Analytical reproducibility and abundances of major oxides, total carbon, organic carbon, and sedimentary components of Miocene and early Pliocene cuttings from the Point Conception Deep Stratigraphic Test well, OCS-CAL 78-164 no. 1, offshore Santa Maria basin, Southern California

The Santa Maria Basin in southern California is a lowland bounded on the south by the Santa Ynez River fault and on the northeast by the Little Pine‐Foxen Canyon‐Santa Maria River faults. It contains Neogene sedimentary rocks which rest unconformably on a basement of Cretaceous and older clastic rocks. Analysis of over 4 000 gravity stations obtained from the Defense Mapping Agency suggests that the Bouguer anomaly contains a short‐wavelength component arising from a variable‐density contrast between the basin’s Neogene units and the Cretaceous basement. A three‐dimensional inversion of the short‐wavelength component (constrained by wells drilled to basement) yields a structure model of the basement and the average density of the overlying sediments, assuming that the basement does not contain large‐scale density variations. The density anomalies modeled in the Neogene sediments, showing higher densities in the basin troughs, can be related to diagenetic changes in the silica facies of the Monterey and Sisquoc formations. The basement structure model shows the basin as composed of parallel ridges and troughs, trending west‐northwest and bounded by steep slopes interpreted as fault scarps. The basin is bounded on the west by a north‐south trending slope which may also represent a fault scarp.

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Effects of grazing intensity on organic carbon stock characteristics in Stipa breviflora desert steppe vegetation soil systems

The Rangeland Journal ◽

10.1071/rj16007 ◽

2017 ◽

Vol 39 (2) ◽

pp. 169 ◽

Cited By ~ 7

Author(s):

Heyun Wang ◽

Zhi Dong ◽

Jianying Guo ◽

Hongli Li ◽

Jinrong Li ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Aboveground Biomass ◽

Carbon Stock ◽

Belowground Biomass ◽

Total Carbon ◽

Desert Steppe ◽

Light Fraction Organic Carbon ◽

Grazing Intensities ◽

Organic Carbon Stock

Grassland ecosystems, an important component of the terrestrial environment, play an essential role in the global carbon cycle and balance. We considered four different grazing intensities on a Stipa breviflora desert steppe: heavy grazing (HG), moderate grazing (MG), light grazing (LG), and an area fenced to exclude livestock grazing as the Control (CK). The analyses of the aboveground biomass, litter, belowground biomass, soil organic carbon and soil light fraction organic carbon were utilised to study the organic carbon stock characteristics in the S. breviflora desert steppe under different grazing intensities. This is important to reveal the mechanisms of grazing impact on carbon processes in the desert steppe, and can provide a theoretical basis for conservation and utilisation of grassland resources. Results showed that the carbon stock was 11.98–44.51 g m–2 in aboveground biomass, 10.43–36.12 g m–2 in plant litters, and 502.30–804.31 g m–2 in belowground biomass (0–40 cm). It was significantly higher in CK than in MG and HG. The carbon stock at 0–40-cm soil depth was 7817.43–9694.16 g m–2, and it was significantly higher in LG than in CK and HG. The total carbon stock in the vegetation-soil system was 8342.14–10494.80 g m–2 under different grazing intensities, with the largest value in LG, followed by MG, CK, and HG. About 90.54–93.71% of the total carbon in grassland ecosystem was reserved in soil. The LG and MG intensities were beneficial to the accumulation of soil organic carbon stock. The soil light fraction organic carbon stock was 484.20–654.62 g m–2 and was the highest under LG intensity. The LG and MG intensities were beneficial for soil nutrient accumulation in the desert steppe.

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Fossil and non-fossil source contributions to atmospheric carbonaceous aerosols during extreme spring grassland fires in Eastern Europe

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-5513-2016 ◽

2016 ◽

Vol 16 (9) ◽

pp. 5513-5529 ◽

Cited By ~ 21

Author(s):

Vidmantas Ulevicius ◽

Steigvilė Byčenkienė ◽

Carlo Bozzetti ◽

Athanasia Vlachou ◽

Kristina Plauškaitė ◽

...

