@article{WolbernJacobBlakeetal.2006, author = {Wolbern, I and Jacob, A. W. B. and Blake, T. A. and Kind, Rainer and Li, X and Yuan, X. H and Duennebier, F and Weber, Michael H.}, title = {Deep origin of the Hawaiian tilted plume conduit derived from receiver functions}, doi = {10.1111/j.1365-246X.2006.03036.x}, year = {2006}, abstract = {We employ P to S converted waveforms to investigate effects of the hot mantle plume on seismic discontinuities of the crust and upper mantle. We observe the Moho at depths between 13 and 17 km, regionally covered by a strong shallow intracrustal converted phase. Coherent phases on the transverse component indicate either dipping interfaces, 3- D heterogeneities or lower crustal anisotropy. We find anomalies related to discontinuities in the upper mantle down to the transition zone evidently related to the hot mantle plume. Lithospheric thinning is confirmed in greater detail than previously reported by Li et al., and we determine the dimensions of the low-velocity zone within the asthenosphere with greater accuracy. Our study mainly focuses on the temperature-pressure dependent discontinuities of the upper mantle transition zone. Effects of the hot diapir on the depths of mineral phase transitions are verified at both major interfaces at 410 and 660 km. We determine a plume radius of about 200 km at the 660 km discontinuity with a core zone of about 120 km radius. The plume conduit is located southwest of Big Island. A conduit tilted in the northeast direction is required in the upper mantle to explain the observations. The determined positions of deflections of the discontinuities support the hypothesis of decoupled upper and lower mantle convection}, language = {en} } @article{KronerWildeO'Brienetal.2005, author = {Kroner, Alfred and Wilde, S. A. and O'Brien, Patrick J. and Li, J. H. and Passchier, C. W. and Walte, N. P. and Liu, Dun Yi}, title = {Field relationships, geochemistry, zircon ages and evolution of a late Archaean to Palaeoproterozoic lower crustal section in the Hengshan Terrain of northern China}, issn = {1000-9515}, year = {2005}, abstract = {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)}, language = {en} } @article{WangFosterYanetal.2019, author = {Wang, Xiaoxi and Foster, William J. and Yan, J. and Li, A. and Mutti, Maria}, title = {Delayed recovery of metazoan reefs on the Laibin-Heshan platform margin following the Middle Permian (Capitanian) mass extinction}, series = {Global and planetary change}, volume = {180}, journal = {Global and planetary change}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0921-8181}, doi = {10.1016/j.gloplacha.2019.05.005}, pages = {1 -- 15}, year = {2019}, abstract = {Following the Middle Permian (Capitanian) mass extinction there was a global 'reef eclipse', and this event had an important role in the Paleozoic-Mesozoic transition of reef ecosystems. Furthermore, the recovery pattern of reef ecosystems in the Wuchiapingian of South China, before the radiation of Changhsingian reefs, is poorly understood. Here, we present a detailed sedimentological account of the Tieqiao section, South China, which records the only known Wuchiapingian reef setting from South China. Six reef growing phases were identified within six transgressive-regressive cycles. The cycles represent changes of deposition in a shallow basin to a subtidal outer platform setting, and the reefal build-ups are recorded in the shallowest part of the cycles above wave base in the euphotic zone. Our results show that the initial reef recovery started from the shallowing up part of the 1st cycle, within the Clarkina leveni conodont zone, which is two conodont zones earlier than previously recognized. In addition, even though metazoans, such as sponges, do become important in the development of the reef bodies, they are not a major component until later in the Wuchiapingian in the 5th and 6th transgressive-regressive cycles. This suggests a delayed recovery of metazoan reef ecosystems following the Middle Permian extinction. Furthermore, even though sponges do become abundant within the reefs, it is the presence and growth of the encrusters Archaeolithoporella and Tubiphytes and abundance of microbial micrites that play an important role in stabilizing the reef structures that form topographic highs.