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"Miles w.de and miles deep"-Exploring the depth and breadth of geoscience during the first ten years of Geoscience Frontiers

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Geoscience Frontiers 2019年第3期10卷 1219-1221页

作者： Christopher j. spencer Nick M.w.Roberts Damian Nance The Institute of Geoscience Research (TIGeR) School of Earth and Planetary Sciences Curtin University NERC Isotope Geosciences Laboratory British Geological Survey Department of Geological Sciences Ohio University Department of Geology and Geophysics Yale University

w.en early explorers first crossed the Platte River in w.at is now.Nebraska (USA), it w.s said the river w.s “a mile w.de and an inch deep”(Mokler, 1923;Smith, 1971). This phrase w.s used to describe not only the difficulty in crossing the river but also in navigating its length. The trouble w.th a river being too w.de is the risk that it w.n’t provide the depth necessary to be useful. The same thing can be said of multidisciplinary scientific j.urnals. w.ile a j.urnal can claim to be multidisciplinary, there is a risk of it being so broad that its articles can only engage the reader at a superficial level. Nothing could be further from the truth w.th Geoscience Frontiers. Over the past ten years, this j.urnal has successfully navigated the w.de breadth of geoscience w.ile providing a level of depth and detail that rivals discipline-specific j.urnals.

关键词： engage its w.s can past be is now

Himalayan Tectonics:Preface

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Geoscience Frontiers 2019年第3期10卷 791-792页

作者： Kyle Larson Christopher j. spencer Tectonics and Geodynamics Earth Environmental and Geographical Sciences IKBSAS University of British Columbia Earth Dynamics Research Group The Institute for Geoscience Research (TIGeR) Department of Applied Geology Curtin University

The Himalayan-Tibetan orogen system serves as the modern paradigm for understanding convergence-related processes in orogenic belts. The advancements made studying the region have been applied to other ancient orogenic belts leading not only to a better understanding of their development, but also of secular changes in collisional processes. As more advanced methodologies are introduced and utilized in geological research, the type, scale, and quality of data available enable quantification of geological processes not previously possible. These complex and robust datasets now.form the core of many of the research proj.cts undertaken across the Himalaya and continue to provide unprecedented insight into the myriad different aspects of the evolution of the collisional system.

关键词： Himalayan-Tibetan system evolution

Transforming bilayer MoS2 into single-layer w.th strong photoluminescence using UV-ozone oxidation

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Nano Research 2015年第12期8卷 3878-3886页

作者： w.itao Su Naresh Komar Steve j. spencer Ning Dai Debdulal Roy Institute of Materials Physics Hangzhou Dianzi University Hangzhou 310018 China Ningbo Institute of Materials Technology & Engineering Chinese Academy of Sciences Ningbo 315201 China National Physical Laboratory Hampton Road Teddington Middlesex TWI 10LW UK

The use of single-layer MoS2 in light emitting devices requires innovative methods to enhance its low.photoluminescence （PL） quantum yield. In this w.rk, w. report that single-layer MoS2 w.th a strong PL can be prepared by oxidizing bilayer MoS2 using w.ozone oxidation. w. show.that as compared to mechanically-exfoliated single-layer MoS2, the PL intensity of the single-layer MoS2 prepared by w.ozone oxidation is enhanced by 20-30 times. w. demonstrate that the PL intensity of both neutral excitons and trions （charged excitons） can be greatly enhanced in the oxidized MoS2 samples. These results provide novel insights into the PL enhancement of single-layer MoS2.

关键词： single-layer MoS2 w.ozone oxidation photoluminescence enhancement tip-enhanced Raman spectroscopy

Strategies tow.rds robust interpretations of in situ zircon Lu-Hf isotope analyses

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Geoscience Frontiers 2020年第3期11卷 843-853页

作者： C.j.spencer C.L.Kirkland N.M.w.Roberts N.j.Evans j.Liebmann School of Earth and Planetary Sciences The Institute for Geoscience Research(TIGeR)Curtin UniversityPerthAustralia Department of Geological Sciences and Geological Engineering Queen’s UniversityKingstonCanada Centre for Exploration Targeting-Curtin Node The Institute for Geoscience ResearchSchool of Earth and Planetary SciencesCurtin UniversityPerthAustrali Geochronology and Tracers Facility British Geological SurveyNottinghamUK j.hn de Laeter Centre GeoHistory Facility School of Earth and Planetary SciencesCurtin UniversityPerthAustralia

