Le magmatisme basique de la boutonniere d'Igherm (Anti-Atlas occidental, Maroc); un jalon des distensions neoproterozoiques sur la bordure nord du craton ouest-africain

2001 ◽  
Vol 172 (3) ◽  
pp. 309-317 ◽  
Author(s):  
El Hassan El Aouli ◽  
Dominique Gasquet ◽  
Moha Ikenne
Keyword(s):  
Field Studies ◽  
The Other ◽  
Alkaline Magmatism ◽  
Calc Alkaline ◽  
Mafic Magmatism ◽  
Fine Grained ◽  
Eu Anomaly ◽  
Northern Border ◽  
Ree Patterns ◽  
Group 1

Abstract In the Igherm inlier (western Anti-Atlas, Morocco) doleritic dyke swarms with various directions and gabbroic intrusive bodies were emplaced during Neoproterozoic times, cutting across either Eburnean micaschists and granites or Panafrican limestones and quartzites. All these rocks were deformed by the main Panafrican schistosity and covered by molassic and volcanic Upper Neoproterozoic series. The primary mineralogical assemblages (plagioclase, augite, olivine...) of the mafic rocks are nearly completely replaced by secondary assemblages (albite, actinolite, chlorite, epidote, calcite, quartz, leucoxene, magnetite, hematite...). However, three main groups have been recognized by the means of relative chronology and petrography. The group 1 is earlier, as shown by the intrusive character of the dykes of the other two groups into its gabbroic bodies. Using incompatible trace elements and rare earth elements it appears that this magmatism is truly heterogeneous and that the three groups have different magmatic affinities. The group 1 corresponds to tholeiitic dolerites and gabbros characterized by intersertal and ophitic textures and by high contents in Fe 2 O 3 (12.16 to 16.64%), TiO 2 (1.46 to 2.5%), Zr (90 to 174 ppm), Nb (7 to 13 ppm), Y (21.68 to 38.74 ppm) and V (264 to 419 ppm). The REE contents are low (Sigma REE = 49 to 137 ppm) and the REE patterns are flat [1.99<(La/Yb) N <4.56] showing a relative slight enrichment in LREE and no anomaly in Eu (0.89>Eu/Eu (super *) <1.11). These features as the TiO 2 vs FeO (super *) /MgO and V vs Ti/1000 diagrams are characteristic of anorogenic intraplate magmas. The group 2 corresponds to calc-alkaline dolerites and gabbros showing fine-grained intersertal textures and high contents of Al 2 O 3 (14.10 to 20.64%) and low contents of Fe 2 O 3 (8.35 to 12.91%), TiO 2 (0.68 to 1.41%), Zr (66 to 106 ppm), Nb (5 to 7 ppm), Y (16.41 to 20.75 ppm) and V (144 to 264 ppm). The REE contents vary from 67 to 155 ppm and the REE patterns are fractionated (2.78<(La/Yb) N <6.62) with a strong enrichment in LREE. The slight positive Eu anomaly (0.91<Eu/Eu (super *) <1.37) is related to the wealth of plagioclases frequently observed in these rocks. The TiO 2 contents of these rocks and their low FeO (super *) /MgO ratios give them a calc-alkaline affinity similar to that of calc-alkaline orogenic basalts related to an oceanic subduction. The group 3 corresponds to alkaline dolerites characterized by fine-grained intersertal textures with high contents of TiO 2 (3.85 to 3.97%), P 2 O 5 (0.66 to 0.77%), Nb (33 to 39 ppm), Zr (262 to 287 ppm), Y (39.6 to 47.7 ppm) and REE (Sigma REE = 205 to 218 ppm). The REE patterns are fractionated (7.77<La/Yb) N <6.65) without no Eu anomaly (0.99<Eu/Eu (super *) <1.02). The Ti/V and Y/Nb ratios (65.26 to 74.95 and 1.19 to 1.22, respectively) are those of alkaline rocks found in intraplate environments. The detailed petrographical, geochemical and field studies of the Igherm inlier show that the mafic magmatism is more complex than previously described. The mafic tholeiitic and alkaline magmatism occurring in the Igherm inlier is also present in the other inliers of the Moroccan Anti-Atlas during Neoproterozoic times. On the other hand the calc-alkaline Neoproterozoic mafic magmatism is very rare elsewhere in the Anti-Atlas except in the Siroua Massif and locally in the Bas Draa and Tagragra d'Akka inliers (western Anti-Atlas). The geodynamical environment of this mafic magmatism is linked to a strong extensional tectonic regime occurring at the northern border of the West African craton during Neoproterozoic times. This regime is related to the oceanic opening described in Central Anti-Atlas and to the emplacement of the ophiolites of Bou Azzer and Siroua or occurs immediately after the oceanic opening. The chemical heterogeneities observed in the three defined groups can be related to heterogeneities of mantellic sources and/or various partial melting ratios of the sub-continental mantle. We can assume that this major fissural magmatic event, not precisely dated, is equivalent to that observed in the other Neoproterozoic provinces in Hoggar, Cameroon, north America and Brazil.

