99 research outputs found
Lineaments and earthquake ruptures on the East Japan megathrust
No full textIn this paper we describe the earthquake geology of East Japan, based on a seismotectonic analysis of foreshocks and aftershocks for the 2011 Tohoku-oki Great Earthquake. The earthquake geology is defined by three compressional buttresses that are separated by channels dominated by extensional earthquakes. In the 2011 earthquake sequence, most activity occurred in the Tohoku-oki extensional channel. This is bounded by seismotectonic lineaments that run subparallel to the slip direction of thrust-fault earthquakes in the adjacent compressional buttresses, and to the slip direction of landward-dipping normal-fault aftershocks in the subducting Pacific plate. The northern bounding seismotectonic lineament of the Tohoku-oki extensional channel runs WNW-ESE ∼15 km north of the Miyagi Volcanic Lineament. The southern bounding seismotectonic lineament runs ∼20 km to the south of the Fukushima Volcanic Lineament. These lineaments may reflect faults that splay from deeper structures beneath the volcanic lineaments. In any case, the seismotectonic lineaments appear to reflect zones of weakness, and as is the case in any load-bearing architecture, precursor movements on such focusing structures may herald the onset of catastrophic failure. We discovered that two-thirds of all major earthquakes with moment magnitude Mw ≥6.9 in the past 40 years in East Japan began within 15 km of the seaward prolongation of a volcanic lineament, and that motion across the northern seismotectonic lineament reversed its sense in the days prior to the 2011 Great Earthquake, suggesting the onset of yield. We infer that continuous geodetic monitoring across the East Japan lineaments might thus provide useful signals for future hazard assessment
Deformation mode switches in the Penninic units of the Urtier Valley (Western Alps): Evidence for a dynamic orogen
No full textNo Stones Women Redeemed from Sexual Addiction
No full textIn this book Marnie C. Ferree offers a unique resource for women struggling with sexual addiction. Written by a counselor who understands the condition from the inside out, No Stones offers practical help for those battling sexual addiction and those who want to come alongside women as they seek help. Important for pastors and church leaders, this book will also be a much sought-after resource for Christian counselors and therapists counseling women who grapple with this type of addiction.Cover -- Endorsements -- Title page -- Copyright -- Dedication -- Contents -- Foreword -- Letter to the Reader -- Preface -- Introduction -- PART ONE -- Chapter 1 -- Chapter 2 -- Chapter 3 -- Chapter 4 -- Chapter 5 -- Chapter 6 -- PART TWO -- Chapter 7 -- Chapter 8 -- Chapter 9 -- Chapter 10 -- Chapter 11 -- PART THREE -- Chapter 12 -- Chapter 13 -- Chapter 14 -- Chapter 15 -- Chapter 16 -- Chapter 17 -- Chapter 18 -- Twelve Steps -- Characteristics of a Sex and Love Addict -- Resources -- Acknowledgments -- Notes -- About the Author -- About Bethesda WorkshopsIn this book Marnie C. Ferree offers a unique resource for women struggling with sexual addiction. Written by a counselor who understands the condition from the inside out, No Stones offers practical help for those battling sexual addiction and those who want to come alongside women as they seek help. Important for pastors and church leaders, this book will also be a much sought-after resource for Christian counselors and therapists counseling women who grapple with this type of addiction.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
Argon data for white mica from the Snake Creek anticline, Mount Isa inlier, NW Queensland, Australia
No full textThis data is the result of a temperature-controller step-heating experiment on white mica from the Snake Creek antiform, Mount Isa inlier. The data is enclosed within XML tags for easy access. The data in the eArgon document was derived from measurements performed by Professor Marnie Forster in the ANU argon laboratory.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
Structure and Metamorphism of Amorgos: A field excursion
