scholarly journals Intra-oceanic submarine arc evolution recorded in an ~1-km-thick rear-arc succession of distal volcaniclastic lobe deposits

Geosphere ◽  
2021 ◽  
Author(s):  
Kyle Johnson ◽  
Kathleen M. Marsaglia ◽  
Philipp A. Brandl ◽  
Andrew P. Barth ◽  
Ryan Waldman ◽  
...  
Keyword(s):  
Debris Flow ◽  
Melt Inclusions ◽  
Detrital Zircons ◽  
Channel Switching ◽  
Magmatic Arc ◽  
Fine Grained ◽  
Mariana Arc ◽  
Depositional Units ◽  
International Ocean Discovery Program ◽  
Definition Of

International Ocean Discovery Program (IODP) Expedition 351 drilled a rear-arc sedimentary succession ~50 km west of the Kyushu-Palau Ridge, an arc remnant formed by rifting during formation of the Shikoku Basin and the Izu-Bonin-Mariana arc. The ~1-km-thick Eocene to Oligocene deep-marine volcaniclastic succession recovered at Site U1438 provides a unique opportunity to study a nearly complete record of intra-oceanic arc development, from a rear-arc perspective on crust created during subduction initiation rather than supra-subduction seafloor spreading. Detailed facies analysis and definition of depositional units allow for broader stratigraphic analysis and definition of lobe elements. Patterns in gravity-flow deposit types and subunits appear to define a series of stacked lobe systems that accumulated in a rear-arc basin. The lobe subdivisions, in many cases, are a combination of a turbidite-dominated subunit and an overlying debris-flow subunit. Debris flow–rich lobe-channel sequences are grouped into four, 1.6–2 m.y. episodes, each roughly the age range of an arc volcano. Three of the episodes contain overlapping lobe facies that may have resulted from minor channel switching or input from a different source. The progressive up-section coarsening of episodes and the increasing channel-facies thicknesses within each episode suggest progressively prograding facies from a maturing magmatic arc. Submarine geomorphology of the modern Mariana arc and West Mariana Ridge provide present-day examples that can be used to interpret the morphology and evolution of the channel (or channels) that fed sediment to Site U1438, forming the sequences interpreted as depositional lobes. The abrupt change from very thick and massive debris flows to fine-grained turbidites at the unit III to unit II boundary reflects arc rifting and progressive waning of turbidity current and ash inputs. This interpretation is consistent with the geochemical record from melt inclusions and detrital zircons. Thus, Site U1438 provides a unique record of the life span of an intra-oceanic arc, from inception through maturation to its demise by intra-arc rifting and stranding of the remnant arc ridge.

scholarly journals On the Definition of Landslide and Debris-flow

Landslides ◽  
1970 ◽  
Vol 7 (1) ◽  
pp. 24-28
Author(s):  
Himshi Fuse
Keyword(s):  
Debris Flow ◽  
Definition Of

scholarly journals Unrestricted Bridging Resolution

2018 ◽  
Vol 44 (2) ◽  
pp. 237-284 ◽  
Author(s):  
Yufang Hou ◽  
Katja Markert ◽  
Michael Strube
Keyword(s):  
High Reliability ◽  
Class Imbalance ◽  
Collective Classification ◽  
Fine Grained ◽  
Joint Inference ◽  
Second Stage ◽  
Information Status ◽  
Novel Method ◽  
Definition Of ◽  
Marginal Reliability

In contrast to identity anaphors, which indicate coreference between a noun phrase and its antecedent, bridging anaphors link to their antecedent(s) via lexico-semantic, frame, or encyclopedic relations. Bridging resolution involves recognizing bridging anaphors and finding links to antecedents. In contrast to most prior work, we tackle both problems. Our work also follows a more wide-ranging definition of bridging than most previous work and does not impose any restrictions on the type of bridging anaphora or relations between anaphor and antecedent. We create a corpus (ISNotes) annotated for information status (IS), bridging being one of the IS subcategories. The annotations reach high reliability for all categories and marginal reliability for the bridging subcategory. We use a two-stage statistical global inference method for bridging resolution. Given all mentions in a document, the first stage, bridging anaphora recognition, recognizes bridging anaphors as a subtask of learning fine-grained IS. We use a cascading collective classification method where (i) collective classification allows us to investigate relations among several mentions and autocorrelation among IS classes and (ii) cascaded classification allows us to tackle class imbalance, important for minority classes such as bridging. We show that our method outperforms current methods both for IS recognition overall as well as for bridging, specifically. The second stage, bridging antecedent selection, finds the antecedents for all predicted bridging anaphors. We investigate the phenomenon of semantically or syntactically related bridging anaphors that share the same antecedent, a phenomenon we call sibling anaphors. We show that taking sibling anaphors into account in a joint inference model improves antecedent selection performance. In addition, we develop semantic and salience features for antecedent selection and suggest a novel method to build the candidate antecedent list for an anaphor, using the discourse scope of the anaphor. Our model outperforms previous work significantly.

