Geochemistry of volcanic rocks from the Tetagouche Group, Bathurst, New Brunswick, Canada

1978 ◽  
Vol 15 (2) ◽  
pp. 207-219 ◽  
Author(s):  
R. E. S. Whitehead ◽  
W. D. Goodfellow
Keyword(s):  
New Brunswick ◽  
Volcanic Rocks ◽  
Island Arc ◽  
Calc Alkaline ◽  
Middle Ordovician ◽  
Intermediate Range ◽  
Felsic Volcanic ◽  
Felsic Volcanic Rocks ◽  
Tectonic Environments

The volcanic rocks of the Tetagouche Group are predominantly dacitic to rhyolitic pyroclastics and lavas; mafic alkaline and tholeiitic volcanic rocks are less abundant. Lavas representing the intermediate range (such as andesites) are uncommon.As a consequence of intense Na2O and K2O metasomatism, the mafic volcanic rocks have been classified on the basis of relatively immobile elements such as Ti, Y, Zr, Nb, Ni and Cr.By reference to volcanic suites described elsewhere for varying geologic and tectonic environments, the Tetagouche Group appears to represent two geologic environments. It is proposed that the deposition of tholeiitic and alkaline basalts accompanied the rifting associated with the opening of the Proto-Atlantic, which began during Hadrynian times. However the calc-alkaline felsic volcanic rocks were deposited on the top of the basaltic sequence along a mature island arc system that developed with the closing of the Proto-Atlantic during Middle Ordovician time.

Age, chemistry, and tectonic setting of Miramichi terrane (Early Paleozoic) volcanic rocks, eastern and east-central Maine, USA

2021 ◽  
Vol 57 ◽  
pp. 239-273
Author(s):  
Allan Ludman ◽  
Christopher McFarlane ◽  
Amber T.H. Whittaker
Keyword(s):  
New Brunswick ◽  
Subduction Zone ◽  
Tectonic Setting ◽  
Volcanic Rocks ◽  
Calc Alkaline ◽  
East Central ◽  
Arc Volcanism ◽  
Middle Ordovician ◽  
Volcanic Suite ◽  
Back Arc

Volcanic rocks in the Miramichi inlier in Maine occur in two areas separated by the Bottle Lake plutonic complex: the Danforth segment (Stetson Mountain Formation) north of the complex and Greenfield segment to the south (Olamon Stream Formation). Both suites are dominantly pyroclastic, with abundant andesite, dacite, and rhyolite tuffs and subordinate lavas, breccias, and agglomerates. Rare basaltic tuffs and a small area of basaltic tuffs, agglomerates, and lavas are restricted to the Greenfield segment. U–Pb zircon geochronology dates Greenfield segment volcanism at ca. 469 Ma, the Floian–Dapingian boundary between the Lower and Middle Ordovician. Chemical analyses reveal a calc-alkaline suite erupted in a continental volcanic arc, either the Meductic or earliest Balmoral phase of Popelogan arc activity. The Maine Miramichi volcanic rocks are most likely correlative with the Meductic Group volcanic suite in west-central New Brunswick. Orogen-parallel lithologic and chemical variations from New Brunswick to east-central Maine may result from eruptions at different volcanic centers. The bimodal Poplar Mountain volcanic suite at the Maine–New Brunswick border is 10–20 myr younger than the Miramichi volcanic rocks and more likely an early phase of back-arc basin rifting than a late-stage Meductic phase event. Coeval calc-alkaline arc volcanism in the Miramichi, Weeksboro–Lunksoos Lake, and Munsungun Cambrian–Ordovician inliers in Maine is not consistent with tectonic models involving northwestward migration of arc volcanism. This >150 km span cannot be explained by a single east-facing subduction zone, suggesting more than one subduction zone/arc complex in the region.

scholarly journals Geochemistry of Carboniferous peralkaline felsic volcanic rocks, central New Brunswick, Canada: examination of uranium potential

2010 ◽  
Vol 46 (0) ◽  
pp. 173-184 ◽  
Author(s):  
Taryn R. Gray ◽  
Jaroslav Dostal ◽  
Malcolm McLeod ◽  
Duncan Keppie ◽  
Yuanyuan Zhang
Keyword(s):  
New Brunswick ◽  
Volcanic Rocks ◽  
Felsic Volcanic ◽  
Felsic Volcanic Rocks

U–Pb zircon ages from the Lynn Lake and Rusty Lake metavolcanic belts, Manitoba: two ages of Proterozoic magmatism

1987 ◽  
Vol 24 (5) ◽  
pp. 1053-1063 ◽  
Author(s):  
D. A. Baldwin ◽  
E. C. Syme ◽  
H. V. Zwanzig ◽  
T. M. Gordon ◽  
P. A. Hunt ◽  
...  
Keyword(s):  
Volcanic Rocks ◽  
Island Arc ◽  
Quartz Diorite ◽  
The North ◽  
Volcanic Sequence ◽  
Metavolcanic Rocks ◽  
Lynn Lake ◽  
Felsic Volcanic ◽  
Felsic Volcanic Rocks