No full textThis field excursion focuses on structural and metamorphic aspects in the island of Amorgos, which is normally considered to represent the stratigraphy of external units in the Hellenides. The excursion includes two itineraries. The first one is in the area northwest of Katapola, where two distinct high-pressure units are exposed. High-pressure mineral assemblages include (1) blue amphibole, garnet and clinopyroxene; and (2) Fe-Mg-carpholite, quartz, phengite and paragonite. The contact between the two units is a low angle detachment fault. The second itinerary starts in the famous monastery of Hozoviotíssas and ends in the northern port of Egiali. The excursion passes through some good examples of folding and provides constraints on the multiple-phase deformation history of the island
Dating microstructures by the 40Ar/39Ar step-heating technique: Deformation–pressure–temperature–time history of the Penninic Units of the Western Alps
No full textCore-complex-related extension of the Aegean lithosphere initiated at the Eocene-Oligocene transition
No full textGeochemical constraints on Cenozoic intraplate magmatism and their relation to Jurassic dolerites in Tasmania, using Sr-Nd-Pb isotopes
No full textTasmania hosts two prominent Meso-Cenozoic mafic magmatic provinces: abundant Jurassic dolerites that belong to the Ferrar Magmatic Province that formed during Gondwana break-up; and Cenozoic, mainly basaltic volcanics, which represent intraplate magmatism, post-Gondwana break-up. The origin of the Cenozoic volcanics is still controversial, in that the detailed role of competing asthenospheric and lithospheric sources remains unclear. This study presents new geochemical and isotopic data which is used to identify and contrast the magmatic sources and their relationship to Jurassic and Cenozoic magmas. The compositions of the Cenozoic lavas span a wide range from highly silica-undersaturated olivine melilitites and nephelinites to basanites, ne-hawaiites, olivine basalts and quartz-tholeiites. New Sr-Nd-Pb isotopic data combined with major and trace element geochemistry show that the most silica-undersaturated rocks are most enriched in incompatible elements and also have the least radiogenic Sr and most radiogenic Nd. Sr-Nd-Pb isotope ratios for the most silica-rich lavas trend towards values for the Ferrar Jurassic dolerite source. More generally, Sr, Nd and Pb isotopes in the Cenozoic lavas can be modelled by a three component mixture of Pacific Mid-Ocean Ridge Basalts (MORB), HIMU-like (characterized by high time-integrated μ (²³⁸U/²⁰⁴Pb)) and Jurassic dolerite sources. Pb isotope values confirm the HIMU-like component in the array. Various degrees of melting during decompression melting has also contributed to the wide range of compositions observed, with most silica-undersaturated rocks originating at the highest pressures (>20 kbar) and by the smallest percentages of melting. We suggest that this process, combined with variable interaction of MORB and HIMU-like asthenospheric sources with lithospheric mantle containing remnant Jurassic signatures, resulted in the wide range of Cenozoic lava compositions observed today.Fun J.E. Meeuws, John D. Foden, Simon P. Holford, Marnie A. Forste
X-ray diffraction (XRD), X-ray fluorescence (XRF) and 40Ar/39Ar data obtained from basaltic rocks cored at IODP Site 369-U1513
No full textA series of basaltic flows and associated dolerite dykes were cored at depths of >680m below the seafloor, at the base of IODP Site U1513. These cores were obtained from the Naturaliste Plateau, offshore SW Australia as part of IODP Expedition 369. Quartered sections of the core were selected during the expedition to establish the age, composition, and mineralogy of these basaltic rocks. This data collection includes the results of X-ray fluorescence (XRF), X-ray diffraction (XRD) and 40Ar/39Ar isotopic analyses of eight basaltic rocks cored at the site.
The XRF measurements were collected using a Spectro Ametek XEPOS III energy dispersive XRF spectrometer at the University of Wollongong. The XRF results are presented as a spreadsheet/table containing the major and minor elemental composition of each sample, together with the reference materials that were run during the same analytical session.
