Lithostratigraphy and map-scale structure in the western Cape Smith Belt, northern Quebec: a tentative correlation between two tectonic domains

1994 ◽  
Vol 31 (6) ◽  
pp. 986-994 ◽  
Author(s):  
Paul D. Barrette
Keyword(s):  
Large Scale ◽  
Volcanic Rocks ◽  
Superior Province ◽  
Hudson Bay ◽  
Western Cape ◽  
Field Investigations ◽  
Group A ◽  
Volcaniclastic Rocks ◽  
Map Scale ◽  
Intrusive Suite

Field investigations in the western part of the Cape Smith Belt outlined four fault-bounded lithological assemblages tectonically overlying foliated to gneissic granitoids of the Archean Superior Province. These assemblages comprise sequences of pillowed volcanic rocks, sedimentary rocks of pelitic and psammitic composition, and volcaniclastic rocks. They are juxtaposed along the Lanyan Lake Fault against a structurally thickened sequence of mafic to ultramafic pillowed volcanic suite belonging to the Chukotat Group. The occurrence of volcaniclastic horizons in the uppermost levels of the Chukotat Group may indicate a northward facies transition from sea-floor volcanism to arc sedimentation, the latter corresponding to the Parent Group. A major pluton intruding the upper Chukotat Group, if assigned to the younger Narsajuaq intrusive suite, provides support for an 1844 – 1826 Ma link between two tectonic domains, formerly considered "suspect." These domains lie on either side of the Bergeron Fault in the east and central parts of the Cape Smith Belt. This fault, formerly interpreted as extending to Hudson Bay, was not recognized in this work. Thrust faulting, involving three kilometre-thick imbricate slices enclosing the Superior Province, was followed by the development of the Cape Smith Synclinorium with overturning of its northern limb, forelimb faulting, and large-scale folding along northwest-trending axes.

Geological evolution of the northwestern Superior Province: Clues from geology, kinematics, and geochronology in the Gods Lake Narrows area, Oxford–Stull terrane, Manitoba

2006 ◽  
Vol 43 (7) ◽  
pp. 749-765 ◽  
Author(s):  
S Lin ◽  
D W Davis ◽  
E Rotenberg ◽  
M T Corkery ◽  
A H Bailes
Keyword(s):  
Large Scale ◽  
Volcanic Rocks ◽  
Shear Zones ◽  
Superior Province ◽  
Continental Margins ◽  
The North ◽  
Geological Evolution ◽  
Southern Half ◽  
Andean Type ◽  
Tectonic Interpretation

The study of lithology, geochronology, and structure in the Oxford–Stull terrane, in particular in the Gods Lake Narrows area, has led to the recognition of three distinct supracrustal sequences: ~2.8–2.9 Ga volcanic rocks; a ~2720 Ma fault-bounded package of volcanics and sandstones; and ~2705 Ma conglomerate and alkaline volcanic rocks of the Oxford Lake Group. Detrital zircon as old as 3647 Ma is present in the Oxford Lake Group. An early generation of folding and shearing occurred prior to deposition of the Oxford Lake Group and was probably synchronous with emplace ment of 2721 Ma tonalite dykes. The second generation of deformation caused south-over-north thrusting of volcanic rocks over the Oxford Lake Group. The youngest fabric resulted from east-southeast-trending, dextral, south-over-north shearing. The youngest rock dated in the area is the 2668 ± 1 Ma Magill Lake pluton, which records crustal melting following deformation. The pattern of sedimentation and deformation in this area is similar to but slightly older than that found in the southern half of the Superior Province, which shows a southward-younging diachroneity. The south-dipping north-vergent shear zones observed in the area contrast with dominantly north-dipping south-vergent structures observed and interpreted south of the North Caribou superterrane (NCS). The limited size of the study area precludes any strongly based large-scale tectonic interpretation; however, data and observations from the Gods Lake Narrows area are most easily accommodated in a model where the NCS served as a nucleus onto which other terranes were accreted and both the northern and southern margins of the NCS were Andean-type continental margins with opposite subduction polarities.

