Early Eocene benthic carbon isotope data of ODP Site 208-1263

The early Eocene represents a time of major changes in the global carbon cycle and fluctuations in global temperatures on both short- and long-time scales. These perturbations of the ocean-atmosphere system have been linked to orbital forcing and changes in net organic carbon burial, but accurate age models are required to disentangle the various forcing mechanisms and assess causal relationships. Discrepancies between the employed astrochronological and radioisotopic dating techniques prevent the construction of a robust time frame between ~49 and ~54 Ma. Here we present an astronomically tuned age model for this critical time period based on a new high-resolution benthic d13C record of ODP Site 1263, SE Atlantic. First, we assess three possible tuning options to the stable long-eccentricity cycle (405-kyr), starting from Eocene Thermal Maximum 2 (ETM2, ~54 Ma). Next we compare our record to the existing bulk carbonate d13C record from the equatorial Atlantic (Demerara Rise, ODP Site 1258) to evaluate our three initial age models and compare them with alternative age models previously established for this site. Finally, we refine our preferred age model by expanding our tuning to the 100-kyr eccentricity cycle of the La2010d solution. This solution appears to accurately reflect the long- and short-term eccentricity-related patterns in our benthic d13C record of ODP Site 1263 back to at least 52 Ma and possibly to 54 Ma. Our time scale not only aims to provide a new detailed age model for this period, but it may also serve to enhance our understanding of the response of the climate system to orbital forcing during this super greenhouse period as well as trends in its background state.

Layer description, carbon and nitrogen content and stable isotope record of bulk sedimentary organic matter from Laguna Potrok Aike

An investigation of stable isotope (d13C TOC and d15N TN) and elemental parameters (TOC, TN contents and TOC/TN ratios) of bulk organic matter (<200 µm) from sediment cores recovered from the Patagonian lake Laguna Potrok Aike (Argentina) in the framework of the ICDP deep drilling project PASADO provided insights into past changes in lake primary productivity and environmental conditions in South Patagonia throughout the last Glacial-Interglacial transition. Stratigraphically constrained cluster analyses of all proxy parameters suggest four main phases. From ca 26,100 to 17,300 cal. years BP, lacustrine phytoplankton was presumably the predominant organic matter source in an aquatic environment with low primary productivity rates. At around 17,300 cal. years BP, abrupt and distinct shifts of isotopic and elemental values indicate that the lacustrine system underwent a rapid reorganization. Lake primary productivity (phytoplankton and aquatic macrophytes) shows higher levels albeit with large variations during most of the deglaciation until 13,000 cal. years BP. The main causes for this development can be seen in improved growing conditions for primary producers because of deglacial warming in combination with expedient availability of nutrients and likely calm wind conditions. After 13,000 cal. years BP, decreased d13C TOC values, TOC, TN contents and TOC/TN ratios indicate that the lake approached a new state with reduced primary productivity probably induced by unfavourable growing conditions for primary producers like strengthened winds and reduced nutrient availability. The steady increase in d15N TN values presumably suggests limitation of nitrate supply for growth of primary producers resulting from a nutrient shortage after the preceding phase with high productivity. Nitrate limitation and consequent decreased lacustrine primary productivity continued into the early Holocene (10,970-8400 cal. years BP) as reflected by isotopic and elemental values.

Stable carbon and oxygen isotope analyses of Neogloboquadrina pachyderma

Detailed records of the carbon and oxygen isotopic ratios of Neogloboquadrina pachyderma are compared between nine high-latitude sediment cores, from the Northern and Southern Hemispheres, covering the last 140000 yrs. The strong analogies between the delta13C records permit to define a delta13C stratigraphic scale, with three clear cut transitions simultaneous with the oxygen isotopic transitions 6/5 (125 kyrs.), 5/4 (65 kyrs.), and 2/1 (13 kyrs.). The delta13C records of N. pachyderma in the high-latitude cores, which follow the changes in delta13C of the surface water TCO2 near areas of deep water formation present trends similar to the benthic foraminifera delta13C records in cores V19-30 and M12-392, although amplitudes of the isotopic shifts are different. This implies that a large part of the observed variations represents global changes in the carbon distribution between biosphere and ocean. The 13C/12C ratios of N. pachyderma in the North Atlantic cores display larger regional variations at 18 kyrs. B.P. than at present. To explain these differences, we have plotted the 18 kyrs. B.P. delta13C values of N. pachyderma from 17 cores distributed N of 40°N. Comparison with published surface water temperature distribution at 18 kyrs. B.P. indicates that a strong divergent cyclonic cell, centered approximatively 55°N and 15°W, was active during most of the last ice-age maximum. This hydrology, analogous to the present Weddell Sea, explains the published evidences of bottom water formation, if located on the northern flank of the gyre, and the strong polar front on the southern flank, probable location of intermediate water formation.

Pliocene-Pleistocene carbon isotope record of foraminifera from DSDP Site 89-586

Oceanographic changes in the western equatorial Pacific during the past 6 m.y. are inferred from carbon isotopic analyses of planktonic and benthic foraminifers from Ontong Java Plateau (DSDP Site 586). Sample spacing is 1.5 m (ca. 35,000-75,000 yr). An overall trend of d13C toward lighter values is evident for the last 5 m.y. in all four foraminiferal taxa analyzed (G. sacculifer, Pulleniatina, P. wuellerstorfi, and O. umbonatus). This trend is interpreted as an enrichment of the global ocean with 12C, because of the addition of carbon from organic carbon reservoirs (or lack of removal of carbon to such reservoirs), as a consequence of an overall drop in sea level. Differences between shallow- and deep-water d13C decrease slightly during this time interval, suggesting a moderate drop in productivity. This drop is not sufficient to explain the drop in sedimentation rate, however, much of which apparently must be ascribed to winnowing effects. A marked convergence in the d13C values of planktonic taxa exists within the last 2 m.y. We propose that this convergence indicates nutrient depletion in thermocline waters, caused by the vigorous removal of phosphate in marginal upwelling regions, or by the stripping of intermediate waters in their source regions. No large shifts are seen in the carbon isotope record of the last 6 m.y., in contrast to the oxygen isotope record. Some indication of cyclicity is present, with a period between 0.5 and 1.0 m.y. (especially in the earlier portion of the record).