Two ages of magmatism have been determined from zircon in felsic flows and plutons in the Churchill Province of Manitoba. A rhyolite flow from the Lynn Lake metavolcanic belt has a U–Pb age of [Formula: see text], and a rhyolite flow from the adjacent Rusty Lake metavolcanic belt has an age of [Formula: see text]. Tonalite and quartz diorite from two composite plutons emplaced into the volcanic rocks at Lynn Lake have ages of [Formula: see text] and [Formula: see text], indistinguishable from the age of the Rusty Lake belt rhyolite. The arcuate domain of metavolcanic rocks that includes the Rusty Lake belt in the southeast, the Lynn Lake belt in the north, and the La Ronge belt (Saskatchewan) in the southwest has previously been considered a single structural sub-province with similar ages throughout. Our results and published U–Pb ages from Saskatchewan indicate that an older magmatism is represented by volcanic rocks in the Lynn Lake belt; a younger magmatism, by volcanic rocks in the Rusty Lake and La Ronge belts and plutons in the Lynn Lake belt. At Lynn Lake the older magmatism (1910 Ma) produced mafic, intermediate, and felsic volcanic rocks and synvolcanic plutons. The volcanic rocks are geochemically similar to Cenozoic island-arc magmatic sequences. These rocks were isoclinally folded and subsequently intruded by the 1876 Ma plutons. The younger, dominantly subaerial, volcanism (1878 Ma) at Rusty Lake was predominantly felsic, and the coeval plutons were granitoid. The distribution of ages and the 8 km thickness of the younger volcanic sequence suggest that the older rock served as basement during the younger magmatism.

U–Pb zircon ages for magmatism in the Red Lake greenstone belt, northwestern Ontario

1986 ◽  
Vol 23 (1) ◽  
pp. 27-42 ◽  
Author(s):  
F. Corfu ◽  
H. Wallace
Keyword(s):  
Greenstone Belt ◽  
Volcanic Rocks ◽  
Gold Deposits ◽  
Calc Alkaline ◽  
Red Lake ◽  
Northwestern Ontario ◽  
Igneous Activity ◽  
Felsic Volcanic ◽  
Felsic Volcanic Rocks ◽  
Chemical Sediments

U–Pb dating was carried out on nine volcanic rocks and two felsic intrusions from the Red Lake greenstone belt in order to establish an absolute time framework for the magmatic evolution of the area and yield first indications on the time of deformation and gold mineralization.The data indicate a protracted period of igneous activity spanning at least 270 Ma. Felsic volcanic rocks near the top of the tholeiitic to komatiitic sequence in the eastern part of the belt yield ages of [Formula: see text] and [Formula: see text]. A third unit, dated at [Formula: see text], contains inherited zircons older than 2982 Ma, which casts some uncertainty on the validity of the inferred intercept age. Rocks in the western part of the belt, previously believed to form a relatively young calc-alkalic sequence but now known to be dominantly tholeiitic, are shown to be relatively old, with ages of [Formula: see text] and [Formula: see text]. These two dates also bracket the age of stromatolites occurring in chemical sediments that are under and overlain by the dated units.Another volcanic horizon in the centre of the belt is dated at 2830 ± 15 Ma, and calc-alkaline volcanic sequences on the southern and northern flanks of the belt yield ages of 2739.0 ± 3.0 and [Formula: see text], respectively. An age of [Formula: see text] was determined for tholeiitic pyroclastic rocks near the base of the predominantly calc-alkaline Heyson sequence.The major gold deposits of the Red Lake belt appear to be present dominantly within older supracrustal sequences. On the other hand, they are also associated with late deformation zones that postdate the intrusion of the Dome Stock dated at 2718.2 ± 1.1 Ma ago. The time of an earlier folding event is bracketed by this age and by the age of [Formula: see text] for an isoclinally folded felsic dike.

An Archaean sill complex and associated supracrustal rocks, Arveprinsen Ejland, north-east Disko Bugt, West Greenland

1999 ◽  
pp. 87-102
Author(s):  
Brian Marshall ◽  
Hans Kristian Schønwandt
Keyword(s):  
Volcanic Rocks ◽  
Calc Alkaline ◽  
Overburden Pressure ◽  
West Greenland ◽  
North East ◽  
Host Materials ◽  
Spider Diagrams ◽  
Felsic Volcanic ◽  
Felsic Volcanic Rocks ◽  
Felsic Rocks

