Paleomagnetism of the Sutton Lake Proterozoic inlier, Ontario, Canada

1982 ◽  
Vol 19 (6) ◽  
pp. 1330-1332
Author(s):  
E. J. Schwarz ◽  
K. R. Clark ◽  
Y. Fujiwara
Keyword(s):  
Pole Position ◽  
North Pole ◽  
The Other ◽  
Stratigraphic Correlation ◽  
Red Beds ◽  
End Points ◽  
Thermal Demagnetization ◽  
Fine Grained ◽  
Dark Layer ◽  
Volcanic Suite

Thirty-eight cores were collected from eight sites in the Sutton Lake Proterozoic inlier, which is thought to be an extension of the Circum-Ungava Belt. Six sites from a 100 m thick diabase sill yielded essentially single-component magnetization averaging D = 35°, I = −54°, k = 39,α95 = 11°. The diabase dips north at 4° and shows only minor alteration (epidote and chlorite). The other two sites were in a fine-grained dark layer within the sill and in a dike. No end points were observed for these sites upon alternating field and thermal demagnetization. The six diabase sites yielded a north pole at 67°E, 3°S, dm = 15, dp = 11. This pole position is similar to that obtained for the youngest volcanic suite (Flaherty Formation) of the Belcher Islands and to that obtained for red beds of the La Grande 4 outlier, suggesting a time-stratigraphic correlation between these units.

Paleomagnetism of the Great Slave Supergroup, Northwest Territories, Canada: the Tochatwi Formation

1976 ◽  
Vol 13 (4) ◽  
pp. 555-562 ◽  
Author(s):  
M. E. Evans ◽  
D. K. Bingham
Keyword(s):  
Northwest Territories ◽  
North American ◽  
Pole Position ◽  
The Other ◽  
Thermal Demagnetization ◽  
Fine Grained ◽  
I 11 ◽  
Two Phases ◽  
Geological Work ◽  
Magnetic Vectors

The Tochatwi Formation comprises some 800 m of fine-grained red to buff sandstone in the upper part of the Great Slave Supergroup. Recent geological work indicates an age of 1700 m.y., but this is not yet known with certainty. Results from 29 sampling sites stratigraphically covering the Tochatwi Formation are presented. Standard paleomagnetic techniques indicate that post-folding remagnetization is common, and this is confirmed by analysis of the magnetic vectors removed as partial thermal demagnetization proceeds. Two phases of remagnetization are recognized, one of which can be attributed to nearby Mackenzie-age intrusions. The other phase is equivalent to a remagnetization observed by other workers in Kahochella Group strata at localities 70 km away. As yet, the source of this remagnetization event cannot be identified. Eight sampling sites have escaped total remagnetization and an earlier, pre-folding remanence has been isolated from these (D = 030, I = −11, k = 14, α95 = 15°). The corresponding pole position (144W, 18S) is remote from those deduced from North American rocks of similar age, and possible explanations of this problem are discussed.

Quantitative Estimates of Temperature Changes Over the Last 2700 Years in Michigan Based on Pollen Data

1981 ◽  
Vol 15 (2) ◽  
pp. 143-159 ◽  
Author(s):  
J. Christopher Bernabo
Keyword(s):  
Sediment Cores ◽  
The Other ◽  
Stratigraphic Correlation ◽  
Calibration Function ◽  
Climate Data ◽  
Pollen Data ◽  
Radiocarbon Dates ◽  
Temperature Changes ◽  
Fine Grained ◽  
Modern Pollen

