TRACE ELEMENTS IN TILLS OF ALBERTA

1967 ◽  
Vol 4 (4) ◽  
pp. 597-607 ◽  
Author(s):  
L. A. Bayrock ◽  
S. Pawluk
Keyword(s):  
Trace Elements ◽  
Regional Scale ◽  
Iron Formation ◽  
Carbonate Content ◽  
Minor Constituents ◽  
Zn Distribution ◽  
Glacial Processes ◽  
Caribou Mountains

Analysis of 475 Keewatin till samples from the Alberta Plains shows well-defined trends in the distribution of certain minor constituents and trace elements. Fe and Cu are most abundant in tills from the Clear Hills region of northwestern Alberta, in which area thin but widespread beds of iron-formation outcrop. Zn distribution in till also is related to bedrock composition and, together with Fe and Cu, is useful in delineating bedrock subcrop patterns. The distribution of CaO, although related to the carbonate content of the underlying bedrock on a regional scale, has been modified to some extent by glacial processes, as demonstrated in the Caribou Mountains area of northernmost Alberta.

Sedimentary and metamorphic lithofacies of the Lower Negaunee Iron Formation, Marquette District, Michigan, USA

2013 ◽  
Vol 50 (12) ◽  
pp. 1165-1177
Author(s):  
Natalie J. Pietrzak-Renaud
Keyword(s):  
Shear Zone ◽  
Mineral Assemblage ◽  
Regional Metamorphism ◽  
Regional Scale ◽  
Open Pit ◽  
Iron Formation ◽  
Banded Iron Formation ◽  
Brittle Fractures ◽  
Granular Iron ◽  
The Republic

The base of the Proterozoic Negaunee Iron Formation is exposed in the open pit at Tilden Mine, Marquette, Michigan. Juxtaposed against the Archean-aged Palmer Gneiss, it is bounded by the regional-scale Southern Shear Zone and cut by two sets of dykes: an older chloritic and schistose set and a younger 1.1 Ga Keweenawan set. Tilden Mine is dominated by a 100 m scale plunging northwest-anticline and is cut by a growth fault locally termed the Tower Hill Fault that intersects the Southern Shear Zone. The base of the exposed iron formation is composed of three lithofacies, including lower clastics that grade into the overlying banded iron formation that in turn grades upward into granular iron formation. This succession is capped by chloritic metadiabases locally termed the Summit Hill Sill and Pillar Intrusive. Petrographic and mineral chemical investigations document primary or early diagenetic hematite, siderite and possibly ferri-hydrite, metamorphic and related hydrothermal magnetite, chlorite, late martite overgrowing earlier magnetite and growth of specularite. All three lithofacies are cut by brittle fractures and late quartz veins. Brittle fractures are coated with chlorite, carbonate minerals, fluor-apatite, and sparse Cu-sulphides. These lithofacies document initial clastic sedimentation of strained detrital quartz into a subsiding fault trough. Over time, as subsidence slowed or sea level fluctuated, clastic deposition competed with quiescent chemical sedimentation, leading to deposition of the banded iron formation facies. As a stable shelf platform emerged, the granular iron formation facies was deposited via wave reworking of hardgrounds. Subsequent diagenesis initiated dissolution of carbonate and chert and promoted diagenetic replacement of primary iron minerals and chert. Regional metamorphism during Penokean orogeny at 1875–1835 Ma produced a suite of secondary metamorphic and related hydrothermal minerals. Metamorphism and hydrothermal flux related to the 1750 Ma development of the Republic Metamorphic Node overprinted the iron formation at Tilden to greenschist facies and infilled brittle fractures with a unique mineral assemblage. This unique mineral assemblage exhibits some striking similarities to Mn, Au, and Cu-sulphides documented at Champion Mine, west of Tilden, and proximal to the core of the Republic Node.