The Slave Province: a distinct Archean craton

1992 ◽  
Vol 29 (10) ◽  
pp. 2072-2086 ◽  
Author(s):  
W. A. Padgham ◽  
W. K. Fyson
Keyword(s):  
Tectonic Evolution ◽  
Large Scale ◽  
Unique Feature ◽  
Volcanic Rocks ◽  
Gold Deposits ◽  
Superior Province ◽  
Slave Province ◽  
Archean Crust ◽  
Distinct Features ◽  
Base Metal Mineralization

The Slave Province is a relatively small Late Archean craton that exhibits distinctive rock associations and structures. By comparison with the much larger Superior Province, differences are evident in (i) the abundance of sedimentary versus volcanic rocks and of felsic versus mafic volcanic rocks; (ii) the greater evidence for sialic basement; (iii) the higher proportion of more evolved potassium-rich granite; (iv) the type, setting, and timing of gold and base-metal mineralization; and (v) a regional zonation of gold deposits that seems to be a unique feature of the Slave Province. Contrasts in structure are also significant: the large-scale linear belts and boundaries (sutures?) that characterize the Superior Province have no obvious counterpart in the Slave Province. Despite some similarities with other Archean cratons, the distinct features of the Slave Province are important, for they imply that no single Archean craton should be used to develop a universal paradigm for the genesis and tectonic evolution of Archean crust.

scholarly journals Constructing Large-Scale Genetic Maps Using an Evolutionary Strategy Algorithm

Genetics ◽  
2003 ◽  
Vol 165 (4) ◽  
pp. 2269-2282
Author(s):  
D Mester ◽  
Y Ronin ◽  
D Minkov ◽  
E Nevo ◽  
A Korol
Keyword(s):  
Discrete Optimization ◽  
High Performance ◽  
Large Scale ◽  
Simulated Data ◽  
Real Data ◽  
Genetic Maps ◽  
Chromosome 1 ◽  
Evolutionary Strategy ◽  
Group A ◽  
The One

Abstract This article is devoted to the problem of ordering in linkage groups with many dozens or even hundreds of markers. The ordering problem belongs to the field of discrete optimization on a set of all possible orders, amounting to n!/2 for n loci; hence it is considered an NP-hard problem. Several authors attempted to employ the methods developed in the well-known traveling salesman problem (TSP) for multilocus ordering, using the assumption that for a set of linked loci the true order will be the one that minimizes the total length of the linkage group. A novel, fast, and reliable algorithm developed for the TSP and based on evolution-strategy discrete optimization was applied in this study for multilocus ordering on the basis of pairwise recombination frequencies. The quality of derived maps under various complications (dominant vs. codominant markers, marker misclassification, negative and positive interference, and missing data) was analyzed using simulated data with ∼50-400 markers. High performance of the employed algorithm allows systematic treatment of the problem of verification of the obtained multilocus orders on the basis of computing-intensive bootstrap and/or jackknife approaches for detecting and removing questionable marker scores, thereby stabilizing the resulting maps. Parallel calculation technology can easily be adopted for further acceleration of the proposed algorithm. Real data analysis (on maize chromosome 1 with 230 markers) is provided to illustrate the proposed methodology.

Petrogenesis of the peralkaline Flowers River Igneous Suite and its significance to the development of the southern Nain Batholith

2021 ◽  
pp. 1-26
Author(s):  
Taylor A. Ducharme ◽  
Christopher R.M. McFarlane ◽  
Deanne van Rooyen ◽  
David Corrigan
Keyword(s):  
Trace Element ◽  
Volcanic Rocks ◽  
Second Phase ◽  
Discrete Events ◽  
Volcanic Event ◽  
Volcanic Succession ◽  
Intrusive Suite ◽  
Tectonic Boundaries ◽  
Host Rocks ◽  
Nain Plutonic Suite

