Early Jurassic evolution of the northern Stikinian arc: evidence from the Laberge Group, northwestern British Columbia

1997 ◽  
Vol 34 (7) ◽  
pp. 1030-1057 ◽  
Author(s):  
Gary G. Johannson ◽  
Paul L. Smith ◽  
Steven P. Gordey
Keyword(s):  
Temporal Trends ◽  
Coastal Sediments ◽  
Depositional History ◽  
Gravity Flows ◽  
Episodic Growth ◽  
History Of ◽  
Rapid Transition ◽  
Volcanic Pile ◽  
Definition Of ◽  
Age Range

This study resolves fundamental questions concerning the age, provenance, and depositional history of Laberge Group strata in the Whitehorse Trough. The Jurassic Inklin Formation straddles the Stikine and Cache Creek terranes along much of the length of the Whitehorse Trough. Ammonite biochronology indicates an age range of early Sinemurian to late Pliensbachian and provides the temporal framework for interpreting basin history. Strong temporal trends in both paleocurrent patterns and sandstone–conglomerate petrofacies allow definition of three discrete phases in basin-fill history. Stable tectonics characterized by relative volcanic quiescence and low sedimentation rates prevailed during the Sinemurian. Sinemurian sandstone–conglomerate petrofacies record a transitional-arc provenance derived from erosion of the Upper Triassic volcanic pile, flanking coastal sediments, and arc roots of Stikinia to the southwest. During the early Pliensbachian, arc dissection was interrupted by a major magmatic episode with widespread rejuvenated volcanism that caused a strong provenance shift to volcanigenic sources, indicating derivation from a largely undissected Stikinian arc. Southwest-derived, northerly longitudinal paleoflow during the Sinemurian changed to opposed bidirectional radial or transverse paleoflow systems in the early Pliensbachian. Cannibalism of broadly coeval basinal strata and (or) reflected sediment gravity flows were the result of episodic growth of a mobile outer forearc rise, initiating southwest-directed paleoflow systems during the early Pliensbachian and the possible development of a ridged forearc phase. U–Pb dates of [Formula: see text] and 186 ± 1 Ma from a granite clast and tuff unit, respectively, of the Kunae Zone (early late Pliensbachian) and sandstone–conglomerate petrofacies indicate a late Pliensbachian depositional regime dominated by tectonic controls. The influx of granitic detritus indicates a rapid transition to a fully dissected arc provenance, where accelerated uplift of segments of the arc massif, accompanied by intra-arc strike-slip faulting, resulted in rapid arc dissection and unroofing of comagmatic Pliensbachian plutons.

scholarly journals U–Pb zircon geochronology and depositional history of the Montresor group, Rae Province, Nunavut, Canada

2017 ◽  
Vol 54 (5) ◽  
pp. 512-528 ◽  
Author(s):  
John A. Percival ◽  
William J. Davis ◽  
Michael A. Hamilton
Keyword(s):  
Detrital Zircon ◽  
Time Window ◽  
Depositional History ◽  
Tectonic Events ◽  
Density Peaks ◽  
Minimum Age ◽  
History Of ◽  
Igneous Zircon ◽  
Definition Of ◽  
Age Constraints

Paleoproterozoic metasedimentary successions of the northwestern Canadian Shield provide records of tectonic events, but the definition of depositional ages has proved elusive. Although previously poorly understood, the Montresor belt of western Nunavut yields new insight into the 2.2–1.8 Ga time window. On the basis of U–Pb analyses of detrital zircon in sedimentary rocks and igneous zircon in sills, we conclude that arenite of the lower Montresor group was deposited between 2.194 and 2.045 Ga, and arkose of the upper Montresor group after 1.924 Ga, adding constraints on the Rae cover sequence. The lower Montresor arenite yielded an older group (3.05–2.58 Ga) and a younger, more tightly constrained group (2.194 ± 0.014 Ga). Four of six zircon grains analyzed from a gabbro sill within the lower Montresor have discordant 207Pb/206Pb ages (2.71, 2.66, 2.53, and 2.39 Ga) and are considered to be inherited, whereas two grains provide an age of 2045 ± 13 Ma, interpreted to date crystallization and providing a minimum age for the lower Montresor package. Upper Montresor arkose contains detrital zircon with probability density peaks at 2.55–2.25 and 2.1–1.92 Ga, together with scattered older grains (3.8–2.65 Ga). The youngest grain yields an age of 1924 ± 6 Ma, establishing a maximum age for sandstone deposition. Provenance is inferred to have been from the west, where igneous sources of 2.5–2.3 Ga (Queen Maud block) and 2.03–1.89 Ga (Thelon orogen) are known. Collectively, the new ages suggest a minimum 120 million year gap between deposition of the pre-2045 ± 13 Ma lower and post-1924 ± 6 Ma upper parts of the Montresor group. Similar age constraints may apply to other parts of the Rae cover sequence.

