柿竹园钨、锡多金属矿田成矿流体地球化学研究

南岭地区是我国最重要的有色、稀有金属矿产资源产地，尤以钨、锡等金属的大规模爆发式成矿而闻名于世，已发现了一大批大型、超大型稀有和有色金属矿床。近年来的研究发现，这些矿床的形成很可能与华南地区中生代发生的大规模地壳拉张、岩石圈伸展减薄以及壳―幔相互作用的独特地质背景有关。本论文以与千里山花岗岩体密切相关的柿竹园钨锡钼铋铅锌矿田（以下简称柿竹园矿田）为研究对象，运用流体包裹体、稳定同位素和稀有气体同位素地球化学等方法，对其成矿流体的物理化学特征、来源及演化进行了研究，并在此基础上探讨了千里山花岗岩体与柿竹园矿田间的成因联系和矿田的成矿作用机制，获得以下主要研究成果： 1. 利用流体包裹体岩相学、显微测温学以及包裹体成分的激光拉曼分析技术，揭示了矿田中柿竹园钨锡钼铋矿床成矿流体的性质和演化特征。研究表明柿竹园钨锡钼铋矿床成矿流体为中高温、中高盐度H2O-NaCl-CaCl2-CO2-CH4-H2S-F体系。成矿流体的均一温度、盐度、密度和压力变化范围均较大，成矿早期夕卡岩阶段和云英岩阶段的流体具有较高的均一温度（239～477℃）和盐度（0～39.08 wt% NaCl eq.），云英岩网脉夕卡岩阶段和后期石英萤石脉阶段均一温度和盐度逐渐降低（分别为160～450℃，1.23～16.53 wt% NaCl eq.和156～340℃，1.23～4.49 wt% NaCl eq.）。夕卡岩阶段发生了流体沸腾作用。流体密度为0.37～1.12 g/cm3，主要集中在0.7～0.9 g/cm3；压力为10～820 bar，一般小于800 bar。野鸡尾锡铜矿床的成矿流体属于中高温度、中等盐度的H2O-NaCl-CaCl2-CO2-CH4-H2S-F型体系，柴山铅锌矿床属中温中等盐度H2O-NaCl-CaCl2-CO2-F体系，其均一温度和压力变化范围也较大。 2. 通过分析主要矿化类型矿石矿物及脉石矿物的C、H、O、S等稳定同位素特征，揭示了柿竹园矿田成矿流体的来源，并对C、O同位素的组成进行了CO2去气、流体混合和水―岩反应的理论模拟。研究表明矿田成矿流体主要来自千里山花岗岩浆，并有大气降水加入。水―岩反应在成矿过程中起着重要作用。 3. 对矿田不同矿化类型矿石矿物黄铁矿、黄铜矿、毒砂、方铅矿等进行了He、Ar同位素研究，其中3He/4He值为0.059～1.662 Ra（Ra为空气的3He/4He值，1 Ra＝1.39×10-6），40Ar/36Ar值为289.8～1071.8，表明矿田成矿流体具有壳-幔两端员混合的特征。壳源组分为获得了大量地壳放射成因4He，但获得放射成因40Ar*较少的经过地下循环的低温饱和大气水。而幔源组分来自千里山花岗岩浆流体，表明千里山花岗岩并非传统的S型花岗岩。 4. 在总结前人研究成果的基础上，结合本次研究，建立了柿竹园矿田成矿作用模式：中生代华南岩石圈发生拉张、伸展作用，地幔物质上涌，发生壳幔相互作用，形成千里山花岗岩浆。花岗岩浆充分分异演化形成富含挥发分和成矿元素的成矿流体，与泥盆系碳酸盐岩发生反应而沉淀成矿。成矿过程有大气降水的加入，并发生了流体沸腾作用。

