scholarly journals Geology of the Monmouth Creek volcanic complex, Garibaldi volcanic belt, British Columbia

2016 ◽  
Author(s):  
A M Wilson ◽  
J K Russell ◽  
M C Kelman ◽  
C J Hickson
Keyword(s):  
British Columbia ◽  
Volcanic Belt ◽  
Volcanic Complex

Geology of the Coquihalla Volcanic Complex, southwestern British Columbia

1980 ◽  
Vol 17 (8) ◽  
pp. 985-995 ◽  
Author(s):  
Robert G. Berman ◽  
Richard Lee Armstrong
Keyword(s):  
British Columbia ◽  
Volcanic Belt ◽  
Fault Scarp ◽  
Volcanic Complex ◽  
Calc Alkaline ◽  
Southeastern Part ◽  
Juan De Fuca Plate ◽  
The North ◽  
Igneous Activity ◽  
Volcanic Belts

The Coquihalla Volcanic Complex consists of calc-alkaline acid to intermediate extrusive and intrusive rocks that have an areal extent of roughly 30 km2 near Hope, British Columbia. The oldest and most voluminous members of the complex are rhyolitic pyroclastic rocks that have an overall thickness of approximately 1600 m. Later igneous activity produced numerous andesite to dacite domes, dykes, and sills. A late stage diorite to quartz diorite stock forms the core of Coquihalla Mountain.Pyroclastic rocks rest unconformably on the Jurassic to Cretaceous Eagle pluton and Lower Cretaceous Pasayten Group rocks. Monolithologic avalanche breccias were deposited against a fault scarp of uplifted Pasayten Group rocks in the southwestern portion of the map area. In the southeastern part of the area, monolithologic granitic avalanche breccias formed in response to lilting and uplift of the underlying Eagle pluton as the basin subsided.Three K–Ar dates average 21.4 ± 0.7 Ma, and are concordant with a Rb–Sr isochron (22.3 ± 4 Ma with initial 87Sr/86Sr = 0.70370 ± 0.00008) based on seven whole-rock samples which span the entire compositional range of the suite. These results indicate that the Coquihalla Volcanic Complex is coeval with calc-alkaline centres in the Pemberton Volcanic Belt (PVB).The north-northwest trend of the PVB is parallel to, but roughly 75 km east, of the Pleistocene to Recent Garibaldi Volcanic Belt (GVB). Both volcanic belts appear to have formed as a result of subduction of the Juan de Fuca plate. Genetic models must explain the easterly displacement of the PVB, the development of larger volumes of rhyolitic compositions in this belt as compared to the GVB, and the decrease in age of igneous rocks from south to north within the PVB.

Combining Distributed Acoustic Sensing and Beamforming in a Volcanic Environment on Mount Meager, British Columbia.

2021 ◽  
Author(s):  
Sara Klaasen ◽  
Patrick Paitz ◽  
Jan Dettmer ◽  
Andreas Fichtner
Keyword(s):  
British Columbia ◽  
Power Distribution ◽  
High Frequency ◽  
Low Frequency ◽  
Volcanic Tremor ◽  
Extreme Environment ◽  
Volcanic Complex ◽  
Acoustic Sensing ◽  
Distributed Acoustic Sensing ◽  
Volcanic Environment

<p>We present one of the first applications of Distributed Acoustic Sensing (DAS) in a volcanic environment. The goals are twofold: First, we want to examine the feasibility of DAS in such a remote and extreme environment, and second, we search for active volcanic signals of Mount Meager in British Columbia (Canada). </p><p>The Mount Meager massif is an active volcanic complex that is estimated to have the largest geothermal potential in Canada and caused its largest recorded landslide in 2010. We installed a 3-km long fibre-optic cable at 2000 m elevation that crosses the ridge of Mount Meager and traverses the uppermost part of a glacier, yielding continuous measurements from 19 September to 17 October 2019.</p><p>We identify ~30 low-frequency (0.01-1 Hz) and 3000 high-frequency (5-45 Hz) events. The low-frequency events are not correlated with microseismic ocean or atmospheric noise sources and volcanic tremor remains a plausible origin. The frequency-power distribution of the high-frequency events indicates a natural origin, and beamforming on these events reveals distinct event clusters, predominantly in the direction of the main peaks of the volcanic complex. Numerical examples show that we can apply conventional beamforming to the data, and that the results are improved by taking the signal-to-noise ratio of individual channels into account.</p><p>The increased data quantity of DAS can outweigh the limitations due to the lower quality of individual channels in these hazardous and remote environments. We conclude that DAS is a promising tool in this setting that warrants further development.</p>

