TY  - JOUR
A1  - Abdalla, H.
A1  - Adam, R.
A1  - Aharonian, Felix A.
A1  - Benkhali, F. Ait
A1  - Angüner, Ekrem Oǧuzhan
A1  - Arcaro, C.
A1  - Armand, C.
A1  - Armstrong, T.
A1  - Ashkar, H.
A1  - Backes, M.
A1  - Baghmanyan, V.
A1  - Martins, V. Barbosa
A1  - Barnacka, A.
A1  - Barnard, M.
A1  - Becherini, Y.
A1  - Berge, D.
A1  - Bernlohr, K.
A1  - Bi, B.
A1  - Bottcher, M.
A1  - Boisson, C.
A1  - Bolmont, J.
A1  - de Lavergne, M. de Bony
A1  - Bordas, Pol
A1  - Breuhaus, M.
A1  - Brun, F.
A1  - Brun, P.
A1  - Bryan, M.
A1  - Buchele, M.
A1  - Bulik, T.
A1  - Bylund, T.
A1  - Caroff, S.
A1  - Carosi, A.
A1  - Casanova, Sabrina
A1  - Chand, T.
A1  - Chandra, S.
A1  - Chen, A.
A1  - Cotter, G.
A1  - Curylo, M.
A1  - Mbarubucyeye, J. Damascene
A1  - Davids, I. D.
A1  - Davies, J.
A1  - Deil, C.
A1  - Devin, J.
A1  - deWilt, P.
A1  - Dirson, L.
A1  - Djannati-Atai, A.
A1  - Dmytriiev, A.
A1  - Donath, A.
A1  - Doroshenko, V.
A1  - Duffy, C.
A1  - Dyks, J.
A1  - Egberts, Kathrin
A1  - Eichhorn, F.
A1  - Einecke, S.
A1  - Emery, G.
A1  - Ernenwein, J. -P.
A1  - Feijen, K.
A1  - Fegan, S.
A1  - Fiasson, A.
A1  - de Clairfontaine, G. Fichet
A1  - Fontaine, G.
A1  - Funk, S.
A1  - Fussling, Matthias
A1  - Gabici, S.
A1  - Gallant, Y. A.
A1  - Giavitto, G.
A1  - Giunti, L.
A1  - Glawion, D.
A1  - Glicenstein, J. F.
A1  - Gottschall, D.
A1  - Grondin, M. -H.
A1  - Hahn, J.
A1  - Haupt, M.
A1  - Hermann, G.
A1  - Hinton, J. A.
A1  - Hofmann, W.
A1  - Hoischen, Clemens
A1  - Holch, T. L.
A1  - Holler, M.
A1  - Horbe, M.
A1  - Horns, D.
A1  - Huber, D.
A1  - Jamrozy, M.
A1  - Jankowsky, D.
A1  - Jankowsky, F.
A1  - Jardin-Blicq, A.
A1  - Joshi, V.
A1  - Jung-Richardt, I.
A1  - Kasai, E.
A1  - Kastendieck, M. A.
A1  - Katarzynski, K.
A1  - Katz, U.
A1  - Khangulyan, D.
A1  - Khelifi, B.
A1  - Klepser, S.
A1  - Kluzniak, W.
A1  - Komin, Nu.
A1  - Konno, R.
A1  - Kosack, K.
A1  - Kostunin, D.
A1  - Kreter, M.
A1  - Lamanna, G.
A1  - Lemiere, A.
A1  - Lemoine-Goumard, M.
A1  - Lenain, J. -P.
A1  - Levy, C.
A1  - Lohse, T.
A1  - Lypova, I.
A1  - Mackey, J.
A1  - Majumdar, J.
A1  - Malyshev, D.
A1  - Malyshev, D.
A1  - Marandon, V.
A1  - Marchegiani, P.
A1  - Marcowith, Alexandre
A1  - Mares, A.
