Precise zircon geochronology in the Adirondack Lowlands and implications for revising plate-tectonic models of the Central Metasedimentary Belt and Adirondack Mountains, Grenville Province, Ontario and New York

1999 ◽  
Vol 36 (6) ◽  
pp. 967-984 ◽  
Author(s):  
Hardolph Wasteneys ◽  
James McLelland ◽  
Sydney Lumbers
Keyword(s):  
New York ◽  
Plate Tectonic ◽  
Adirondack Mountains ◽  
Grenville Province ◽  
Metasedimentary Rocks ◽  
Minimum Age ◽  
Single Grain ◽  
Shrimp Zircon ◽  
Shrimp Zircon Dating ◽  
St Lawrence River

New high-precision, single-grain dating of leucogranites from the Adirondack Lowlands, dated previously by multigrain zircon methods at ca. 1416 Ma (Wellesley Island) and ca. 1285-1230 Ma (Hyde School Gneiss), has yielded U-Pb zircon ages of ca. 1172 Ma, identical to that of Rockport granite of the Frontenac terrane. In addition, sensitive high resolution ion microprobe (SHRIMP) zircon dating of the intrusive Antwerp-Rossie suite in the Adirondack Lowlands indicates a maximum emplacement age of ca. 1207+26-11 Ma which fixes a minimum age for deposition of regional metasedimentary rocks that it crosscuts. These results remove apparent chronological discrepancies across the St. Lawrence River, thus expanding the significance of the Rockport granite and Hyde School Gneiss and requiring modification of plate-tectonic models for the Central Metasedimentary Belt and Adirondack Mountains in the interval ca. 1350-1125 Ma.

scholarly journals Syn-collisional exhumation of hot middle crust in the Adirondack Mountains (New York, USA): Implications for extensional orogenesis in the southern Grenville province

Geosphere ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 1240-1261 ◽  
Author(s):  
S.P. Regan ◽  
G.J. Walsh ◽  
M.L. Williams ◽  
J.R. Chiarenzelli ◽  
M. Toft ◽  
...  
Keyword(s):  
New York ◽  
Fluid Flow ◽  
Structural Evolution ◽  
Granite Gneiss ◽  
Shear Zones ◽  
Ore Deposits ◽  
Adirondack Mountains ◽  
Grenville Province ◽  
Granulite Facies Metamorphism ◽  
Detachment Zone

Abstract Extensional deformation in the lower to middle continental crust is increasingly recognized and shown to have significant impact on crustal architecture, magma emplacement, fluid flow, and ore deposits. Application of the concept of extensional strain to ancient orogenic systems, like the Grenville province of eastern North America, has helped decipher the structural evolution of these regions. The Marcy massif is a ∼3000 km2 Mesoproterozoic anorthosite batholith in the Adirondack Mountains (New York, USA) of the southern Grenville province. Bedrock geology mapping at 1:24,000 scale paired with characterization of bedrock exposed by recent landslides provides a glimpse into the structural architecture of the massif and its margin. New data demonstrate granulite- to amphibolite-facies deformational fabrics parallel the margin of the batholith, and that the Marcy massif is draped by a southeast-directed detachment zone. Within the massif, strain is localized into mutually offsetting conjugate shear zones with antithetic kinematic indicators. These relationships indicate that strain was coaxial within the Marcy massif, and that subsimple shear components of strain were partitioned along its margin. In situ U–Th–total Pb monazite analysis shows that deformation around and over the Marcy massif occurred from 1070 to 1060 Ma during granulite-facies metamorphism, and monazite from all samples record evidence for fluid-mediated dissolution reprecipitation from 1050 to 980 Ma. We interpret that rocks cooled isobarically after accretionary orogenesis and emplacement of the anorthosite-mangerite-charnockite-granite plutonic suite at ca. 1160–1140 Ma. Gravitational collapse during the Ottawan phase of the Grenville orogeny initiated along a southeast-directed detachment zone (Marcy massif detachment zone), which accommodated intrusion of the Lyon Mountain Granite Gneiss, and facilitated substantial fluid flow that catalyzed the formation of major ore deposits in the Adirondack Highlands.

scholarly journals The Kilmar Magnesite Deposits: Evaporitic Metasediments in the Grenville Supergroup, Morin Terrane, Quebec

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 554 ◽  
Author(s):  
Peck ◽  
Eppich
Keyword(s):  
New York ◽  
Stable Isotope ◽  
Isotope Ratios ◽  
Granulite Facies ◽  
Ore Deposits ◽  
Depositional Environments ◽  
Dolomitic Marble ◽  
Grenville Province ◽  
Metasedimentary Rocks ◽  
Δ18o And Δ13c

Mesoproterozoic magnesite deposits are found associated with dolomitic marble and intercalated with metasedimentary rocks of the Grenville Supergroup in the granulite facies Morin terrane (Grenville Province, Quebec). This study examines one of the remaining ore deposits exposed on the surface (at the Dobbie mine), and presents stable isotope and mineralogical data for a marine evaporitic origin. The magnesite ore zone has δ18O(Mag) = 25.5 ± 0.4‰ (VSMOW) and δ13C(Mag) = 1.7 ± 0.2‰ (VPDB; n = 7), while surrounding dolomitic marble has δ18O(Dol) = 24.2 ± 0.6‰ and δ13C(Dol) = −0.2 ± 0.7‰ (n = 11). These values are at the high end of the range for other Morin terrane marbles, and this and sharp transitions in stable isotope ratios between lithologies argue for preservation of evaporitic enrichment in δ18O and δ13C. Boron isotope ratios (δ11B = 15.5‰ to 22.7‰) are also consistent with a marine evaporite origin. Identifying evaporitic protoliths in metasedimentary rocks is important for determining pre-metamorphic depositional environments, and in this case links the sedimentary setting of the Morin terrane to the Adirondack Lowlands (New York, NY, USA). The identification of the Kilmar magnesite deposits as evaporitic also has implications for the formation of sedimentary exhalative base metal deposits in the Grenville Supergroup.