The type section of the Codell Sandstone

2021 ◽  
Vol 58 (3) ◽  
pp. 211-248
Author(s):  
James Hagadorn ◽  
Mark Longman ◽  
Richard Bottjer ◽  
Virginia Gent ◽  
Christopher Holm-Denoma ◽  
...  
Keyword(s):  
Surface Expression ◽  
Potassium Feldspar ◽  
Detrital Zircons ◽  
Niobrara Formation ◽  
Denver Basin ◽  
Fine Grained ◽  
Type Section ◽  
Fossil Fish ◽  
Fish Teeth ◽  
Reference Section

We formally assign, describe and interpret a principal reference section for the middle Turonian Codell Sandstone Member of the Carlile Shale near Codell, Kansas. This section, at the informally named Pumpjack Road, provides the thickest surface expression (9 m, ~30 ft) of the unit in Ellis County. The outcrop exposes features that typify the Codell throughout the southern Denver Basin and vicinity. At this reference section, the Codell conformably overlies the Blue Hill Shale Member of the Carlile Shale and is unconformably overlain by the Fort Hays Limestone Member of the Niobrara Formation or locally by a thin (<0.9 m, <3 ft) discontinuous mudstone known as the Antonino facies. The top contact of the Codell is slightly undulatory with possible compaction features or narrow (<30.5 m, <100 ft), low-relief (0.3-0.6 m, 1-2 ft) scours, all of which hint that the Codell is a depositional remnant, even at the type section. At Pumpjack Road, the Codell coarsens upward from a recessive-weathering argillaceous medium-grained siltstone with interbedded mudstone at its base to a more indurated cliff-forming muddy, highly bioturbated, very fine-grained sandstone at its top. The unit contains three informal gradational packages: a lower Codell of medium to coarse siltstone and mudstone, a middle Codell of muddy coarse siltstone, and an upper muddy Codell dominated by well-sorted very fine-grained sandstone. The largest grain fractions, all <120 mm in size, are mostly quartz (40-80%), potassium feldspar (7-12%), and albite (1-2%), with some chert (<15%), zircon, and other constituents such as abraded phosphatic skeletal debris. Rare fossil fish teeth and bones also occur. Detrital and authigenic clays make up 9 to 42% of the Codell at the reference section. Detrital illite and mixed layer illite/smectite are common, along with omnipresent kaolinite as grain coatings or cement. As is typical for the Codell, the sandstone at the type section has been pervasively bioturbated. Most primary structures and bedding are obscured, particularly toward the top of the unit where burrows are larger, deeper and more diverse than at its base. This bioturbation has created a textural inversion in which the larger silt and sand grains are very well sorted but are mixed with mud. Detrital zircons from the upper Codell are unusual in that they are mostly prismatic to acicular, euhedral, colorless, unpitted, and unabraded, and have a near-unimodal age peak centered at ~94 Ma. These characteristics suggest they were reworked mainly from Cenomanian bentonites; their ultimate source was likely from the Cordilleran orogenic belt to the west and northwest.

scholarly journals U–Pb Age and Hf Isotope Geochemistry of Detrital Zircons from Cambrian Sandstones of the Severnaya Zemlya Archipelago and Northern Taimyr (Russian High Arctic)

Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 36 ◽  
Author(s):  
Victoria B. Ershova ◽  
Andrei V. Prokopiev ◽  
Andrey K. Khudoley ◽  
Tom Andersen ◽  
Kåre Kullerud ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
Isotope Geochemistry ◽  
High Arctic ◽  
Detrital Zircons ◽  
Hf Isotope ◽  
Magmatic Arc ◽  
Novaya Zemlya ◽  
Late Neoproterozoic ◽  
Severnaya Zemlya ◽  
Severnaya Zemlya Archipelago