Abstract The Flowers River Igneous Suite of north-central Labrador comprises several discrete peralkaline granite ring intrusions and their coeval volcanic succession. The Flowers River Granite was emplaced into Mesoproterozoic-age anorthosite–mangerite–charnockite–granite (AMCG) -affinity rocks at the southernmost extent of the Nain Plutonic Suite coastal lineament batholith. New U–Pb zircon geochronology is presented to clarify the timing and relationships among the igneous associations exposed in the region. Fayalite-bearing AMCG granitoids in the region record ages of 1290 ± 3 Ma, whereas the Flowers River Granite yields an age of 1281 ± 3 Ma. Volcanism occurred in three discrete events, two of which coincided with emplacement of the AMCG and Flowers River suites, respectively. Shared geochemical affinities suggest that each generation of volcanic rocks was derived from its coeval intrusive suite. The third volcanic event occurred at 1271 ± 3 Ma, and its products bear a broad geochemical resemblance to the second phase of volcanism. The surrounding AMCG-affinity ferrodiorites and fayalite-bearing granitoids display moderately enriched major- and trace-element signatures relative to equivalent lithologies found elsewhere in the Nain Plutonic Suite. Trace-element compositions also support a relationship between the Flowers River Granite and its AMCG-affinity host rocks, most likely via delayed partial melting of residual parental material in the lower crust. Enrichment manifested only in the southernmost part of the Nain Plutonic Suite as a result of its relative proximity to multiple Palaeoproterozoic tectonic boundaries. Repeated exposure to subduction-derived metasomatic fluids created a persistent region of enrichment in the underlying lithospheric mantle that was tapped during later melt generation, producing multiple successive moderately to strongly enriched magmatic episodes.

Rubidium–strontium ages from the Oxford Lake – Knee Lake greenstone belt, northern Manitoba

1980 ◽  
Vol 17 (5) ◽  
pp. 560-568 ◽  
Author(s):  
G. S. Clark ◽  
S.-P. Cheung
Keyword(s):  
Greenstone Belt ◽  
Volcanic Rocks ◽  
Superior Province ◽  
Granitic Intrusion ◽  
Greenstone Belts ◽  
Archean Greenstone Belts

Rb–Sr whole-rock ages have been determined for rocks from the Oxford Lake – Knee Lake – Gods Lake greenstone belt, in the Superior Province of northeastern Manitoba.The age of the Magill Lake Pluton is 2455 ± 35 Ma (λ87Rb = 1.42 × 10−11 yr−1), with an initial 87Sr/86Sr ratio of 0.7078 ± 0.0043. This granitic stock intrudes the Oxford Lake Group, so it is post-tectonic and probably related to the second, weaker stage of metamorphism.The age of the Bayly Lake Pluton is 2424 ± 74 Ma, with an initial 87Sr/86Sr ratio of 0.7029 ± 0.0001. This granodioritic batholith complex does not intrude the Oxford Lake Group. It is syn-tectonic and metamorphosed.The age of volcanic rocks of the Hayes River Group, from Goose Lake (30 km south of Gods Lake Narrows), is 2680 ± 125 Ma, with an initial 87Sr/86Sr ratio of 0.7014 ± 0.0009.The age for the Magill Lake and Bayly Lake Plutons can be interpreted as the minimum ages of granitic intrusion in the area.The age for the Hayes River Group volcanic rocks is consistent with Rb–Sr ages of volcanic rocks from other Archean greenstone belts within the northwestern Superior Province.

Two key switches in regional stress field during multi-stage deformation in the Carboniferous−Triassic southernmost Altaids (Beishan, NW China): Response to orocline-related roll-back processes

2021 ◽  
Author(s):  
Zhonghua Tian ◽  
Wenjiao Xiao ◽  
Brian F. Windley ◽  
Peng Huang ◽  
Ji’en Zhang ◽  
...  
Keyword(s):  
Stress Field ◽  
Large Scale ◽  
Electron Backscatter Diffraction ◽  
Volcanic Rocks ◽  
Structural Deformation ◽  
Regional Stress ◽  
Regional Stress Field ◽  
Multi Stage ◽  
Beishan Orogenic Collage ◽  
Roll Back