新疆萨瓦亚尔顿（穆龙套型）金矿床物质来源与成矿机制

萨瓦亚尔顿金矿床是我国90年代金矿地质工作者在新疆西南天山地区寻找穆龙套型金矿床的一个突破。本文通过对新疆萨瓦亚尔顿金矿床的矿石矿物组成、稀土元素地球化学、同位素地球化学以及流体包裹体特征等方面的研究，探讨了萨瓦亚尔顿金矿床地质地球化学特征、金的赋存状态及成矿流体特征、成矿流体来源，提出了该矿床的成矿机制，取得如下认识：1．流体包裹体岩相学研究表明，萨瓦亚尔顿金矿床的流体包裹体主要为V＋L相和富CO_2相包裹体，前者为NaCl-H_2O体系，后者主要有L_(CO2)、L_(CO2)+L、V_(CO2)+L、V_(CO2)＋L_(CO2)＋L相包裹体；并发现极少量含子晶流体包裹体。2．通过流体包裹体显微测温学研究，表明金矿床的均一温度成矿早阶段为270～320 ℃，成矿主阶段为170～250 ℃，成矿晚阶段为110-250 ℃，呈逐渐降低的趋势，低温成矿作用明显。3．单个流体包裹体的激光拉曼分析表明，流体包裹体中除含有CO2之外，还含有一定量的N_2和CH_4。4.成矿物质来源的复杂性。萨瓦亚尔顿金矿床矿石中微量元素组成、稀土配分模式大都反映了成矿金属物质主要来自赋矿地层本身。金属硫化物的6345：-3.4‰～+2.6‰，西南天山地区下古生界地层中广泛存在各类火山岩可能是该矿床的主要硫源，部分可能有深部物质的参与。矿石中主要脉石矿物石英和菱铁矿 中包裹体水的氢氧同位素组成为δD = -72％～-62‰，δ~(18)O ＝ -11.6‰～＋5.4‰。成矿流体主要为大气降水补给的地下卤水，并有少量岩浆水的混合。5．Ar-Ar同位素地球化学研究表明，萨瓦亚尔顿金矿床的主要成矿时代为印支晚期，210 Ma。6. 对矿石中的流体包裹体进行了温度、压力、成分、pH、含盐度等的分要的，并系统的进行了矿床形成时的物理化学条件的理论计算，基中包括EH、PH、f_(O_2)、f_(S_2)等及金在矿液运移中的搬运形式。指出减压过程或伴生沸腾的减压过程，是矿床形成过程中矿质卸载的基本机制，此外，酸蚀变过程（如绢云母化等）中由于H~+的消耗促进了溶液中pH值的升高；含高炭质的围岩，降低了矿液的氧逸度以及含矿热液与地表下渗冷水的混合等诸多因素，则是矿订形成的辅助机制。

Syngas production using an oxygen-permeating membrane reactor with cofeed of methane and carbon dioxide

CH4-CO2-O-2 reforming to syngas in a never Ba0.5Sr0.5Co0.8Fe0.2O3.delta oxygen-permeable membrane reactor using LiLaNiO/gamma-Al2O3 as catalyst was successfully reported. Excellent reaction performance was achieved with around 92% methane conversion efficiency, 95% CO2 conversion rate, and nearly 8.5mL/min.cm(2) oxygen permeation flux. In contrast to the oxygen permeation model with the presence of large concentration of CO2 (under such condition the oxygen permeation flux deteriorates with time), the oxygen permeation flux is really stable under the CH4CO2-O-2 reforming condition.

Catalytic steam reforming of ethanol to produce hydrogen and acetone

Steam reforming of ethanol over CuO/CeO2 was studied. Acetaldehyde and hydrogen were mainly produced at 260degreesC. At 380degreesC, acetone was the main product, and 2 mol of hydrogen was produced from 1 mol of ethanol. The formation of hydrogen accompanied by the production of acetone was considered to proceed through the following, consecutive reactions: dehydrogenation of ethanol to acetaldehyde. aldol condensation of the acetaldehyde, and the reaction of the aldol with the lattice oxygen [O(s)] on the catalyst to form a surface intermediate, followed by its dehydrogenation and decarboxylation. The overall reaction was expressed by2C(2)H(5)OH + H2O --> CH3COCH3 + CO2 + 4H(2). Ceria played an important role as an oxygen supplier. The addition of MgO to CuO/CeO2 resulted in the production of hydrogen at lower temperatures by accelerating aldol condensation. (C) 2004 Elsevier B.V. All rights reserved.