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Marshall, B., & Schønwandt, H. K. (1999). An Archaean sill complex and associated supracrustal rocks, Arveprinsen Ejland, north-east Disko Bugt, West Greenland. Geology of Greenland Survey Bulletin, 181, 87-102. https://doi.org/10.34194/ggub.v181.5117 _______________ Archaean supracrustal rocks on Arveprinsen Ejland comprise mafic and felsic volcanic rocks overlain by an epiclastic sedimentary sequence invaded by a mafic to ultramafic sill complex. The latter has a strike-length of 7500 m and a cumulative preserved thickness of 2000–2500 m and amounts to nearly 50% of the exposed thickness of the supracrustal rocks. Chilled and locally peperitic contacts are developed between component sills and the inter-sill metasedimentary septa. The sub-alkalic sill complex and mafi c lavas and tuffs are high-magnesium tholeiites and basaltic komatiites whereas the felsic rocks are calc-alkaline rhyolites and dacites. Chondrite- and MORB-normalised spider diagrams affirm the close similarity of the mafic volcanic rocks and the sill complex; they are also consistent with a tholeiitic or komatiitic affinity. Tectonomagmatic discrimination plots suggest an ensialic arc-related setting for the sill complex and the mafic and felsic volcanic rocks. The sill complex was progressively emplaced, as an upward-younging sequence of component sills, beneath 2 to 2.5 km of seawater and substantially less than 0.5 km of wet sediment. Sills formed when the magmatic pressure exceeded the effective overburden pressure of the sediment plus the vertical tensile strength (To) of the host materials. Intrusion was probably promoted by the drop in To at the interface between contact-lithified and poorly lithified strata. The thickness of the sill complex was accommodated by dilational lifting plus the capacity of an intrusion to create space through expulsion of water from wet sediment.

A radiometric age of deformed granitic rocks in north-central New Brunswick

1977 ◽  
Vol 14 (7) ◽  
pp. 1687-1689 ◽  
Author(s):  
L. R. Fyffe ◽  
R. R. Irrinki ◽  
R. F. Cormier
Keyword(s):  
New Brunswick ◽  
Half Life ◽  
Volcanic Rocks ◽  
Granitic Rocks ◽  
North Central ◽  
Lower Ordovician ◽  
Felsic Volcanic ◽  
Felsic Volcanic Rocks

A Rb–Sr whole-rock isochron age of 489 ± 14 Ma based on a half-life of 5.0 × 1010 years is obtained from deformed granites in north-central New Brunswick indicating a Lower Ordovician age for these rocks. The corresponding age using a half-life of 4.88 × 1010 years is 479 ± 14 Ma. The granite is consanguineous with felsic volcanic rocks of the Tetagouche Group.

Revised stratigraphy of the Long Reach area, southern New Brunswick: evidence for major, northwestward-directed Acadian thrusting

1981 ◽  
Vol 18 (3) ◽  
pp. 646-656 ◽  
Author(s):  
S. R. McCutcheon
Keyword(s):  
New Brunswick ◽  
Lower Cambrian ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Thrust Fault ◽  
Northern Boundary ◽  
Granitoid Rocks ◽  
Felsic Volcanic ◽  
Stratigraphic Succession ◽  
Felsic Volcanic Rocks

In the Long Reach area of southern New Brunswick, a new stratigraphic succession has been delineated; it consists of Precambrian (?) volcanic rocks, Cambrian sedimentary, volcanic and hypabyssal rocks, Silurian sedimentary rocks, and Devonian plus Precambrian (?) heterogeneous, granitoid rocks. The northern boundary of this succession is postulated to be a northwestward-directed thrust fault of Acadian age. Other Acadian thrust faults are interpreted in the area and major reverse movement of the same age occurred along the Belleisle Fault.Mafic and felsic volcanic rocks that were previously thought to be either Precambrian or Silurian are demonstrably part of the Lower Cambrian section. Some of the granitoid rocks intrude Silurian strata and therefore cannot be basement to the Cambrian succession. Other granitoid rocks appear to be older and may be Precambrian in age.

Calc-Alkaline Volcanism and Plutonism from the Great Bear Batholith, N.W.T.

1973 ◽  
Vol 10 (8) ◽  
pp. 1319-1328 ◽  
Author(s):  
J. P. N. Badham
Keyword(s):  
Continental Margin ◽  
Volcanic Rocks ◽  
Orogenic Belt ◽  
Calc Alkaline ◽  
Bay Area ◽  
Alkaline Volcanism ◽  
Andean Type ◽  
Felsic Volcanic ◽  
Orogenic Belts ◽  
Felsic Volcanic Rocks

The Camsell River – Conjuror Bay area is a pendant of Aphebian intermediate and felsic volcanic rocks, lying in a granitic complex, and is part of the Great Bear batholith. This batholith complex has been interpreted as being the orogenic belt of the Coronation geosyncline.Twenty-four analyses of volcanic and plutonic rocks are presented; these show that, in spite of alteration, the rocks can be classified as comagmatic and part of an alkali-rich calc-alkaline suite. The suite is chemically similar to younger suites from continental-margin orogenic belts. These similarities support proposals that the Coronation geosyncline was of Andean type and that the magmas may have been generated by subduction.

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