THE EASTERN OTWAY BASIN WANGERRIP GROUP REVISITED USING AN INTEGRATED SEQUENCE STRATIGRAPHIC METHODOLOGY

1995 ◽  
Vol 35 (1) ◽  
pp. 372 ◽  
Author(s):  
P. A. Arditto
Keyword(s):  
Seismic Data ◽  
Well Log ◽  
Third Order ◽  
Traditional Methods ◽  
Depositional History ◽  
Sequence Stratigraphic ◽  
Reflection Seismic ◽  
Stratigraphic Subdivision ◽  
History Of ◽  
Definition Of

Recent exploration by BHP Petroleum in VIC/ P30 and VIC/P31, within the eastern Otway Basin, has contributed significantly to our understanding of the depositional history of the Paleocene to Eocene siliciclastic Wangerrip Group. The original lithostratigraphic definition of this group was based on outcrop description and subsequently applied to onshore and, more recently, offshore wells significantly basinward of the type sections. This resulted in confusing individual well lithostratigraphies which hampered traditional methods of subsurface correlation.A re-evaluation of the Wangerrip Group stratigraphy is presented based on the integration of outcrop, wireline well log, palynological and reflection seismic data. The Wangerrip Group can be divided into two distinct units based on seismic and well log character. A lower Paleocene succession rests conformably on the underlying Maastrichtian and older Sherbrook Group, and is separated from an overlying Late Paleocene to Eocene succession by a significant regional unconformity. This upper unit displays a highly progradational seismic character and is named here as the Wangerrip Megasequence.Regional seismic and well log correlation diagrams are used to illustrate a subdivision of the Wangerrip Megasequence into eight third-order sequences. This sequence stratigraphic subdivision of the Wangerrip Group is then used to construct a chronostratigraphic chart for the succession within this part of the Otway Basin.

scholarly journals Standardizing the Definition of a “Pulse” Thunderstorm

2017 ◽  
Vol 98 (5) ◽  
pp. 905-913 ◽  
Author(s):  
Paul W. Miller ◽  
Thomas L. Mote
Keyword(s):  
Content Analysis ◽  
Large Scale ◽  
Temporal Trends ◽  
Severe Weather ◽  
Reproducible Research ◽  
Air Masses ◽  
Effective Dissemination ◽  
History Of ◽  
Definition Of ◽  
Weather Risks

Abstract Isolated, short-lived thunderstorms forming in weakly forced environments are referenced through a surplus of terminology. Further, the language used to describe the strongest, severe-weather-producing subset of these storms is applied inconsistently, posing a communication hurdle for the effective dissemination of hazardous weather risks. The term “pulse thunderstorm” was originally coined to describe an anomalously strong airmass thunderstorm often associated with a larger convective complex. However, recent applications of “pulse” have evolved to also describe nonsevere, single-cell storms, and both uses can currently be observed within research, operational, and educational texts. This paper reviews the history of the term “pulse,” performs a content analysis on nearly 1,500 pulse-referencing Storm Prediction Center (SPC) convective outlooks (CO) and mesoscale discussions (MD), and summarizes the deficiencies with the contemporary disorganized convection nomenclature. The larger CO sample (n = 997) establishes that temporal trends in “pulse” references model traditional expectations whereas the detailed MDs (n = 458) showcase examples of pulse-related terminology. The MD content analysis reveals that 1) the term “pulse” frequently appears in conjunction with severe-weather-related language and 2) that pulse-related words (e.g., brief, isolated) are equally represented in multicell-referencing MDs. In the interest of effective communication and reproducible research, the definition of “pulse” is proposed to be standardized according to the term’s original (i.e., severe, multicellular) meaning. Further, thunderstorms forming within synoptically homogeneous air masses in the absence of large-scale dynamical lift are suggested to be termed “weakly forced thunderstorms.” By corollary, pulse storms represent the subset of weakly forced thunderstorms associated with severe weather.

Towards the digital land reclamation

2020 ◽  
pp. 5-9
Author(s):  
Sergey Vasil'ev ◽  
Vyacheslav Schedrin ◽  
Aleksandra Slabunova ◽  
Vladimir Slabunov
Keyword(s):  
Retrospective Analysis ◽  
Land Reclamation ◽  
Practical Experience ◽  
Maximum Effect ◽  
Optimal Management ◽  
Scientific Potential ◽  
History Of ◽  
Definition Of ◽  
Further Development ◽  
Full Cooperation

The aim of the research is a retrospective analysis of the history and stages of development of digital land reclamation in Russia, the definition of «Digital land reclamation» and trends in its further development. In the framework of the retrospective analysis the main stages of melioration formation are determined. To achieve the maximum effect of the «digital reclamation» requires full cooperation of practical experience and scientific potential accumulated throughout the history of the reclamation complex, and the latest achievements of science and technology, which is currently possible only through the full digitalization of reclamation activities. The introduction of «digital reclamation» will achieve greater potential and effect in the modernization of the reclamation industry in the «hightech industry», through the use of innovative developments and optimal management decisions.