A1  - Marti-Devesa, G.
A1  - Marx, R.
A1  - Maurin, G.
A1  - Meintjes, P. J.
A1  - Meyer, M.
A1  - Mitchell, A.
A1  - Moderski, R.
A1  - Mohamed, M.
A1  - Mohrmann, L.
A1  - Montanari, A.
A1  - Moore, C.
A1  - Morris, P.
A1  - Moulin, Emmanuel
A1  - Muller, J.
A1  - Murach, T.
A1  - Nakashima, K.
A1  - Nayerhoda, A.
A1  - de Naurois, M.
A1  - Ndiyavala, H.
A1  - Niederwanger, F.
A1  - Niemiec, J.
A1  - Oakes, L.
A1  - O'Brien, Patrick
A1  - Odaka, H.
A1  - Ohm, S.
A1  - Olivera-Nieto, L.
A1  - Wilhelmi, E. de Ona
A1  - Ostrowski, M.
A1  - Oya, I.
A1  - Panter, M.
A1  - Panny, S.
A1  - Parsons, R. D.
A1  - Peron, G.
A1  - Peyaud, B.
A1  - Piel, Q.
A1  - Pita, S.
A1  - Poireau, V.
A1  - Noel, A. Priyana
A1  - Prokhorov, D. A.
A1  - Prokoph, H.
A1  - Puhlhofer, G.
A1  - Punch, M.
A1  - Quirrenbach, A.
A1  - Raab, S.
A1  - Rauth, R.
A1  - Reichherzer, P.
A1  - Reimer, A.
A1  - Reimer, O.
A1  - Remy, Q.
A1  - Renaud, M.
A1  - Rieger, F.
A1  - Rinchiuso, L.
A1  - Romoli, C.
A1  - Rowell, G.
A1  - Rudak, B.
A1  - Ruiz-Velasco, E.
A1  - Sahakian, V.
A1  - Sailer, S.
A1  - Sanchez, D. A.
A1  - Santangelo, A.
A1  - Sasaki, M.
A1  - Scalici, M.
A1  - Schussler, F.
A1  - Schutte, H. M.
A1  - Schwanke, U.
A1  - Schwemmer, S.
A1  - Seglar-Arroyo, M.
A1  - Senniappan, M.
A1  - Seyffert, A. S.
A1  - Shafi, N.
A1  - Shiningayamwe, K.
A1  - Simoni, R.
A1  - Sinha, A.
A1  - Sol, H.
A1  - Specovius, A.
A1  - Spencer, S.
A1  - Spir-Jacob, M.
A1  - Stawarz, L.
A1  - Sun, L.
A1  - Steenkamp, R.
A1  - Stegmann, C.
A1  - Steinmassl, S.
A1  - Steppa, C.
A1  - Takahashi, T.
A1  - Tavernier, T.
A1  - Taylor, A. M.
A1  - Terrier, R.
A1  - Tiziani, D.
A1  - Tluczykont, M.
A1  - Tomankova, L.
A1  - Trichard, C.
A1  - Tsirou, M.
A1  - Tuffs, R.
A1  - Uchiyama, Y.
A1  - van der Walt, D. J.
A1  - van Eldik, C.
A1  - van Rensburg, C.
A1  - van Soelen, B.
A1  - Vasileiadis, G.
A1  - Veh, J.
A1  - Venter, C.
A1  - Vincent, P.
A1  - Vink, J.
A1  - Volk, H. J.
A1  - Vuillaume, T.
A1  - Wadiasingh, Z.
A1  - Wagner, S. J.
A1  - Watson, J.
A1  - Werner, F.
A1  - White, R.
A1  - Wierzcholska, A.
A1  - Wong, Yu Wun
A1  - Yusafzai, A.
A1  - Zacharias, M.
A1  - Zanin, R.
A1  - Zargaryan, D.
A1  - Zdziarski, A. A.
