Hoefs, Jochen

[["dc.bibliographiccitation.firstpage","203"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Earth and Planetary Science Letters"],["dc.bibliographiccitation.lastpage","213"],["dc.bibliographiccitation.volume","273"],["dc.contributor.author","Schmidt, Alexander"],["dc.contributor.author","Weyer, Stefan"],["dc.contributor.author","Mezger, Klaus"],["dc.contributor.author","Scherer, Erik E."],["dc.contributor.author","Xiao, Yilin"],["dc.contributor.author","Hoefs, Jochen"],["dc.contributor.author","Brey, Gerhard P."],["dc.date.accessioned","2018-11-07T11:11:59Z"],["dc.date.available","2018-11-07T11:11:59Z"],["dc.date.issued","2008"],["dc.description.abstract","The Qinling-Dabie-Sulu orogenic belt in eastern China is one of the largest ultrahigh-pressure (UHP) terranes worldwide. Mineral Sm-Nd- and zircon U-Pb dating has been widely used to reveal the metamorphic history of this collisional orogen. However, the exact timing of the UHP metamorphic event(s) remains controversial and ages ranging from 245 Ma to 220 Ma have been suggested. We present high precision garnet-cpx Lu-Hf ages for six eclogites from the Dabie and Sulu areas. All ages fall in a narrow range between 219.6 and 224.4 Ma. Five samples define a mean age of 223.0 +/- 0.9 Ma and one sample yields a slightly younger age of 219.6 +/- 1.4 Ma. This very tight age range is particularly remarkable considering the large regional distribution of sample localities (on the order of 100 km at the time of UHP metamorphism) and the wide variety of garnet and eclogite chemical compositions represented. Two samples yield Sm-Nd ages that are indistinguishable from their Lu-Hf ages, albeit with larger uncertainties. The identical ages of eclogites from both the Dabie and the Sulu region emphasize their close genetic relationship and similar metamorphic histories. The Lu-Hf results appear to date a punctuated event of garnet growth. Alternatively, the Lu-Hf garnet ages may represent the onset of rapid, contemporaneous uplift and subsequent cooling. However, trace element zoning of Lu and Hf is still preserved in garnet porphyroblasts, even in those with a homogeneous major element distribution. Thus, complete reequilibration of the Lu-Hf system during peak-temperature conditions probably did not occur. The garnet forming event can be placed toward the final stage of the UHP metamorphism, in agreement with some published U-Pb zircon ages. A possible trigger for this short-lived and widespread mineral growth episode may have been a fluid that became available at that stage of the metamorphic history. Although HREE-depleted patterns of older zircon grains may indicate the presence of an older generation of garnet, complete eclogitisation may have been inhibited during the major part of the prograde P-T path due to dry conditions during most of the UHP metamorphism. The uniform Lu-Hf (and Sm-Nd) ages of all investigated Dabie and Sulu eclogites suggest that garnet growth and thus possibly fluid availability were limited to a short time interval over a remarkably large regional scale. (C) 2008 Elsevier B.V. All rights reserved."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG) [WE 2850-2/1]"],["dc.identifier.doi","10.1016/j.epsl.2008.06.036"],["dc.identifier.isi","000259729000020"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11244"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/53559"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1385-013X"],["dc.relation.issn","0012-821X"],["dc.relation.orgunit","Fakultät für Geowissenschaften und Geographie"],["dc.rights","CC BY-NC-ND 3.0"],["dc.rights.uri","http://creativecommons.org/licenses/by-nc-nd/3.0/"],["dc.title","Rapid eclogitisation of the Dabie-Sulu UHP terrane: Constraints from Lu-Hf garnet geochronology"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2018"],["dc.bibliographiccitation.issue","18"],["dc.bibliographiccitation.journal","Chinese Science Bulletin"],["dc.bibliographiccitation.lastpage","2023"],["dc.bibliographiccitation.volume","48"],["dc.contributor.author","Shen, K."],["dc.contributor.author","Zhang, Z. M."],["dc.contributor.author","van den Kerkhof, Alfons