}, language = {en} } @article{ThompsonChenYangetal.2018, author = {Thompson, Jessica A. and Chen, Jie and Yang, Huili and Li, Tao and Bookhagen, Bodo and Burbank, Douglas}, title = {Coarse- versus fine-grain quartz OSL and cosmogenic Be-10 dating of deformed fluvial terraces on the northeast Pamir margin, northwest China}, series = {Quaternary geochronology : the international research and review journal on advances in quaternary dating techniques}, volume = {46}, journal = {Quaternary geochronology : the international research and review journal on advances in quaternary dating techniques}, publisher = {Elsevier}, address = {Oxford}, issn = {1871-1014}, doi = {10.1016/j.quageo.2018.01.002}, pages = {1 -- 15}, year = {2018}, abstract = {Along the NE Pamir margin, flights of late Quaternary fluvial terraces span actively deforming fault-related folds. We present detailed results on two terraces dated using optically stimulated luminescence (OSL) and cosmogenic radionuclide Be-10 (CRN) techniques. Quartz OSL dating of two different grain sizes (4-11 mu m and 90-180 mu m) revealed the fine-grain quartz fraction may overestimate the terrace ages by up to a factor of ten. Two-mm, small-aliquot, coarse-grain quartz OSL ages, calculated using the minimum age model, yielded stratigraphically consistent ages within error and dated times of terrace deposition to similar to 9 and similar to 16 ka. We speculate that, in this arid environment, fine-grain samples can be transported and deposited in single, turbid, and (sometimes) night-time floods that prevent thorough bleaching and, thereby, can lead to relatively large residual OSL signals. In contrast, sand in the fluvial system is likely to have a much longer residence time during transport, thereby providing greater opportunities for thorough bleaching. CRN Be-10 depth profiles date the timing of terrace abandonment to similar to 8 and similar to 14 ka: ages that generally agree with the coarse-grain quartz OSL ages. Our new terrace age of similar to 13-14 ka is broadly consistent with other terraces in the region that indicate terrace deposition and subsequent abandonment occurred primarily during glacial-interglacial transitions, thereby suggesting a climatic control on the formation of these terraces on the margins of the Tarim Basin. Furthermore, tectonic shortening rates calculated from these deformed terraces range from similar to 1.2 to similar to 4.6 mm/a and, when combined with shortening rates from other structures in the region, illuminate the late Quaternary basinward migration of deformation to faults and folds along the Pamir-Tian Shan collisional interface.}, language = {en} } @article{ThompsonBurbankLietal.2015, author = {Thompson, Jessica A. and Burbank, Douglas W. and Li, Tao and Chen, Jie and Bookhagen, Bodo}, title = {Late Miocene northward propagation of the northeast Pamir thrust system, northwest China}, series = {Tectonics}, volume = {34}, journal = {Tectonics}, number = {3}, publisher = {American Geophysical Union}, address = {Washington}, issn = {0278-7407}, doi = {10.1002/2014TC003690}, pages = {510 -- 534}, year = {2015}, abstract = {Piggyback basins on the margins of growing orogens commonly serve as sensitive recorders of the onset of thrust deformation and changes in source areas. The Bieertuokuoyi piggyback basin, located in the hanging wall of the Pamir Frontal Thrust, provides an unambiguous record of the outward growth of the northeast Pamir margin in northwest China from the Miocene through the Quaternary. To reconstruct the deformation along the margin, we synthesized structural mapping, stratigraphy, magnetostratigraphy, and cosmogenic burial dating of basin fill and growth strata. The Bieertuokuoyi basin records the initiation of the Pamir Frontal Thrust and the Takegai Thrust similar to 5-6Ma, as well as clast provenance and paleocurrent changes resulting from the Pliocene-to-Recent uplift and exhumation of the Pamir to the south. Our results show that coeval deformation was accommodated on the major structures on the northeast Pamir margin throughout the Miocene to Recent. Furthermore, our data support a change in the regional kinematics around the Miocene-Pliocene boundary (similar to 5-6Ma). Rapid exhumation of NE Pamir extensional domes, coupled with cessation of the Kashgar-Yecheng Transfer System on the eastern margin of the Pamir, accelerated the outward propagation of the northeastern Pamir margin and the southward propagation of the Kashi-Atushi fold-and-thrust belt in the southern Tian Shan. This coeval deformation signifies the coupling of the Pamir and Tarim blocks and the transfer of shortening north to the Pamir frontal faults and across the quasi-rigid Tarim Basin to the southern Tian Shan Kashi-Atushi fold-and-thrust system.