U–Pb and Lu–Hf isotope analyses of detrital zircons collected from metasedimentary rocks from the southern part of Kara Terrane (northern Taimyr and Severnaya Zemlya archipelago) provide vital information about the paleogeographic and tectonic evolution of the Russian High Arctic. The detrital zircon signatures of the seven dated samples are very similar, suggesting a common provenance for the clastic detritus. The majority of the dated grains belong to the late Neoproterozoic to Cambrian ages, which suggests the maximum depositional age of the enclosing sedimentary units to be Cambrian. The εHf(t) values indicate that juvenile magma mixed with evolved continental crust and the zircons crystallized within a continental magmatic arc setting. Our data strongly suggest that the main provenance for the studied clastics was located within the Timanian Orogen. A review of the available detrital zircon ages from late Neoproterozoic to Cambrian strata across the wider Arctic strongly suggests that Kara Terrane, Novaya Zemlya, Seward Peninsula (Arctic Alaska), Alexander Terrane, De Long Islands, and Scandinavian Caledonides all formed a single tectonic domain during the Cambrian age, with clastics predominantly sourced from the Timanian Orogen.

Ambivalent Humanitarian Crises and Complex Emergencies

2020 ◽  
Author(s):  
Dennis Dijkzeul ◽  
Diana Griesinger
Keyword(s):  
Academic Disciplines ◽  
International Humanitarian Law ◽  
Humanitarian Law ◽  
Humanitarian Crisis ◽  
Fine Grained ◽  
Humanitarian Action ◽  
Humanitarian Crises ◽  
Different Types ◽  
Local Actors ◽  
Definition Of

The term “humanitarian crisis” combines two words of controversial meaning and definitions that are often used in very different situations. For example, there is no official definition of “humanitarian crisis” in international humanitarian law. Although some academic disciplines have developed ways of collecting and analyzing data on (potential) crises, all of them have difficulties understanding, defining, and even identifying humanitarian crises. Following an overview of the use of the compound noun “humanitarian crisis,” three perspectives from respectively the disciplines International Humanitarian Law, Public Health, and Humanitarian Studies are discussed in order to explore their different but partly overlapping approaches to (incompletely) defining, representing, and negotiating humanitarian crises. These disciplinary perspectives often paint an incomplete and technocratic picture of crises that is rarely contextualized and, thus, fails to reflect adequately the political causes of crises and the roles of local actors. They center more on defining humanitarian action than on humanitarian crises. They also show four different types of humanitarian action, namely radical, traditional Dunantist, multimandate, and resilience humanitarianism. These humanitarianisms have different strengths and weaknesses in different types of crisis, but none comprehensively and successfully defines humanitarian crises. Finally, a multiperspective and power-sensitive definition of crises, and a more fine-grained language for comprehending the diversity of crises will do more justice to the complexity and longevity of crises and the persons who are surviving—or attempting to survive—them.

scholarly journals Neighbourhood Social Resilience (NSR): Definition, Conceptualisation, and Measurement Scale Development

2020 ◽  
Vol 12 (16) ◽  
pp. 6363
Author(s):  
Taimaz Larimian ◽  
Arash Sadeghi ◽  
Garyfalia Palaiologou ◽  
Robert Schmidt III
Keyword(s):  
Reliability And Validity ◽  
Measurement Instrument ◽  
Measurement Scale ◽  
Social Resilience ◽  
Fine Grained ◽  
Complex Concept ◽  
Clear Guideline ◽  
Perceptions And Expectations ◽  
Neighbourhood Scale ◽  
Definition Of

The literature on social resilience lacks a precise definition of this concept and a clear guideline on how to measure it. Particularly, social resilience at the neighbourhood scale has received remarkably little scholarly attention. This study contributes toward filling these gaps in the literature by developing and empirically testing the neighbourhood social resilience (NSR) model as a robust and reliable measurement instrument that integrates various aspects of this complex concept into one coherent and fine-grained psychometric model. The reliability and validity of the NSR model are empirically tested using questionnaire data collected from 234 respondents in five neighbourhoods of Dunedin city, New Zealand. Furthermore, a more nuanced definition for neighbourhood social resilience is provided. Results indicate that social resilience is a second-order and multidimensional concept incorporating eight dimensions. Each of these dimensions captures a distinct piece in the jigsaw of social resilience; therefore, failure to incorporate all dimensions may provide an incomplete picture of this complex phenomenon. Our research bridges the gap between top-down approach of stakeholders and policymakers and bottom-up perceptions and expectations of residents about social resilience of their urban neighbourhood.

scholarly journals A Versatile and Robust Serine Protease Inhibitor Scaffold from Actinia tenebrosa

