@article{QuandtTrumbullAltenbergeretal.2018,
  author    = {Quandt, Dennis and Trumbull, Robert B. and Altenberger, Uwe and Cardona, Agustin and Romer, Rolf L. and Bayona, Germ{\´a}n A. and Ducea, Mihai N. and Valencia, Victor and Vasquez, Monica and Cortes, Elizabeth and Guzman, Georgina},
  title     = {The geochemistry and geochronology of Early Jurassic igneous rocks from the Sierra Nevada de Santa Marta, NW Colombia, and tectono-magmatic implications},
  series = {Journal of South American earth sciences},
  volume    = {86},
  journal   = {Journal of South American earth sciences},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0895-9811},
  doi       = {10.1016/j.jsames.2018.06.019},
  pages     = {216 -- 230},
  year      = {2018},
  abstract  = {The Sierra Nevada de Santa Marta in NW Colombia is an isolated massif at the northernmost end of the Andes chain near the boundary with the Caribbean plate. Previous geologic mapping and K-Ar dating have shown that Jurassic plutonic and volcanic units make up a large part of the Santa Marta Massif (SMM). These rocks have been considered to be part of a Jurassic magmatic arc extending from NW Colombia to northern Chile, but without any geochemical basis for comparison. This paper reports on a geochemical and Sr-Nd-Pb isotope study of the Jurassic rocks in the SMM and provides 12 new U-Pb zircon ages from in-situ laser ICP-MS dating. The plutonic and volcanic units span a range from 45 to 78 wt.\% SiO2, with a dominance of intermediate to felsic compositions with SiO2 > 57 wt.\%. They classify as calc-alkaline, medium to high-K, metaluminous rocks with trace-element features typical for arc-derived magma series. In terms of their major and trace-element compositions, the SMM Jurassic units overlap with contemporary plutonic and volcanic rocks from other regions of the Central and Eastern Cordilleras of Colombia, and confirm an arc affinity. The new U-Pb ages range from 176 +/- 1 Ma to 192 +/- 2 Ma (n = 12), with most between 180 and 188 Ma (n = 7). The initial Sr isotope ratios (at 180 Ma) are between 0.7012 and 0.7071 (n = 29), with 3 outliers attributed to mobilization of Rb and/or Sr, Nearly all samples have negative( )epsilon Nd-(180) values between - 10.3 and 0.0 (n = 30), the two exceptions being only slightly positive (1.1 and 1.9). Measured Pb isotope ratios fall in a narrow range, with Pb-206/Pb-204 from 18.02 to 19.95, (207) Pb/(204) Pb from 15.56 to 15.67 and Pb-208/Pb-204 from 37.76 to 39.04 (n = 28). In the regional context of previous studies, these results confirm early Jurassic ages and an arc affinity for the widespread magmatism exposed in the eastern and northeastern Colombian Andes. We also note patterns in the distribution and composition of magmas. The magmatic activity in the Central Cordillera tends to be younger than in the Eastern Cordillera and is spatially more restricted to the vicinity of regional fault systems. In terms of composition, Jurassic igneous rocks in the Eastern Cordillera have systematically lower epsilon Nd-(180) values than those from the Central Cordillera, whereas the Pb isotope ratios overlap. We ascribe the Nd isotope variations to heterogeneity in the mantle source and/or degree of crustal contamination, whereas the Pb isotope ratios are crust-dominated and similar throughout the region. The spatio-temporal and compositional evolution of Jurassic magmatic rocks in the Northern Andes reflect the major plate kinematic readjustment between the Triassic and the Early Jurassic in the proto-Andean margin.},
  language  = {en}
}
@article{AltenbergerMejiaJimenezGuenteretal.2012,
  author    = {Altenberger, Uwe and Mejia Jimenez, D. M. and G{\"u}nter, C. and Sierra Rodriguez, G. I. and Scheffler, F. and Oberh{\"a}nsli, Roland},
  title     = {The Garzn Massif, Colombia-a new ultrahigh-temperature metamorphic complex in the early Neoproterozoic of northern South America},
  series = {Mineralogy and petrology},
  volume    = {105},
  journal   = {Mineralogy and petrology},
  number    = {3-4},
  publisher = {Springer},
  address   = {Wien},