Quelques aspects pétrographiques et géochimiques du volcanisme archéen du Malartic en Abitibi (Province du Québec, Canada)

1979 ◽  
Vol 16 (5) ◽  
pp. 1041-1059 ◽  
Author(s):  
C. Alsac ◽  
M. Latulippe
Keyword(s):  
Regional Metamorphism ◽  
Volcanic Rocks ◽  
Major Elements ◽  
The Other ◽  
Island Arcs ◽  
Calc Alkaline ◽  
Fine Grained ◽  
Geochemical Study ◽  
Group A ◽  
Copper Zinc

The Archean metavolcanic formations of the Malartic Group in Abitibi, northwestern Quebec (Canada), are several kilometres thick and made up of lavas and pyroclastic rocks, a large part of which are of submarine origin with pillows and hyaloclastites.The mafic phases, with ultramafic material (komatiites), dominate at the base of the unit, the felsitic flows and other derived material, locally associated with copper and zinc sulphides, are located towards the summit of the unit.The regional metamorphism of greenschist and locally amphibolite–almandine facies, has destroyed the magmatic paragenesis; on the other hand, the original textures and structures are generally well preserved.A geochemical study of major elements was carried out on 67 well chosen fine-grained lavas. These were retained for analysis after thin section examination showed them to be nonporphyritic, homogeneous, with a minimum of alteration, and a lack of secondary fillings of amygdales and microfissures. This study led to the following conclusions:(1) The original composition of the volcanic rocks of the Malartic Group is still identifiable in spite of the modification in the content of Na, K, Ca, S, H2O, CO2 and to a lesser degree of Mg and Fe.(2) The variable percentages, generally high in Na and low in K, give to this volcanic group a spilitic characteristic; this may simply be an accentuation of an original tendency for series poor in K.(3) Apart from the ultramafic flows and certain magnesian basalts for which a komatiitic relationship is considered, the Malartic volcanism has magmatic characteristics comparable to those of volcanic island arcs. It begins with dominantly mafic extrusions with a tholeiitic composition poor in K. It continues in the upper Malartic with eruptions in which felsitic phases, locally associated with copper–zinc mineralization, become more abundant; these products seem to belong to two different magmatic series: one tholeiitic, the other calc-alkaline, both poor in K. The phases of these two magmatic series are spatially tightly imbricated.

scholarly journals Ghrelin and orexin levels in infertile male: evaluation of effects on varicocele pathophysiology, relationship seminal and hormonal parameter

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Üçler Kısa ◽  
M. Murad Başar ◽  
Timuçin Şipal ◽  
Özlem Doğan Ceylan
Keyword(s):  
The Other ◽  
Control Group ◽  
Infertile Male ◽  
Seminal Parameters ◽  
Other Hand ◽  
Healthy Control ◽  
Regulatory Effects ◽  
Serum Ghrelin ◽  
Infertile Patients ◽  
Group 1