M."],["dc.contributor.author","Xiao, Y. L."],["dc.contributor.author","Xu, Z. Q."],["dc.contributor.author","Hoefs, Jochen"],["dc.date.accessioned","2018-11-07T10:36:23Z"],["dc.date.available","2018-11-07T10:36:23Z"],["dc.date.issued","2003"],["dc.description.abstract","Primary high-density fluid inclusions were identified in garnet from ultrahigh pressure eclogite in the southern part of the Sulu terrane. They occur isolatedly or in cluster together with relatively low-density two-phase inclusions. The eutectic temperature of the inclusions is as low as less than or equal to-52degreesC. A bubble was nucleated in a liquid inclusion during the specific stage of cyclic cooling-heating runs, and the liquid-gas homogenization temperature was measured to be less than or equal to-12.5degreesC. The composition of the inclusions modeled by the system CaCl2-NaCl-H2O, yields the fluid density of 1.27 g/cm(3) that corresponds to a pressure of ca. 2.4 GPa at the temperature of peak eclogite-facies metamorphism, close to the ultrahigh pressure metamorphic conditions. During the exhumation of the eclogite the inclusions reacted with the host mineral, forming hydrous silicate minerals that resulted in lowering of the fluid density and its transformation to multi-phase inclusions."],["dc.identifier.doi","10.1360/02wd0536"],["dc.identifier.isi","000185748100023"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/45311"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Science China Press"],["dc.relation.issn","1001-6538"],["dc.title","Unusual high-density and saline aqueous inclusions in ultrahigh pressure metamorphic rocks from Sulu terrane in eastern China"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","297"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","International Geology Review"],["dc.bibliographiccitation.lastpage","309"],["dc.bibliographiccitation.volume","47"],["dc.contributor.author","Zhang, Z. M."],["dc.contributor.author","Shen, K."],["dc.contributor.author","Xiao, Y. L."],["dc.contributor.author","van den Kerkhof, Alfons M."],["dc.contributor.author","Hoefs, Jochen"],["dc.contributor.author","Liou, J. G."],["dc.date.accessioned","2018-11-07T11:19:57Z"],["dc.date.available","2018-11-07T11:19:57Z"],["dc.date.issued","2005"],["dc.description.abstract","Rocks from the first pre-pilot hole of the Chinese Continental Scientific Drilling Project (CCSD-PPH1, 432 in), located in the eastern part of the Dabie-Sulu ultrahigh-pressure (UHP) metamorphic belt, have been subjected to a coesite-eclogite-facies metamorphic event, followed by an amphibolite-facies overprint. Primary fluid inclusions occur in garnet, omphacite, and apatite from eclogite; in kyanite and in topaz from quartzite; and in garnet, epidote, and apatite from paragneiss. Secondary fluid inclusions are present in all lithologies. Fluid inclusions are absent from ultramafic rocks. Based on fluid compositions and textural criteria we distinguished: (1) low-salinity aqueous-carbonic inclusions in topaz from quartzite, which may have originated from a supracrustal protolith; (2) primary CaCl2-NaCl-rich brine inclusions in garnet and in omphacite from eclogite and in kyanite from quartzite, representing UHP metamorphic fluids; (3) high-salinity aqueous-carbonic inclusions in quartz from eclogite and quartzite, representing amphibolite-facies fluids; (4) aqueous fluids of low- and intermediate salinity trapped as primary inclusions in garnet, epidote (or allanite) and apatite from gneiss, or as secondary inclusions, representing amphibolite-facies and later retrograde fluids; (5) carbonic inclusions are distributed along transgranular fractures in quartz from quartzite, and probably represent the latest retrograde fluid. The diversity in fluid inclusion populations and compositions from different vertical depths suggests a closed fluid system without large-scale fluid migration during UHP metamorphism. However, the common low- and medium-salinity inclusions in most rock types suggests that a water-dominated fluid from an external source infiltrated into the rock system during amphibolite-facies metamorphism, resulting in extensive retrogression of the UHP