Metamorphic amphiboles in the Ironwood Iron-Formation, Gogebic Iron Range, Wisconsin: Implications for potential resource development

2020 ◽  
Vol 105 (8) ◽  
pp. 1259-1269
Author(s):  
Carlin J. Green ◽  
Robert R. Seal ◽  
Nadine M. Piatak ◽  
William F. Cannon ◽  
Ryan J. McAleer ◽  
...  
Keyword(s):  
Objective Assessment ◽  
Regional Scale ◽  
Resource Development ◽  
The United States ◽  
Contact Metamorphism ◽  
Iron Formation ◽  
Detailed Knowledge ◽  
Lower Grade ◽  
Iron Range ◽  
Wide Range

Abstract The Paleoproterozoic Ironwood Iron-Formation, a Superior-type banded iron formation located in the western Gogebic Iron Range in Wisconsin, is one of the largest undeveloped iron ore resources in the United States. Interest in the development of this resource is complicated by potential environmental and health effects related to the presence of amphibole minerals in the Ironwood, a consequence of Mesoproterozoic contact metamorphism. The presence of these amphiboles and their contact metamorphic origin have long been recognized; however, recent interest in this resource has highlighted the lack of detailed knowledge on their distribution, mineral chemistry, and morphology. Optical microscopy, X-ray diffraction, scanning electron microscopy, and electron microprobe analysis were utilized to investigate the origin, distribution, morphology, and chemistry of amphiboles in the Ironwood. Amphibole is present in the western portion of the study area due to regional-scale contact meta-morphism associated with the intrusion of the 1.1 Ga Mellen Intrusive Complex. Locally amphibole is also present, adjacent to diabase and/or gabbro dikes and sills in the lower-grade Ironwood in the eastern portion of the study area. In both localities, amphiboles in the Ironwood most commonly developed in massive and prismatic habits, and locally assumed a fibrous habit. Fibrous amphiboles were recognized locally in the two potential ore zones of the Ironwood but were not observed in the portion likely to be waste rock. Massive and prismatic amphiboles show a wide range of Mg# [molar Mg/(Mg+Fe2+)] values (0.06 to 0.87), whereas Mg# values of fibrous amphiboles are restricted from 0.14 to 0.35. Factors that influenced the compositional variability of amphiboles in the Ironwood may have included temperature of formation, morphology, bulk chemistry of the iron formation, and variations in prograde and retrograde metamorphism. The presence of amphiboles in the Ironwood is a known issue that will need to be factored into any future mine plans. This study provides an objective assessment of the distribution and character of amphiboles in the Ironwood to aid all decision-makers in any future resource development scenarios.

Interspecies calibration in mosses at regional scale—heavy metal and trace elements results from Ile-de-France

2003 ◽  
Vol 37 (2) ◽  
pp. 241-251 ◽  
Author(s):  
L Galsomiès ◽  
S Ayrault ◽  
F Carrot ◽  
C Deschamps ◽  
M.A Letrouit-Galinou
Keyword(s):  
Heavy Metal ◽  
Trace Elements ◽  
Regional Scale

scholarly journals Bedrock geology, northwest part of Nuluujaak Mountain, Baffin Island, Nunavut, part of NTS 37-G/5

2021 ◽  
Author(s):  
G D Jackson
Keyword(s):  
Regional Scale ◽  
Iron Formation ◽  
Small Scale ◽  
Baffin Island ◽  
The North ◽  
Bedrock Geology ◽  
Iron Mine ◽  
Iron Deposits ◽  
Legacy Data ◽  
East West

