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Ecological Processes 2024年第1期13卷 108-119页

作者： Benny Selle Berliner Hochschule Für Technik Fachbereich geowissenschaften Universit?t Tübingen

Background Discovering causality in environmental systems is challenging because frequently controlled experiments or numerical simulations are difficult. Algorithms to learn directed acyclic graphs from system data are powerful, but they often result in too many possible causal structures that cannot be properly *** An approach to this problem proposed here is to initially restrict the system to a target variable with its two major drivers. Subsequently, testable causal structures are obtained from rules to infer directed acyclic graphs and expert knowledge. The proposed approach, which is essentially based on correlation and regression, was applied to understand drivers of a toxic algal bloom in the Odra River in summer 2022. Through this application, useful insight on the interplay between river flow and salt inputs that likely caused the algal bloom was *** The Odra River example demonstrated that carefully applied correlation and regression techniques together with expert knowledge can help to discover reliable casual structures in environmental systems.

关键词： Causal effect Causal model Causal diagram Mediation analysis Directed acyclic graph Classification and regression trees

The lacustrine sedimentary records of coal-burning atmospheric pollution

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Science China Earth Sciences 2005年第10期48卷 1740-1746页

作者： E. Appel V. Hoffmann Institut für geowissenschaften Universitt Tübingen 72076 Tübingen GermanyInstitut für Geowissenschaften Universitt Tübingen 72076 Tübingen Germany

Based on the studies on diatom, ostracods and magnetism on a core acquired from lacustrine sediments, as well as correlation analysis between concentration of acid diatom and the instantaneous lowest pH value, the processes of environment evolution in Lake Yangzonghai were reconstructed. The lacustrine environment was favorable in the 1950s, and began to be polluted by a coal-burning power plant since 1960. During 1965―1980, the instantaneous lowest pH value of lake water decreased to 5―6 when heavily polluted. There was a decrease trend in the pollution from 1983 to 1999, but coal-burning atmospheric pollution was still a main problem for environmental retrieving. As acid precipitated, acid-tolerant species overspread, and shellfish disappeared, as well as ferromagnetic particulates dissolved because of the consequent change of pH-Eh values in the interface of water and soil, which results in the change of environmental proxies versus depth. Thus, the environmental evolution of Lake Yangzonghai is reconstructed in this paper based on the inferences mentioned above.

关键词： atmospheric pollution, proxies, environmental reconstruction, lacustrine sediment, Lake Yangzonghai.

U-Pb zircon ages for the Luzhenguan Complex in northern part of the eastern Dabie orogen

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Science China Earth Sciences 2005年第9期48卷 1357-1367页

作者： Wolfgang Siebe Institut für geowissenschaften Universit?t Tübingen Tübingen 72074 Germany

The study presents U-Pb zircon ages for granitic gneiss and amphibolite from the Luzhenguan Complex (LZC) in northern part of the eastern Dabie Orogen and their geological significance. Two granitic gneisses and one amphibolite give protolith zircon U-Pb ages of 740 Ma and 725 Ma, respectively. The ages show that the LZC is composed mainly of Neoproterzoic acid and basic igneous rocks, suggesting that there is no Paleozoic active continental marginal rock association in the southern margin of the North China Block in northern part of the eastern Dabie Mountain. Based on the ages and combining the geological and geophysical analyses, the middle-low grade metamorphic rocks in the North Huiyang Belt (NHB) can be divided into three parts, which are the LZC composed mainly of the Neoproterzoic acid and basic igneous rocks, the Neoproterzoic Xianrechong Formation and Xiangyunzhai Formation and the Devonian Zhu- foan Formation and Pangjialing Formation of the Foziling Group, and the suture zone between the Yongtze Block and the North China Block is inferred to be thrust under the NHB.

关键词： Dabie orogen, Luzhenguan Complex, U-Pb zircon age, Neoproterzoic.

