Mineralogy and geochemistry of an Archean tuffaceous exhalite: the Main Contact Tuff, Millenbach mine area, Noranda, Quebec

1989 ◽  
Vol 26 (1) ◽  
pp. 88-105 ◽  
Author(s):  
Stavros I. Kalogeropoulos ◽  
Steven D. Scott

The Main Contact Tuff, in the vicinity of Millenbach mine, Noranda, Quebec, is an extensive, although discontinuous, ore-related volcanic exhalative metalliferous sediment, or "tuffaceous exhalite," of Archean age. It was formed by the variable contribution of two constituents: (1) exhalite (chemical) composed mainly of pyrite, quartz, sphalerite, pyrrhotite, and chalcopyrite and (2) tuff (clastic) composed of quartz, chlorite, and sericite.Tuffaceous exhalites such as the Main Contact Tuff and the similar tetsusekiei of the Japanese Kuroko deposits (Miocene age) indicate a fossil hydrothermal system that may or may not have produced economic concentrations of metallic sulfides. The Main Contact Tuff displays cryptic variations, which provide exploration guides at different scales: (1) the Fe/[Fe + Mg] ratios of chlorite decrease from 0.63 to 0.32 over a distance of 0.3 km approaching ore from the north, and from 0.72 to 0.32 over 1.5 km from the south; (2) the FeO/[FeO + MgO] (sulfide-free) ratios of whole-rock specimens decrease from about 0.8 to 0.3 approaching the ore; (3) ilmenite is replaced in the ore zone by rutile and (or) sphene; and (4) the most manganiferous ilmenite is found close to ore. On the other hand, trace elements of exhalative origin (e.g., Ag, Co) in the Main Contact Tuff appear not to provide useful vectors towards ore. They are concentrated relative to normal pelagic rocks, but their distributions with respect to ore are complicated by multiple input sources and postexhalative redistributions of elements.

2018 ◽  
Vol 52 (2) ◽  
pp. 455-462 ◽  
Author(s):  
G. Ya. Doroshina ◽  
I. A. Nikolajev

Sphagnum mires on the Greater Caucasus are rare, characterized by the presence of relict plant communities of glacial age and are in a stage of degradation. The study of Sphagnum of Chefandzar and Masota mires is carried out for the first time. Seven species of Sphagnum are recorded. Their distribution and frequency within the North Caucasus are analyzed. Sphagnum contortum, S. platyphyllum, S. russowii, S. squarrosum are recorded for the first time for the study area and for the flora of North Ossetia. The other mosses found in the study area are listed.


2018 ◽  
Vol 69 (2) ◽  
pp. 305-309 ◽  
Author(s):  
Daniela Gitea ◽  
Simona Vicas ◽  
Manuel Alexandru Gitea ◽  
Sebastian Nemeth ◽  
Delia Mirela Tit ◽  
...  

Our study compares the content in polyphenolic compounds and hypericin, in four species of Hypericum - H. perforatum L., H. maculatum Cr., H. hirsutum L., H. tetrapterum Fr. (syn. Hypericumacutum Mnch.) harvested from spontaneous flora in the north-western area of Transylvania, Romania. These species represent an important source of such compounds with different biological actions. After making the extracts, they were subjected to HPLC-SM analysis. The presence of rutoside in the largest amount (462.82 mg %) in the H. perforatum extract was observed, this containing most of the flavonoid heterosides. For the species H. maculatum, the presence in a much higher amount of the hyperoside (976.36 mg %) is characteristic compared to the other species. Quercetol is the best represented of the flavonoid aglycons, its concentration being the highest in H. hirsutum (659.66 mg %). The hypericin content ranges from 0.2171 g % in the H. tetrapterum extract, to 0.0314 g % in the methanol extract of H. maculatum.The highest antioxidant properties measured by FRAP method were recorded in the case of H. perforatum and H. maculatum.


Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 307
Author(s):  
Makoto Inoue ◽  
Atsushi Ugajin ◽  
Osamu Kiguchi ◽  
Yousuke Yamashita ◽  
Masashi Komine ◽  
...  

In this study, we investigated the effects of the Tibetan High near the tropopause and the North Pacific High in the troposphere on occurrences of hot or cool summers in Japan. We first classified Japan into six regions and identified hot and cool summer years in these regions from a 38-year sample (1980–2017) based on the monthly air temperature. To investigate the features of circulation fields over Asia during hot and cool summers in Japan, we calculated the composite differences (hot summer years minus cool summer years) of several variables such as geopotential height, which indicated significant high-pressure anomalies in the troposphere and lower stratosphere. These results suggest that both the North Pacific and the Tibetan Highs tend to extend to Japan during hot summer years, while cool summers seem to be associated with the weakening of these highs. We found that extension of the Tibetan High to the Japanese mainland can lead to hot summers in Northern, Eastern, and Western Japan. On the other hand, hot summers in the Southwestern Islands may be due to extension of the Tibetan High to the south. Similarly, the latitudinal direction of extension of the North Pacific High is profoundly connected with the summer climate in respective regions.