rocks."],["dc.identifier.doi","10.2747/0020-6814.47.3.297"],["dc.identifier.isi","000227403000005"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/55414"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","V H Winston & Son Inc"],["dc.relation.issn","0020-6814"],["dc.title","Fluid composition and evolution attending UHP metamorphism: Study of fluid inclusions from drill cores, southern Sulu Belt, Eastern China"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1160"],["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","International Geology Review"],["dc.bibliographiccitation.lastpage","1177"],["dc.bibliographiccitation.volume","47"],["dc.contributor.author","Zhang, Z. M."],["dc.contributor.author","Xiao, Y. L."],["dc.contributor.author","Hoefs, Jochen"],["dc.contributor.author","Xu, Z. Q."],["dc.contributor.author","Liou, J. G."],["dc.date.accessioned","2018-11-07T10:54:40Z"],["dc.date.available","2018-11-07T10:54:40Z"],["dc.date.issued","2005"],["dc.description.abstract","The Pre-pilot Hole No. 1 of the Chinese Continental Scientific Drilling Project (CCSD-PPH1) in the southern Sulu terrane recovered a continuous core of eclogite, garnet peridotite, orthogneiss, paragneiss, and minor schist and quartzite. Geochemical characteristics indicate that the garnet peridotite was derived from depleted mantle; all other rock types are metamorphosed supracrustal rocks with continental affinities. The eclogite consists of garnet, omphacite, phengite, quartz (coesite), amphibole, rutile, and zircon; P-T estimates of peak metamorphism are 785-820 degrees C and >2.7 to 3.7 GPa. The gneisses show common amphibolite-facies mineral assemblages consisting of plagioclase, K-feldspar, muscovite, and quartz, with minor garnet, epidote (or zoisite), and biotite; coesite inclusions in zircon indicate that the gneisses together with eclogites were subjected to an early UHP metamorphism prior to amphibolite-facies retrogression. The Garnet peridotites show porphyroblastic textures, and consist mainly of garnet, clinopyroxene, orthopyroxene, and olivine with minor phlogopite. Garnet and clinopyroxene porphyroblasis show significant compositional zoning. Applying relevant geothermobarometers, core compositions of the minerals indicate P-T conditions of 6.0-7.0 GPa and 1100-1200 degrees C. For the rim, similar or slightly higher P-T conditions compared to the eclogites were obtained. We suggest that the former represent crystallization conditions of garnet peridotite in the upper mantle, whereas the latter reflect reequilibrium conditions during incorporation of mantle rocks into the subducted slab. We conclude that the garnet peridotite may have been derived from the mantle wedge above the subduction zone. If so, these mantle-derived rocks were sandwiched between continental-derived country rocks."],["dc.identifier.doi","10.2747/0020-6814.47.11.1160"],["dc.identifier.isi","000232750200005"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49618"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","V H Winston & Son Inc"],["dc.relation.issn","0020-6814"],["dc.title","Petrogenesis of UHP metamorphic crustal and Mande rocks from the Chinese Continental Scientific Drilling Pre-pilot Hole 1, Sulu belt, eastern China"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","378"],["dc.bibliographiccitation.issue","3-4"],["dc.bibliographiccitation.journal","Lithos"],["dc.bibliographiccitation.lastpage","398"],["dc.bibliographiccitation.volume","92"],["dc.contributor.author","Zhang, Z."],["dc.contributor.author","Shen, Kun"],["dc.contributor.author","Xiao, Yilin"],["dc.contributor.author","Hoefs, Jochen"],["dc.contributor.author","Liou, J. G."],["dc.date.accessioned","2018-11-07T08:54:49Z"],["dc.date.available","2018-11-07T08:54:49Z"],["dc.date.issued","2006"],["dc.description.abstract","The Chinese Continental Scientific Drilling (CCSD) main drill hole (0-3000 m) in Donghai, southern Sulu orogen, consists of eclogite, paragneiss, orthogneiss, schist and gamet peridotite. Detailed investigations of Raman, cathodoluminescence, and microprobe analyses show that zircons from most eclogites, gneisses and schists have oscillatory zoned magmatic cores with