AbstractTemperatures for the past 2700 yr are estimated using well-dated pollen data from northwestern lower Michigan. The pollen data were sampled from sediment cores of four lakes along a 75-km transect, with fine-grained morainic soils around the two western lakes and sandy outwash soils around the lakes to the east. Climatic reconstructions based on the pollen data from the sandy sites show less temperature change than the reconstructions from the other sites, because variations in the composition of the vegetation at the sandy sites are edaphically restricted. One of the cores studied was dated by counting visible annual laminations (varves). The cores from the other lakes were dated based on three radiocarbon dates per core as well as the historically determined age of the settlement horizons. All the time scales were cross-checked using pollen-stratigraphic correlation between the four sites. A calibration function was developed using a network of modern pollen and climate data covering all of lower Michigan. Based on this calibration function, the 2700-yr reconstruction for Marion Lake indicates an estimated growing-season temperature range of 1.3°C between extreme 30-yr means. Mild conditions persisted prior to ca. A.D. 400, but a cold interval occurred between ca. A.D. 500 and 800. The well-marked warm period evident from ca. A.D. 1000 to 1200 was the last time when temperatures were about equal to the 1931–1960 mean. A prolonged longed cooling occurred after A.D. 1200 and reached 1°C below the 1931–1960 mean by the 1700s. A warming of 0.5°C is indicated from ca. A.D. 1750 to 1850. The estimated temperatures for the 1830s at Marion Lake agree with the instrumental data for that period and this provides some validation of the calibration-function results.

Late Hadrynian and Helikian pole positions from the Spokane Formation, Montana

1977 ◽  
Vol 14 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Icaro Vitorello ◽  
Rob Van der Voo
Keyword(s):  
Heat Flow ◽  
Geomagnetic Field ◽  
Pole Position ◽  
The Other ◽  
Low Grade ◽  
Thermal Event ◽  
Thermal Demagnetization ◽  
Grade Metamorphism ◽  
Laramide Orogeny ◽  
Good Agreement

The natural remanent magnetizations of Beltian argillites from the Spokane Formation (formerly Grinnell Formation) have been analyzed with alternating field and thermal demagnetization techniques. Two groups of magnetic directions have been observed. One is assumed to be the primary magnetization, representative of the Helikian (approx. 1300 Ma) geomagnetic field: D = 201.5°; I = +40°; k = 61; and α95 = 5.1° for N = 14 sites (51 samples), yielding a pole position at 15.5 °S. 134.5 °W, dp = 3.7°, dm = 6.2°. Comparisons with contemporaneous pole positions reveal good agreement. The other direction of magnetization corresponds to a Late Hadrynian age (approx. 600 to 750 Ma) and resulted from low-grade metamorphism. It is speculated that this thermal event resulted from enhanced heat flow during continental breakup in the Late Hadrynian. This direction (D = 267.5°; I = +17; k = 10; α95 = 9.1° for N = 28 specimens) yields a pole position at 5°N, 163.5°E, with dp = 4.9°, dm = 9.4°. Both groups of directions of magnetization are pre-folding, which occurred during the Laramide orogeny. Laramide deformation was only moderate, however, and the eastward thrusting of the Beltian sediments over the Lewis thrust was probably not accompanied by significant structural rotation.

Paleomagnetism of the Middle Proterozoic Mount Nelson Formation: evidence for a regional remagnetization event in the Late Precambrian of the Cordillera

1983 ◽  
Vol 20 (4) ◽  
pp. 561-567 ◽  
Author(s):  
W. A. Morris ◽  
M. E. McMechan
Keyword(s):  
British Columbia ◽  
National Park ◽  
Acid Leaching ◽  
Pole Position ◽  
Glacier National Park ◽  
Geological Process ◽  
Thermal Demagnetization ◽  
Fine Grained ◽  
Late Precambrian ◽  
Middle Proterozoic

Chemical and thermal demagnetization of 92 specimens from the Mount Nelson Formation (uppermost Purcell Supergroup) in the Purcell Mountains of southeastern British Columbia yields two distinct directional groups. MN-A, found by thermal and chemical demagnetization, has a mean direction of D = 274°, I = 19° (α95 = 10°, tilt corrected), which corresponds to a pole position at 156 °E, 10 °N, MN-A resides in fine-grained hematite and is similar to other overprint directions reported from middle and upper Belt–Purcell strata in the Glacier National Park – Clark Range area. Genesis of this overprint is related to some regional geological process, most probably the Goat River Orogeny [Formula: see text]. Direction MN-B, which is found after acid leaching of more than 250 h, has a mean direction of D = 331°, I = 47°(α95 = +4°, tilt corrected), corresponding to a pole at 119 °E, 59 °N. The MN-B pole is significantly different from all poles previously reported from the Belt–Purcell Supergroup (ca. 210 °E, 20 °S). As the age of the MN-B pole is unconstrained the significance of this marked discrepancy is at present uncertain.

