scholarly journals AN ESTIMATE OF THE COMPOSITION OF PART OF THE CANADIAN SHIELD IN NORTHWESTERN ONTARIO

1967 ◽  
Vol 4 (4) ◽  
pp. 725-739 ◽  
Author(s):  
G. A. Reilly ◽  
D. M. Shaw
Keyword(s):  
Trace Elements ◽  
Significant Variation ◽  
Major Element ◽  
Canadian Shield ◽  
Element Analysis ◽  
Red Lake ◽  
Rock Types ◽  
Northwestern Ontario ◽  
House Area ◽  
Composite Samples

An attempt has been made to estimate the abundance of trace and major constituents in the Precambrian surficial rocks of a large part (43 000 square miles) of the Red Lake–Lansdowne House area in northwestern Ontario. One-hundred and two composite samples were made to represent eight rock types in seven adjacent map-areas of equal size. Major element analysis was carried out on eight composite samples representing rock types for the whole area. Analysis of variance techniques have detected significant regional variations of Cr, Mn, Sr, and Ba. Significant variation exists between rock types for all trace elements analyzed except Cu.

Copper content of Canadian shield rocks, red Lake-lansdowne house area, northwestern Ontario

1966 ◽  
Author(s):  
R F Emslie ◽  
R H C Holman
Keyword(s):  
Copper Content ◽  
Canadian Shield ◽  
Red Lake ◽  
Northwestern Ontario ◽  
House Area

Red Lake-Landsdowne house area, northwestern Ontario

1963 ◽  
Author(s):  
S Duffell ◽  
A S Maclaren ◽  
R H C Holman
Keyword(s):  
Red Lake ◽  
Northwestern Ontario ◽  
House Area

An estimate of the oxygen isotope composition of a large segment of the Canadian Shield in northwestern Ontario

1977 ◽  
Vol 14 (5) ◽  
pp. 927-931 ◽  
Author(s):  
Yuch-Ning Shieh ◽  
Henry P. Schwarcz
Keyword(s):  
Isotope Composition ◽  
Volcanic Rocks ◽  
Weighted Average ◽  
Canadian Shield ◽  
Granitic Rocks ◽  
Large Segment ◽  
Metasedimentary Rocks ◽  
Northwestern Ontario ◽  
Intrusive Rocks ◽  
Composite Samples

The O18/O16 ratios of the plutonic and supracrustal rocks from a large segment of the Superior province of the Canadian Precambrian Shield in Ontario (total area 111 000 km2) have been determined, using 8 composite samples prepared from 8076 individual specimens. The δO18 values (in ‰) relative to SMOW are: granitic rocks, 7.6–8.6; basic intrusive rocks, 7.2; metasedimentary rocks, 9.2; and volcanic rocks, 7.6. The composites from the granitic, basic intrusive, and volcanic rocks display δ values very similar to their contemporary or younger equivalents reported in the literature. The metasedimentary composite shows significantly lower δO18 than most Phanerozoic and Proterozoic metasediments of comparable metamorphic grades, possibly reflecting the presence of a high percentage of little-altered igneous rock detritus in the Archean sediments. The weighted average δ value (according to percent outcrop of each rock type) of this part of the Canadian Shield is estimated to be 8.1‰.

scholarly journals A red pine provenance test in northwestern Ontario: 48-year results

2010 ◽  
Vol 86 (3) ◽  
pp. 348-353 ◽  
Author(s):  
Ali A Rahi ◽  
Colin Bowling ◽  
Dale Simpson
Keyword(s):  
Significant Variation ◽  
Pinus Resinosa ◽  
Red Pine ◽  
Provenance Trial ◽  
Maritime Provinces ◽  
Poor Growth ◽  
Breast Height ◽  
Seed Sources ◽  
Northwestern Ontario ◽  
Provenance Test

Survival, total height and diameter at breast height (DBH) were measured in the fall of 2005 in a 48-year-old red pine (Pinus resinosa Ait.) provenance trial growing in northwestern Ontario. There was significant variation in both height and diameter among the 23 provenances. Generally, westerly provenances performed well while those from the Maritime Provinces exhibited relatively poor growth. Considering that the plantation is at the northern biological range of red pine, survival was high, averaging 96% after 48 years. Provenances with the best growth rates exceeded a volume of 420 m3 ha-1. Some provenances from Minnesota and Wisconsin as well as Fort Frances, Ontario exhibited superior growth and should be considered as seed sources for future planting programs in northwestern Ontario. Key words: red pine, provenance test, survival, diameter, height, volume, Northwestern Ontario

Metabentonite geochemistry: magmatic cycles and graptolite extinctions at Dob's Linn, southern Scotland

1988 ◽  
Vol 79 (1) ◽  
pp. 19-41 ◽  
Author(s):  
R. A. Batchelor ◽  
J. A. Weir
Keyword(s):  
Trace Elements ◽  
Deleterious Effect ◽  
Major Element ◽  
Magma Mixing ◽  
Volcanic Origin ◽  
Intermediate Composition ◽  
Ash Composition ◽  
Mineralogical Study ◽  
Local Extinctions ◽  
Phosphorus Levels