scholarly journals A Review of Boron-Bearing Minerals (Excluding Tourmaline) in the Adirondack Region of New York State

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 644 ◽  
Author(s):  
David G. Bailey ◽  
Marian V. Lupulescu ◽  
Robert S. Darling ◽  
Jared W. Singer ◽  
Steven C. Chamberlain
Keyword(s):  
New York ◽  
New York State ◽  
Grenville Province ◽  
York State ◽  
Metasedimentary Rocks ◽  
Upstate New York ◽  
Geological Processes ◽  
Boron Minerals ◽  
Metamorphic Terranes ◽  
Raman Spectral Data

Boron is a biologically important element, but its distribution in the natural environment and its behavior during many geological processes is not fully understood. In most metamorphic and igneous environments, boron is incorporated into minerals of the tourmaline supergroup. In high-grade metamorphic terranes like that of the Adirondack region of northern New York State, uncommon rock compositions combined with unusual and variable geologic conditions resulted in the formation of many additional boron-bearing minerals. This paper reviews the occurrences and geological settings of twelve relatively uncommon boron-bearing minerals in the southern Grenville Province of upstate New York and provides new chemical and Raman spectral data for seven of these minerals. The boron minerals range from relatively simple metal borates (e.g., vonsenite), to chemically complex borosilicates (e.g., prismatine), to a relatively rare borosilicate-carbonate (e.g., harkerite). Some are of primary igneous origin, while others are formed by a variety of prograde and retrograde metamorphic processes or by metasomatic/hydrothermal processes. Most of the boron minerals are formed within, or adjacent to, metasedimentary lithologies that surround the anorthositic massifs of the central Adirondacks. The metasedimentary rocks are thought to be the source of most of the boron, although additional boron isotope studies are needed to confirm this and to constrain the mechanisms of the formation of these unusual minerals.

Geology and age of the Precambrian basement in the Windsor, Chatham, and Sarnia area, southwestern Ontario

1982 ◽  
Vol 19 (8) ◽  
pp. 1627-1634 ◽  
Author(s):  
A. Turek ◽  
R. N. Robinson
Keyword(s):  
Oil And Gas ◽  
Precambrian Basement ◽  
Grenville Province ◽  
Metasedimentary Rocks ◽  
Gas Drilling ◽  
Arch System ◽  
Grenvillian Orogeny ◽  
Anomaly Map ◽  
Paleozoic Rocks ◽  
Basement Surface

Precambrian basement in the Windsor–Chatham–Sarnia area is covered by Paleozoic rocks that are up to 1300 m thick. The basement surface is characterized by a northeast–southwest arch system with a relief of about 350 m. Extensive oil and gas drilling has penetrated and sampled this basement, and an examination of core and chip samples from 133 holes and an assessment of the magnetic anomaly map of the area have been used to produce a lithologic map of the Precambrian basement. The predominant rocks are granite gneisses and syenite gneisses but also significant are gabbros, granodiorite gneisses, and metasedimentary rocks. The average foliation dips 50° and is inferred to have a northeasterly trend. The Precambrian basement has been regarded as part of the Grenville Province. An apparent Rb–Sr whole rock isochron, for predominantly meta-igneous rocks, yields an age of 1560 ± 140 Ma. This we interpret as pre-Grenvillian, surviving the later imprint of the Grenvillian Orogeny. Points excluded from the isochron register ages of 1830, 915, and 670 Ma, and can be interpreted as geologically meaningful.

Performance of Indigenous, Exotic, and Hybrid Strains of Brook Trout (Salvelinus fontinalis) in Waters of the Adirondack Mountains, New York

1981 ◽  
Vol 38 (12) ◽  
pp. 1701-1707 ◽  
Author(s):  
Dwight A. Webster ◽  
William A. Flick
Keyword(s):  
New York ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Hybrid Vigor ◽  
Superior Performance ◽  
Adirondack Mountains ◽  
Wild Strains ◽  
Early Fall ◽  
Survival And Growth ◽  
Wild Trout

Eleven year-classes of wild, domestic, and wild × domestic hybrid strains of brook trout (Salvelinus fontinalis) were stocked in a 0.19-ha Adirondack pond. Comparative survival and growth were assessed upon drainage in early fall. Rearing native wild strains to maturity in a hatchery, or domestic strains in a natural environment, did not consistently or materially affect survival of progeny, suggesting that superior performance of wild strains was largely inherent. Interstrain hybrids of wild × domestic showed survivals equivalent to the wild parents, but hybrids of two Canadian strains gave evidence of heterosis in both survival and net yield. Supplementary observations in other waters also indicated that one strain (Assinica) may be less adaptable to Adirondack conditions than the other (Temiscamie).Key words: brook trout, wild trout, domesticated trout, interstrain hybrid trout, survival, growth, heterosis, hybrid vigor

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