AbstractObjectiveThe aim of the present study was to investigate serum ghrelin and orexin levels in patients with varicocele and compare these levels with idiopathic infertile male and healthy control cases.MethodsThis study enrolled 24 men with varicocele, 24 males having idiopathic infertility, and 21 fertile men as the control group. Hormonal analyses, ghrelin and orexin levels were measured samples. Semen was analyzed after 3 and 5 days of sexual abstinence.ResultsSerum ghrelin levels were statistically different among the three groups (p=0.015), and it was due to a statistically lower level in group-1 than the level in the control cases (p=0.012). On the other hand, serum orexin levels were lower than healthy subjects in infertile groups with/without varicocele, but there was no difference (p=0.685) among three groups. Serum ghrelin level showed a negative and significant correlation only with sperm motility (r=−0.646, p=0.022), there was no correlation with other parameters. On the other hand, serum orexin levels did not show a significant correlation with seminal parameters.ConclusionBoth new investigated peptides ghrelin and orexin have regulatory effects on testicular function. However, ghrelin has a more obvious and complex effect on spermatogenesis. Impaired seminal parameters, especially motility was associated with increased serum ghrelin levels in infertile patients, especially with varicocele.

scholarly journals Petrogenesis of a late-stage calc-alkaline granite in a giant S-type batholith: geochronology and Sr–Nd–Pb isotopes from the Nomatsaus granite (Donkerhoek batholith), Namibia

2021 ◽  
Author(s):  
S. Aspiotis ◽  
S. Jung ◽  
F. Hauff ◽  
R. L. Romer
Keyword(s):  
Partial Melting ◽  
Mineral Assemblage ◽  
Central Zone ◽  
Calc Alkaline ◽  
Pb Isotope ◽  
Alkaline Granite ◽  
Ti Oxides ◽  
Eu Anomaly ◽  
Environment Characteristic ◽  
Southern Central

AbstractThe late-tectonic 511.4 ± 0.6 Ma-old Nomatsaus intrusion (Donkerhoek batholith, Damara orogen, Namibia) consists of moderately peraluminous, magnesian, calc-alkalic to calcic granites similar to I-type granites worldwide. Major and trace-element variations and LREE and HREE concentrations in evolved rocks imply that the fractionated mineral assemblage includes biotite, Fe–Ti oxides, zircon, plagioclase and monazite. Increasing K2O abundance with increasing SiO2 suggests accumulation of K-feldspar; compatible with a small positive Eu anomaly in the most evolved rocks. In comparison with experimental data, the Nomatsaus granite was likely generated from meta-igneous sources of possibly dacitic composition that melted under water-undersaturated conditions (X H2O: 0.25–0.50) and at temperatures between 800 and 850 °C, compatible with the zircon and monazite saturation temperatures of 812 and 852 °C, respectively. The Nomatsaus granite has moderately radiogenic initial 87Sr/86Sr ratios (0.7067–0.7082), relatively radiogenic initial εNd values (− 2.9 to − 4.8) and moderately evolved Pb isotope ratios. Although initial Sr and Nd isotopic compositions of the granite do not vary with SiO2 or MgO contents, fSm/Nd and initial εNd values are negatively correlated indicating limited assimilation of crustal components during monazite-dominated fractional crystallization. The preferred petrogenetic model for the generation of the Nomatsaus granite involves a continent–continent collisional setting with stacking of crustal slices that in combination with high radioactive heat production rates heated the thickened crust, leading to the medium-P/high-T environment characteristic of the southern Central Zone of the Damara orogen. Such a setting promoted partial melting of metasedimentary sources during the initial stages of crustal heating, followed by the partial melting of meta-igneous rocks at mid-crustal levels at higher P–T conditions and relatively late in the orogenic evolution.

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.