The XRD and argon isotopic analyses were collected at the Research School of Earth Sciences at the Australian National University. The XRD analyses were obtained using a Malvern PanAnalytical Empyrean Series 3 x-ray diffractometer equipped with a Bragg-BrentanoHD divergent beam optic and a PIXcel3D detector (1D scanning mode, 3.347 degrees active length), with a CoK⍺ radiation source. The samples were spiked with 20 wt.% corundum (Baikalox, 1 μm), suspended on a low-background holder (Si or quartz) and analysed over a range of 4-85° 2, with a step width of 0.0131303° 2 and a total dwell time of 71 s per step. Phase identification was carried out with the software Match! and the Crystallographic Open Database (Inorganic, Revision 248644, 03.03.2020). Phase quantification was performed using the direct derivation method within the Match! software package. The 20 wt.% corundum spike was used as a reference value to quantify the wt.% of other mineral phases, the percentage of unidentified phases and the amorphous content of each sample. The XRD data are presented as a series of worksheets within a spreadsheet and consist of two columns (2-theta angle, intensity). The calculations and phase identification data are also included as a separate worksheet within the same Excel file.
The argon analyses were conducted on eight whole-rock samples that were processed in the Australian National University Mineral Separation Laboratory. These samples were crushed and sieved, with the 250–420 µm size fraction being retained for argon dating. Each sample aggregate was placed in a 5L beaker, the beaker was continually filled with water and occasionally stirred over a ~30-minute period, leading to the fine and low-density material being flushed from the aggregate. The sample was then air-dried and later washed in deionised water before being air-dried once more. The air-dried material was then hand-picked using a binocular microscope and wrapped in aluminium packets. Care was taken to ensure the hand-picked material did not include alteration minerals. The aluminium packets were placed into a quartz irradiation canister together with aliquots of the fluence monitor GA1550. Packets containing K2SO4 and CaF2 were placed in the middle of the canister to monitor 40Ar production from potassium and other reactions. The samples were then sent for irradiation at the UC Davis MNRC nuclear reactor in California, USA prior to analysis. The samples were irradiated between the 2nd to 4th October, 2018 (inclusive). The irradiated samples were unwrapped on their return to ANU, weighed and rewrapped in tin-foil ready for analysis in the mass spectrometer. Samples were dropped into a furnace that was designed and constructed at ANU. This consists of dual, temperature-controlled furnaces that function independently in the extraction line. The furnace temperature is calibrated using the melting-point of five different metals, with video monitoring of the melting point to assess accuracy. A thermocouple is located immediately adjacent to each sample within the furnace for accurate temperature readings. The furnace maintains the selected temperature for the entire duration of the heating step. During this study, the furnace was heated to 400°C to melt the tin. The contaminated gas from the tin and sample was then pumped away prior to the analysis of the sample. Backgrounds were measured prior to each step analysis and subtracted from each step analysis. The basaltic samples were analysed with 29 steps and with temperatures of the overall schedule rising from 450°C to 1450°C. The furnace was degassed four times at 1450°C for 20 min and the gas was pumped away prior to a new sample being dropped into the furnace. Temperature steps in the schedule were increased in small increments to minimize mixing of different gas populations on each step. Contamination and erroneous data were recorded at the start and end of the experiments as these data can reflect 39Ar recoil from clay and Ca derived 37Ar recoil. This can be seen in the spectra due to the low temperatures at which the experiments start, and these data are recorded so as not to lose potential information that aids the interpretation of the results. Fluence monitors, GA 1550, were analysed using a CO2 continuous wave laser and an ARGUS VI Mass Spectrometer at the Research School of Earth Sciences at the Australian National University. Samples were analysed using the temperature-controlled step heating method. Gas released from laser analysis and each step of the furnace experiments were exposed to three different Zr-Al getters to remove active gases for 10 min, the purified gas then being isotopically analysed in the mass spectrometer. Corrections for argon produced by interaction of neutrons with K and Ca were calculated using the following correction factors: (36Ar/37Ar)Ca: 2.297E-04, (39Ar/37Ar)Ca: 7.614E-04, (40Ar/39Ar)K: 5.992E-02, (38Ar/39Ar)K: 1.158E-02 and (38Ar)Cl/(39Ar)K: 8.170E-02. 40K abundances and decay constants are taken from standard values recommended by the IUGS subcommission on Geochronology. Steps with low radiogenic argon were not used in the age interpretation. Stated precisions for 40Ar/39Ar ages include all uncertainties in the measurement of isotope ratios and are recorded at the one sigma level in the data files
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