2021 ◽  
Vol 97 ◽  
pp. 103754
Author(s):  
Naghmeh Soltani ◽  
Michel Marengo ◽  
Behnam Keshavarzi ◽  
Farid Moore ◽  
Peter S. Hooda ◽  
...  

1874 ◽  
Vol 1 (1) ◽  
pp. 1-2
Author(s):  
Edward Hull

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.


2013 ◽  
Vol 20 (1) ◽  
pp. 99-122 ◽  
Author(s):  
Jonathan Fennell

High rates of desertion and surrender during the battles in North Africa in the summer of 1942 were a major factor in Eighth Army’s poor combat performance. At the time, some suggested that these problems were symptomatic of a lack of courage or even of cowardice. There are two broad strands to the conceptualization of courage and cowardice. One focuses on the willingness of the person to fight; the other puts emphasis on how actions express an individual’s ability to cope with fear. Whichever conceptualization is used, high morale motivates the soldier to fight and shields the ordinary recruit from his fear, preventing it from overcoming him in battle. Where morale fails, the soldier is left demotivated and burdened with his terror and, therefore, and is therefore prone to desertion or surrender. Because it is extremely difficult to maintain morale at a continuously high level in an environment governed by chance and managed by humans, all soldiers can find themselves in situations where their actions may be judged as cowardly. Alternatively, if they are properly motivated to fight and prepared by the state and military to deal with the unavoidable fear of combat, all soldiers can be labelled courageous. Accordingly, emotive terms should be avoided when attempting to describe rationally explainable outcomes. The undoubtedly negative connotations attached to cowardice in battle and the positive ones attached to courage are, therefore, arguably unhelpful in understanding Eighth Army’s performance in the summer of 1942 and the human dimension in warfare more generally.


1916 ◽  
Vol 3 (10) ◽  
pp. 435-441 ◽  
Author(s):  
G. W. Tyrrell

The new material on which this paper is based has lately been received through Mr. D. Ferguson, who recently investigated the geology of the island, and collected the rocks described in an earlier paper. It consists of twenty-seven rock specimens from the south-eastern end of the island, between Cape Disappointment and Cooper Island, and nine specimens from Gold Harbour on the north-east coast between Cooper Island and Royal Bay. All these were collected by the staff of the South Georgia Co., Ltd., under the instructions of Mr. Th. E. Salvesen, managing director, of Leith.


Author(s):  
P.A. Popov ◽  
◽  
V.S. Babunova ◽  

Hormones are an integral part of milk and throughout lactation, the content of certain hormones is unstable. Hormones regulate the process of starting lactation of animals, the lactation process itself, and also the other functions of the body. Milk is of great importance for the growth of young animals and the formation of immunity. Milk is a special product in the diet and is an important food and raw material for the production of dairy products for people. It contains a large amount of protein, fat, carbohydrates, vitamins and trace elements in biologically available form. But at the same time, over the past few years, more and more evidence has emerged that hormones in dairy products can impact on human health. Thus, some estrogens and insulin-like growth factor IGF-1 are involved in the initiation and provocation of breast, prostate and endometrial tumors. That’s why, it is necessary to normalize and control the content of certain hormones in milk with highly sensitive methods.


1968 ◽  
Vol 25 (5) ◽  
pp. 877-901 ◽  
Author(s):  
Wilfred Templeman

Three specimens of Halargyreus johnsonii taken on the southwestern and southeastern slopes of the Grand Bank in 1959 and 1964 are apparently the first records of this species and genus from the western Atlantic. These specimens are compared with the holotypes of H. johnsonii Günther and of H. brevipes Vaillant and with the syntypes of H. affinis Collett and also with specimens identified as H. affinis from the north-central and northeast Atlantic and with specimens of H. johnsonii from Madeira and New Zealand. These three nominal species are also compared. Is it concluded that for the present all North Atlantic specimens may be referred to H. johnsonii and that the other two species names should be considered as junior synonyms of H. johnsonii.The New Zealand specimens of Halargyreus, described by Günther (1887, Challenger Rept., 22(Zoology), p. 1–268) as H. johnsonii, have higher numbers for some meristic characters than Atlantic specimens of H. johnsonii but these differences are not too great to be possibly due to environmental differences. Pending the study of additional specimens in better condition, these New Zealand specimens are tentatively allowed to remain as H. johnsonii.


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