Keyword(s):

Organic Carbon ◽

Biomass Burning ◽

Nitrogen Isotopes ◽

Early Spring ◽

Total Carbon ◽

Carbonaceous Aerosols ◽

Pmf Model ◽

Source Contributions ◽

The Baltic ◽

The Impact

Abstract. In early spring the Baltic region is frequently affected by high-pollution events due to biomass burning in that area. Here we present a comprehensive study to investigate the impact of biomass/grass burning (BB) on the evolution and composition of aerosol in Preila, Lithuania, during springtime open fires. Non-refractory submicron particulate matter (NR-PM1) was measured by an Aerodyne aerosol chemical speciation monitor (ACSM) and a source apportionment with the multilinear engine (ME-2) running the positive matrix factorization (PMF) model was applied to the organic aerosol fraction to investigate the impact of biomass/grass burning. Satellite observations over regions of biomass burning activity supported the results and identification of air mass transport to the area of investigation. Sharp increases in biomass burning tracers, such as levoglucosan up to 683 ng m−3 and black carbon (BC) up to 17 µg m−3 were observed during this period. A further separation between fossil and non-fossil primary and secondary contributions was obtained by coupling ACSM PMF results and radiocarbon (14C) measurements of the elemental (EC) and organic (OC) carbon fractions. Non-fossil organic carbon (OCnf) was the dominant fraction of PM1, with the primary (POCnf) and secondary (SOCnf) fractions contributing 26–44 % and 13–23 % to the total carbon (TC), respectively. 5–8 % of the TC had a primary fossil origin (POCf), whereas the contribution of fossil secondary organic carbon (SOCf) was 4–13 %. Non-fossil EC (ECnf) and fossil EC (ECf) ranged from 13–24 and 7–13 %, respectively. Isotope ratios of stable carbon and nitrogen isotopes were used to distinguish aerosol particles associated with solid and liquid fossil fuel burning.

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Australian net (1950s–1990) soil organic carbon erosion: implications for CO<sub>2</sub> emission and land–atmosphere modelling

Biogeosciences ◽

10.5194/bg-11-5235-2014 ◽

2014 ◽

Vol 11 (18) ◽

pp. 5235-5244 ◽

Cited By ~ 19

Author(s):

A. Chappell ◽

N. P. Webb ◽

R. A. Viscarra Rossel ◽

E. Bui

Keyword(s):

Soil Erosion ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Land Surface ◽

Total Carbon ◽

Catchment Scale ◽

European Settlement ◽

Surface Models ◽

Management Context ◽

Land Use And Management

Abstract. The debate remains unresolved about soil erosion substantially offsetting fossil fuel emissions and acting as an important source or sink of CO2. There is little historical land use and management context to this debate, which is central to Australia's recent past of European settlement, agricultural expansion and agriculturally-induced soil erosion. We use "catchment" scale (∼25 km2) estimates of 137Cs-derived net (1950s–1990) soil redistribution of all processes (wind, water and tillage) to calculate the net soil organic carbon (SOC) redistribution across Australia. We approximate the selective removal of SOC at net eroding locations and SOC enrichment of transported sediment and net depositional locations. We map net (1950s–1990) SOC redistribution across Australia and estimate erosion by all processes to be ∼4 Tg SOC yr−1, which represents a loss of ∼2% of the total carbon stock (0–10 cm) of Australia. Assuming this net SOC loss is mineralised, the flux (∼15 Tg CO2-equivalents yr−1) represents an omitted 12% of CO2-equivalent emissions from all carbon pools in Australia. Although a small source of uncertainty in the Australian carbon budget, the mass flux interacts with energy and water fluxes, and its omission from land surface models likely creates more uncertainty than has been previously recognised.

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CARBON CONTENTS AND MODELLING OF TOTAL ORGANIC CARBON FOR Pinus taeda L. FROM NATURAL REGENERATION

Revista Árvore ◽

10.1590/0100-67622016000400009 ◽

2016 ◽

Vol 40 (4) ◽

pp. 661-668 ◽

Cited By ~ 1

Author(s):

Rafael Cubas ◽

Emanuel Arnoni Costa ◽

Viviane Zaniz

Keyword(s):

Organic Carbon ◽

Total Organic Carbon ◽

Pinus Taeda ◽

Natural Regeneration ◽

Ground Level ◽

Total Carbon ◽

Forest Understory ◽

Planted Forest ◽

Pinus Taeda L ◽

Selection Of

ABSTRACT This study aimed to quantify total carbon and its compartments: roots, stems, branches, and aciculas, in order to select an estimated equation of the total organic carbon for Pinus taeda L. settled from natural regeneration in the forest understory of a planted forest in the municipality of Três Barras, SC. Data have been collected from a random selection of 96 individuals with diameter at 0.3 meters above ground level, varying from 2.5 to 19cm. The selected individuals had their dimensional variables (dendrometric and morphometric variables) measured being subsequently felled and their compartments separated, weighed and samples were collected and taken to analysis of carbon contents. Eight traditional models were tested, six arithmetic and two logarithmic, as well as a model developed by the Stepwise process, being total organic carbon the dependent variable, and dimensional variables the independent variables. The total organic carbon found was 46.7% on average, and Tukey-Kramer test indicated significant differences of carbon contents amongst compartments. In comparison with traditional equations tested, the equation adjusted by Stepwise seemed more accurate, with good fit (R2aj. = 0.931) and precision (Syx% = 18.5).

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