A1  - Zech, Alraune
A1  - Zhu, S. J.
A1  - Ziegler, A.
A1  - Zorn, J.
A1  - Zouari, S.
A1  - Zywucka, N.
T1  - An extreme particle accelerator in the Galactic plane
BT  - HESS J1826-130
JF  - Astronomy and astrophysics : an international weekly journal
N2  - The unidentified very-high-energy (VHE; E > 0.1 TeV) gamma -ray source, HESS J1826-130, was discovered with the High Energy Stereoscopic System (HESS) in the Galactic plane. The analysis of 215 h of HESS data has revealed a steady gamma -ray flux from HESS J1826-130, which appears extended with a half-width of 0.21 degrees +/- 0.02 <br /> (stat)degrees <br /> stat degrees +/- 0.05 <br /> (sys)degrees sys degrees . The source spectrum is best fit with either a power-law function with a spectral index Gamma = 1.78 +/- 0.10(stat) +/- 0.20(sys) and an exponential cut-off at 15.2 <br /> (+5.5)(-3.2) -3.2+5.5 TeV, or a broken power-law with Gamma (1) = 1.96 +/- 0.06(stat) +/- 0.20(sys), Gamma (2) = 3.59 +/- 0.69(stat) +/- 0.20(sys) for energies below and above E-br = 11.2 +/- 2.7 TeV, respectively. The VHE flux from HESS J1826-130 is contaminated by the extended emission of the bright, nearby pulsar wind nebula, HESS J1825-137, particularly at the low end of the energy spectrum. Leptonic scenarios for the origin of HESS J1826-130 VHE emission related to PSR J1826-1256 are confronted by our spectral and morphological analysis. In a hadronic framework, taking into account the properties of dense gas regions surrounding HESS J1826-130, the source spectrum would imply an astrophysical object capable of accelerating the parent particle population up to greater than or similar to 200 TeV. Our results are also discussed in a multiwavelength context, accounting for both the presence of nearby supernova remnants, molecular clouds, and counterparts detected in radio, X-rays, and TeV energies.
KW  - ISM: supernova remnants
KW  - ISM: clouds
KW  - gamma rays: general
KW  - gamma rays:
KW  - ISM
Y1  - 2020
U6  - https://doi.org/10.1051/0004-6361/202038851
SN  - 0004-6361
SN  - 1432-0746
VL  - 644
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Kroner, Alfred
A1  - Wilde, S. A.
A1  - O'Brien, Patrick J.
A1  - Li, J. H.
A1  - Passchier, C. W.
A1  - Walte, N. P.
A1  - Liu, Dun Yi
T1  - Field relationships, geochemistry, zircon ages and evolution of a late Archaean to Palaeoproterozoic lower crustal section in the Hengshan Terrain of northern China
N2  - The Hengshan complex forms part of the central zone of the North China Craton and consists predominantly of ductilely-deformed late Archaean to Palaeoproterozoic high-grade, partly migmatitic, granitoid orthogneisses, intruded by mafic dykes of gabbroic composition. Many highly strained rocks were previously misinterpreted as supracrustal sequences and represent mylonitized granitoids and sheared dykes. Our single zircon dating documents magmatic granitoid emplacement ages between 2.52 Ga and 2.48 Ga, with rare occurrences of 2.7 Ga gneisses, possibly reflecting an older basement. A few granitic gneisses have emplacement ages between 2.35 and 2.1 Ga and show the same structural features as the older rocks, indicating that the main deformation occurred after similar to 2.1 Ga. Intrusion of gabbroic dykes occurred at similar to 1920 Ma, and all Hengshan rocks underwent granulite-facies metamorphism at 1.88-1.85 Ga, followed by retrogression, shearing and uplift. We interpret the Hengshan and adjacent Fuping granitoid gneisses as the lower, plutonic, part of a late Archaean to early Palaeoproterozoic Japan-type magmatic arc, with the upper, volcanic part represented by the nearby Wutai complex. Components of this arc may have evolved at a continental margin as indicated by the 2.7 Ga zircons. Major deformation and HP metamorphism occurred in the late Palaeoproterozoic during the Luliang orogeny when the Eastern and Western blocks of the North China Craton collided to form the Trans-North China orogen. Shear zones in the Hengshan are interpreted as major lower crustal discontinuities post-dating the peak of HP metamorphism, and we suggest that they formed during orogenic collapse and uplift of the Hengshan complex in the late Palaeoproterozoic (< 1.85 Ga)
Y1  - 2005
SN  - 1000-9515
ER  - 
TY  - JOUR
A1  - O'Brien, Patrick J.