}, language = {en} } @article{AtsawawaranuntComasBruMozhdehietal.2018, author = {Atsawawaranunt, Kamolphat and Comas-Bru, Laia and Mozhdehi, Sahar Amirnezhad and Deininger, Michael and Harrison, Sandy P. and Baker, Andy and Boyd, Meighan and Kaushal, Nikita and Ahmad, Syed Masood and Brahim, Yassine Ait and Arienzo, Monica and Bajo, Petra and Braun, Kerstin and Burstyn, Yuval and Chawchai, Sakonvan and Duan, Wuhui and Hatvani, Istvan Gabor and Hu, Jun and Kern, Zoltan and Labuhn, Inga and Lachniet, Matthew and Lechleitner, Franziska A. and Lorrey, Andrew and Perez-Mejias, Carlos and Pickering, Robyn and Scroxton, Nick and Atkinson, Tim and Ayalon, Avner and Baldini, James and Bar-Matthews, Miriam and Pablo Bernal, Juan and Breitenbach, Sebastian Franz Martin and Boch, Ronny and Borsato, Andrea and Cai, Yanjun and Carolin, Stacy and Cheng, Hai and Columbu, Andrea and Couchoud, Isabelle and Cruz, Francisco and Demeny, Attila and Dominguez-Villar, David and Dragusin, Virgil and Drysdale, Russell and Ersek, Vasile and Finne, Martin and Fleitmann, Dominik and Fohlmeister, Jens Bernd and Frappier, Amy and Genty, Dominique and Holzkamper, Steffen and Hopley, Philip and Kathayat, Gayatri and Keenan-Jones, Duncan and Koltai, Gabriella and Luetscher, Marc and Li, Ting-Yong and Lone, Mahjoor Ahmad and Markowska, Monika and Mattey, Dave and McDermott, Frank and Moreno, Ana and Moseley, Gina and Nehme, Carole and Novello, Valdir F. and Psomiadis, David and Rehfeld, Kira and Ruan, Jiaoyang and Sekhon, Natasha and Sha, Lijuan and Sholz, Denis and Shopov, Yavor and Smith, Andrew and Strikis, Nicolas and Treble, Pauline and Unal-Imer, Ezgi and Vaks, Anton and Vansteenberge, Stef and Veiga-Pires, Cristina and Voarintsoa, Ny Riavo and Wang, Xianfeng and Wong, Corinne and Wortham, Barbara and Wurtzel, Jennifer and Zong, Baoyun}, title = {The SISAL database}, series = {Earth System Science Data}, volume = {10}, journal = {Earth System Science Data}, number = {3}, publisher = {Copernicus}, address = {G{\"o}ttingen}, organization = {SISAL Working Grp Members}, issn = {1866-3508}, doi = {10.5194/essd-10-1687-2018}, pages = {1687 -- 1713}, year = {2018}, abstract = {Stable isotope records from speleothems provide information on past climate changes, most particularly information that can be used to reconstruct past changes in precipitation and atmospheric circulation. These records are increasingly being used to provide "out-of-sample" evaluations of isotope-enabled climate models. SISAL (Speleothem Isotope Synthesis and Analysis) is an international working group of the Past Global Changes (PAGES) project. The working group aims to provide a comprehensive compilation of speleothem isotope records for climate reconstruction and model evaluation. The SISAL database contains data for individual speleothems, grouped by cave system. Stable isotopes of oxygen and carbon (delta O-18, delta C-13) measurements are referenced by distance from the top or bottom of the speleothem. Additional tables provide information on dating, including information on the dates used to construct the original age model and sufficient information to assess the quality of each data set and to erect a standardized chronology across different speleothems. The metadata table provides location information, information on the full range of measurements carried out on each speleothem and information on the cave system that is relevant to the interpretation of the records, as well as citations for both publications and archived data.}, language = {en} } @article{ComasBruHarrisonWerneretal.2019, author = {Comas-Bru, Laia and Harrison, Sandy P. and Werner, Martin and Rehfeld, Kira and Scroxton, Nick and Veiga-Pires, Cristina and Ahmad, Syed Masood and Brahim, Yassine Ait and Mozhdehi, Sahar Amirnezhad and Arienzo, Monica and Atsawawaranunt, Kamolphat and Baker, Andy and Braun, Kerstin and Breitenbach, Sebastian Franz Martin and Burstyn, Yuval and Chawchai, Sakonvan and Columbu, Andrea and Deininger, Michael and Demeny, Attila and Dixon, Bronwyn and Hatvani, Istvan Gabor and Hu, Jun and Kaushal, Nikita and Kern, Zoltan and Labuhn, Inga and Lachniet, Matthew S. and Lechleitner, Franziska A. and Lorrey, Andrew and Markowska, Monika and Nehme, Carole and Novello, Valdir F. and Oster, Jessica and Perez-Mejias, Carlos and Pickering, Robyn and Sekhon, Natasha and Wang, Xianfeng and Warken, Sophie and Atkinson, Tim and Ayalon, Avner and Baldini, James and Bar-Matthews, Miryam and Bernal, Juan Pablo and Boch, Ronny and Borsato, Andrea and Boyd, Meighan and Brierley, Chris and Cai, Yanjun and Carolin, Stacy and Cheng, Hai and Constantin, Silviu and Couchoud, Isabelle and Cruz, Francisco and Denniston, Rhawn and Dragusin, Virgil and Duan, Wuhui and Ersek, Vasile and Finne, Martin and Fleitmann, Dominik and Fohlmeister, Jens Bernd and Frappier, Amy and Genty, Dominique and Holzkamper, Steffen and Hopley, Philip and Johnston, Vanessa