low-pressure mineral inclusions of Qtz, Pl, Kf and Ap, and a metamorphic rim with relatively uniform luminescence and eclogite-facies mineral inclusions of Grt, Omp, Phn, Coe and Rt. The chemical compositions of the UHP metamorphic mineral inclusions in zircon are similar to those from the matrix of the host rocks. Similar UHP metamorphic P-T conditions of about 770 degrees C and 32 kbar were estimated from coexisting minerals in zircon and in the matrix. These observations suggest that all investigated lithologies experienced a joint in situ UHP metamorphism during continental deep subduction. In rare cases, magmatic cores of zircon contain coesite and omphacite inclusions and show patchy and irregular luminescence, implying that the cores have been largely altered possibly by fluid-mineral interaction during UHP metamorphism. Abundant H2O-CO2, H2O- or CO2-dominated fluid inclusions with low to medium salinities occur isolated or clustered in the magmatic cores of some zircons, coexisting with low-P mineral inclusions. These fluid inclusions should have been trapped during magmatic crystallization and thus as primary. Only few H2O- and/or CO2-dominated fluid inclusions were found to occur together with UHP mineral inclusions in zircons of metamorphic origin, indicating that UHP metamorphism occurred under relatively dry conditions. The diversity in fluid inclusion populations in UHP rocks from different depths suggests a closed fluid system, without large-scale fluid migration during subduction and exhumation. (c) 2006 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.lithos.2006.04.003"],["dc.identifier.isi","000242984700005"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22757"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0024-4937"],["dc.title","Mineral and fluid inclusions in zircon of UHP metamorphic rocks from the CCSD-main drill hole: A record of metamorphism and fluid activity"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1505"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Journal of Petrology"],["dc.bibliographiccitation.lastpage","1527"],["dc.bibliographiccitation.volume","43"],["dc.contributor.author","Xiao, Y. L."],["dc.contributor.author","Hoefs, Jochen"],["dc.contributor.author","van den Kerkhof, A. M."],["dc.contributor.author","Simon, Klaus"],["dc.contributor.author","Fiebig, J."],["dc.contributor.author","Zheng, Y."],["dc.date.accessioned","2018-11-07T10:16:29Z"],["dc.date.available","2018-11-07T10:16:29Z"],["dc.date.issued","2002"],["dc.description.abstract","The Dabie Shan ultrahigh-pressure (UHP) metamorphic terrane is located in the eastern part of the east-west-striking Qinling-Dabie orogenic belt in China. A major mylonitized contact zone of 200-300 m width divides Dabie Shan into the South Dabie Terrane (SDT) and the North Dabie Complex (NDC). Combined investigation of major and trace element geochemistry, fluid inclusions, and oxygen and hydrogen isotopes constrains the fluid history during the metamorphic evolution of the two metamorphic belts, which differ in their fluid and metamorphic evolution. Fluid inclusions in rocks from the SDT are mainly aqueous with varying salinities, whereas those from the NDC are dominated by CO2. Low delta(18)O values in the SDT rocks (-2.8 to 8.6parts per thousand) indicate meteoric water-rock interactions before UHP metamorphism, whereas rocks from the NDC show 'normal' delta(18)O values (6.7-9.0parts per thousand) with no obvious meteoric water-rock signature. Whole-rock rare earth element (REE) contents correlate with oxygen isotope compositions: samples from the SDT have higher REE contents and lower delta(18)O values, whereas samples from the NDC have lower REE contents and higher delta(18)O values. During retrograde metamorphism fluids with different hydrogen isotope compositions interacted with the rocks from the SDT."],["dc.identifier.doi","10.1093/petrology/43.8.1505"],["dc.identifier.isi","000177226600004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/41048"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","0022-3530"],["dc.title","Fluid evolution during HP and UHP metamorphism in Dabie Shan, China: Constraints