Marine Drugs ◽  
2019 ◽  
Vol 17 (12) ◽  
pp. 701 ◽  
Author(s):  
Xingchen Chen ◽  
Darren Leahy ◽  
Jessica Van Haeften ◽  
Perry Hartfield ◽  
Peter J. Prentis ◽  
...  
Keyword(s):  
Serine Protease ◽  
Protease Inhibitors ◽  
Serine Proteases ◽  
Inhibitor Design ◽  
Consensus Analysis ◽  
Fine Grained ◽  
Human Sequence ◽  
Physiological Processes ◽  
Definition Of ◽  
Dynamics Simulations

Serine proteases play pivotal roles in normal physiology and a spectrum of patho-physiological processes. Accordingly, there is considerable interest in the discovery and design of potent serine protease inhibitors for therapeutic applications. This led to concerted efforts to discover versatile and robust molecular scaffolds for inhibitor design. This investigation is a bioprospecting study that aims to isolate and identify protease inhibitors from the cnidarian Actinia tenebrosa. The study isolated two Kunitz-type protease inhibitors with very similar sequences but quite divergent inhibitory potencies when assayed against bovine trypsin, chymostrypsin, and a selection of human sequence-related peptidases. Homology modeling and molecular dynamics simulations of these inhibitors in complex with their targets were carried out and, collectively, these methodologies enabled the definition of a versatile scaffold for inhibitor design. Thermal denaturation studies showed that the inhibitors were remarkably robust. To gain a fine-grained map of the residues responsible for this stability, we conducted in silico alanine scanning and quantified individual residue contributions to the inhibitor’s stability. Sequences of these inhibitors were then used to search for Kunitz homologs in an A. tenebrosa transcriptome library, resulting in the discovery of a further 14 related sequences. Consensus analysis of these variants identified a rich molecular diversity of Kunitz domains and expanded the palette of potential residue substitutions for rational inhibitor design using this domain.

U-Pb detrital zircon ages of Cambrian−Ordovician sandstones from the Taebaeksan Basin, Korea: Provenance variability in platform shelf sequences and paleogeographic implications

2020 ◽  
Author(s):  
Moonsup Cho ◽  
Wonseok Cheong ◽  
W.G. Ernst ◽  
Yoonsup Kim ◽  
Keewook Yi
Keyword(s):  
Distribution Patterns ◽  
Isotopic Signature ◽  
Detrital Zircons ◽  
Data Sets ◽  
Early Paleozoic ◽  
Fine Grained ◽  
Taebaeksan Basin ◽  
Double Peaks ◽  
The North ◽  
Detrital Zircon Ages

The early Paleozoic paleogeography of East Gondwanan terranes, including the North China Craton (NCC), is contentious, primarily reflecting the paucity of integrated geochronological, biogeographic, and tectonic data sets. Our new sensitive high-resolution ion microprobe data from 14 sandstones of the Taebaeksan Basin, Korea, indicate that its platform shelf sequences, typified by trilobite faunal assemblages diagnostic of the NCC, record the vestige of coeval arc magmatism. Detrital zircons analyzed from the sandstones yielded Eoarchean to Early Ordovician ages, which define three distinct types of distribution patterns characterized by: (1) double peaks at ca. 1.85 Ga and 2.50 Ga diagnostic of basement rocks in the NCC; (2) minor peaks at ca. 1.75, 1.6, and 1.2−1.1 Ga in addition to double peaks; and finally (3) a scattered array of late Paleoproterozoic to Neoproterozoic zircons lacking double peaks. The marked contrasts among the three types reflect significant changes in provenance, most likely linked to variations in paleo-water depths during the “Sauk” transgression. Longshore- or onshore-directed currents, associated with an increase in water depth, apparently brought outboard oceanic detritus and benthic trilobites into the relatively flat outer shelf of the Taebaeksan Basin. As a result, fine-grained sandstones received a large amount of detritus from distal sources, yielding mixed signatures in zircon age patterns and trilobite assemblages. Excluding the basal sandstone-conglomerate unit, five siliciclastic formations contain syndepositional zircon populations, and their weighted mean 206Pb/238U ages decrease upsection from 512 ± 5 Ma to 483 ± 2 Ma, indicating a sedimentary influx from contemporaneous volcanic activity. In conjunction with arc-related bulk-rock geochemistry and juvenile Nd isotopic signature, early Paleozoic detrital zircons likely represent the first-cycle detritus supplied for ∼30 m.y. from the proto-Japan arc that initially formed at ca. 520 Ma. Together with the occurrence of ca. 700−500 Ma detrital Pacific Gondwana zircons in fine-grained sandstones, Paleozoic arc-sourced detritus suggests that the Korean Peninsula was paleogeographically linked to an ancient convergent margin, perhaps extending from the Terra Australis orogen.

