Solute chemistry of inclusion fluids from sparry dolomites and magnesites in Middle Cambrian carbonate rocks of the southern Canadian Rocky Mountains

1998 ◽  
Vol 35 (5) ◽  
pp. 546-555 ◽  
Author(s):  
Bruce E Nesbitt ◽  
Walter Prochaska
Keyword(s):  
Rocky Mountains ◽  
Carbonate Rocks ◽  
Open Space ◽  
Mississippi Valley ◽  
Canadian Rocky Mountains ◽  
Middle Cambrian ◽  
Solute Chemistry ◽  
Hydrothermal Replacement ◽  
D Values ◽  
Total Salinity

Middle Cambrian carbonate rocks of the southern Canadian Rocky Mountains are host to widespread units of white, sparry, hydrothermal, replacement, and open-space filling dolomite. Contained within the dolomites are occurrences of talc and Mississippi Valley type Pb-Zn (the former Kicking Horse and Monarch mines) mineralization and economic concentrations of magnesite (Mount Brussilof mine). Results of studies of solute chemistry of saline (18-25 equivalent wt.% NaCl) inclusion fluids reveal distinctly low Na/Br (55-220) and Cl/Br (95-340) values. These values indicate that the brines which formed the dolomite originated from seawater that had deposited large amounts of halite in an evaporitic environment. Low I/Br ratios for the dolomite-magnesite inclusion fluids are consistent with their derivation from seawater and contrast sharply with the high I/Br ratios of Laramide-age fluids, which formed veins throughout the Rocky Mountains. Variations in F/Br ratios between texturally early and late magnesites indicate the involvement of a second fluid in the formation of the late magnesites. Results of the study of solute chemistry of inclusion fluids from hydrothermal dolomites, magnesites, and associated mineralization are consistent with a model of the pre-Laramide formation of these materials from seawater that had undergone extensive evaporation and halite deposition. Distinct differences in I/Br, total salinity, and delta D values between the dolomite-magnesite depositing fluids and Laramide-age vein-forming fluids clearly indicate the lack of the involvement of Laramide-age fluids in the genesis of the dolomites, magnesites, and associated mineralization.

scholarly journals VII.—The Canadian Rockies. Part I : On a Collection of Middle Cambrian Fossils obtained by Edward Whymper, Esq., F.R.G.S., from Mount Stephen, British Columbia

1902 ◽  
Vol 9 (11) ◽  
pp. 502-505 ◽  
Author(s):  
Henry Woodward
Keyword(s):  
British Columbia ◽  
Rocky Mountains ◽  
Canadian Rocky Mountains ◽  
Canadian Rockies ◽  
Middle Cambrian ◽  
Pacific Railroad ◽  
Northern Side

In the Summer of 1901 my friend Mr. Edward Whymper, the well-known traveller, mountain explorer, and writer, paid a visit to the watershed of the Canadian Rocky Mountains, and during a stay at Field, the highest pass reached on the Canadian and Pacific Railroad, he examined the slopes of Mount Stephen, and at a height of 6,000 feet on its northern side found numerous Trilobites, and brought home a considerable collection.

Mineral control on the geochemistry of the Rock Canyon Creek REE-F-Ba deposit, British Columbia, Canada

2021 ◽  
Vol 21 (2) ◽  
pp. geochem2020-010
Author(s):  
George J. Simandl ◽  
Suzanne Paradis ◽  
Johnathan Savard ◽  
Deanna Miller ◽  
Rameses D'Souza ◽  
...  
Keyword(s):  
Rocky Mountains ◽  
Carbonate Rocks ◽  
Three Dimensional ◽  
Chemical Heterogeneity ◽  
Mississippi Valley ◽  
Mineralized Zone ◽  
Geochemical Profiles ◽  
Ree Pattern ◽  
Fluorite Content ◽  
Geochemical Assessment