from mineral chemistry, fluid inclusions and stable isotopes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","PII S0009-2541(01)00287-X"],["dc.bibliographiccitation.firstpage","179"],["dc.bibliographiccitation.issue","2-4"],["dc.bibliographiccitation.journal","Chemical Geology"],["dc.bibliographiccitation.lastpage","194"],["dc.bibliographiccitation.volume","182"],["dc.contributor.author","Wiechert, U."],["dc.contributor.author","Fiebig, J."],["dc.contributor.author","Przybilla, R."],["dc.contributor.author","Xiao, Yilin"],["dc.contributor.author","Hoefs, Jochen"],["dc.date.accessioned","2018-11-07T10:31:52Z"],["dc.date.available","2018-11-07T10:31:52Z"],["dc.date.issued","2002"],["dc.description.abstract","A technique using isotope-ratio-monitoring gas chromatography-mass spectrometry (irmGCMS) and excimer laser fluorination for in situ oxygen isotope analysis of silicates is described. The irmGCMS and oxygen extraction line is connected by a newly developed interface, reducing the time for a single analysis to less than 10 min. The precision obtained for 5180 is similar to what has been reported for excimer laser fluorination using dual inlet systems. 5180 values of two olivine standards had I sigma precision of +/- 0.14parts per thousand (n 19 and n = 10) and that of Dorentrup, quartz had 0.17parts per thousand. Eleven analyses of a large zircon crystal had a precision of +/- 0.12parts per thousand. However, between 300 and 600 nmol oxygen was liberated for a single analysis, equivalent to cylindrical laser holes 250 to 350 mum in diameter and depth, In the future it will be feasible to measure the isotope ratio of cylindrical volumes 150 pm in diameter simply by reducing the volume of the extraction line. While this is still significantly larger than what is possible with ion probes, the ratios obtained by excimer laser-irmGCMS are highly accurate and precise without correction. The value of this technique for in situ oxygen isotope measurements is demonstrated with two rock slabs from metamorphic rocks of the Dabie-Sulu ultra-high-pressure belt, China. (C) 2002 Elsevier Science B.V. All rights reserved."],["dc.identifier.doi","10.1016/S0009-2541(01)00287-X"],["dc.identifier.isi","000174188000004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/44212"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0009-2541"],["dc.title","Excimer laser isotope-ratio-monitoring mass spectrometry for in situ oxygen isotope analysis"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Contributions to Mineralogy and Petrology"],["dc.bibliographiccitation.lastpage","16"],["dc.bibliographiccitation.volume","139"],["dc.contributor.author","Xiao, Y. L."],["dc.contributor.author","Hoefs, Jochen"],["dc.contributor.author","van den Kerkhof, Alfons M."],["dc.contributor.author","Fiebig, J."],["dc.contributor.author","Zheng, Y."],["dc.date.accessioned","2018-11-07T10:52:56Z"],["dc.date.available","2018-11-07T10:52:56Z"],["dc.date.issued","2000"],["dc.description.abstract","The coesite-bearing eclogites and associated ultramafic rocks of Bixiling form the largest metamorphic complex in the Dabie-Sulu ultrahigh-pressure (UHP) metamorphic belt. They mainly consist of \"fresh' eclogite, kyanite-rich eclogite, retrograded eclogite and garnet peridotite. Fluid inclusion and oxygen isotope studies have been carried out on the different types of eclogite and peridotite in order to identify the role of fluids during the metamorphic evolution culminating in UHP metamorphism. Five types of fluid inclusions were distinguished based on textural criteria and fluid compositions: (1) primary Ca-rich brines in quartz blebs in kyanite; (2) primary NaCl-dominated high-salinity inclusions in omphacite and kyanite; (3) primary NaCl-dominated medium- to high-salinity inclusions in matrix quartz; (4) carbonic inclusions in omphacite and matrix quartz, (5) secondary low-salinity aqueous (or pure water) inclusions in matrix quartz. The Ca-rich fluid inclusions in quartz blebs in kyanite represent the earliest recognizable fluids (prograde metamorphism) as they largely escaped late re-equilibration. Fluid inclusions in omphacite and kyanite may have been