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A new inclination-based method to evaluate the global geomagnetic configuration and axial dipole moment

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Earth and Planetary Physics 2022年第4期6卷 359-365页

作者： KaiHua Xu Fei He Yong Wei ross n.mitchell Si Chen YuQi Wang ZhaoJin Rong Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China School of Earth and Environment University of LeedsLeedsLS29JTUK

The strength and configuration of the geomagnetic field control the average shape of the *** pure dipole assumption and the virtual dipole moment(VDM),determined by individual records,have been widely adopted to evaluate the strength of the geomagnetic field in geological ***,such an assumption might not be valid during geomagnetic transitions,such as reversals and *** traditional spherical harmonic modeling of the geomagnetic field could be difficult to implement because accurate global records are ***,we report that an empirical relationship exists between the ratio of the VDM to the true axial dipole moment(VDM/ADM)and the ratio of the power of the axial dipole to that of the non-axial dipole(AD/nAD)based on a new method utilizing globally distributed inclination *** root mean square global deviation of inclination(RMSΔI)to the standard inclination distribution of the AD was fitted to the AD/nAD with a cubic polynomial by utilizing a large number of geodynamo *** with geomagnetic field models showed that the AD/nAD derived from the RMSΔI agreed well with that calculated by using the Gauss coefficients,and the estimated ADM was consistent with the true ***,the application of volcanic records during the Laschamp excursion showed the VDM might overestimate the ADM by a factor of *** new method will be useful in future studies that characterize the configuration of the geomagnetic field and the strength of the axial dipole.

关键词： axial dipole magnetic inclination virtual dipole moment

A Great late Ediacaran ice age

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national Science Review 2023年第8期10卷 105-118页

作者： Ruimin Wang Bing Shen Xianguo Lang Bin Wen ross n. mitchell Haoran Ma Zongjun Yin Yongbo Peng Yonggang Liu Chuanming Zhou Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education and School of Earth and Space SciencesPeking University 2. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation and Institute of Sedimentary GeologyChengdu University of Technology 3. State Key Laboratory of Geological Processes and Mineral Resources School of Earth Sciences China University of Geosciences State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of Sciences College of Earth and Planetary Sciences University of Chinese Academy of Sciences School of Earth Sciences and Engineering Nanjing University State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment Chinese Academy of Sciences School of Physics Peking University

The emergence of the Ediacara biota soon after the Gaskiers glaciation ca. 580 million years ago(Ma)implies a possible glacial fuse for the evolution of animals. However, the timing of Ediacaran glaciation remains controversial because of poor age constraints on the ～30 Ediacaran glacial deposits known worldwide. In addition, paleomagnetic constraints and a lack of convincing Snowball-like cap carbonates indicate that Ediacaran glaciations likely did not occur at low latitudes. Thus, reconciling the global occurrences without global glaciation remains a paradox. Here, we report that the large amplitude, globally synchronous ca. 571–562 Ma Shuram carbon isotope excursion occurs below the Ediacaran Hankalchough glacial deposit in Tarim, confirming a post-Shuram glaciation. Leveraging paleomagnetic evidence for a～90° reorientation of all continents due to true polar wander, and a non-Snowball condition that rules out low-latitude glaciations, we use paleogeographic reconstructions to further constrain glacial ages. Our results depict a ‘Great Ediacaran Glaciation’ occurring diachronously but continuously from ca.580–560 Ma as different continents migrated through polar–temperate latitudes. The succession of radiation, turnover and extinction of the Ediacara biota strongly reflects glacial–deglacial dynamics.

关键词： carbonate carbon isotopes Shuram excursion inertial interchange true polar wander (IITPW) hankalchough glaciation Tarim Block

Dichotomy in crustal melting on early Mars inferred from antipodal effect

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The Innovation 2022年第5期3卷 107-113页

作者： Lei Zhang Jinhai Zhang ross n.mitchell Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China

The Martian crustal dichotomy(MCD)between the southern highlands and the northern lowlands is the planet’s most ancient crustal structure,but its origins and evolution remain *** of the MCD comes largely from present-day and shallow crustal *** ancient and deeper constraints,hypotheses for the origin of the MCD range from an early giant impact,partial melting from sustained mantle convection,or some *** investigate with seismological modeling the best-preserved case of the“antipodal effect”-energy from an impact that concentrates and induces uplift and fracturing promoting volcanism at its antipode-the Hellas crater and the Alba Patera volcano on Mars.