The Rock Canyon Creek carbonate-hosted REE-F-Ba deposit has tectonic, stratigraphic and structural similarities with Mississippi Valley-type and sparry magnesite deposits in the SE Rocky Mountains. The main REE-fluorite zone is a steeply dipping body, extending 1100 m along-strike, 50 m wide and 100 m deep. It spatially coincides with pre-existing crackle breccias in carbonate rocks, and consists of dolomite, fluorite, barite, pyrite, quartz, K-feldspar, calcite, porous apatite, REE-fluorocarbonates and REE-phosphates. The main fluorocarbonates are bastnaesite, parisite and synchysite. Monazite, crandallite group minerals and apatite are the main phosphates. Fluorite content varies from less than 1 to 13.5% (by weight) and ∑REE  +  Y concentrations vary from trace to 1.95% (by weight). The mineralized zone is heterogeneous on the deposit scale, as indicated by three-dimensional geochemical modelling combined with a geochemical assessment based on 89 mineralized samples and detailed downhole mineral and geochemical profiles of a key borehole. Chemical heterogeneity and key elemental co-variations are explained by strong mineralogical control and have implications for the design of exploration and development programmes for this type of deposit. The chondrite-normalized REE pattern of samples from the mineralized zone shows enrichment in LREE, similar to typical carbonatite-related mineralization; however, no carbonatite is exposed nearby.

scholarly journals Supplemental Material: Regional fault-controlled shallow dolomitization of the Middle Cambrian Cathedral Formation by hydrothermal fluids fluxed through a basal clastic aquifer

2021 ◽  
Author(s):  
Jack Stacey ◽  
et al.
Keyword(s):  
Rocky Mountains ◽  
Earth Element ◽  
Noble Gas ◽  
Hydrothermal Fluids ◽  
Geochemical Data ◽  
Canadian Rocky Mountains ◽  
Bulk Rock ◽  
Middle Cambrian ◽  
Element Carbon ◽  
Oxygen Stable Isotope

Geochemical data for dolomite and limestone (trace element, rare earth element, carbon and oxygen stable isotope, clumped oxygen isotope, noble gas, fluid inclusion and bulk rock XRD) of the Middle Cambrian Cathedral Formation, Southern Canadian Rocky Mountains.

The Middle Cambrian Burgess Shale and its relationship to the Stephen Formation in the southern Canadian Rocky Mountains

1998 ◽  
Vol 35 (4) ◽  
pp. 413-436 ◽  
Author(s):  
Terence P Fletcher ◽  
Desmond H Collins
Keyword(s):  
Rocky Mountains ◽  
Main Part ◽  
Canadian Rocky Mountains ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
Royal Ontario Museum ◽  
Shale Formation ◽  
Geologic Setting ◽  
Continuous Deposition ◽  
Zonal Boundary

The Burgess Shale has been an anomalous geologic unit ever since Walcott named it in 1911 as the geographic equivalent of the Ogygopsis Shale in the Middle Cambrian Stephen Formation of southeastern British Columbia, but it has never been recognized outside of its type locality, so its status relative to the Stephen Formation remained uncertain. The geologic setting of the Burgess Shale was determined by Aitken and Fritz in 1968, when they recognized the Cathedral Escarpment and divided the Stephen Formation into a "thin" platformal succession on top of the Escarpment, and a "thick" basinal succession, which included Walcott's Burgess Shale, in front. Fieldwork by Royal Ontario Museum parties between 1982 and 1997 has now demonstrated that the thin and thick Stephen successions lie within different facies belts and should be regarded as separate formations; the Stephen Shale Formation is part of the Middle Carbonate Belt succession, whereas the name Burgess Shale Formation is applied to the thick basinal succession within the Outer Detrital Belt Chancellor Group. Ten distinct members are recognized in the Burgess Shale: Kicking Horse Shale, Yoho River Limestone, Campsite Cliff Shale, Wash Limestone, Walcott Quarry Shale, Raymond Quarry Shale, Emerald Lake Oncolite, Odaray Shale, Paradox Limestone, and Marpole Limestone. In contrast to the Stephen Shale Formation with its nonsequences, the thicker Burgess Shale Formation seems to represent continuous deposition spanning the Glossopleura to Bathyuriscus-Elrathina zonal boundary, incorporating the Polypleuraspis insignis and Pagetia bootes subzones and the main part of the Pagetia walcotti subzone.

scholarly journals Supplemental Material: Regional fault-controlled shallow dolomitization of the Middle Cambrian Cathedral Formation by hydrothermal fluids fluxed through a basal clastic aquifer

2021 ◽  
Author(s):  
Jack Stacey ◽  
et al.
Keyword(s):  
Rocky Mountains ◽  
Earth Element ◽  
Noble Gas ◽  
Hydrothermal Fluids ◽  
Geochemical Data ◽  
Canadian Rocky Mountains ◽  
Bulk Rock ◽  
Middle Cambrian ◽  
Element Carbon ◽  
Oxygen Stable Isotope

Geochemical data for dolomite and limestone (trace element, rare earth element, carbon and oxygen stable isotope, clumped oxygen isotope, noble gas, fluid inclusion and bulk rock XRD) of the Middle Cambrian Cathedral Formation, Southern Canadian Rocky Mountains.