and Kathayat, Gayatri and Keenan-Jones, Duncan and Koltai, Gabriella and Li, Ting-Yong and Lone, Mahjoor Ahmad and Luetscher, Marc and Mattey, Dave and Moreno, Ana and Moseley, Gina and Psomiadis, David and Ruan, Jiaoyang and Scholz, Denis and Sha, Lijuan and Smith, Andrew Christopher and Strikis, Nicolas and Treble, Pauline and Unal-Imer, Ezgi and Vaks, Anton and Vansteenberge, Stef and Voarintsoa, Ny Riavo G. and Wong, Corinne and Wortham, Barbara and Wurtzel, Jennifer and Zhang, Haiwei}, title = {Evaluating model outputs using integrated global speleothem records of climate change since the last glacial}, series = {Climate of the past : an interactive open access journal of the European Geosciences Union}, volume = {15}, journal = {Climate of the past : an interactive open access journal of the European Geosciences Union}, number = {4}, publisher = {Copernicus}, address = {G{\"o}ttingen}, organization = {SISAL Working Grp}, issn = {1814-9324}, doi = {10.5194/cp-15-1557-2019}, pages = {1557 -- 1579}, year = {2019}, abstract = {Although quantitative isotope data from speleothems has been used to evaluate isotope-enabled model simulations, currently no consensus exists regarding the most appropriate methodology through which to achieve this. A number of modelling groups will be running isotope-enabled palaeoclimate simulations in the framework of the Coupled Model Intercomparison Project Phase 6, so it is timely to evaluate different approaches to using the speleothem data for data-model comparisons. Here, we illustrate this using 456 globally distributed speleothem δ18O records from an updated version of the Speleothem Isotopes Synthesis and Analysis (SISAL) database and palaeoclimate simulations generated using the ECHAM5-wiso isotope-enabled atmospheric circulation model. We show that the SISAL records reproduce the first-order spatial patterns of isotopic variability in the modern day, strongly supporting the application of this dataset for evaluating model-derived isotope variability into the past. However, the discontinuous nature of many speleothem records complicates the process of procuring large numbers of records if data-model comparisons are made using the traditional approach of comparing anomalies between a control period and a given palaeoclimate experiment. To circumvent this issue, we illustrate techniques through which the absolute isotope values during any time period could be used for model evaluation. Specifically, we show that speleothem isotope records allow an assessment of a model's ability to simulate spatial isotopic trends. Our analyses provide a protocol for using speleothem isotope data for model evaluation, including screening the observations to take into account the impact of speleothem mineralogy on δ18O values, the optimum period for the modern observational baseline and the selection of an appropriate time window for creating means of the isotope data for palaeo-time-slices.}, language = {en} } @article{HerzschuhLiBoehmeretal.2022, author = {Herzschuh, Ulrike and Li, Chenzhi and Boehmer, Thomas and Postl, Alexander K. and Heim, Birgit and Andreev, Andrei A. and Cao, Xianyong and Wieczorek, Mareike and Ni, Jian}, title = {LegacyPollen 1.0}, series = {Earth system science data : ESSD}, volume = {14}, journal = {Earth system science data : ESSD}, number = {7}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1866-3508}, doi = {10.5194/essd-14-3213-2022}, pages = {3213 -- 3227}, year = {2022}, abstract = {Here we describe the LegacyPollen 1.0, a dataset of 2831 fossil pollen records with metadata, a harmonized taxonomy, and standardized chronologies. A total of 1032 records originate from North America, 1075 from Europe, 488 from Asia, 150 from Latin America, 54 from Africa, and 32 from the Indo-Pacific. The pollen data cover the late Quaternary (mostly the Holocene). The original 10 110 pollen taxa names (including variations in the notations) were harmonized to 1002 terrestrial taxa (including Cyperaceae), with woody taxa and major herbaceous taxa harmonized to genus level and other herbaceous taxa to family level. The dataset is valuable for synthesis studies of, for example, taxa areal changes, vegetation dynamics, human impacts (e.g., deforestation), and climate change at global or continental scales. The harmonized pollen and metadata as well as the harmonization table are available from PANGAEA (https://doi.org/10.1594/PANGAEA.929773; Herzschuh et al., 2021). R code for the harmonization is provided at Zenodo (https://doi.org/10.5281/zenodo.5910972; Herzschuh et al., 2022) so that datasets at a customized harmonization level can be easily established.}, language = {en} }