Vyshnivetsky Castle Library of Prince Mychailo Servaty Vyshnivetsky – Historical Book Heritage and Object of Bibliological and Historical Reconstruction

2014 ◽  
Vol 3 ◽  
pp. 166-182
Author(s):  
Iryna Tsiborovska-Rymarovych
Keyword(s):  
18Th Century ◽  
Historical Analysis ◽  
Cultural Significance ◽  
Historical Sources ◽  
Cultural Images ◽  
The Enlightenment ◽  
Printed Books ◽  
History Of ◽  
Grand Duchy Of Lithuania ◽  
Definition Of

The article has as its object the elucidation of the history of the Vyshnivetsky Castle Library, definition of the content of its fund, its historical and cultural significance, correlation of the founder of the Library Mychailo Servaty Vyshnivetsky with the Book.The Vyshnivetsky Castle Library was formed in the Ukrainian historical region of Volyn’, in the Vyshnivets town – “family nest” of the old Ukrainian noble family of the Vyshnivetskies under the “Korybut” coat of arm. The founder of the Library was Prince Mychailo Servaty Vyshnivetsky (1680–1744) – Grand Hetman and Grand Chancellor of the Grand Duchy of Lithuania, Vilno Voievoda. He was a politician, an erudite and great bibliophile. In the 30th–40th of the 18th century the main Prince’s residence Vyshnivets became an important centre of magnate’s culture in Rich Pospolyta. M. S. Vyshnivetsky’s contemporaries from the noble class and clergy knew quite well about his library and really appreciated it. According to historical documents 5 periods are defined in the Library’s history. In the historical sources the first place is occupied by old-printed books of Library collection and 7 Library manuscript catalogues dating from 1745 up to the 1835 which give information about quantity and topical structures of Library collection.The Library is a historical and cultural symbol of the Enlightenment epoch. The Enlightenment and those particular concepts and cultural images pertaining to that epoch had their effect on the formation of Library’s fund. Its main features are as follow: comprehensive nature of the stock, predominance of French eighteenth century editions, presence of academic books and editions on orientalistics as well as works of the ideologues of the Enlightenment and new kinds of literature, which generated as a result of this movement – encyclopaedias, encyclopaedian dictionaries, almanacs, etc. Besides the universal nature of its stock books on history, social and political thought, fiction were dominating.The reconstruction of the history of Vyshnivetsky’s Library, the historical analysis of the provenances in its editions give us better understanding of the personality of its owners and in some cases their philanthropic activities, and a better ability to identify the role of this Library in the culture life of society in a certain epoch.

(A review). BRAUN-BLANQUETIA. Recueil de travaux de geobotanique / review of geobotanical monographs. Vol. 46. Centenaire de la phytosociologie. CAMERINO, 2010. 423 p.

2011 ◽  
pp. 143-147
Author(s):  
L. G. Naumova ◽  
V. B. Martynenko ◽  
S. M. Yamalov
Keyword(s):  
Plant Association ◽  
Northern Asia ◽  
The Third ◽  
International Botanical ◽  
International Botanical Congress ◽  
History Of ◽  
Definition Of

Date of «birth» of phytosociology (phytocenology) is considered to be 1910, when at the third International Botanical Congress in Brussels adopted the definition of plant association in the wording Including Flaó and K. Schröter (Flahault, Schröter, 1910; Alexandrov, 1969). The centenary of this momentous event in the history of phytocenology devoted to the 46th edition of the Yearbook «Braun-Blanquetia», which began to emerge in 1984 in Camerino (Italy) and it has a task to publish large geobotanical works. During the years of the publication of the Yearbook on its pages were published twice work of the Russian scientists — «The steppes of Mongolia» (Z. V. Karamysheva, V. N. Khramtsov. Vol. 17. 1995), and «Classification of continental hemiboreal forests of Northern Asia» (N. B. Ermakov in collaboration with English colleagues and J. Dring, J. Rodwell. Vol. 28. 2000).

Light and Sensitivity: Love in the Time of the Daguerreotype

2015 ◽  
Author(s):  
Katarzyna Czeczot
Keyword(s):  
Male Gaze ◽  
History Of Photography ◽  
Sensitive Material ◽  
History Of ◽  
The Subject ◽  
Definition Of ◽  
Relationship Of ◽  
Point Of Departure ◽  
Passive Object

The article deals with the love of Zygmunt Krasiński to Delfina Potocka. The point of departure is the poet's definition of love as looking and reads Krasiński's relationship with his beloved in the context of two phenomena that fascinated him at the time: daguerreotype and magnetism. The invention of the daguerreotype in which the history of photography and spiritism comes together becomes a pretext for the formulation of a new concept of love and the loving subject. In the era of painting the woman was treated as a passive object of the male gaze; photography reverses this scheme of power. Love ceases to be a static relationship of the subject in love and the passive object – the beloved. The philosophy of developing photographs (and invoking phantoms) allows Krasiński - the writing subject to become like a light-sensitive material that reveals the image of the beloved.

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