TY - JOUR A1 - Ferrero, Silvio A1 - Ziemann, Martin Andreas A1 - Angel, Ross J. A1 - Wunder, Bernd T1 - Kumdykolite, kokchetavite, and cristobalite crystallized in nanogranites from felsic granulites, Orlica-Snieznik Dome (Bohemian Massif): not evidence for ultrahigh-pressure conditions JF - Contributions to mineralogy and petrology N2 - A unique assemblage including kumdykolite and kokchetavite, polymorphs of albite and K-feldspar, respectively, together with cristobalite, micas, and calcite has been identified in high-pressure granulites of the Orlica-Snieznik dome (Bohemian Massif) as the product of partial melt crystallization in preserved nanogranites. Previous reports of both kumdykolite and kokchetavite in natural rocks are mainly from samples that passed through the diamond stability field. However, because the maximum pressure recorded in these host rocks is <3 GPa, our observations indicate that high pressure is not required for the formation of kumdykolite and kokchetavite, and their presence is not therefore an indicator of ultrahigh-pressure conditions. Detailed microstructural and microchemical investigation of these inclusions indicates that such phases should instead be regarded as (1) a direct mineralogical criteria to identify former melt inclusions with preserved original compositions, including H2O and CO2 contents and (2) indicators of rapid cooling of the host rocks. Thus, the present study provides novel criteria for the interpretation of melt inclusions in natural rocks and allows a more rigorous characterization of partial melts during deep subduction to mantle depth as well as their behavior on exhumation. KW - Partial melt KW - Polymorphs KW - Deep fluids KW - Nanogranites KW - Kumdykolite KW - Kokchetavite KW - Cristobalite Y1 - 2016 U6 - https://doi.org/10.1007/s00410-015-1220-x SN - 0010-7999 SN - 1432-0967 VL - 171 SP - 61 EP - 65 PB - Springer CY - New York ER - TY - JOUR A1 - Schmidt, Birgit Angelika A1 - Ziemann, Martin Andreas A1 - Pentzien, Simone A1 - Gabsch, Toralf A1 - Koch, Werner A1 - Krüger, Jörg T1 - Technical analysis of a Central Asian wall painting detached from a Buddhist cave temple on the northern Silk Road JF - Studies in Conservation N2 - A great number of Central Asian wall paintings, archeological materials, architectural fragments, and textiles, as well as painting fragments on silk and paper, make up the so called Turfan Collection at the Asian Art Museum in Berlin. The largest part of the collection comes from the Kucha region, a very important cultural center in the third to ninth centuries. Between 1902 and 1914, four German expeditions traveled along the northern Silk Road. During these expeditions, wall paintings were detached from their original settings in Buddhist cave complexes. This paper reports a technical study of a wall painting, existing in eight fragments, from the Buddhist cave no. 40 (Ritterhohle). Its original painted surface is soot blackened and largely illegible. Gruwedel, leader of the first and third expeditions, described the almost complete destruction of the rediscovered temple complex and evidence of fire damage. The aim of this case study is to identify the materials used for the wall paintings. Furthermore, soot deposits as well as materials from conservation interventions were of interest. Non-invasive analyses were preferred but a limited number of samples were taken to provide more precise information on the painting technique. By employing optical and scanning electron microscopy, energy dispersive X-ray spectroscopy, micro X-ray fluorescence spectroscopy, X-ray diffraction analysis, and Raman spectroscopy, a layer sequence of earthen render, a ground layer made of gypsum, and a paint layer containing a variety of inorganic pigments were identified. KW - Wall paintings KW - Central Asia KW - Silk Road KW - Pigments KW - Microscopy KW - EDX KW - XRF KW - Raman spectroscopy Y1 - 2016 U6 - https://doi.org/10.1179/2047058414Y.0000000152 SN - 0039-3630 SN - 2047-0584 VL - 61 SP - 113 EP - 122 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - GEN A1 - Voropaev, S. A1 - Korochantsev, A. A1 - Petukhov, D. A1 - Kocherov, A. A1 - Kaeter, David A1 - Ziemann, Martin Andreas A1 - Boettger, Ute T1 - Ordinary chondrites of Chelyabinsk meteorite and comparison with asteroid 25143 (Itokawa) T2 - PLoS one Y1 - 2016 SN - 1086-9379 SN - 1945-5100 VL - 51 SP - A644 EP - A644 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Ferrero, Silvio A1 - Wunder, Bernd A1 - Ziemann, Martin Andreas A1 - Waelle, Markus T1 - Carbonatitic and granitic melts produced under conditions of primary immiscibility during anatexis in the lower crust JF - Earth & planetary science letters N2 - Carbonatites are peculiar magmatic rocks with mantle-related genesis, commonly interpreted as the products of melting of CO2-bearing peridotites, or resulting from the chemical evolution of mantle derived magmas, either through extreme "differentiation or secondary immiscibility. Here we report the first finding of anatectic carbonatites of crustal origin, preserved as calcite-rich polycrystalline inclusions in garnet from low-to-medium pressure migmatites of the Oberpfalz area, SW Bohemian Massif (Central Europe). These inclusions originally trapped a melt of calciocarbonatitic composition with a characteristic enrichment in Ba, Sr and LREE. This interpretation is supported by the results of a detailed microstructural and microchemical investigation, as well as re-melting experiments using a piston cylinder apparatus. Carbonatitic inclusions coexist in the same cluster with crystallized silicate melt inclusions (nanogranites) and COH fluid inclusions, suggesting conditions of primary immiscibility between two melts and a fluid during anatexis. The production of both carbonatitic and granitic melts during the same anatectic event requires a suitable heterogeneous protolith. This may be represented by a sedimentary sequence containing marble lenses of limited extension, similar to the one still visible in the adjacent central Moldanubian Zone. The presence of CO2-rich fluid inclusions suggests furthermore that high CO2 activity during anatexis may be required to stabilize a carbonate-rich melt in a silica-dominated, system. This natural occurrence displays a remarkable similarity with experiments on carbonate-silicate melt immiscibility, where CO2 saturation is a condition commonly imposed. In conclusion, this study shows how the investigation of partial melting through melt inclusion studies may unveil unexpected processes whose evidence, while preserved in stiff minerals such as garnet, is completely obliterated in the rest of the rock due to metamorphic re-equilibration. Our results thus provide invaluable new insights into the processes which shape the geochemical evolution of our planet, such as the redistribution of carbon and strategic metals during orogenesis. (C) 2016 Elsevier B.V. All rights reserved. KW - partial melting KW - carbonatites KW - nanogranites KW - garnet KW - melt inclusions; nanocarbonatites Y1 - 2016 U6 - https://doi.org/10.1016/j.epsl.2016.08.043 SN - 0012-821X SN - 1385-013X VL - 454 SP - 121 EP - 131 PB - Elsevier CY - Amsterdam ER -