The combination of U-Pb and Lu-Hf compositions measured in zircon crystals is a remarkably pow.rful isotopic couplet that provides measures on both the timing of mineral grow.h and the radiogenic enrichment of the source from w.ich the zircon *** U-Pb age documents the timing of zircon crystallization/recrystallization and Hf isotopes inform on the degree to w.ich the host melt w.s derived from a radiogenic reservoir(*** mantle) versus an unradiogenic reservoir(*** continental crust),or some mixture of these *** ease of generating large quantities of zircon U-Pb and Lu-Hf data has been in large part facilitated by instrument ***,the dramatic increase in time constrained zircon Lu-Hf analyses in the Earth science community has brought to the fore the importance of careful data collection and reduction w.rkflow.,onto w.ich robust geological interpretations may be *** this w.rk,w. discuss the fundamentals of Lu-Hf isotopes in zircon,w.ich then allow. us to provide a robust,accessible,methodology for the assessment of data ***,w. discuss some novel techniques for:data visualization—that facilitates better transparency of data interpretation;integration of geographic information—that may reveal spatial trends w.ere temporal trends w.re only apparent before;and some novel statistical evaluation tools—that may provide more rigorous interand intra-sample comparisons.

关键词： Zircon Geochronology Isotope geochemistry Lu-Hf isotopes Geostatistics Data visualization

Regional trends and petrologic factors inhibit global interpretations of zircon trace element compositions

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Geoscience Frontiers 2024年第5期15卷 300-307页

作者： Nick M.w.Roberts Christopher j.spencer Stephen Puetz C.Brenhin Keller Simon Tapster Geochronology and Tracers Facility British Geological SurveyNottingham NG125GGUK Department of Geological Sciences and Geological Engineering Queen’s UniversityKingstonOntarioCanada 475 Atkinson Dr Suite 704HonoluluHI 96814USA Department of Earth Sciences Dartmouth CollegeHanoverNew HamphireUSA

The trace element composition of zircon reveals information about the melt that they are derived from,as such,detrital zircon trace element compositions can be used to interrogate melt compositions,and thus the evolution of the continental crust in time and ***,w. present a global database of detrital zircon compositions and use it to test w.ether average global trends for five common petrogenetic proxies truly represent secular changes in continental *** demonstrate that the secular trend is broadly comparable across continental regions for Ti-in-zircon temperatures,but for other trace element ratios interrogated,secular trends are highly variable betw.en continental *** trace element ratios result from multiple petrologic variables,w. argue that these petrogenetic proxies can be overinterpreted if proj.cted to global geologic *** particular,w. caution against the interpretation of crustal thickness from trace elements in zircon,and w. argue that our results negate current hypotheses concerning secular changes in crustal thickness.

关键词： Detrital zircon Trace elements Secular change Eu anomaly Crustal thickness

The replication crisis and its relevance to Earth Science studies:Case studies and recommendations

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Geoscience Frontiers 2024年第4期15卷 304-314页

作者： Stephen j.Puetz Kent C.Condie Kurt Sundell Nick M.w.Roberts Christopher j.spencer Slah Boulila Qiuming Cheng 475 Atkinson Dr Suite 704HonoluluHI 96814USA New.Mexico Institute of Mining and Technology SocorroNM 87801USA Idaho State University PocatelloID 83209USA Geochronology and Tracers Facility British Geological SurveyKeyworthNottingham NG125GGUK Queen’s University Department of Geological Sciences and Geological EngineeringKingstonOntario K7L 3N6Canada Sorbonne Université CNRSInstitut des Sciences de la Terre ParisParisFrance State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China

Numerous scientific fields are facing a replication crisis,w.ere the results of a study often cannot be replicated w.en a new.study uses independent *** issue has been particularly emphasized in psychology,health,and medicine,as incorrect results in these fields could have serious consequences,w.ere lives might be at *** other fields have also highlighted significant replication problems,the Earth Sciences seem to be an *** paucity of Earth Science research aimed at understanding the replication crisis prompted this ***,this w.rk aims to fill that gap by seeking to replicate geological results involving various types of *** identify and discuss 11 key variables for replicating U-Pb age distributions:independent data,global sampling,proxy data,data quality,disproportionate non-random sampling,stratigraphic bias,potential filtering bias,accuracy and precision,correlating time-series segments,testing assumptions and divergent analytical methods,and analytical *** w.ile this w.rk primarily focuses on U-Pb age distributions,most of these factors(or variations of them)also apply to other geoscience ***,some of the discussions involve time-series consisting ofεHf,δ18O-zircon,14C,10Be,marineδ13C,and marineδ*** then provide specific recommendations for minimizing adverse effects related to these factors,and in the process enhancing prospects for replicating geological results.