Temperature and structure measurements of heavy-ion-heated diamond using in situ X-ray diagnostics

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Matter and Radiation at Extremes 2024年第4期9卷 80-89页

作者： J.Lutgert P.Hesselbach M.Schorner V.Bagnoud R.Belikov P.Drechsel B.Heuser O.SHumphries P.Katrik B.Lindqvist C.Qu R.Redmer D.Riley G.Schaumann S.Schumacher A.Tauschwitz D.Varentsov K.Weyrich X.Yu B.Zielbauer Zs.Major P.Neumayer D.Kraus Institut fur Physik Universitat RostockAlbert-Einstein-Str.2318059 RostockGermany GSI Helmholtzzentrum fur Schwerionenforschung Planckstr.164291 DarmstadtGermany Institut für Angewandte Physik Goethe-Universität Frankfurt am MainMax-von-Laue-Str.160438 Frankfurt am MainGermany Institut fur geowissenschaften Goethe-Universitat Frankfurt am MainAltenhoferallee 160438 Frankfurt am MainGermany Helmholtz-Zentrum Dresden-Rossendorf Bautzner Landstr.40001328 DresdenGermany European XFEL GmbH Holzkoppel 422869 SchenefeldGermany Centre for Plasma Physics School of Mathematics and PhysicsQueen’s University BelfastUniversity RoadBelfast BT71NNUnited Kingdom Institut für Kernphysik Technische Universität DarmstadtSchlossgartenstr.964289 DarmstadtGermany State Key Laboratory of Nuclear Physics and Technology Institute of Heavy Ion PhysicsPeking UniversityBeijing 100871China Helmholtz Institut Jena Frobelstieg 307743 JenaGermany

We present in situ measurements of spectrally resolved X-ray scattering and X-ray diffraction from monocrystalline diamond samples heatedwith an intense pulse of heavy *** this way,we determine the samples’heating dynamics and their microscopic and macroscopic structuralintegrity over a timespan of several *** the ratio of elastic to inelastic scattering with state-of-the-art density functionaltheory molecular dynamics simulations allows the inference of average temperatures around 1300 K,in agreement with predictions fromstopping power *** simultaneous diffraction measurements show no hints of any volumetric graphitization of the material,butdo indicate the onset of fracture in the diamond *** experiments pave the way for future studies at the Facility for Antiproton andIon Research,where a substantially increased intensity of the heavy ion beam will be available.

关键词： heated intense structure

Tectonic Evolution of an Early Precambrian High-Pressure Granulite Belt in the North China Craton

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Acta Geologica Sinica(English Edition) 2000年第2期74卷 246-258页

作者： Alfred KRONER P.O.BRIEN Institut fuer geowissenschaften Universitaet Mainz 55099 Mainz GermanyBayerisches Geoinstitut Universitat Bayreuth 95440 Bayreuth Germany

A large-scale high-pressure granulite belt (HPGB), more than 700 km long, is recognized within the metamorphic basement of the North China craton. In the regional tectonic framework, the Hengshan-Chengde HPGB is located in the central collision belt between the western block and eastern block, and represents the deep crustal structural level. The typical high-pressure granulite (HPG) outcrops are distributed in the Hengshan and Chengde areas. HPGs commonly occur as mafic xenoliths within ductile shear zones, and underwent multipile deformations. To the south, the Hengshan-Chengde HPGB is juxtaposed with the Wutai greenstone belt by several strike-slip shear zones. Preliminary isotopic age dating indicates that HPGs from North China were mainly generated at the end of the Neoarchaean, assocaited with tectonic assembly of the western and eastern blocks.

关键词： North China craton high-pressure metamorphism collision belt Neoarchaean

Age and Origin of Paleogene Granitoids from Western Yunnan Province,China:Geochemistry,SHRIMP Zircon Ages,and Hf-in-Zircon Isotopic Compositions

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Acta Geologica Sinica(English Edition) 2015年第5期89卷 1601-1615页

作者： SHI Yuruo WU Zhonghai Alfred KRoNER FAN Taoyuan YANG Zhenyu Beijing SHRIMP Center Institute of GeologyChinese Academy of Geological Sciences Institute of Geomechanics Chinese Academy of Geological Sciences Institut für geowissenschaften Universitat Mainz