trapped during peak metamorphic conditions, whereas low-salinity aqueous inclusions in matrix quartz were trapped during the latest stage of uplift. UV-laser oxygen isotope measurements show that garnet and clinopyroxene from the \"fresh\" eclogite, kyanite-rich eclogite and garnet peridotite have narrow delta(18)O values ranging from 3.0 to 3.9 parts per thousand. In contrast, garnet and omphacite in retrograded eclogite have delta(18)O values of -1.8 to -1.2 and of -1.1 to -0.6 parts per thousand,, respectively. The difference in oxygen isotope composition is interpreted to result from partial oxygen isotope exchange between the UHP complex and retrograde fluids during late exhumation. Fluids derived from the surrounding gneiss were probably responsible for the low-salinity solutions found in secondary fluid inclusions and the lowering of the delta(18)O values of the retrograded eclogite."],["dc.identifier.doi","10.1007/s004100050570"],["dc.identifier.isi","000087429100001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49233"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0010-7999"],["dc.title","Fluid history of UHP metamorphism in Dabie Shan, China: a fluid inclusion and oxygen isotope study on the coesite-bearing eclogite from Bixiling"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","443"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Contributions to Mineralogy and Petrology"],["dc.bibliographiccitation.lastpage","458"],["dc.bibliographiccitation.volume","152"],["dc.contributor.author","Xiao, Yilin"],["dc.contributor.author","Zhang, Z."],["dc.contributor.author","Hoefs, Jochen"],["dc.contributor.author","van den Kerkhof, Alfons M."],["dc.date.accessioned","2018-11-07T09:09:28Z"],["dc.date.available","2018-11-07T09:09:28Z"],["dc.date.issued","2006"],["dc.description.abstract","In order to reconstruct the formation and exhumation mechanisms of UHP metamorphic terrains, the Chinese Continental Scientific Drilling Program (CCSD) has been carried out in Donghai of the Dabie-Sulu ultrahigh-pressure (UHP) metamorphic belt, East China. Eclogite, gneiss, amphibolite (retrograded from eclogite), ultramafic rocks, and minor schist and quartzite have been drilled. Aiming to reveal the fluid behaviour in a vertical sequence of an UHP slab, we investigated fluid inclusion and oxygen isotope characteristics of selected drillcores from the main hole and the pilot-holes PP2 and ZK 703 of the CCSD. More than 540 laser-ablation oxygen isotope analyses on garnet, omphacite, quartz, kyanite, amphibole, phengite, rutile, epidote, amphibole, plagioclase, and biotite from various rocks in the depth range of 0-3,000 m (mainly eclogite and gneiss) show that the investigated rocks can be divided into two groups: O-18-depleted rocks (as low as delta O-18 = -7.4 degrees for garnet) indicate interaction with cold climate meteoric waters, whereas O-18-normal rocks (with bulk delta O-18 > +5.6 degrees) have preserved the O-isotopic compositions of their protoliths. Meteoric water/rock interaction has reached depths of at least 2,700 m. Oxygen isotope equilibrium has generally been achieved. Isotopic compositions of mineral phases are homogeneous on a mm to cm scale regardless of lithology, but heterogeneous on the scale of a few metres. Oxygen isotope distributions in the vertical sections favour an \"in situ\" origin of the UHP metamorphic rocks. The very negative delta O-18 eclogites usually have higher hydroxyl-mineral contents than the normal delta O-18 rocks, indicating higher water content during UHP metamorphism. Fluid inclusion data suggest that rocks with depleted O-18 compositions have had different fluid histories compared to those with normal delta O-18 values. Rocks with depleted O-18 mainly have primary medium-to-high salinity inclusions in omphacite, kyanite and quartz, and abundant secondary low-salinity or pure water inclusions in quartz, indicating a high-salinity-brine-dominated fluid system during peak UHP metamorphism; no carbonic inclusions have been identified in these rocks. By contrast, primary very high-density CO2 inclusions are commonly found in the rocks with normal delta O-18 values. These observations