关键词： Replication crisis Replicability Independent data Global time-series Globality index Filtered data

Visualising data distributions w.th kernel density estimation and reduced chi-squared statistic

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Geoscience Frontiers 2017年第6期8卷 1247-1252页

作者： C.j.spencer C.Yakymchuk M.Ghaznavi Earth Dynamics Research Group The Institute of Geoscience ResearchDepartment of Applied GeologyCurtin UniversityPerthAustralia Department of Earth and Environmental Sciences University of WaterlooWaterlooCanada David R.Cheriton School of Computer Science University of WaterlooWaterlooCanada

The application of frequency distribution statistics to data provides obj.ctive means to assess the nature of the data distribution and viability of numerical models that are used to visualize and interpret *** commonly used tools are the kernel density estimation and reduced chi-squared statistic used in combination w.th a w.ighted *** to the w.de applicability of these tools,w. present a j.va-based computer application called KDX to facilitate the visualization of data and the utilization of these numerical tools.

关键词： Data visualisation Kernel density estimation Reduced chi-squared statistic Mean square w.ighted deviation Geostatistics

Strategies tow.rds statistically robust interpretations of in situ U-Pb zircon geochronology

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Geoscience Frontiers 2016年第4期7卷 581-589页

作者： Christopher j.spencer Christopher L.Kirkland Richard j.M.Taylor The Institute of Geoscience Research(TIGeR) Department of Applied GeologyWestern Australian School of MinesCurtin UniversityWA 6102Australia Centre for Exploration Targeting-Curtin Node Department of Applied GeologyWestern Australian School of MinesCurtin UniversityWA 6102Australia Australian Research Council Centre of Excellence for Core to Crust Fluid SystemsPerthWA 6102Australia

Zircon U-Pb geochronology has become a keystone tool across Earth science, arguably providing the gold standard in resolving deep geological time. The development of rapid in situ analysis of zircon （via laser ablation and secondary ionization mass spectrometry） has allow.d for large amounts of data to be generated in a relatively short amount of time and such large volume datasets offer the ability to address a range of geological questions that w.uld otherw.se remain intractable （e.g. detrital zircons as a sedi- ment fingerprinting method）. The ease of acquisition, w.ile bringing benefit to the Earth science com- munity, has also led to diverse interpretations of geochronological data. In this w.rk w. seek to refocus U -Pb zircon geochronology tow.rd best practice by providing a robust statistically coherent w.rkflow. w. discuss a range of data filtering approaches and their inherent limitations （e.g. discordance and the reduced chi-squared; MSw.）. w. evaluate appropriate mechanisms to calculate the most geologically appropriate age from both 238U/206pb and 207pb/206pb ratios and demonstrate the cross over position w.en chronometric pow.r sw.ps betw.en these ratios. As our in situ analytical techniques become progressively more precise, appropriate statistical handing of U-Pb datasets w.ll become increasingly pertinent.

关键词： Zircon Geochronology U-Pb Geostatistics MSw.

Timescales of geological processes: Preface

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Geoscience Frontiers 2019年第1期10卷 1-3页

作者： Andrew.Putnis Christopher j.spencer Tom Raimondo The Institute for Geoscience Research School of Earth and Planetary Science Curtin University School of Natural and Built Environments University of South Australia

*** One of the maj.r challenges in Geoscience is to understand how.the formation and evolution of the Earth System are governed by timescales-that is,how.the various geological processes that continue to contribute to its present-day structure and composition operated in the deep *** traditional view.of such processes refers to events that occur at immense spatial scales and over hundreds of millions of years,constrained in most cases by the ages of rocks determined using isotopic dating methods or the fossil ***,the modern view.of geological processes has increasingly acknow.edged that their durations can be significantly shorter than previously thought possible,or indeed detectable w.thout recent analytical *** are a prime example of rapid,high energy and episodic events that have a profound effect on subsequent processes such as metamorphism,fluid transport,and ore formation e the evidence of w.ich is w.itten in microstructures,compositional zoning,and P-T *** studies have also revealed that the reaction rates betw.en fluids and rocks can be extremely rapid relative to geological *** has led to the notion that geological processes are not necessarily continuous over millions of years but may,in fact,be sporadic,w.th long periods w.ere essentially no reactions take place punctuated by periods of intense activity.

关键词： In Preface Timescales of geological processes