A1  - Walte, N. P
A1  - Li, J. H.
T1  - The petrology of two distinct granulite types in the Hengshan Mts, China, and tectonic implications
N2  - The Archean to Proterozoic Hengshan Complex (North China Craton), comprises tonalitic and granodioritic gneisses with subordinate mafic lenses, pegmatites and granites. Amphibolite facies assemblages predominate, although granulite-facies relics are widespread, and greenschist-facies retrogression occurs in km-wide shear zones. Mafic lenses, locally abundant, occur as strongly deformed amphibolite (hornblende + plagioclase) boudins or sheets. In contrast to previously published models we find two series of mafic rocks with distinctly different granulite-facies evolutions. In the north of the complex, relict high-pressure mafic granulites are garnet + clinopyroxene-bearing rocks with a secondary development of orthopyroxene around both garnet (kelyphites) and clinopyroxene (coronas). South of the newly defined central, E-W-trending, Zhujiafang shear zone, numerous mafic boudins and less-deformed dykes exhibit a macroscopically visible magmatic texture with coronitic growth of metamorphic garnet (full of quartz inclusions) between the magmatic plagioclase and pyroxene domains. Additional orthopyroxene (after magmatic augite) and sodic rims to magmatic plagioclase clearly indicate medium-pressure granulite-facies metamorphism. These findings suggest tectonic juxtaposition in this area of three different structural levels of the same Proterozoic-imprinted crust: high-pressure granulite grade in the northern Hengshan, medium-pressure granulite grade in the southern Hengshan and amphibolite- to greenschist-facies grade in the Wutaishan to the SE. (c) 2004 Elsevier Ltd. All rights reserved
Y1  - 2005
SN  - 1367-9120
ER  - 
TY  - JOUR
A1  - Carswell, D. A.
A1  - Brueckner, H. K.
A1  - Cuthbert, S. J.
A1  - Mehta, K.
A1  - O'Brien, Patrick J.
T1  - The timing of stabilisation and the exhumation rate for ultra-high pressure rocks in the Western Gneiss Region of Norway
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Treloar, P. J.
A1  - O'Brien, Patrick J.
A1  - Parrish, R. R.
A1  - Khan, M. A.
T1  - Exhumation of early Tertiary, coesite-bearing eclogites from the Pakistan Himalaya
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Li, J. H.
A1  - Kröner, Alfred
A1  - Qian, X. L.
A1  - O'Brien, Patrick J.
T1  - Tectonic evolution of an early Precambrian high-pressure granulite belt in the North China Craton
Y1  - 2000
ER  - 
TY  - JOUR
A1  - O'Brien, Patrick J.