Wildfires in the southern Canadian Rocky Mountains and their relationship to mid-tropospheric anomalies

1993 ◽  
Vol 23 (6) ◽  
pp. 1213-1222 ◽  
Author(s):  
E.A. Johnson ◽  
D.R. Wowchuk
Keyword(s):  
North America ◽  
Rocky Mountains ◽  
Large Scale ◽  
Fire Frequency ◽  
Fuel Moisture ◽  
Large Fire ◽  
Canadian Rocky Mountains ◽  
Area Burned ◽  
Upper Level ◽  
Moisture Conditions

In this paper we present evidence for a large-scale (synoptic-scale) meteorological mechanism controlling the fire frequency in the southern Canadian Rocky Mountains. This large-scale control may explain the similarity in average fire frequencies and timing of change in average fire frequencies for the southern Canadian Rocky Mountains. Over the last 86 years the size distribution of fires (annual area burned) in the southern Canadian Rockies was distinctly bimodal, with a separation between small- and large-fire years at approximately 10–25 ha annual area burned. During the last 35 years, large-fire years had significantly lower fuel moisture conditions and many mid-tropospheric surface-blocking events (high-pressure upper level ridges) during July and August (the period of greatest fire activity). Small-fire years in this period exhibited significantly higher fuel moisture conditions and fewer persistent mid-tropospheric surface-blocking events during July and August. Mid-tropospheric surface-blocking events during large-fire years were teleconnected (spatially and temporally correlated in 50 kPa heights) to upper level troughs in the North Pacific and eastern North America. This relationship takes the form of the positive mode of the Pacific North America pattern.

Canadian Rocky Mountains

1903 ◽  
Vol 21 (6) ◽  
pp. 685
Author(s):  
J. Norman Collie
Keyword(s):  
Rocky Mountains ◽  
Canadian Rocky Mountains

Spatial and temporal variations of fire regimes in the Canadian Rocky Mountains and Foothills of southern Alberta

2016 ◽  
Vol 25 (11) ◽  
pp. 1117 ◽  
Author(s):  
Marie-Pierre Rogeau ◽  
Mike D. Flannigan ◽  
Brad C. Hawkes ◽  
Marc-André Parisien ◽  
Rick Arthur
Keyword(s):  
Rocky Mountains ◽  
Fire History ◽  
Fire Severity ◽  
Ecological Integrity ◽  
Fire Regimes ◽  
Temporal Variations ◽  
Fire Season ◽  
Canadian Rocky Mountains ◽  
Southern Alberta ◽  
Fire Exclusion

Like many fire-adapted ecosystems, decades of fire exclusion policy in the Rocky Mountains and Foothills natural regions of southern Alberta, Canada are raising concern over the loss of ecological integrity. Departure from historical conditions is evaluated using median fire return intervals (MdFRI) based on fire history data from the Subalpine (SUB), Montane (MT) and Upper Foothills (UF) natural subregions. Fire severity, seasonality and cause are also documented. Pre-1948 MdFRI ranged between 65 and 85 years in SUB, between 26 and 35 years in MT and was 39 years in UF. The fire exclusion era resulted in a critical departure of 197–223% in MT (MdFRI = 84–104 years). The departure in UF was 170% (MdFRI = 104 years), while regions of continuous fuels in SUB were departed by 129% (MdFRI = 149 years). The most rugged region of SUB is within its historical range of variation with a departure of 42% (MdFRI = 121 years). More mixed-severity burning took place in MT and UF. SUB and MT are in a lightning shadow pointing to a predominance of anthropogenic burning. A summer fire season prevails in SUB, but occurs from spring to fall elsewhere. These findings will assist in developing fire and forest management policies and adaptive strategies in the future.

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