A new locality for primary xenolith-bearing nephelinites in northwestern British Columbia

1985 ◽  
Vol 22 (10) ◽  
pp. 1556-1559 ◽  
Author(s):  
Michael D. Higgins ◽  
John M. Allen
Keyword(s):  
British Columbia ◽  
Trace Element ◽  
Volcanic Belt ◽  
Primary Magma ◽  
Similar Composition ◽  
Element Abundances ◽  
Late Tertiary

High Ni abundances (420–500 ppm) and Mg* values (100 × Mg/(Mg + Fe2+) = 69–71) and the presence of mantle-derived xenoliths indicate that a subvolcanic nephelinite intrusion in northwestern British Columbia represents an unmodified primary magma. A separate, closely associated nephelinite intrusion shows evidence of minor olivine fractionation from a similar composition. Only three other occurrences of primary nephelinite have been described. This new occurrence suggests that these magmas may not be so rare as previously supposed. The trace-element abundances closely resemble those of primary nephelinites of similar La content from Freemans Cove, Canada. Such compositions are usually taken as evidence of intraplate rifting and doming. Therefore, these rocks are further evidence of late Tertiary or Quaternary rifting in the Stikine volcanic belt.

scholarly journals Anatomy of the magmatic plumbing system of Los Humeros Caldera (Mexico): implications for geothermal systems

2019 ◽  
Author(s):  
Federico Lucci ◽  
Gerardo Carrasco-Núñez ◽  
Federico Rossetti ◽  
Thomas Theye ◽  
John C. White ◽  
...  
Keyword(s):  
Volcanic Belt ◽  
Mineral Chemistry ◽  
Volcanic Complex ◽  
Geothermal Systems ◽  
Plumbing System ◽  
Geothermal Exploration ◽  
Geothermal Fields ◽  
Mexican Volcanic Belt ◽  
Plumbing Systems ◽  
Magmatic Plumbing System

Abstract. Understanding the anatomy of magma plumbing systems of active volcanoes is essential not only for unraveling magma dynamics and eruptive behaviors, but also to define the geometry, depth and temperature of the heat sources for geothermal exploration. The Pleistocene-Holocene Los Humeros volcanic complex is part of the Eastern Trans-Mexican Volcanic Belt (Central Mexico) and it represents one of the most important exploited geothermal fields in Mexico with ca. 90 MW of produced electricity. A field-based petrologic and thermobarometric study of lavas erupted during the Holocene (post-Caldera stage) has been performed with the aim to decipher the anatomy of the magmatic plumbing system existing beneath the caldera. New petrographical, whole rock major element data and mineral chemistry were integrated within a suite of inverse thermobarometric models. Compared with previous studies where a single voluminous melt-controlled magma chamber (or "Standard Model") at shallow depths was proposed, our results support a more complex and realistic scenario characterized by a heterogeneous multilayered system comprising a deep (ca. 30 km) basaltic reservoir feeding progressively shallower and smaller distinct stagnation layers, pockets and batches up to very shallow conditions (1 kbar, ca. 3 km). Evolution of melts in the feeding system is mainly controlled by differentiation processes via fractional crystallization, as recorded by polybaric crystallization of clinopyroxenes and orthopyroxenes. Moreover, this study attempts to emphasize the importance to integrate field-petrography, texture observations and mineral chemistry of primary minerals to unravel the pre-eruptive dynamics and therefore the anatomy of the plumbing system beneath an active volcanic complex, which notwithstanding the numerous existing works is still far to be well understood. A better knowledge of the heat source feeding geothermal systems is very important to improve geothermal exploration strategies.

scholarly journals The 2007 Nazko, British Columbia, Earthquake Sequence: Injection of Magma Deep in the Crust beneath the Anahim Volcanic Belt