suggest that fluid and oxygen isotope composition of minerals are related and reflect variable degrees of alterations of the Dabie-Sulu UHP metamorphic rocks."],["dc.identifier.doi","10.1007/s00410-006-0084-5"],["dc.identifier.isi","000240548000003"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/26269"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0010-7999"],["dc.title","Ultrahigh-pressure metamorphic rocks from the Chinese Continental Scientific Drilling Project: II Oxygen isotope and fluid inclusion distributions through vertical sections"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","421"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Contributions to Mineralogy and Petrology"],["dc.bibliographiccitation.lastpage","441"],["dc.bibliographiccitation.volume","152"],["dc.contributor.author","Zhang, Z."],["dc.contributor.author","Xiao, Yilin"],["dc.contributor.author","Hoefs, Jochen"],["dc.contributor.author","Liou, J. G."],["dc.contributor.author","Simon, Klaus"],["dc.date.accessioned","2018-11-07T09:09:25Z"],["dc.date.available","2018-11-07T09:09:25Z"],["dc.date.issued","2006"],["dc.description.abstract","The main hole (MH) of the Chinese Continental Scientific Drilling Project (CCSD) in southern Sulu has penetrated into an ultrahigh-pressure (UHP) metamorphic rock slice which consists of orthogneiss, paragneiss, eclogite, ultramafic rock and minor schist. Recovered eclogites have a UHP metamorphic mineral assemblage of garnet + omphacite + rutile +/- phengite +/- kyanite +/- coesite +/- epidote. Ultramafic rocks contain garnet + olivine + clinopyroxene + orthopyroxene +/- Ti-clinohumite +/- phlogopite. Gneisses and schists contain an amphibolite-facies paragenesis, but their zircons have coesite, garnet, omphacite (or jadeite) and phengite inclusions, indicating that eclogites and gneisses have been subjected to in situ UHP metamorphism. Using available geothermobarometers, P-T estimates of 3.1-4.4 GPa and 678-816 degrees C for eclogites were obtained. If surface outcrops and neighboring shallow drill holes are considered together, we suggest that a huge supracrustal rock slab (> 50 km long x 100 km wide x 5 km deep) was subducted to a depth > 100 km and then exhumed to the surface. The depth interval (0-2,050 m) of the CCSD-MH can be divided into six lithological units. Unit 1 consists of alternating layers of quartz-rich and rutile-rich eclogites, with thin interlayers of gneiss and schist. Eclogites of unit 1 are characterized by Nb, Ta, Sr and Ti depletions, low Mg number and general LREE enrichment. Unit 2 comprises rutile- and ilmenite-rich eclogite and minor \"normal\" eclogite and is characterized by high TiO2, total Fe, V, Co and Sr, and very low SiO2, alkali, Zr, Ba, Nb, Ta and total REE contents, and LREE-depleted REE patterns with slightly positive Eu anomalies. Unit 3 contains ultramafic rock and minor MgO-rich eclogite. Protoliths of UHP rocks from units 1, 2 and 3 represent a layered mafic to ultramafic intrusion at crustal depth. Units 4 and 6 consist of interlayered eclogite and paragneiss; the eclogites are characterized by Th, U, Nb, Ta and Ti depletion and K enrichment and LREE-enriched REE patterns. Paragneisses show Nb, Ta, Sr and Ti depletions and LREE-enriched REE patterns occasionally with slightly negative Eu anomalies, indicating that their protoliths represent metamorphic supracrustal series. Unit 5 consists mainly of orthogneisses, showing distinct Nb, Ta, Sr and Ti depletions, and LREE-enriched REE patterns with pronounced negative Eu anomalies, suggesting granitic protoliths. In conclusion it is proposed that the southern Sulu UHP belt consists of a series of meta-supracrustal rocks, a layered mafic-ultramafic complex and granites."],["dc.identifier.doi","10.1007/s00410-006-0120-5"],["dc.identifier.isi","000240548000002"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/26257"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0010-7999"],["dc.title","Ultrahigh pressure metamorphic rocks from the Chinese Continental Scientific Drilling Project: I. Petrology and geochemistry of the main hole (0-2,050 m)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]