scholarly journals Neutron Imaging Using a Fine-Grained Nuclear Emulsion

2021 ◽  
Vol 7 (1) ◽  
pp. 4
Author(s):  
Katsuya Hirota ◽  
Tomoko Ariga ◽  
Masahiro Hino ◽  
Go Ichikawa ◽  
Shinsuke Kawasaki ◽  
...  
Keyword(s):  
Image Analysis ◽  
High Resolution ◽  
Neutron Detector ◽  
Nuclear Emulsion ◽  
Neutron Imaging ◽  
The Other ◽  
Crystal Oscillator ◽  
Fine Grained ◽  
Cold Neutrons ◽  
Track Analysis

A neutron detector using a fine-grained nuclear emulsion has a sub-micron spatial resolution and thus has potential to be applied as high-resolution neutron imaging. In this paper, we present two approaches to applying the emulsion detectors for neutron imaging. One is using a track analysis to derive the reaction points for high resolution. From an image obtained with a 9 μm pitch Gd grating with cold neutrons, periodic peak with a standard deviation of 1.3 μm was observed. The other is an approach without a track analysis for high-density irradiation. An internal structure of a crystal oscillator chip, with a scale of approximately 30 μm, was able to be observed after an image analysis.

scholarly journals Global-Local Enhancement Network for NMF-Aware Sign Language Recognition

2021 ◽  
Vol 17 (3) ◽  
pp. 1-19
Author(s):  
Hezhen Hu ◽  
Wengang Zhou ◽  
Junfu Pu ◽  
Houqiang Li
Keyword(s):  
Sign Language ◽  
Daily Life ◽  
The Other ◽  
Challenging Problem ◽  
Language Recognition ◽  
Local Enhancement ◽  
Sign Language Recognition ◽  
Vocabulary Size ◽  
Hand Gestures ◽  
Fine Grained

Sign language recognition (SLR) is a challenging problem, involving complex manual features (i.e., hand gestures) and fine-grained non-manual features (NMFs) (i.e., facial expression, mouth shapes, etc .). Although manual features are dominant, non-manual features also play an important role in the expression of a sign word. Specifically, many sign words convey different meanings due to non-manual features, even though they share the same hand gestures. This ambiguity introduces great challenges in the recognition of sign words. To tackle the above issue, we propose a simple yet effective architecture called Global-Local Enhancement Network (GLE-Net), including two mutually promoted streams toward different crucial aspects of SLR. Of the two streams, one captures the global contextual relationship, while the other stream captures the discriminative fine-grained cues. Moreover, due to the lack of datasets explicitly focusing on this kind of feature, we introduce the first non-manual-feature-aware isolated Chinese sign language dataset (NMFs-CSL) with a total vocabulary size of 1,067 sign words in daily life. Extensive experiments on NMFs-CSL and SLR500 datasets demonstrate the effectiveness of our method.

scholarly journals I.—Microscopic Structure of Irish Granites. No. 2. Granite of Aillemore, Co. Mayo

1874 ◽  
Vol 1 (1) ◽  
pp. 1-2
Author(s):  
Edward Hull
Keyword(s):  
The Other ◽  
Microscopic Structure ◽  
South Side ◽  
North West ◽  
Fine Grained ◽  
Lower Silurian ◽  
The North ◽  
Geological Map ◽  
Vertical Walls ◽  
Dark Green