  issn      = {0930-0708},
  doi       = {10.1007/s00710-012-0202-1},
  pages     = {171 -- 185},
  year      = {2012},
  abstract  = {The Garzn Complex of the Garzn Massif in SW Colombia is composed of the Vergel Granulite Unit (VG) and the Las Margaritas Migmatite Unit (LMM). Previous studies reveal peak temperature conditions for the VG of about 740 A degrees C. The present study considers the remarkable exsolution phenomena in feldspars and pyroxenes and titanium-in-quartz thermometry. Recalculated ternary feldspar compositions indicate temperatures around 900-1,000 A degrees C just at or above the ultra-high temperature-metamorphism (UHTM) boundary of granulites. The calculated temperatures range of exsolved ortho- and clinopyroxenes also supports the existence of an UHTM event. In addition, titanium-in-quartz thermometry points towards ultra-high temperatures. It is the first known UHTM crustal segment in the northern part of South America. Although a mean geothermal gradient of ca 38 A degrees C km(-1) could imply additional heat supply in the lower crust controlling this extreme of peak metamorphism, an alternative model is suggested. The formation of the Vergel Granulite Unit is supposed to be formed in a continental back-arc environment with a thinned and weakened crust behind a magmatic arc (Guapotn-Mancagua Gneiss) followed by collision. In contrast, rocks of the adjacent Las Margaritas Migmatite Unit display "normal" granulite facies temperatures and are formed in a colder lower crust outside the arc, preserved by the Guapotn-Mancagu Gneiss. Back-arc formation was followed by inversion and thickening of the basin. The three units that form the modern-day Garzn Massif, were juxtaposed upon each other during collision (at ca. 1,000 Ma) and exhumation. The collision leading to the deformation of the studied area is part of the Grenville orogeny leading to the amalgamation of Rodinia.},
  language  = {en}
}
@article{RizzoLauritaAltenberger2018,
  author    = {Rizzo, Giovanna and Laurita, Salvatore and Altenberger, Uwe},
  title     = {The Timpa delle Murge ophiolitic gabbros, southern Apennines},
  series = {Periodico di Mineralogia},
  volume    = {87},
  journal   = {Periodico di Mineralogia},
  number    = {1},
  publisher = {Edizioni nuova cultura},
  address   = {Roma},
  issn      = {0369-8963},
  doi       = {10.2451/2018PM741},
  pages     = {5 -- 20},
  year      = {2018},
  abstract  = {The Timpa delle Murge ophiolite in the North Calabrian Unit is part of the Liguride Complex (southern Apennines). The study is concentrated on the gabbroic part of the ophiolite of the Pollino area. They preserve the high-grade ocean floor metamorphic and locally developed flaser textures under ocean floor conditions. The primary magmatic assemblages are clinopyroxene, plagioclase, and opaques. Brown hornblende is a late magmatic phase. Green hornblende, actinolite, albite, chlorite and epidote display metamorphic recrystallization under lower amphibolite facies conditions, followed by greenschist facies. The gabbros show subalkaline near to alkaline character with a tendency to a more calkalkaline trend. The normalization to primitive mantle and mid-ocean ridge basalt (N-MORB) compositions indicates a considerable depletion in Nb, P, Zr and Ti and an enrichment in Ba, Rb, K, Sr and Eu. This points to a mantle source, which is not compatible with a "normal" mid-ocean ridge situation. Rather, the gabbros are generated from a N-MORB-like melt with a strong crustal component, which was influenced by subduction related fluids and episodic melting during mid-ocean-ridge processes. Plausible geodynamic settings of the Timpa delle Murge gabbros are oceanic back-arc positions with embryonic MORB-activities. Similar slab contaminated magmatism is also known from the early stage of island arc formation in supra-subduction zone environments like the Izu-Bonin-Mariana island arc.},
  language  = {en}
}
@article{WilkeO'BrienAltenbergeretal.2010,
  author    = {Wilke, Franziska Daniela Helena and O'Brien, Patrick J. and Altenberger, Uwe and Konrad-Schmolke, Matthias and Khan, M. Ahmed},