We report geochemical data, SHRIMP zircon ages and Hf-in-zircon isotopic compositions for Cenozoic granitoids from major fault systems in the Tethyan belt in western Yunnan Province, southwestern *** magmatic pulses occurred in the Paleogene, namely at ca.57 Ma, ca.50 Ma, 45–40 Ma, and 38–34 *** magmatism of this episode（57–50 Ma） produced S-type granites whose zircons yielded εHf（t） values of-5.0 *** contrast, late magmatism of this episode reflects heterogeneous *** from a granite porphyry along the Ailaoshan-Red River fault system have slightly positive εHf（t） values suggesting derivation from relatively young crust and/or a juvenile ***, zircons from a granite along the Gaoligong fault system have strongly negative εHf（t） values and suggest derivation from a Paleoproterozoic crustal *** composition of the granitoids varies with age（from ca.57 Ma to ca.34 Ma） from peraluminous to metaluminous and also suggests a change from syn-collisional to late-orogenic tectonic setting.A new tectonic model, impacting lithospheric wedge（ILW） is shown for the origin of Paleogene granitoids in this paper.

关键词： Paleogene magmatism SHRIMP zircon ages Hf-in-zircon isotopic compositions western Yunnan

Palynological investigation of a Holocene profile section from the Palaeo-Gaxun-Nur-Basin

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Chinese Science Bulletin 2003年第14期48卷 1418-1422页

作者： D.Demske S.Mischke Institut f geologische Wissenschaften (Palntologie) FB Geowissenschaften Freie UniversitBerlin Malteser Str. 74-100 D 12249 Berlin Germany Institut f geologische Wissenschaften (Palntologie) FB Geowissenschaften Freie UniversitBerlin Malteser Str. 74-100 D 12249 Berlin Germany

Palynological investigations on lacustrine sediment samples revealed a general dominance of open Artemisia-Chenopodiaceae vegetation in the Palaeo-Gaxun- Nur-Basin (Inner Mongolia) between 5250 and 3500 cal. aBP. Riverside woods (Hippopha? Populus) developed between 35003250 cal. aBP and reflect moister growing conditions. During the following moist-dry transition pronounced cooling occurred around 3000 cal. aBP, in upper elevations favouring the spread of montane woods (Picea, Betula). Aridity strongly increased from 2900 to 2700 cal. aBP. The recorded vegetational and environmental changes after 3500 cal. aBP can be correlated with glacier advances in the mountains and with a humid phase in the Tengger Shamo followed by desertification.

关键词：孢粉学全新世纵剖面湖泊沉积物中国内蒙古

Single zircon evaporation ages: Evidence for the Mesoproterozoic crust in the southeastern Nigerian basement complex

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Chinese Journal Of Geochemistry 2012年第1期31卷 48-54页

作者： Ekere E.Ukwang Barth N.Ekwueme Alfred Krner Department of Geology University of CalabarEtta AgborP.M.B.1115 CalabarNigeria Institut fur geowissenschaften Universitat MainzGermany

The Ukwortung area of the Obudu Plateau exposes high-grade metamorphic rocks of upper amphibolite to granulite facies. Zircon grains from three locations of Southwest Obudu Plateau were dated by the Pb-Pb dating method. This single zircon radiometric dating method confirms the occurrence of Mesoproterozoic crust in the southeastern Nigeria basement complex. The pyroxene gneiss (granulite facies) sample from Biereberi near Ukpe yielded a mean age of 2061.4±0.4 Ma, suggesting the presence of Paleoproterozoic crust. The combined 207Pb/206Pb ratios from the garnet-biotite gneiss in the area gave a mean age of 1794.4±0.4 Ma. This further confirms the pres-ence of Paleoproterozoic crustal components within the Obudu Plateau. The Mesoproterozoic (1548.8±0.5 Ma) and Neoproterozoic (619.8±0.9 Ma) ages were obtained from two populations of zircon grains from the leucogranite in Okordem, Southwest Obudu. These "signatures" collaborate the occurrence of Mesoproterozoic ages in the Afar region and Cameroon basements along with the southeastern Nigerian basement complex, constituting the major portion of the West Central African mobile belt. The zircon age of 1794.4±0.4 Ma may probably be the maximum depositional age of the meta-sediment (garnet-biotite gneiss) and the age of 1548.8±0.5 Ma may be interpreted as the time of emplacement of the granitoid. The Neoproterozoic age (619.8±0.9 Ma) probably records the metamorphic event that was prevalent during the Pan-African period and thus affected the area.