ABSTRACTThe Moffat Shale Group is a condensed, variable and partly pelagic sequence of mudrocks of Llandeilo—Llandovery age. The sequence has a five-fold lithological subdivision based mainly on the occurrence of grey mudstones within a succession otherwise dominated by fully euxinic black graptolitic mudrocks. Associated with the black mudrocks, especially in the Llandovery, are metabentonite beds which achieve a climax, both in thickness and in number, within the top quarter of the mudrock sequence. A geochemical and mineralogical study has confirmed a volcanic origin for the metabentonites. Major element data highlight a carbonate-dominated environment above the gregarius—convolutus Zones boundary. Phosphorus levels reach a peak at the same boundary, as well as at the Caradoc—Ashgill boundary where phosphorite horizons are known from Wales and Norway. Immobile trace elements have highlighted regular changes in source magma composition. Prolonged periods of crystal fractionation in magmas of intermediate composition gave rise, on eruption, to large volumes of silicic ash which had a deleterious effect on graptolite species and led to local extinctions. Regular fluctuations in ash composition from silicic to intermediate are ascribed to alternating fractionation and magma mixing cycles.

A study of the composition of Clun Forest ewe's milk. II. Mineral constituents

1966 ◽  
Vol 67 (1) ◽  
pp. 77-80 ◽  
Author(s):  
W. M. Ashton ◽  
I. M. Yousef
Keyword(s):  
Trace Elements ◽  
Statistical Analysis ◽  
Significant Variation ◽  
Mineral Content ◽  
Major Elements ◽  
Lactation Period ◽  
Average Composition ◽  
Sodium Potassium ◽  
Ewe's Milk ◽  
Mineral Constituents

1. This paper provides further information on the mineral content of the milk of Clun Forest ewes, particularly those elements not dealt with in a previous paper, namely, magnesium, sodium, potassium, and certain trace elements.2. The average composition was as follows: calcium 0.200, magnesium 0.0147, sodium 0.046, potassium 0.168, phosphorus 0.140 and chlorine 0.076%; copper 0.22, iron 0.77, manganese 0.07 and aluminium 1.7 parts per million. Where possible the results are compared with those obtained by other workers for ewe's and cow's milk.3. Statistical analysis of the data showed that, with the exception of phosphorus, the content of major elements varied significantly during the lactation period. There was also a significant variation in all major elements between sheep.

scholarly journals Parental magma composition of the Main Zone of the Bushveld Complex: Evidence from in-situ LA-ICP-MS trace element analysis of silicate minerals in the cumulate rocks

2020 ◽  
Author(s):  
Shenghong Yang ◽  
Wolfgang D. Maier ◽  
Belinda Godel ◽  
Sarah-Jane Barnes ◽  
Eero Hanski ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Bushveld Complex ◽  
Trace Element Analysis ◽  
Parental Magma ◽  
Main Zone ◽  
Element Analysis ◽  
Silicate Minerals ◽  
Incompatible Elements

<p>In-situ trace element analysis of cumulus minerals may provide a clue to the parental magma from which the minerals crystallized. However, this is hampered by effects of the trapped liquid shift (TLS). In the Main Zone (MZ) of the Bushveld Complex, the Ti content in plagioclase grains shows a clear increase from core to rim, whereas most other elements (e.g., rare earth elements (REEs), Zr, Hf, Pb) do not. This is different from the prominent intra-grain variation of all trace elements in silicate minerals in mafic dikes and smaller intrusion, which have a faster cooling rate. We suggest that crystal fractionation of trapped liquid occurred in the MZ of Bushveld and the TLS may have modified the original composition of the cumulus minerals for most trace elements except Ti during slow cooling. Quantitative model calculations suggest that the influence of the TLS depends on the bulk partition coefficient of the element. The effect on highly incompatible elements is clearly more prominent ­­than on moderately incompatible and compatible elements because of different concentration gradients between cores and rims of cumulate minerals. This is supported by the following observations in the MZ of Bushveld: 1) positive correlation between Cr, Ni and Mg# of clinopyroxene and orthopyroxene, 2) negative correlation between moderately incompatible elements (e.g., Mn and Sc in clinopyroxene and orthopyroxene, Sr, Ba, Eu in plagioclase), but 3) poor correlation between highly incompatible elements and Mg# of clinopyroxene and orthopyroxene or An# of plagioclase. Modeling suggests that the extent of the TLS for a trace element is also dependent on the initial fraction of the primary trapped liquid, with strong TLS occurring if the primary trapped liquid fraction is high. This is supported by the positive correlation between highly incompatible trace element abundances in cumulus minerals and whole-rock Zr contents.</p><p>We have calculated the composition of the parental magma of the MZ of the Bushveld Complex. The compatible and moderately incompatible element contents of the calculated parental liquid are generally similar to those of the B3 marginal rocks, but different from the B1 and B2 marginal rocks. For the highly incompatible elements, we suggest that the use of the sample with the lowest whole-rock Zr content and the least degree of TLS is the best approach to obtain the parental magma composition. Based on calculation, we propose that a B3 type liquid is the most likely parental magma to the MZ of the Bushveld Complex.</p>

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