(Table 1) Organic carbon and radiogenic isotopes analysis of DSDP Hole 22-218 sediments

Modern erosion of the Himalaya, the world's largest mountain range, transfers huge dissolved and particulate loads to the ocean. It plays an important role in the long-term global carbon cycle, mostly through enhanced organic carbon burial in the Bengal Fan. To understand the role of past Himalayan erosion, the influence of changing climate and tectonic on erosion must be determined. Here we use a 12 Myr sedimentary record from the distal Bengal Fan (Deep Sea Drilling Project Site 218) to reconstruct the Mio-Pliocene history of Himalayan erosion. We use carbon stable isotopes (d13C) of bulk organic matter as paleo-environmental proxy and stratigraphic tool. Multi-isotopic - Sr, Nd and Os - data are used as proxies for the source of the sediments deposited in the Bengal Fan over time. d13C values of bulk organic matter shift dramatically towards less depleted values, revealing the widespread Late Miocene (ca. 7.4 Ma) expansion of C4 plants in the basin. Sr, Nd and Os isotopic compositions indicate a rather stable erosion pattern in the Himalaya range during the past 12 Myr. This supports the existence of a strong connection between the southern Tibetan plateau and the Bengal Fan. The tectonic evolution of the Himalaya range and Southern Tibet seems to have been unable to produce large re-organisation of the drainage system. Moreover, our data do not suggest a rapid change of the altitude of the southern Tibetan plateau during the past 12 Myr. Variations in Sr and Nd isotopic compositions around the late Miocene expansion of C4 plants are suggestive of a relative increase in the erosion of High Himalaya Crystalline rock (i.e. a simultaneous reduction of both Transhimalayan batholiths and Lesser Himalaya relative contributions). This could be related to an increase in aridity as suggested by the ecological and sedimentological changes at that time. A reversed trend in Sr and Nd isotopic compositions is observed at the Plio-Pleistocene transition that is likely related to higher precipitation and the development of glaciers in the Himalaya. These almost synchronous moderate changes in erosion pattern and climate changes during the late Miocene and at the Plio-Pleistocene transition support the notion of a dominant control of climate on Himalayan erosion during this time period. However, stable erosion regime during the Pleistocene is suggestive of a limited influence of the glacier development on Himalayan erosion.

Total organic carbon (TOC) on ground bulk and carbonate-free sediment samples of ODP Hole 151-911A

A multiproxy analysis of Hole 911A (Ocean Drilling Program (ODP) Leg 151) drilled on the Yermak Plateau (eastern Arctic Ocean) is used to investigate the behaviour of the Svalbard/Barents Sea ice sheet (SBIS) during late Pliocene and early Pleistocene (~3.0-1.7 Ma) climate changes. Contemporary with the 'Mid-Pliocene (~3 Ma) global warmth' (MPGW), a warmer period lasting ~300 kyr with seasonally ice-free conditions in the marginal eastern Arctic Ocean is assumed to be an important regional moisture source, and possibly one decisive trigger for intensification of the Northern Hemisphere glaciation in the Svalbard/Barents Sea area at ~2.7 Ma. An abrupt pulse of ice-rafted debris (IRD) to the Yermak Plateau at ~2.7 Ma reflects distinct melting of sediment-laden icebergs derived from the SBIS and may indicate the protruding advance of the ice sheet onto the outer shelf. Spectral analysis of the total organic carbon (TOC) record being predominantly of terrigenous/fossil-reworked origin indicates SBIS and possibly Scandinavian Ice Sheet response to incoming solar radiation at obliquity and precession periodicities. The strong variance in frequencies near the 41 kyr obliquity cycle between 2.7 and 1.7 Ma indicates, for the first time in the Arctic Ocean, a close relationship of SBIS growth and decay patterns to the Earth's orbital obliquity amplitudes, which dominated global ice volume variations during late Pliocene/early Pleistocene climate changes.

Treatment of petroleum refinery, petrochemical, and combined industrial-municipal wastewaters with activated carbon : literature review /

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Problems of physics in the ion source /

"The Y-12 Plant of the Clinton Engineer Works was operated by the Tennessee Eastman Corporation under Contract No. W-7401-eng-23 from Januaury 1943 until May 4, 1947, at which time operations were taken over by Carbide and Carbon Chemicals Corporation for the U.S. Atomic Energy Commission under Contract No. W-7405-eng-26"--Page 2 of cover.

Carbon credit trading in Brazil: an overview of a new business sector

This article discusses the Carbon Credit Trading Market in Brazil and opportunities for technological development and innovation related. The international trade in carbon credits becomes a source of opportunities for developing countries because of the Clean Development Mechanism. Committed to reduce polluting levels from 2008 to 2012, and ahead, industrialized countries started to seek ecological solutions internally or compensatory actions such as buying carbon credits from low-emission countries. This strategy brought up a brand-new industrial sector that still requires productive structures and a solid international commercialization system. This is a qualitative study, based on documentary research, referring to the Brazilian territory. The data obtained point out a set of efforts such as researching and developing products and processes environment friendly. Other findings indicate opportunities to expand Green Economy Sector through supporting a set of newborn firms such as waste management and recycling, in addition to other actions that reinforce sustainable development opportunities to the country and, at the end, to the world.