Particle export during a bloom of Emiliania huxleyi in the North-West European continental margin

Coccolithophores, the dominant pelagic calcifiers in the oceans, play a key role in the marine carbon cycle through calcification, primary production and carbon export, the main drivers of the biological CO2 pump. In May 2002 a cruise was conducted on the outer shelf of the North-West European continental margin, from the north Bay of Biscay to the Celtic Sea (47.0 degrees-50.5 degrees N, 5.0 degrees-11.0 degrees W), an area where massive blooms of Emiliania huxleyi are observed annually. Biogeochemical variables including primary production, calcification, partial pressure of CO2 (pCO(2)), chlorophyll-a (Chl-a), particle load, particulate organic and inorganic carbon (POC, PIC) and Th-234, were measured in surface waters to assess particle dynamic and carbon export in relation to the development of a coccolithophore bloom. We observed a marked northward decrease in Chl-a concentration and calcification rates: the bloom exhibited lower values and may be less well developed in the Goban Spur area. The export fluxes of POC and PIC from the top 80 m, determined using the ratios of POC and PIC to Th-234 of particles, ranged from 81 to 323 mg C m(-2) d(-1) and from 30 to 84 mg C m(-2) d(-1), respectively. The highest fluxes were observed in waters presenting a well-developed coccolithophore bloom, as shown by high reflectance of surface waters. This experiment confirms that the occurrence of coccolithophores promotes efficient export of organic and inorganic carbon on the North-West European margin.

On the complexity of the water-gas shift reaction mechanism over a Pt/CeO2 catalyst: Effect of the temperature on the reactivity of formate surface species studied by operando DRIFT during isotopic transient at chemical steady-state

The present report investigates the role of formate species as potential reaction intermediates for the WGS reaction (CO + H2O -> CO2 + H-2) over a Pt-CeO2 catalyst. A combination of operando techniques, i.e., in situ diffuse reflectance FT-IR (DRIFT) spectroscopy and mass spectrometry (MS) during steady-state isotopic transient kinetic analysis (SSITKA), was used to relate the exchange of the reaction product CO2 to that of surface formate species. The data presented here suggest that a switchover from a non-formate to a formate-based mechanism could take place over a very narrow temperature range (as low as 60 K) over our Pt-CeO2 catalyst. This observation clearly stresses the need to avoid extrapolating conclusions to the case of results obtained under even slightly different experimental conditions. The occurrence of a low-temperature mechanism, possibly redox or Mars van Krevelen-like, that deactivates above 473 K because of ceria over-reduction is suggested as a possible explanation for the switchover, similarly to the case of the CO-NO reaction over Cu, I'd and Rh-CeZrOx (see Kaspar and co-workers [1-3]). (c) 2006 Elsevier B.V. All rights reserved.

On the need to use steady-state or operando techniques to investigate reaction mechanisms: An in situ DRIFTS and SSITKA-based study example

The nature of the surface species formed at the surface of 2 wt.% Pt/CeO2 catalyst during the forward water-gas-shift (WGS, CO + H2O -> CO2 + H-2) and the reverse reaction (RWGS) were essentially identical. More, the surface concentration of formate, carbonate and carbonyl species was similar in each case. The presence of well-resolved IR bands allowed an unequivocal relative quantitative analysis of each species, avoiding the use of the carboxylate stretching region (1600-1200 cm(-1)). However, the quantitative analysis in the case of an isotopic study was complicated due to the overlapping of the various isotope bands, yet this problem could be overcome by integrating the high-wavenumber part of the bands. The reactivity of the surface species formed under RWGS conditions was followed under two different gaseous streams. Firstly, the reactivity of these intermediates were followed under an inert gas (i.e., At), in which case carbonates were essentially stable and less reactive than formates. Secondly, the reactivity of the same surface species was followed when switching to the corresponding C-13-labelled feed (i.e., (CO2)-C-13 + H-2), in which case carbonates were exchanged significantly faster than formates. While carbonates species have been reported as reaction intermediate under reaction conditions, the increased stability or surface poisoning by these carbonates in the absence of reaction mixture was highlighted. Ultimately, this work re-emphasises the need to use steady-state conditions if the true operando reactivity of the adsorbates and structure of the solid are to be determined. (c) 2005 Elsevier B.V. All rights reserved.