关键词： crustal shallow mantle

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华北克拉通太古宙地壳生长的峰期

Science Bulletin 2022年第15期67卷 1553-1555,M0003页

作者：刘鹏郭敬辉彭澎 ross n.mitchell 毛梦霞姜能翟明国 State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

长期以来2.7~2.8 Ga被普遍接受为华北克拉通太古宙地壳生长的主峰期,与全球地壳生长同步,其主要依据是华北克拉通多数锆石的亏损地幔Hf模式年龄的峰值分布在2.7~2.8 Ga.然而Hf模式年龄受源区成分和地幔模式的选择以及源区不均一性等多... 详细信息

长期以来2.7~2.8 Ga被普遍接受为华北克拉通太古宙地壳生长的主峰期,与全球地壳生长同步,其主要依据是华北克拉通多数锆石的亏损地幔Hf模式年龄的峰值分布在2.7~2.8 Ga.然而Hf模式年龄受源区成分和地幔模式的选择以及源区不均一性等多种因素影响,具体数值未必有确切地质含义.而全球公认的2.7 Ga地壳生长峰期并非依据模式年龄,而主要依据:以绿岩带为代表的巨量镁铁质岩浆活动峰期在2.7 Ga,由此引发的巨量长英质岩浆活动峰期在2.7 Ga,全球地幔亏损事件的峰期也在2.7 Ga.与此相对应,对于华北克拉通,以绿岩带为代表的巨量镁铁质岩浆活动峰期在2.5 Ga,由此引发的巨量长英质岩浆活动峰期也在2.5 Ga.因此,如不考虑不同构造背景保存偏差的影响,~2.5 Ga应被视作华北克拉通较为明确的地壳生长的主峰期.

关键词：华北克拉通绿岩带太古宙峰期模式年龄岩浆活动地壳生长不均一性

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火山磷供给推动中国北方中生代陆地生物繁荣

Science Bulletin 2023年第12期68卷 1317-1326,M0004页

作者：马超汤艳杰 ross n.mitchell 李永飞孙守亮朱吉昌 Stephen F.Foley 王敏叶辰阳英基丰朱日祥 State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Shenyang Center of China Geological Survey Shenyang 110034China Australia School of natural Sciences Macquarie UniversityNorth Ryde NSW 2109Australia Research School of Earth Sciences Australian National UniversityCanberra ACT 2601Australia Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China Center for Excellence in Life and Paleoenvironment Chinese Academy of SciencesBeijing 100044China

中国北方中生代热河生物群的生物量和生物多样性超过了同时期的其他陆地生物群,早白垩世热河生物群的辐射可能是对华北克拉通峰期破坏过程的响应,然而,克拉通破坏的深部过程和陆地生物群演化之间的内在联系尚不清楚。磷是生命所必需的... 详细信息

中国北方中生代热河生物群的生物量和生物多样性超过了同时期的其他陆地生物群,早白垩世热河生物群的辐射可能是对华北克拉通峰期破坏过程的响应,然而,克拉通破坏的深部过程和陆地生物群演化之间的内在联系尚不清楚。磷是生命所必需的营养元素,火山产物(包括熔岩和火山碎屑岩)中的磷可通过风化作用供给陆地生态系统。中国北方中生代连续的火山-沉积序列记录了火山磷供给、生物生产力和物种丰度的变化,为研究地球深部过程、火山作用与陆地生物群的协同演化提供了关键证据.火山磷供给与生物群演化之间的耦合关系表明,在华北克拉通峰期破坏期间,大量火山产物的风化作用为陆地生态系统供给了丰富的营养物质,创造了有利于热河生物群繁荣的陆地环境。与华北克拉通破坏初期相对应的侏罗纪燕辽生物群的演化也反映了上述火山-生物之间的耦合机制。

关键词：风化作用华北克拉通火山碎屑岩陆地生物火山作用陆地环境地球深部沉积序列

Trial by fire:Testing the paleolongitude of Pangea of competing reference frames with the African LLSVP

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Geoscience Frontiers 2020年第4期11卷 1253-1256页

作者： ross n.mitchell Lei Wu J.Brendan Murphy Zheng-Xiang Li State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijingChina Earth Dynamics Research Group The Institute for Geoscience Research(TIGeR)School of Earth and Planetary SciencesCurtin UniversityGPO Box U1987PerthWAAustralia Department of Earth Sciences St.Francis Xavier UniversityAntigonishNova ScotiaCanada

