been suggested as a method of sequestering atmospheric carbon dioxide (CO2), however, many questions remain unanswered regarding the short-term efficacy of the production method and knowledge gaps exist regarding possible interactions with essential nutrient cycles, and the production of non-CO2 GHGs, such as nitrous oxide (N2O). Between autumn 2005 and 2009, a micrometeorological flux system was used to determine net CO2 and N2O exchange from an annual cropping system situated on clay soil in the Red River Valley of southern Manitoba. Four plots (4-ha each) were independently evaluated and planted to corn in 2006 and faba bean in 2007; in 2008, two spring wheat plots were monitored. As well, during the non-growing season in 2006-2007 following corn harvest, a second micrometeorological flux system capable of simultaneously measuring stable C isotopologue (12CO2 and 13CO2) fluxes was operated at the site. Tillage intensity and crop management practices were examined for their influence on GHG emissions. Significant inter-annual variability in CO2 and N2O fluxes as a function of crop and related management activities was observed. Tillage intensity did not affect GHG emissions from the site. After accounting for harvest removals, the net ecosystem C budgets were 510 (source), 3140 (source) and -480 (sink) kg C/ha/year for the three respective crop years, summing to a three-year loss of 3170 kg C/ha. Stable C isotope flux measurements during the non-growing season following corn harvest indicated that approximately 70 % and 20 – 30 % of the total respiration flux originated from crop residue C during the fall of 2006 and spring of 2007, respectively. The N2O emissions at the site further exacerbated the net global warming potential of this annual agroecosystem.

Agriculture contributes significantly to national and global greenhouse gas (GHG) inventories but there is considerable control over management decisions and changes in production methods could lead to a significant reduction and possible mitigation of emissions from the sector. For example, conservation tillage practices have been suggested as a method of sequestering atmospheric carbon dioxide (CO2), however, many questions remain unanswered regarding the short-term efficacy of the production method and knowledge gaps exist regarding possible interactions with essential nutrient cycles, and the production of non-CO2 GHGs, such as nitrous oxide (N2O). Between autumn 2005 and 2009, a micrometeorological flux system was used to determine net CO2 and N2O exchange from an annual cropping system situated on clay soil in the Red River Valley of southern Manitoba. Four plots (4-ha each) were independently evaluated and planted to corn in 2006 and faba bean in 2007; in 2008, two spring wheat plots were monitored. As well, during the non-growing season in 2006-2007 following corn harvest, a second micrometeorological flux system capable of simultaneously measuring stable C isotopologue (12CO2 and 13CO2) fluxes was operated at the site. Tillage intensity and crop management practices were examined for their influence on GHG emissions. Significant inter-annual variability in CO2 and N2O fluxes as a function of crop and related management activities was observed. Tillage intensity did not affect GHG emissions from the site. After accounting for harvest removals, the net ecosystem C budgets were 510 (source), 3140 (source) and -480 (sink) kg C/ha/year for the three respective crop years, summing to a three-year loss of 3170 kg C/ha. Stable C isotope flux measurements during the non-growing season following corn harvest indicated that approximately 70 % and 20 – 30 % of the total respiration flux originated from crop residue C during the fall of 2006 and spring of 2007, respectively. The N2O emissions at the site further exacerbated the net global warming potential of this annual agroecosystem.