Solventless continuous flow homogeneous hydroformylation of 1-octene

The hydroformylation of 1-octene under continuous flow conditions is described. The system involves dissolving the catalyst, made in situ from [ Rh(acac)(CO)(2)] (acacH = 2,4- pentanedione) and [RMIM][TPPMS] ( RMIM = 1-propyl (Pr), 1-pentyl (Pn) or 1-octyl (O)-3-methyl imidazolium, TPPMS = Ph2P(3-C6H4SO3)), in a mixture of nonanal and 1-octene and passing the substrate, 1-octene, together with CO and H-2 through the system dissolved in supercritical CO2 (scCO(2)). [PrMIM][TPPMS] is poorly soluble in the medium so heavy rhodium leaching (as complexes not containing phosphine) occurs in the early part of the reaction. [PnMIM][ PPMS] affords good rates at relatively low catalyst loadings and relatively low overall pressure (125 bar) with rhodium losses <1 ppm, but the catalyst precipitates at higher catalyst loadings, leading to lower reaction rates. [OMIM][ TPPMS] is the most soluble ligand and promotes high reaction rates, although preliminary experiments suggested that rhodium leaching was high at 5-10 ppm. Optimisation aimed at balancing flows so that the level within the reactor remained constant involved a reactor set up based around a reactor fitted with a sight glass and sparging stirrer with the CO2 being fed by a cooled head HPLC pump, 1-octene by a standard HPLC pump and CO/H-2 through a mass flow controller. The pressure was controlled by a back pressure regulator. Using this set up, [OMIM][ TPPMS] as the ligand and a total pressure of 140 bar, it was possible to control the level within the reactor and obtain a turnover frequency of ca. 180 h(-1). Rhodium losses in the optimised system were 100 ppb. Transport studies showed that 1-octene is preferentially transported over the aldehydes at all pressures, although the difference in mol fraction in the mobile phase was less at lower pressures. Nonanal in the mobile phase suppresses the extraction of 1-octene to some extent, so it is better to operate at high conversion and low pressure to optimise the extraction of the products relative to the substrate. CO and H2 in the mobile phase also suppress the extraction effciency by as much as 80%.

Cultivo masivo de microalgas en Biorreactores verticales

El cultivo masivo de microalgas en biorreactores presenta una alta tasa de productividad frente a los cultivos abiertos, esta ventaja, aunada a determinados factores ambientales, se relaciona directamente con la cantidad y calidad de biomasa algal obtenida como producto final en el proceso de cultivo. El presente trabajo centró sus investigaciones en la evaluación de los parámetros físicos del ambiente (temperatura e intensidad lumínica), así como, físico-químicos (temperatura, pH y CO2) en la capacidad de carga de los cultivos. La investigación se desarrolló en el invernadero del Área de Biotecnología Acuática, del Instituto del Mar del Perú, dentro del marco del Proyecto IMARPE-EEP-FINCyT, denominado “Determinación de la Biomasa Microalgal potencialmente acumuladora de lípidos para la obtención de combustibles”, según contrato Nº025-FINCYT-PIBAP-2007. Los cultivos se realizaron empleando la cepa IMP-LBA-009, correspondiente a la microalga Nannochloropsis spp., con un flujo de producción semi-continuo por 48 horas, en un periodo de 6 meses, entre julio a diciembre, Bajo condiciones de iluminación (22,003.93 Lux.m-2.seg-1 ±10640.94), temperatura ambiental (31.7°C±2.8), temperatura de cultivo (25.7°C±1.2), CO2 (0.2 g.L-1) y pH (8.36 ±0.18); los resultados mostraron que la producción de biomasa húmeda fue 0.48g.L-1, equivalente a 0.13 g.L-1 de biomasa seca, durante los meses de octubre y noviembre, con una razón de conversión BS/BH del 28%. El impacto lumino-térmico, al interior del invernadero, favoreció el incremento progresivo de la concentración celular del cultivo en biorreactores, por ende, la producción de biomasa húmeda y seca, durante el periodo de trabajo.

Syntheses of two new 1D and 3D networks of Cu(II) and Co(II) using malonate and urotropine as bridging ligands: Crystal structures and magnetic studies