Paleogeography can be reconstructed using various crust-or mantle-based reference frames that make fundamentally different *** various reconstruction models differ significantly in continental paleolongitude,but it has been difficult to assess which models are more *** suggest here a "LLSVP test",where an assumed correlation between present-day large low velocity shear-wave provinces and the paleogeography of supercontinent Pangea at breakup ca.200 million years ago can be used to assess the relative accuracy of published *** correlations between continental paleolongitude and the African LLSVP are achieved with mantle-based reference frames(moving hotspots and true polar wander),whereas shallower crustbased reference frames are shown to be *** relative success of mantle-based frames,and thus the importance of the depth of reference frame,supports the notion that mantle convection is largely vertical compared to the horizontal plate motion of tectonics.

关键词： Palaeogeography Plate tectonics LLSVPs Reference frames

Evolving mantle convection from bottom up to top down

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The Innovation 2022年第6期3卷 13-14页

作者： ross n.mitchell Michael Brown Thomas M.Gernon Christopher J.Spencer State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Laboratory for Crustal Petrology Department of GeologyUniversity of MarylandCollege ParkMD 20742USA School of Ocean and Earth Science University of SouthamptonSouthampton SO224JRUK Department of Geological Sciences and Geological Engineering Queen’s UniversityKingstonON K7L 2N8Canada

When it comes to convection,what goes up must come *** is it,what goes down must come up?The truth is,it *** convection must be mass-balanced,there is no reason that it must be force-balanced:the positive and negative buoyancy forces driving convection up and down,respectively,do not necessarily need to be *** balance,or imbalance,all depends on the top and bottom boundary layers.

关键词： necessarily boundary hough

火山磷供给推动中国北方中生代陆地生物繁荣（英文）

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Science Bulletin 2023年第12期 1317-1326页

作者：马超汤艳杰 ross n.mitchell 李永飞孙守亮朱吉昌 Stephen F.Foley 王敏叶辰阳英基丰朱日祥 State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences College of Earth and Planetary Sciences University of Chinese Academy of Sciences Shenyang Center of China Geological Survey Australia School of natural Sciences Macquarie University Research School of Earth Sciences Australian National University Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Center for Excellence in Life and Paleoenvironment Chinese Academy of Sciences

中国北方中生代热河生物群的生物量和生物多样性超过了同时期的其他陆地生物群.早白垩世热河生物群的辐射可能是对华北克拉通峰期破坏过程的响应.然而,克拉通破坏的深部过程和陆地生物群演化之间的内在联系尚不清楚.磷是生命所必需的营...

中国北方中生代热河生物群的生物量和生物多样性超过了同时期的其他陆地生物群.早白垩世热河生物群的辐射可能是对华北克拉通峰期破坏过程的响应.然而,克拉通破坏的深部过程和陆地生物群演化之间的内在联系尚不清楚.磷是生命所必需的营养元素,火山产物(包括熔岩和火山碎屑岩)中的磷可通过风化作用供给陆地生态系统.中国北方中生代连续的火山-沉积序列记录了火山磷供给、生物生产力和物种丰度的变化,为研究地球深部过程、火山作用与陆地生物群的协同演化提供了关键证据.火山磷供给与生物群演化之间的耦合关系表明,在华北克拉通峰期破坏期间,大量火山产物的风化作用为陆地生态系统供给了丰富的营养物质,创造了有利于热河生物群繁荣的陆地环境.与华北克拉通破坏初期相对应的侏罗纪燕辽生物群的演化也反映了上述火山-生物之间的耦合机制.

关键词：

Four-month intrinsic viral cycle in COVID-19

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The Innovation 2022年第1期3卷 91-92页

作者： ross n.mitchell Jinhai Zhang Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China

InTRODUCTIOn Although“waves”of pandemics are common knowledge,a rigorous timeseries analysis has not been conducted to test for *** COVID-19 pandemic,caused by the transmission of the severe acute respiratory syndrome-coronavirus 2(SARS-CoV-2),is one of themost significant events inmodern human *** is ongoing,and any means that can be used to understand its dynamics are critical for mitigating its harmful *** conducted a timeseries analysis on COVID-19 case data,which relies on the efficacy of *** countries were analyzed as well as a global dataset including 189 *** time-series methods were employed.

关键词： acute respiratory rigorous