T1  - The age of deep, steep continental subduction in the NW Himalaya : relating zircon growth to metamorphic history. Comment on: "The onset of India-Asia continental collision: Early, steep subduction required by the timing of UHP metamorphism in the western Himalaya" by Mary L. Leech, S. Singh, A.K. Jain, Simon L. Klemperer and R.M. Manickavasagam, Earth and Planetary Science Letters 234 (2005) 83-97
N2  - Leech et al. [Mary L. Leech, S. Singh, A.K. Jain, Simon L. Klemperer and R.M. Manickavasagam, Earth and Planetary Science Letters 234 (2005) 83-97], present 3 clusters of ages for growth stages in zircon from quartzo- feldspathic gneisses hosting coesite-bearing eclogite from the Tso Morari Complex, NW India. These age clusters, from oldest to youngest, are interpreted to represent the age of ultrahigh-pressure metamorphism, a subsequent eclogite facies overprint and a later amphibolite facies retrogression and require subduction of Indian crust to have started earlier than previously accepted. However, no petrographic evidence, such as inclusions in the zircons relating to particular metamorphic events, is presented to substantiate the proposed sequence of metamorphic stages. Previously published data from eclogites of the same area indicate that coesite-eclogite is not the first but at least the second eclogite facies stage. In addition, the newly proposed time interval between coesite-eclogite and the amphibolite facies overprint is longer than previously indicated by diffusion modelling of natural garnet-garnet couples in eclogite. Neither the age of ultrahigh-pressure metamorphism nor the timing of initiation of subduction is reliably constrained by the presented data
Y1  - 2006
UR  - http://www.sciencedirect.com/science/journal/0012821X
U6  - https://doi.org/10.1016/j.epsl.2006.03.033
ER  - 
TY  - JOUR
A1  - Konrad-Schmolke, Matthias
A1  - Handy, Mark R.
A1  - Babist, Jochen
A1  - O'Brien, Patrick J.
T1  - Thermodynamic modelling of diffusion-controlled garnet growth
N2  - Numerical thermodynamic modelling of mineral composition and modes for specified pressure-temperature paths reveals the strong influence of fractional garnet crystallisation, as well as water fractionation, on garnet growth histories in high pressure rocks. Disequilibrium element incorporation in garnet due to the development of chemical inhomogeneities around porphyroblasts leads to pronounced episodic growth and may even cause growth interruptions. Discontinuous growth, together with pressure- and temperature-dependent changes in garnet chemistry, cause zonation patterns that are indicative of different degrees of disequilibrium element incorporation. Chemical inhomogeneities in the matrix surrounding garnet porphyroblasts strongly affect garnet growth and lead to compositional discontinuities and steep compositional gradients in the garnet zonation pattern. Further, intergranular diffusion-controlled calcium incorporation can lead to a characteristic rise in grossular and spessartine contents at lower metamorphic conditions. The observation that garnet zonation patterns diagnostic of large and small fractionation effects coexist within the same sample suggests that garnet growth is often controlled by small-scale variations in the bulk rock chemistry. Therefore, the spatial distribution of garnet grains and their zonation patterns, together with numerical growth models of garnet zonation patterns, yield information about the processes limiting garnet growth. These processes include intercrystalline element transport and dissolution of pre-existing grains. Discontinuities in garnet growth induced by limited element supply can mask traces of the thermobarometric history of the rock. Therefore, thermodynamic modelling that considers fractional disequilibrium crystallisation is required to interpret compositional garnet zonation in terms of a quantitative pressure and temperature path of the host rock
Y1  - 2005
SN  - 0010-7999
ER  - 
TY  - JOUR
A1  - Konrad-Schmolke, Matthias
A1  - Zack, Thomas
A1  - O'Brien, Patrick J.
T1  - Combining thermodynamic and trace element modeling : a tool to quantify mineral reactions and trace element budgets during metamorphism
Y1  - 2009
UR  - http://www.sciencedirect.com/science/journal/00167037
U6  - https://doi.org/10.1016/j.gca.2009.05.009
SN  - 0016-7037
ER  - 
TY  - JOUR
A1  - Möller, Andreas
A1  - O'Brien, Patrick J.
A1  - Kennedy, Allen
A1  - Kröner, Alfred
T1  - Linking growth episodes of zircon and metamorphic textures to zircon chemistry : an example from the ultra-high temperature granulites of Rogaland (SW Norway)
Y1  - 2003
ER  -