Two new metal-organic based polymeric complexes, [Cu-4(O2CCH2CO2)(4)(L)].7H(2)O (1) and [CO2(O2CCH2CO2)(2)(L)].2H(2)O (2) [L = hexamethylenetetramine (urotropine)], have been synthesized and characterized by X-ray crystal structure determination and magnetic studies. Complex 1 is a 1D coordination polymer comprising a carboxylato, bridged Cu-4 moiety linked by a tetradentate bridging urotropine. Complex 2 is a 3D coordination polymer made of pseudo-two-dimensional layers of Co(II) ions linked by malonate anions in syn-anticonformation which are bridged by bidentate urotropine in trans fashion, Complex 1 crystallizes in the orthothombic system, space group Pmmn, with a = 14,80(2) Angstrom, b = 14.54(2) Angstrom, c = 7.325(10) Angstrom, beta = 90degrees, and Z = 4. Complex 2 crystallizes in the orthorhombic system, space group Imm2, a = 7.584(11) Angstrom, b = 15.80(2) Angstrom, c = 6.939(13) Angstrom, beta = 90.10degrees(1), and Z = 4. Variable temperature (300-2 K) magnetic behavior reveals the existence of ferro- and antiferromagnetic interactions in 1 and only antiferromagnetic interactions in 2. The best fitted parameters for complex 1 are J = 13.5 cm(-1), J = -18.1 cm(-1), and g = 2.14 considering only intra-Cu-4 interactions through carboxylate and urotropine pathways. In case of complex 2, the fit of the magnetic data considering intralayer interaction through carboxylate pathway as well as interlayer interaction via urotropine pathway gave no satisfactory result at this moment using any model known due to considerable orbital contribution of Co(II) ions to the magnetic moment and its complicated structure. Assuming isolated Co(II) ions (without any coupling, J = 0) the shape of the chi(M)T curve fits well with experimental data except at very low temperatures.

Pressure-dependent product distribution of citral hydrogenation over micelle-hosted Pd and Ru nanoparticles in supercritical carbon dioxide

In situ synthesis and testing of Ru and Pd nanoparticles as catalysts in the presence of ammonium perfluorohydrocarbo-carboxylate surfactant in supercritical carbon dioxide were carried out in a stainless steel batch reactor at 40 degrees C over a pressure range of 80-150 bar CO2/H-2. Direct Visualization of the formation of a supercritical phase at above 80 bar, followed by the formation of homogeneous microemulsions containing dispersed Ru nanoparticles and Pd nanoparticles in scCO(2) at above 95-100 bar, were conducted through a sapphire window reactor using a W-0 (molar water to surfactant ratio) of 30. The synthesised RU and Pd nanoparticles showed interesting product distributions in the selective hydrogenation of organic molecules, depending critically oil the density and polarity of the fluid (which ill turn depends on the pressure applied). Thus, selective hydrogenation of the citral molecule, which contains three reducible groups (aldehydes and double bonds at the 23 and 6,7 positions), is feasible Lis a chemical probe. (c) 2005 Elsevier Inc. All rights reserved.

Micelle-hosted palladium nanoparticles catalyze citral molecule hydrogenation in supercritical carbon dioxide

A new approach of employing metal particles in micelles for the hydrogenation of organic molecules in the presence of fluorinated surfactant and water in supercritical carbon dioxide has very recently been introduced. This is allegedly to deliver many advantages for carrying out catalysis including the use of supercritical carbon dioxide (scCO(2)) as a greener solvent. Following this preliminary account, the present work aims to provide direct visual evidence on the formation of metal microemulsions and to investigate whether metal located in the soft micellar assemblies could affect reaction selectivity. Synthesis of Pd nanoparticles in perfluorohydrocarboxylate anionic micelles in scCO(2) is therefore carried out in a stainless steel batch reactor at 40 degreesC and in a 150 bar CO2/H-2 mixture. Homogeneous dispersion of the microemulsion containing Pd nanoparticles in scCO(2) is observed through a sapphire window reactor at W-0 ratios (molar water-to-surfactant ratios) ranging from 2 to 30. It is also evidenced that the use of micelle assemblies as new metal catalyst nanocarriers could indeed exert a great influence on product selectivity. The hydrogenation of a citral molecule that contains three reducible groups (aldehyde, double bonds at the 2,3-position and the 6,7-position) is studied. An unusually high selectivity toward citronellal (a high regioselectivity toward the reduction of the 2,3-unsaturation) is observed in supercritical carbon dioxide. On the other hand, when the catalysis is carried out in the conventional liquid or vapor phase over the same reaction time, total hydrogenation of the two double bonds is achieved. It is thought that the high kinetic reluctance for double bond hydrogenation of the citral molecule at the hydrophobic end (the 6,7-position) is due to the unique micelle environment that is in close proximity to the metal surface in supercritical carbon dioxide that guides a head-on attack of the molecule toward the core metal particle.