The map area lies about 40 km northwest of Baffinland's iron mine. Dykes of unit mAnA3 within unit mAnA2 suggest that unit mAnA2 predates unit mAnA3. Unit nAMqf, basal Mary River Group unit, includes regolith material from units mAnA2 and mAnA3. Unit mAnAm may include some dykes of unit nAMb. The Mary River Group was deposited in a volcanic-arc environment, yielding zircon U-Pb ages mostly in the range of 2.88 to 2.72 Ga. Iron-formation (unit nAMi) is approximately 276 m thick locally, with oxide facies (unit nAMio) being most abundant. The quartzite triangle west of 'Iron lake' (unofficial name) may be a small horst. The main east-west-trending synclinal fold, including the area around 'Iron lake' and the no. 4 ore deposit, is upright, nearly isoclinal, and plunges mostly easterly at both ends with small scale anticlines and synclines in the middle. Magnetite constitutes about 75% of high-grade iron deposits in the north limb, whereas hematite predominates in south-limb deposits. K-Ar and Rb-Sr ages indicate middle Paleoproterozoic overprinting. Central Borden Fault Zone was active at ca. 1.27 Ga and during or after Ordovician time. Note: please be aware that the information contained in CGM 408 is based on legacy data from the 1960-1990s and that it has been superseded by regional-scale information contained in CGM 403.

scholarly journals Investigating the Potential Role of Geological Context on Groundwater Quality: A Case Study of the Grenville and St. Lawrence Platform Geological Provinces in Quebec, Canada

Geosciences ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 503
Author(s):  
Roxane Tremblay ◽  
Julien Walter ◽  
Romain Chesnaux ◽  
Lamine Boumaiza
Keyword(s):  
Trace Elements ◽  
Groundwater Quality ◽  
Chemical Elements ◽  
Groundwater Resources ◽  
Regional Scale ◽  
Major Elements ◽  
Groundwater Chemistry ◽  
Geochemical Evolution ◽  
Geological Context

The hydrogeochemical study of the Lanaudière and Eastern Mauricie regions (Canada) demonstrates that trace elements appear to be better tracers of geological influence on groundwater chemistry than major elements. Isotopic ratios and the similar chemical composition of groundwater suggest that the physicochemical parameters of groundwater have a greater effect on hydrogeochemical mechanisms than the immediate geological environment The results allow us to propose a conceptual model of groundwater geochemical evolution with the aim to guide the protection and sustainable management of regional groundwater resources in the Lanaudière and Eastern Mauricie regions. These regions were selected because of their location at the boundary of the Grenville and St. Lawrence Platform geological provinces, representing two distinct geological contexts (Precambrian crystalline rocks and Paleozoic sedimentary rocks). Regional-scale hydrogeochemical and isotopic groundwater characterization was carried out to identify the role of the differences in regional geology on groundwater quality. Our analyses included major and trace elements, stable isotopes, and multivariate statistics. Similar processes are at the origin of dissolved major chemical elements and suggest that soluble minerals common to both geological provinces control groundwater chemistry. If differences exist, they are due to the hydrogeological conditions of the samples, such as residence time or groundwater entrapment at the time of the postglacial marine incursion of the Champlain Sea, rather than the geological context. Some differences, sometimes significant, were observed for some minor elements (F−, Mn2+, H2S), which implies a more comprehensive knowledge of the chemistry of the stratigraphic units within the Lanaudière and Eastern Mauricie aquifers.

scholarly journals Factors controlling alpine glaciations in the Sierra Baguales Mountain Range of southern Patagonia (50º S), inferred from the morphometric analysis of glacial cirques

2018 ◽  
Vol 45 (3) ◽  
pp. 357 ◽  
Author(s):  
Jose M. Araos ◽  
Jacobus P. Le Roux ◽  
Michael R. Kaplan ◽  
Matteo Spagnolo
Keyword(s):  
Climatic Factors ◽  
Regional Scale ◽  
Climatic Conditions ◽  
Mountain Range ◽  
Southern Patagonia ◽  
Ice Field ◽  
Glacial Processes ◽  
Patagonian Andes ◽  
First Time