scholarly journals A MULTIMEDIA MODEL BASED ON STRUCTURED MEDIA AND SUB-ELEMENTS FOR COMPLEX MULTIMEDIA AUTHORING AND PRESENTATION

2002 ◽  
Vol 12 (05) ◽  
pp. 473-500 ◽  
Author(s):  
TRAN_THUONG TIEN ◽  
CECILE ROISIN
Keyword(s):  
New Media ◽  
Significant Advance ◽  
Extended Model ◽  
Multimedia Model ◽  
Multimedia Authoring ◽  
Fine Grained ◽  
Model Based ◽  
Structured Media ◽  
Spatio Temporal ◽  
Definition Of

Declarative definition of multimedia presentation such as provided by SMIL standard can be considered as the most significant advance in the multimedia integration domain. However, the requirements of a model that could express richer scenarios for presentations are always a challenge. The work presented here proposes an extended model based on the concept of structured media and sub-elements that allows a finer granularity and a more semantic specification of significant events and locations inside media fragments. The new media fragments can be composed in multimedia scenarios through the specification of temporal, spatial and spatio-temporal relations. Moreover, we propose an abstract animation model that can be combined with the intra-media temporal structuration to specify animation effects in a flexible, not redundant and easy to maintain way. The underlying model is the Madeus model that is a flexible model based on the structural, interval, region and relative constraints. This paper describes the sub-element and the abstract animation models and shows how they are implemented in the Madeus multimedia framework. A complete schema of the video authoring tool based on this model is also specified. Thanks to that, the fine-grained authoring of multimedia scenarios with video media can be done in an easy and effective way.

Development of a sampling protocol for the resource definition of sulphidic Cu-Zn-Pb tailings in an industrial tailings storage facility

2020 ◽  
Author(s):  
Rosie Blannin ◽  
Max Frenzel ◽  
Raimon Tolosana-Delgado ◽  
Jens Gutzmer
Keyword(s):  
Bulk Sample ◽  
Mining District ◽  
Surface Zone ◽  
Sampling Protocol ◽  
Fine Grained ◽  
Mineral Liberation ◽  
Mineral Associations ◽  
Graded Layers ◽  
Definition Of ◽  
Drill Holes

&lt;p&gt;Fine-grained residues of ore processing, known as tailings, are an inevitable product of metal production. Such tailings are typically stored in dedicated Tailings Storage Facilities (TSF). The sedimentary-style deposition of tailings within the TSF results in a structure of sub-horizontal, internally graded layers which heterogeneously concentrate the minerals comprising the residues. Primary depositional structures may be overprinted by subsequent chemical redistribution of minerals and elements during chemical reactions and metal mobilisation. Sulphidic tailings are problematic in terms of the potential for generation of Acid and Metalliferous Drainage, while providing interesting prospects for extraction of recoverable metals. However, efforts to build accurate and reproducible geospatial models of TSFs are hampered by a lack of understanding of how to sample heterogeneous tailings materials in a way that allows the effective characterisation of both the horizontal and vertical variability. This study introduces a sampling protocol for the resource characterisation of TSFs, following the Theory of Sampling. The Davidschacht TSF in Freiberg, Germany, was used as a case study. The Davidschacht TSF was deposited between 1944 and 1969; it contains around 760,000 m&lt;sup&gt;3 &lt;/sup&gt;of Cu-Zn-Pb sulphidic flotation residues originating from the processing of polymetallic hydrothermal vein ores of the Freiberg mining district. A historical drilling campaign of 10 drill holes through the whole depth of the tailings provided a basis for the study. A second drilling campaign of 68 drill holes to a depth of 3 m was carried out on a 30 m grid, and nested grids of 15 m and 7.5 m in the centre of the TSF. The drill cores were logged and a bulk sample was collected for each 1 m section. Representative samples, with 10% randomly selected for duplication, will be analysed with X-Ray Fluorescence for chemical composition and sieving and laser diffraction for particle size distribution. The modal mineralogy, mineral associations and mineral liberation of selected samples will be assessed with the Scanning Electron Microscope-based Mineral Liberation Analyser. A detailed geospatial model of the surface zone of the tailings will be constructed to assess the intrinsic horizontal variability of the TSF. Comparison with the 3D model produced by the previous deep drilling campaign will determine if the sampling and modelling was sufficient to account for the variability of the tailings.&lt;/p&gt;

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