Genotypic variation in photosynthetic and leaf traits in cocoa

The photosynthetic characteristics of eight contrasting cocoa genotypes were studied with the aim of examining genotypic variation in maximum (light-saturated) photosynthetic rates, light-response curve parameters and water use efficiency. Photosynthetic traits were derived from single leaf gas exchange measurements using a portable infra-red gas analyser. All measurements were conducted in a common greenhouse environment. Significant variation was observed in light-saturated photosynthesis ranging from 3.4 to 5.7 µmol CO2 m-2 s-1 for the clones IMC 47 and SCA 6, respectively. Furthermore, analyses of photosynthetic light response curves indicated genotypic differences in light saturation point and quantum efficiency (i.e. the efficiency of light use). Stomatal conductance was a significant factor underlying genotypic differences in assimilation. Genotypic variation was also observed in a number of leaf traits, including specific leaf area (the ratio of leaf area to leaf weight), chlorophyll concentration and nitrogen content. There was a positive correlation between leaf nitrogen per unit area and light-saturated photosynthesis. Water use efficiency, defined as the ratio of photosynthetic rate to transpiration rate, also varied significantly between clones (ranging from 3.1 mmol mol-1 H2O for the clone IMC 47 to 4.2 mmol mol-1 H2O for the clone ICS 1). Water use efficiency was a negative function of specific leaf area, suggesting that low specific leaf area might be a useful criterion for selection for increased water use efficiency. It is concluded that both variation in water use efficiency and the photosynthetic response to light have the potential to be exploited in breeding programmes.

The proportionality of global warming to cumulative carbon emissions

The global temperature response to increasing atmospheric CO2 is often quantified by metrics such as equilibrium climate sensitivity and transient climate response1. These approaches, however, do not account for carbon cycle feedbacks and therefore do not fully represent the net response of the Earth system to anthropogenic CO2 emissions. Climate–carbon modelling experiments have shown that: (1) the warming per unit CO2 emitted does not depend on the background CO2 concentration2; (2) the total allowable emissions for climate stabilization do not depend on the timing of those emissions3, 4, 5; and (3) the temperature response to a pulse of CO2 is approximately constant on timescales of decades to centuries3, 6, 7, 8. Here we generalize these results and show that the carbon–climate response (CCR), defined as the ratio of temperature change to cumulative carbon emissions, is approximately independent of both the atmospheric CO2 concentration and its rate of change on these timescales. From observational constraints, we estimate CCR to be in the range 1.0–2.1 °C per trillion tonnes of carbon (Tt C) emitted (5th to 95th percentiles), consistent with twenty-first-century CCR values simulated by climate–carbon models. Uncertainty in land-use CO2 emissions and aerosol forcing, however, means that higher observationally constrained values cannot be excluded. The CCR, when evaluated from climate–carbon models under idealized conditions, represents a simple yet robust metric for comparing models, which aggregates both climate feedbacks and carbon cycle feedbacks. CCR is also likely to be a useful concept for climate change mitigation and policy; by combining the uncertainties associated with climate sensitivity, carbon sinks and climate–carbon feedbacks into a single quantity, the CCR allows CO2-induced global mean temperature change to be inferred directly from cumulative carbon emissions.

Effect of cattle urine addition on the surface emissions and subsurface concentrations of greenhouse gases in a UK peat grassland

Grazing systems represent a substantial percentage of the global anthropogenic flux of nitrous oxide (N2O) as a result of nitrogen addition to the soil. The pool of available carbon that is added to the soil from livestock excreta also provides substrate for the production of carbon dioxide (CO2) and methane (CH4) by soil microorganisms. A study into the production and emission of CO2, CH4 and N2O from cattle urine amended pasture was carried out on the Somerset Levels and Moors, UK over a three-month period. Urine-amended plots (50 g N m−2) were compared to control plots to which only water (12 mg N m−2) was applied. CO2 emission peaked at 5200 mg CO2 m−2 d−1 directly after application. CH4 flux decreased to −2000 μg CH4 m−2 d−1 two days after application; however, net CH4 flux was positive from urine treated plots and negative from control plots. N2O emission peaked at 88 mg N2O m−2 d−1 12 days after application. Subsurface CH4 and N2O concentrations were higher in the urine treated plots than the controls. There was no effect of treatment on subsurface CO2 concentrations. Subsurface N2O peaked at 500 ppm 12 days after and 1200 ppm 56 days after application. Subsurface NO3− concentration peaked at approximately 300 mg N kg dry soil−1 12 days after application. Results indicate that denitrification is the key driver for N2O release in peatlands and that this production is strongly related to rainfall events and water-table movement. N2O production at depth continued long after emissions were detected at the surface. Further understanding of the interaction between subsurface gas concentrations, surface emissions and soil hydrological conditions is required to successfully predict greenhouse gas production and emission.