The Sierra Baguales Mountain Range, forming the eastern foothills of the Southern Patagonian Andes, has well-developed alpine-glaciated landforms which present an ideal opportunity to study climatic and non-climatic factors that control cirque development and morphology. One hundred and forty-three glacial cirques were studied with reference to 14 morphometric attributes which were analyzed using statistical analysis and GIS methodologies. The cirques were classified into two types using cluster analysis complimented with a composite map based on the attributes, the latter technique that is applied to glacial cirque analysis for the first time. Type 1 cirques are associated with glacial processes isolated from the Southern Patagonian Ice Field (SPIF), developed under locally cold and dry climatic conditions. Type 2 glacial cirques are associated with older, more extensive glacial processes controlled by regional-scale climate variables and the presence of the Pleistocene Ice Sheet. The results show that the development of most of the glacial cirques has been controlled mainly by their aspect, exposure to solar radiation, Southern Hemisphere Westerly winds, and cirque floor slope. Finally, we concluded that our analyses show the evolution of cirques in the Sierra Baguales Mountain Range was not uniform. Cirque glaciers that developed to the west, close to the Southern Patagonian Ice field, have been more dynamic, and therefore their cirques experienced more erosion than those located to the east.

scholarly journals Minor Constituents and Trace Elements in Negev Phosphate Rocks

Nature ◽  
1958 ◽  
Vol 181 (4624) ◽  
pp. 1676-1676 ◽  
Author(s):  
E. FOA
Keyword(s):  
Trace Elements ◽  
Phosphate Rocks ◽  
Minor Constituents

scholarly journals Seasonal impact of natural and anthropogenic emissions on the highest glacier of the Eastern European Alps

2011 ◽  
Vol 11 (2) ◽  
pp. 6493-6530 ◽  
Author(s):  
J. Gabrieli ◽  
L. Carturan ◽  
P. Gabrielli ◽  
C. Turetta ◽  
N. Kehrwald ◽  
...  
Keyword(s):  
Trace Elements ◽  
Regional Scale ◽  
Atmospheric Stability ◽  
Eastern Alps ◽  
European Alps ◽  
Eastern European ◽  
Data Set ◽  
Back Trajectories ◽  
Atmospheric Depositions ◽  
Snow Samples

Abstract. In June 2009, we conducted the first extensive glaciological survey of Alto dell'Ortles, the uppermost glacier of Mt. Ortles which at 3905 meters above sea level (m a.s.l.) is the highest summit of the Eastern European Alps. We analyzed snow samples collected from a 4.5 m snow-pit at 3830 m a.s.l. Here, we present a comprehensive data set including a large suite of trace elements and ionic compounds that comprise the atmospheric depositions over the past few years. Trace element concentrations measured in snow samples are extremely low with mean concentrations at pg g−1 level. Only Al and Fe present median values of 1.8 and 3.3 ng g−1, with maximum concentrations of 21 and 25 ng g−1. The median EFc values for Be, Rb, Sr, Ba, U, Li, Al, Ca, Cr, Mn, Fe, Co, Ga and V are lower than 10 suggesting that these elements originated mainly from soil and mineral aerosol. EFc higher than 100 are reported for Zn (118), Ag (135), Bi (185), Sb (401) and Cd (514), demonstrating the predominance of non-crustal depositions and suggesting an anthropogenic origin. Our data show that the physical stratigraphy and the chemical signals of several species were well preserved in the uppermost snow of the Alto dell'Ortles glacier. A clear seasonality emerges from the data as the summer snow is more affected by anthropogenic and marine contributions while the winter aerosol flux is dominated by crustal sources. For trace elements, the largest mean EFc seasonal variations are displayed by V (with a factor of 3.8), Sb (3.3), Cu (3.3), Pb (2.9), Bi (2.8), Cd (2.1), Zn (1.9), Ni (1.8), Ag (1.8), As (1.7) and Co (1.6). The chemical data are also discussed in light of the atmospheric stability and back-trajectories analyses in order to explain the observed seasonal variability and how human activities impact the high altitude environment in the Eastern Alps. The origin and behavior of air masses as inferred from the evaluation of 48-h back-trajectories show significant seasonal differences. However, the large changes in trace elements concentrations seem to be more related to the vertical structure of the troposphere at a regional scale rather than the synoptic weather patterns.

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