2011 ◽  
Vol 101 (4) ◽  
pp. 1732-1741 ◽  
Author(s):  
J. F. Cassidy ◽  
N. Balfour ◽  
C. Hickson ◽  
H. Kao ◽  
R. White ◽  
...  
Keyword(s):  
British Columbia ◽  
Volcanic Belt ◽  
Earthquake Sequence

Eocene Challis-Kamloops volcanism in central British Columbia: an example from the Buck Creek basin

1998 ◽  
Vol 35 (8) ◽  
pp. 951-963 ◽  
Author(s):  
J Dostal ◽  
D A Robichaud ◽  
B N Church ◽  
P H Reynolds
Keyword(s):  
British Columbia ◽  
Rare Earth ◽  
Rare Earth Element ◽  
Fractional Crystallization ◽  
Earth Element ◽  
Volcanic Rocks ◽  
Volcanic Belt ◽  
The United States ◽  
Calc Alkaline ◽  
Heavy Rare Earth Element

Eocene volcanic rocks of the Buck Creek basin in central British Columbia are part of the Challis-Kamloops volcanic belt extending from the United States across British Columbia to central Yukon. The volcanic rocks include two units, the Buck Creek Formation, composed of high-K calc-alkaline rocks with predominant andesitic composition, and the overlying Swans Lake unit made up of intraplate tholeiitic basalts. Whole rock 40Ar/39Ar data for both units show that they were emplaced at 50 Ma. They have similar mantle-normalized trace element patterns characterized by a large-ion lithophile element enrichment and Nb-Ta depletion, similar chondrite-normalized rare earth element patterns with (La/Yb)n ~4-14 and heavy rare earth element fractionation, and overlapping epsilonNd values (2.4-3.1) and initial Sr-isotope ratios ( ~ 0.704). These features suggest derivation of these two units from a similar mantle source, probably garnet-bearing subcontinental lithosphere. The differences between tholeiitic and calc-alkaline suites can be due, in part, to differences in the depth of fractional crystallization and the crystallizing mineral assemblage. Fractional crystallization of the calc-alkaline magmas began at a greater (mid-crustal) depth and included fractionation of Fe-Ti oxides. The volcanic rocks are probably related to subduction of the Farallon plate under the North American continent in a regime characterized by transcurrent movements and strike-slip faulting.

Evidence for catastrophic volcanic debris flows in Pemberton Valley, British Columbia

2006 ◽  
Vol 43 (6) ◽  
pp. 679-689 ◽  
Author(s):  
K A Simpson ◽  
M Stasiuk ◽  
K Shimamura ◽  
J J Clague ◽  
P Friele
Keyword(s):  
British Columbia ◽  
Debris Flow ◽  
Debris Flows ◽  
Clay Content ◽  
Volcanic Complex ◽  
Large Magnitude ◽  
Volcanic Material ◽  
Inundation Maps ◽  
The Matrix ◽  
Volcanic Debris

The Mount Meager volcanic complex in southern British Columbia is snow and ice covered and has steep glaciated and unstable slopes of hydrothermally altered volcanic deposits. Three large-volume (>108 m3) volcanic debris flow deposits derived from the Mount Meager volcanic complex have been identified. The volcanic debris flows travelled at least 30 km downstream from the volcanic complex and inundated now populated areas of Pemberton Valley. Clay content and mineralogy of the deposits indicate that the volcanic debris flows were clay-rich (5%–7% clay in the matrix) and derived from hydrothermally altered volcanic material. The youngest volcanic debris flow deposit is interpreted to be associated with the last known volcanic eruption, ~2360 calendar (cal) years BP. The other two debris flows may not have been directly associated with eruptions. Volcanic debris flow hazard inundation maps have been produced using the Geographic Information System (GIS)-based modelling program, LAHARZ. The maps provide estimates of the areas that would be inundated by future moderate to large-magnitude events. Given the available data, the probability of a volcanic debris flow reaching populated areas in Pemberton Valley is ~1 in 2400 years. Additional mapping in the source regions is necessary to determine if sufficient material remains on the volcanic edifice to generate future large-magnitude, clay-rich volcanic debris flows.

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