Myeloid neoplasms in the setting of chronic lymphocytic leukaemia/chronic lymphocytic leukaemia-like disease: a clinicopathological study of 66 cases comparing cases with prior history of treatment to those without

2021 ◽  
pp. jclinpath-2020-207334
Author(s):  
Catherine Luedke ◽  
Yue Zhao ◽  
Jenna McCracken ◽  
Jake Maule ◽  
Lian-He Yang ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukaemia ◽  
Lymphocytic Leukaemia ◽  
The Other ◽  
Prior History ◽  
Myeloid Neoplasm ◽  
Myeloid Neoplasms ◽  
History Of ◽  
Cytogenetic Profile ◽  
Group 2 ◽  
Group 1

AimsMyeloid neoplasms occur in the setting of chronic lymphocytic leukaemia (CLL)/CLL-like disease. The underlying pathogenesis has not been elucidated.MethodsRetrospectively analysed 66 cases of myeloid neoplasms in patients with CLL/CLL-like disease.ResultsOf these, 33 patients (group 1) had received treatment for CLL/CLL-like disease, while the other 33 patients (group 2) had either concurrent diagnoses or untreated CLL/CLL-like disease before identifying myeloid neoplasms. The two categories had distinct features in clinical presentation, spectrum of myeloid neoplasm, morphology, cytogenetic profile and clinical outcome. Compared with group 2, group 1 demonstrated a younger age at the diagnosis of myeloid neoplasm (median, 65 vs 71 years), a higher fraction of myelodysplastic syndrome (64% vs 36%; OR: 3.1; p<0.05), a higher rate of adverse unbalanced cytogenetic abnormalities, including complex changes, −5/5q- and/or −7/7q- (83% vs 28%; OR: 13.1; p<0.001) and a shorter overall survival (median, 12 vs 44 months; p<0.05).ConclusionsMyeloid neoplasm in the setting of CLL/CLL-like disease can be divided into two categories, one with prior treatment for CLL/CLL-like disease and the other without. CLL-type treatment may accelerate myeloid leukaemogenesis. The risk is estimated to be 13-fold higher in patients with treatment than those without. The causative agent could be attributed to fludarabine in combination with alkylators, based on the latency of myeloid leukaemogenesis and the cytogenetic profile.

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.

scholarly journals Geochemical Characteristics and Tectonic Setting of Amphibolites in Ifewara Area, Ife-Ilesha Schist Belt, Southwestern Nigeria

2016 ◽  
Vol 6 (1) ◽  
pp. 43 ◽  
Author(s):  
Anthony Temidayo Bolarinwa ◽  
Adebimpe Atinuke Adepoju
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Major Element ◽  
Tectonic Setting ◽  
Crustal Contamination ◽  
Geochemical Evolution ◽  
Schist Belt ◽  
Southwestern Nigeria ◽  
Eu Anomaly ◽  
Ree Patterns

Trace and Rare Earth Elements (REEs) data are used to constrain the geochemical evolution of the amphibolites from Ifewara in the Ife-Ilesha schist belt of southwestern Nigeria. The amphibolites can be grouped into banded and sheared amphibolites. Major element data show SiO2 (48.34%), Fe2O3 (11.03-17.88%), MgO (5.76-9.90%), CaO (7.76-18.6%) and TiO2 (0.44-1.77%) contents which are similar to amphibolites in other schist belts in Nigeria. The Al2O3 (2.85-15.55%) content is varied, with the higher values suggesting alkali basalt protolith. Trace and rare earth elements composition reveal Sr (160-1077ppm), Rb (0.5-22.9ppm), Ni (4.7-10.2ppm), Co (12.2-50.9 ppm) and Cr (2-7ppm). Chondrite-normalized REE patterns show that the banded amphibolites have HREE depletion and both negative and positive Eu anomalies while the sheared variety showed slight LREE enrichment with no apparent Eu anomaly. The study amphibolites plot in the Mid Oceanic Ridge Basalts (MORB) and within plate basalt fields on the Zr/Y vs Zr discriminatory diagrams. They are further classified as volcanic arc basalt and E-type MORB on the Th- Hf/3- Ta and the Zr-Nb-Y diagrams. The amphibolites precursor is considered a tholeiitic suite that suffered crustal contamination, during emplacement in a rifted crust.

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