  title     = {Multi-stage reaction history in different eclogite types from the Pakistan Himalaya and implications for exhumation processes},
  issn      = {0024-4937},
  doi       = {10.1016/j.lithos.2009.07.015},
  year      = {2010},
  abstract  = {Metabasites were sampled from rock series of the subducted margin of the Indian Plate, the so-called Higher Himalayan Crystalline, in the Upper Kaghan Valley, Pakistan. These vary from corona dolerites, cropping out around Saif- ul-Muluk in the south, to coesite-eclogite close to the suture zone against rocks of the Kohistan arc in the north. Bulk rock major- and trace-element chemistry reveals essentially a single protolith as the source for five different eclogite types, which differ in fabric, modal mineralogy as well as in mineral chemistry. The study of newly-collected samples reveals coesite (confirmed by in situ Raman spectroscopy) in both garnet and omphacite. All eclogites show growth of amphiboles during exhumation. Within some coesite-bearing eclogites the presence of glaucophane cores to barroisite is noted whereas in most samples porphyroblastic sodic-calcic amphiboles are rimmed by more aluminous calcic amphibole (pargasite, tschermakite, and edenite). Eclogite facies rutile is replaced by ilmenite which itself is commonly surrounded by titanite. In addition, some eclogite bodies show leucocratic segregations containing phengite, quartz, zoisite and/or kyanite. The important implication is that the complex exhumation path shows stages of initial cooling during decompression (formation of glaucophane) followed by reheating: a very similar situation to that reported for the coesite-bearing eclogite series of the Tso Morari massif, India, 450 km to the south-east.},
  language  = {en}
}
@article{VasquezAltenberger2005,
  author    = {Vasquez, M and Altenberger, Uwe},
  title     = {Mid-Cretaceous extension-related magmatism in the eastern Colombian Andes},
  year      = {2005},
  abstract  = {Cretaceous magmatism in the Eastern Cordillera of Colombia is related to lithospheric stretching during the late Early-early Late Cretaceous. The small amount of preserved igneous material is represented by small mafic intrusions. This study focuses on three localities, from east to west: Pajarito, Pacho, and Caceres. The investigated igneous bodies are classified as gabbros, pyroxene-hornblende-gabbros, and pyroxene-hornblendites mainly composed of plagioclase, clinopyroxene, and/or amphibole. Although their timing of emplacement and geodynamic position seem similar, significant differences in their geochemical and petrological characteristics rule out simple models of melt genesis. Clinopyroxene and bulk chemistry indicate increasing alkalinity from west to east. Trace element concentrations point to melt sources that range from a slightly enriched mantle in the west to a highly enriched one in the east. In addition, the data reflect a decreasing degree of partial melting from west to east and the decreasing importance of residual garnet in the mantle source. Probable mantle metasomatism in the source region by slab-derived fluids, as displayed by high Ba/Nb and moderate Sr-n/P-n, is clear in the west and very slight to the east. Mantle metasomatism and melt generation probably are processes of different epochs. The lack of large volumes of igneous rocks and the absence of tectonically controlled unconformities in the investigated areas indicate that a mantle plume did not affect the regional tectonics and magmatism. We favor a model of rift-related magmatism in which melt composition is modified from east to west from a highly enriched to a less enriched mantle region, the latter metasomatized by fluids derived from an older subduction phase. (c) 2005 Elsevier Ltd. All rights reserved},
  language  = {en}
}
@misc{RizzoLauritaAltenberger2018,
  author    = {Rizzo, Giovanna and Laurita, Salvatore and Altenberger, Uwe},