The orogenic architecture of the Altaids of Central Asia was created by multiple large-scale slab roll-back and oroclinal bending. However, no regional structural deformation related to roll-back processes has been described. In this paper, we report a structural study of the Beishan orogenic collage in the southernmost Altaids, which is located in the southern wing of the Tuva-Mongol Orocline. Our new field mapping and structural analysis integrated with an electron backscatter diffraction study, paleontology, U-Pb dating, 39Ar-40Ar dating, together with published isotopic ages enables us to construct a detailed deformation-time sequence: During D1 times many thrusts were propagated northwards. In D2 there was ductile sinistral shearing at 336−326 Ma. In D3 times there was top-to-W/WNW ductile thrusting at 303−289 Ma. Two phases of folding were defined as D4 and D5. Three stages of extensional events (E1−E3) separately occurred during D1−D5. Two switches of the regional stress field were identified in the Carboniferous to Early Permian (D1-E1-D2-D3-E2) and Late Permian to Early Triassic (D4-E3-D5). These two switches in the stress field were associated with formation of bimodal volcanic rocks, and an extensional interarc basin with deposition of Permian-Triassic sediments, which can be related to two stages of roll-back of the subduction zone on the Paleo-Asian oceanic margin. We demonstrate for the first time that two key stress field switches were responses to the formation of the Tuva-Mongol Orocline.

scholarly journals Maternal factor PABPN1L is essential for maternal mRNA degradation during maternal-to-zygotic transition

2020 ◽  
Author(s):  
Ying Wang ◽  
Tianhao Feng ◽  
Xiaodan Shi ◽  
Siyu Liu ◽  
Zerui Wang ◽  
...  
Keyword(s):  
Mouse Model ◽  
Large Scale ◽  
Mrna Degradation ◽  
Female Infertility ◽  
Control Group ◽  
Rna Seq ◽  
Cell Stage ◽  
Maternal Mrna ◽  
Maternal To Zygotic Transition ◽  
Group A

AbstractInfertility affects 10% - 15% of families worldwide. However, the pathogenesis of female infertility caused by abnormal early embryonic development is not clear. We constructed a mouse model (Pabpn1l -/-) simulating the splicing abnormality of human PABPN1L and found that the female was sterile and the male was fertile. The Pabpn1l -/- oocytes can be produced, ovulated and fertilized normally, but cannot develop beyond the 2-cell stage. Using RNA-Seq, we found a large-scale upregulation of RNA in Pabpn1l -/- MII oocytes. Of the 2401 transcripts upregulated in Pabpn1l-/- MII oocytes, 1523 transcripts (63.4%) were also upregulated in Btg4 -/- MII oocytes, while only 53 transcripts (2.2%) were upregulated in Ythdf2 -/- MII oocytes. We documented that transcripts in zygotes derived from Pabpn1l -/- oocytes have a longer poly(A) tail than the control group, a phenomenon similar to that in Btg4-/- mice. Surprisingly, the poly(A) tail of these mRNAs was significantly shorter in the Pabpn1l -/- MII oocytes than in the Pabpn1l +/+. These results suggest that PABPN1L is involved in BTG4-mediated maternal mRNA degradation, and may antagonize poly(A) tail shortening in oocytes independently of its involvement in maternal mRNA degradation. Thus, PABPN1L variants could be a genetic marker of female infertility.

scholarly journals Renovation of Shantytowns and Construction of New Communities

2021 ◽  
pp. 121-152
Author(s):  
Guoqing Li
Keyword(s):  
Social Integration ◽  
Urban Communities ◽  
Social Mobility ◽  
Future Development ◽  
Large Scale ◽  
Urban Society ◽  
Living Environment ◽  
Field Investigations ◽  
New Type ◽  
China’S Cities