This granite forms an isolated mass, rising into two eminences a few miles south of Louisburg, called Corvock Brack (1287 feet) and Knockaskeheen (1288 feet). It is a greyish granite—generally fine—grained—consisting of quartz, two felspars,—one orthoclase, the other triclinic, probably oligoclase—and dark green mica. In some places there are patches in which the felspar assumes the appearance of “graphic granite.” Numerous boulders of this granite are strewn over the district to the north-west, and on the south side of Knockaskeheen; the rock is traversed by regular joints ranging N. 10 W., along which it splits off into nearly vertical walls. The position of the granite is shown on Griffith's Geological Map of Ireland, and it is surrounded by schistose beds, generally metamorphosed, and probably of Lower Silurian age. The granite itself is of older date than the Upper Llandovery beds, which lie to the southward.

Conditional Belief and the Ramsey Test

2002 ◽  
Vol 51 ◽  
pp. 215-232
Author(s):  
Scott Sturgeon
Keyword(s):  
Everyday Life ◽  
Common Sense ◽  
The Other ◽  
Coarse Grained ◽  
Degrees Of Belief ◽  
Conditional Belief ◽  
Ramsey Test ◽  
Fine Grained

Consider the frameS believes that—.Fill it with a conditional, sayIf you eat an Apple, you'll drink a Coke.what makes the result true? More generally, what facts are marked by instances ofS believes (A→C)?In a sense the answer is obious: beliefs are so marked. Yet that bromide leads directly to competing schools of thought. And the reason is simple.Common-sense thinks of belief two ways. Sometimes it sees it as a three-part affair. When so viewed either you believe, disbelieve, or suspend judgment. This take on belief is coarse-grained. It says belief has three flavours: acceptance, rejection, neither. But it's not the only way common-sense thinks of belief. Sometimes it's more subtle: ‘How strong is your faith?’ can be apposite between believers. That signals an important fact. Ordinary practice also treats belief as a fine-grained affair. It speaks of levels of confidence. It admits degrees of belief. It contains a fine-grained take as well. There are two ways belief is seen in everyday life. One is coarse-grained. The other is fine-grained.

Stratigraphic correlation of the Permian-Triassic red beds constrained by detrital zircon geochronology: Moscow basin, East European platform

2021 ◽  
Author(s):  
Alvina Chistyakova ◽  
Roman Veselovskiy
Keyword(s):  
Detrital Zircon ◽  
East European Platform ◽  
Lower Triassic ◽  
Detrital Zircons ◽  
Upper Permian ◽  
Stratigraphic Correlation ◽  
Red Beds ◽  
East European ◽  
Moscow Basin ◽  
Stratigraphic Position

<p>There's no doubt that nowadays detrital zircon U-Pb geochronology is actually required method of sedimentary basins analysis. Furthermore, this approach may have a lot of applications, such as a stratigraphic correlation. Here we present the first results of U–Pb LA–ICP–MS dating of detrital zircon from the Permian-Triassic red beds located within the Moscow Basin of the East European platform. Two outcrops have been studied: the Zhukov Ravine P/T boundary reference section and the Nedubrovo strata with uncertain stratigraphic position (uppermost Permian or lower Triassic?).</p><p>U–Pb ages of detrital zircon grains have been obtained for two samples – the Upper Permian and Lower Triassic age, which were taken in the proximity to the Permian–Triassic boundary in the Zhukov Ravine. Corresponding age distributions show contrasting provenance of the studied sedimentary rocks, pointing out that principal change in source of clastic material occurred on the Paleozoic-Mesozoic boundary. It means that detrital zircon U–Pb geochronology can be used as an additional independent tool for stratigraphic correlation of the Permian-Triassic red beds, at least within the Moscow Basin. We demonstrate this in the case of the Nedubrovo section with debated (Permian or Triassic?) stratigraphic position: the obtained data on detrital zircons persuasively suggests Early Triassic age of the Nedubrovo strata.</p><p>This study is supported by the Russian Foundation for Basic Research (project no. 18-05-00593).</p>

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