Investigation of the fate of nitrogen in Palaeozoic shales of the Central European Basin

Kinetic nitrogen isotope fractionation associated with thermal decomposition of NH3: Experimental results and potential applications to trace the origin of N2 in natural gas and hydrothermal systems

“…The investigation of thermal evolution of organic matter and silicate minerals using non-isothermal pyrolysis techniques have reported large variations of d 15 N (up to 15&) with the lowest value of À12& for the instantaneous N 2 (Krooss et al, 2005(Krooss et al, , 2006Jurisch and Krooss, 2008). It is noteworthy that the cumulative isotopic values of the N 2 released from the shale samples up to 1200°C in those pyrolysis experiments (Krooss et al, 2005(Krooss et al, , 2006Jurisch and Krooss, 2008) are significantly lower (at least 4&) than the d 15 N of the bulk N in the shales (Mingram et al, 2005), suggesting that some 15 N-enriched N phase was missing somewhere (maybe a remaining phase in the rocks and/or gaseous NH 3 that was not examined). Integrated with our experimental results, this implies that the production of 15 N-depletd N 2 in the pyrolysis experiments might relate to partial decomposition of NH 3 if it is the intermediate phase in those experiments.…”

Estimation of nitrogen-to-carbon ratios of organics and carbon materials at the submicrometer scale

“…This is not exactly true for samples exhibiting a higher degree of atomic organization as they may exhibit EXAFS structures (i.e., oscillations above the K-edges) over an energy range of about 500 eV [42]. In addition, nitrogen overestimation may occur when the investigated organics are closely associated with clay minerals that may host nitrogen as ammonia within interlayer spaces [43,44]. Acquiring Xray absorption spectra over the entire C + N energy range thus appears important in order to identify these clays minerals based on their potassium (K L-edge region -295-305 eV) and calcium (Ca L-edge region -340-360 eV) contents.…”

Source rocks and petroleum systems in the Hungarian part of the Pannonian Basin: The potential for shale gas and shale oil plays

“…These gases have been sourced by the kerogen and the ammonium-bearing minerals in the re-heated source rocks of the Mesozoic basement. It is likely that the gases remaining in those source rocks are also rich in nitrogen (Krooss et al, 2005(Krooss et al, , 2006Jurisch et al, 2007;Jurisch and Krooss, 2008).…”