AbstractLarge-scale shantytown renovation initiated in 2005 has completely changed the living environment of lower-income residents in Chinese cities. It has also brought about great changes in the make-up of urban communities. Over 100 million people now live in newly renovated former shantytowns, creating a new type of communityacross China's cities and towns. This chapter summarises the evolutionary phases in this process, outlining the characteristics and the different models involved. It then uses research from field investigations into four models of shantytown reconstruction to consider changes in social mobility and levels of segregation within the reconstructed communities. It also establishes the more holistic features of these new communities as a model for future development and greater social integration. The process draws on the shared heritage—the ‘roots and souls’—of earlier communities and reshapes ‘shantytown removal’ in a more socially integrated way for the future development of Chinese urban society.

scholarly journals HEAVY CLASTIC MINERALS AS AN INDICATOR OF GEODYNAMIC SETTINGS OF ACCUMULATION AND PROVENANCE OF CRETACEOUS SEDIMENTS OF THE WEST SAKHALIN TERRANE

2021 ◽  
pp. 68-86
Author(s):  
A.I. Malinovsky ◽  
Keyword(s):  
Large Scale ◽  
Volcanic Rocks ◽  
Source Area ◽  
Heavy Minerals ◽  
Clastic Material ◽  
The West ◽  
Geodynamic Settings ◽  
Eurasian Continent ◽  
Ocean Boundary ◽  
By Products

The article discusses the results of studying heavy clastic minerals from the Cretaceous sandy rocks of the West Sakhalin Terrane, and also presents their paleogeodynamic interpretation. It is shown that in terms of mineralogical and petrographic parameters, the terrane sandstones correspond to typical graywackes and are petrogenic rocks formed mainly by destruction of igneous rocks of the source areas. The sediments were found to contain both sialic, granite-metamorphic association minerals, and femic, formed by products of the destruction of basic and ultrabasic volcanic rocks. The interpretation of the entire set of data on the content, distribution and microchemical composition of heavy minerals was carried out by comparing them with minerals from older rocks and modern sediments accumulated in known geodynamic settings. The results obtained indicate that during the Cretaceous, sedimentation occurred along the continent-ocean boundary in a basin associated with large-scale left-lateral transform movements of the Izanagi Plate relative to the Eurasian continent. The source area that supplied clastic material to that basin combined a sialic landmass composed of granite-metamorphic and sedimentary rocks, a mature deeply dissected ensialic island arc, and fragments of accretion prisms, in the structure of which involved ophiolites.

scholarly journals Survey of Human Group C Rotaviruses in Japan during the Winter of 1992 to 1993

1998 ◽  
Vol 36 (1) ◽  
pp. 6-10 ◽  
Author(s):  
Mitsutaka Kuzuya ◽  
Ritsushi Fujii ◽  
Masako Hamano ◽  
Masao Yamada ◽  
Kuniko Shinozaki ◽  
...  
Keyword(s):  
Large Scale ◽  
Blot Hybridization ◽  
Human Group ◽  
Dot Blot ◽  
Passive Hemagglutination ◽  
Group A Rotaviruses ◽  
Group A ◽  
Outer Capsid ◽  
Very High ◽  
Vp7 Gene

Fecal specimens from patients with acute diarrhea were collected from 10 prefectures in Japan over a 6-month period (November 1992 to April 1993), and the specimens that were negative for human group A rotaviruses were screened for the presence of human group C rotaviruses (CHRVs) by the reverse passive hemagglutination test. Of 784 specimens examined, 53 samples (6.8%) that were collected in 7 of 10 prefectures were positive for CHRV, indicating that CHRVs are widely distributed across Japan. Most of the CHRV isolates were detected in March and April, and CHRVs mainly prevailed in children ages 3 to 8 years. The genome electropherotypes of eight strains isolated in five individual prefectures were surprisingly similar to each other and were different from those of CHRV strains isolated to date. The outer capsid glycoprotein (VP7) gene homologies of the isolates retrieved in 1993 were subsequently analyzed by the dot blot hybridization method. As a result, the VP7 genes of the isolates revealed very high levels of homology not only with each other but also with the VP7 gene of the OK118 strain isolated in 1988. These results suggest that a large-scale outbreak of CHRV occurred during the winter of 1992 and 1993 in Japan.

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