关键词：单颗粒锆石平均年龄地壳成分中元古代尼日利亚地下室东南部证据

Elastic and Seismic Properties of Dabie-Sulu Ultrahigh Pressure Metamorphic Rocks

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Acta Geologica Sinica(English Edition) 2012年第1期86卷 20-37页

作者： WANG Qian JI Shaocheng SUN Shengsi Matthew H.SALISBURY Hartmut KERN State Key Laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Departement des Genies Civil Geologique et des MinesEcole Polytechnique de Montreal Montreal H3C 3A7Canada State Key Laboratory of Continental Tectonics and Dynamics Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China Geological Survey of Canada-Atlantic Bedford Institute of OceanographyDartmouth B2Y 4A2Canada institutfur geowissenschaften Universitat Kiel24098 KielGermany

Lame modulus （λ） and shear modulus （μ） are among the most important, intrinsic, elastic constants of rocks. Using 7. and μ could be much more advantageous than using P- and S-wave velocities （Vp and Vs）. Here we quantified these equivalent isotropic elastic moduli for 115 representative rocks from the ultrahigh pressure （UHP） metamorphic terrane of the Dabie-Sulu orogenic belt （China） and their variations with pressure （P）, temperature （T）, density （p）, Vp, Vs and mineralogical composition. Both moduli increase nonlinearly and linearly with increasing pressure at low （〈200-300 MPa） and high （〉200-300 MPa） pressures, respectively. In the regime of high pressures, 7. and IX decrease quasi-linearly with increasing temperature with temperature derivatives dλ/dT and dμ/dT generally in the range of -10×10-3 to -1×10-3 GPa/℃. Dehydration of water-bearing minerals such as serpentine in peridotites and chlorite in retrograde eciogites results in an abrupt drop in 7. while μ remains almost unchanged. In Z-p, μ-p and 7.-IX plots, the main categories of UHP rocks can be characterized. Serpentinization leads to significant decreases in μ and 7. as serpentine has extremely low values of Z, μ and p. Eclogites, common mafic rocks （mafic gneiss, metagabbro and amphibolite）, and felsic rocks （orthogneiss and paragneiss） have high, moderate and low μ and λ values, respectively. For pyroxenes and olivines, λ increases but μ decreases with increasing Fe/Mg ratios. For plagioclase feldspars, both Z and μ exhibit a significant positive correlation with anorthite content. SiO2-rich felsic rocks and quartzites are deviated remarkably from the general trend lines of the acid-intermediate-mafic rocks in Vs-p, μ-p, λ-Vp,λ-Vs and μ-λ diagrams because quartz has extremely low λ （-8.1 GPa） and p （2.65 g/cm3） but moderate μ （44.4 GPa） values. Increasing the contents of garnet, rutile, ilmenite and magnetite results in a significant increase in the λ and μ values of the UHP metamorphic rocks. Howev

关键词： seismic properties elastic constants ultrahigh pressure metamorphic rocks Dabie-Sulu,deep continental roots

ESR Dating of the Evolution of the Shuanghu Basin in the Northern Tibetan Plateau

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Acta Geologica Sinica(English Edition) 1999年第3期73卷 289-293页

作者： WU Zhenhan JIANG Wan Peter Blisniuk BI Siwen ZHANG Shukun Olaf Kuchel MAO Yi Institute of Geomechcmics CAGS Minzu Xueyuan Nanlu Beijing 100081 Institut für geowissenschaften Universitat Potsdam Postfach 601553 D-14415 Potsdam Germany

The Shuanghu basin is a NE-trending rift basin bounded by NE-striking normal faults and NW-striking shear-extensional faults of the northern Tibetan Plateau. Four samples from calcite veins in marginal faults and one sample from mudstone (S-3) were collected for dating the evolution of the Shuanghu basin by using the ESR spectrograph of EXM-type. Ages were calculated according to the close-equilibrium model on the basis of the measured ESR signal spectra of samples, providing good chronological information. It is known from the ESR dating that the extensional faulting and rifting of the Shuanghu area began at 4.92 Ma B.P., followed by regional folding in 3.56–1.36 Ma, NW-striking faulting in 0.60 Ma and normal faulting in 0.024 Ma in the Shuanghu basin.

关键词： ESR dating tectonic events Shuanghu basin Tibetan Plateau.