  title     = {The Timpa delle Murge ophiolitic gabbros, southern Apennines},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1002},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-45992},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-459928},
  pages     = {5 -- 20},
  year      = {2018},
  abstract  = {The Timpa delle Murge ophiolite in the North Calabrian Unit is part of the Liguride Complex (southern Apennines). The study is concentrated on the gabbroic part of the ophiolite of the Pollino area. They preserve the high-grade ocean floor metamorphic and locally developed flaser textures under ocean floor conditions. The primary magmatic assemblages are clinopyroxene, plagioclase, and opaques. Brown hornblende is a late magmatic phase. Green hornblende, actinolite, albite, chlorite and epidote display metamorphic recrystallization under lower amphibolite facies conditions, followed by greenschist facies. The gabbros show subalkaline near to alkaline character with a tendency to a more calkalkaline trend. The normalization to primitive mantle and mid-ocean ridge basalt (N-MORB) compositions indicates a considerable depletion in Nb, P, Zr and Ti and an enrichment in Ba, Rb, K, Sr and Eu. This points to a mantle source, which is not compatible with a "normal" mid-ocean ridge situation. Rather, the gabbros are generated from a N-MORB-like melt with a strong crustal component, which was influenced by subduction related fluids and episodic melting during mid-ocean-ridge processes. Plausible geodynamic settings of the Timpa delle Murge gabbros are oceanic back-arc positions with embryonic MORB-activities. Similar slab contaminated magmatism is also known from the early stage of island arc formation in supra-subduction zone environments like the Izu-Bonin-Mariana island arc.},
  language  = {en}
}
@article{WeidingerKorupMunacketal.2014,
  author    = {Weidinger, Johannes T. and Korup, Oliver and Munack, Henry and Altenberger, Uwe and Dunning, Stuart A. and Tippelt, Gerold and Lottermoser, Werner},
  title     = {Giant rockslides from the inside},
  series = {Earth \& planetary science letters},
  volume    = {389},
  journal   = {Earth \& planetary science letters},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0012-821X},
  doi       = {10.1016/j.epsl.2013.12.017},
  pages     = {62 -- 73},
  year      = {2014},
  abstract  = {The growing body of research on large-scale mass wasting events so far has only scarcely investigated the sedimentology of chaotic deposits from non-volcanic terrestrial landslides such that any overarching and systematic terminological framework remains elusive. Yet recent work has emphasized the need for better understanding the internal structure and composition of rockslide deposits as a means to characterise the mechanics during the final stages of runout and emplacement. We offer a comprehensive overview on the occurrence of rock fragmentation and frictional melt both at different geographic locations, and different sections within large (>10(6) m(3)) rockslide masses. We argue that exposures of pervasively fragmented and interlocked jigsaw-cracked rock masses; basal melange containing rip-up clasts and phantom blocks; micro-breccia; and thin bands of basal frictionite are indispensable clues for identifying deposits from giant rockslides that may remain morphologically inconspicuous otherwise. These sedimentary assemblages are diagnostic tools for distinguishing large rockslide debris from macro and microscopically similar glacial deposits, tectonic fault-zone breccias, and impact breccias, and thus help avoid palaeoclimatic and tectonic misinterpretations, let alone misestimates of the hazard from giant rockslides. Moreover, experimental results from Mossbauer spectroscopy of frictionite samples support visual interpretations of thin sections, and demonstrate that short-lived (<10 s) friction-induced partial melting at temperatures >1500 degrees C in the absence of water occurred at the base of several giant moving rockslides. This finding supports previous theories of dry excess runout accompanied by comminution of rock masses down to gm-scale, and indicates that catastrophic motion of large fragmenting rock masses does not require water as a potential lubricant.},
  language  = {en}
}
@article{OmraniMoazzenOberhaenslietal.2013,
  author    = {Omrani, Hadi and Moazzen, Mohssen and Oberh{\"a}nsli, Roland and Altenberger, Uwe and Lange, Manuela},
  title     = {The Sabzevar blueschists of the North-Central Iranian micro-continent as remnants of the Neotethys-related oceanic crust subduction},
  series = {International journal of earth sciences},
  volume    = {102},
  journal   = {International journal of earth sciences},
  number    = {5},
  publisher = {Springer},
  address   = {New York},
  issn      = {1437-3254},
  doi       = {10.1007/s00531-013-0881-9},
  pages     = {1491 -- 1512},
  year      = {2013},
  abstract  = {The Sabzevar ophiolites mark the Neotethys suture in east-north-central Iran. The Sabzevar metamorphic rocks, as part of the Cretaceous Sabzevar ophiolitic complex, consist of blueschist, amphibolite and greenschist. The Sabzevar blueschists contain sodic amphibole, epidote, phengite, calcite +/- A omphacite +/- A quartz. The epidote amphibolite is composed of sodic-calcic amphibole, epidote, albite, phengite, quartz +/- A omphacite, ilmenite and titanite. The greenschist contains chlorite, plagioclase and pyrite, as main minerals. Thermobarometry of a blueschist yields a pressure of 13-15.5 kbar at temperatures of 420-500 A degrees C. Peak metamorphic temperature/depth ratios were low (similar to 12 A degrees C/km), consistent with metamorphism in a subduction zone. The presence of epidote in the blueschist shows that the rocks were metamorphosed entirely within the epidote stability field. Amphibole schist samples experienced pressures of 5-7 kbar and temperatures between 450 and 550 A degrees C. The presence of chlorite, actinolite, biotite and titanite indicate greenschist facies metamorphism. Chlorite, albite and biotite replacing garnet or glaucophane suggests temperatures of > 300 A degrees C for greenschist facies. The formation of high-pressure metamorphic rocks is related to north-east-dipping subduction of the Neotethys oceanic crust and subsequent closure during lower Eocene between the Central Iranian Micro-continent and Eurasia (North Iran).},
  language  = {en}
}
@article{VsssquezAltenbergerRomer2009,
  author    = {Vßsquez, M{\´o}nica and Altenberger, Uwe and Romer, Rolf L.},
  title     = {Neogene magmatism and its possible causal relationship with hydrocarbon generation in SW Colombia},
  issn      = {1437-3254},
  doi       = {10.1007/s00531-008-0303-6},
  year      = {2009},
  abstract  = {The Cretaceous oil-bearing source and reservoir sedimentary succession in the Putumayo Basin, SW Colombia, was intruded by gabbroic dykes and sills. The petrological and geochemical character of the magmatic rocks shows calc- alkaline tendency, pointing to a subduction-related magmatic event. K/Ar dating of amphibole indicates a Late Miocene to Pliocene age (6.1 +/- A 0.7 Ma) for the igneous episode in the basin. Therefore, we assume the intrusions to be part of the Andean magmatism of the Northern Volcanic Zone (NVZ). The age of the intrusions has significant tectonic and economic implications because it coincides with two regional events: (1) the late Miocene/Pliocene Andean orogenic uplift of most of the sub-Andean regions in Peru, Ecuador and Colombia and (2) a pulse of hydrocarbon generation and expulsion that has reached the gas window. High La/Yb, K/Nb and La/Nb ratios, and the obtained Sr-Nd-Pb isotopic compositions suggest the involvement of subducted sediments and/or the assimilation of oceanic crust of the subducting slab. We discuss the possibility that magma chamber(s) west of the basin, below the Cordillera, did increase the heat flow in the basin causing generation and expulsion of hydrocarbons and CO2.},
  language  = {en}
}
@article{KlappenbachAltenberger1997,
  author    = {Klappenbach, K{\"a}the and Altenberger, Uwe},
  title     = {Kostbare H{\"o}hle f{\"u}r Nymphen und Meeresg{\"o}tter : der Grottensaal im Neuen Palais},
  year      = {1997},
  language  = {de}
}