Update search
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
NARROW
Format
Article Type
Journal
Publisher
Section
GeoRef Subject
-
all geography including DSDP/ODP Sites and Legs
-
Atlantic Ocean
-
North Atlantic (1)
-
-
Avalon Zone (1)
-
Caledonides (1)
-
Canada
-
Eastern Canada
-
Maritime Provinces
-
New Brunswick (1)
-
Nova Scotia (1)
-
-
Newfoundland and Labrador
-
Newfoundland (1)
-
-
-
-
Europe
-
Alps
-
Prealps (1)
-
-
-
Green Mountains (1)
-
Hartford Basin (1)
-
North America
-
Appalachians
-
Northern Appalachians (6)
-
-
-
United States
-
Bronson Hill Anticlinorium (19)
-
Connecticut
-
Litchfield County Connecticut (1)
-
Middlesex County Connecticut (1)
-
New Haven County Connecticut (1)
-
-
Connecticut Valley (2)
-
Hudson Valley (1)
-
Maine (2)
-
Massachusetts
-
Franklin County Massachusetts (5)
-
Hampden County Massachusetts (1)
-
Hampshire County Massachusetts (1)
-
Worcester County Massachusetts (1)
-
-
Merrimack Synclinorium (2)
-
New England (11)
-
New Hampshire
-
Cheshire County New Hampshire (4)
-
Coos County New Hampshire (2)
-
Grafton County New Hampshire (3)
-
Sullivan County New Hampshire (1)
-
-
New York
-
Adirondack Mountains (1)
-
Essex County New York (1)
-
-
Tennessee (1)
-
Vermont
-
Windham County Vermont (3)
-
-
Virginia (1)
-
-
-
elements, isotopes
-
isotope ratios (2)
-
isotopes
-
radioactive isotopes
-
Pb-206/Pb-204 (1)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
Rb-87/Sr-86 (1)
-
Sm-147/Nd-144 (1)
-
-
stable isotopes
-
Nd-144/Nd-143 (2)
-
Pb-206/Pb-204 (1)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
Rb-87/Sr-86 (1)
-
Sm-147/Nd-144 (1)
-
Sr-87/Sr-86 (1)
-
-
-
metals
-
alkali metals
-
rubidium
-
Rb-87/Sr-86 (1)
-
-
-
alkaline earth metals
-
strontium
-
Rb-87/Sr-86 (1)
-
Sr-87/Sr-86 (1)
-
-
-
lead
-
Pb-206/Pb-204 (1)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
-
rare earths
-
neodymium
-
Nd-144/Nd-143 (2)
-
Sm-147/Nd-144 (1)
-
-
samarium
-
Sm-147/Nd-144 (1)
-
-
-
-
-
fossils
-
Graptolithina (2)
-
Invertebrata (2)
-
-
geochronology methods
-
(U-Th)/He (1)
-
Ar/Ar (2)
-
fission-track dating (2)
-
Pb/Pb (1)
-
Pb/Th (1)
-
thermochronology (1)
-
U/Pb (6)
-
U/Th/Pb (1)
-
-
geologic age
-
Mesozoic
-
Cretaceous
-
Lower Cretaceous (1)
-
-
Jurassic
-
Middle Jurassic (1)
-
Upper Jurassic (1)
-
-
-
Paleozoic
-
Devonian
-
Lower Devonian (1)
-
-
middle Paleozoic (1)
-
Ordovician
-
Martinsburg Formation (1)
-
Middle Ordovician
-
Ammonoosuc Volcanics (5)
-
Partridge Formation (1)
-
Schenectady Formation (1)
-
-
Upper Ordovician (1)
-
Utica Shale (1)
-
-
Permian (1)
-
Silurian (1)
-
-
Precambrian
-
upper Precambrian
-
Proterozoic
-
Neoproterozoic (1)
-
-
-
-
-
igneous rocks
-
igneous rocks
-
plutonic rocks
-
diorites
-
tonalite (3)
-
trondhjemite (2)
-
-
granites (2)
-
granodiorites (1)
-
-
volcanic rocks (4)
-
-
-
metamorphic rocks
-
metamorphic rocks
-
gneisses
-
granite gneiss (1)
-
paragneiss (1)
-
tonalite gneiss (1)
-
-
metaigneous rocks
-
metatuff (1)
-
-
metaplutonic rocks (1)
-
metasedimentary rocks
-
paragneiss (1)
-
-
metavolcanic rocks (2)
-
-
-
minerals
-
phosphates
-
apatite (2)
-
monazite (1)
-
-
silicates
-
chain silicates
-
amphibole group
-
clinoamphibole
-
hornblende (1)
-
-
-
-
framework silicates
-
feldspar group
-
alkali feldspar
-
K-feldspar (1)
-
-
-
-
orthosilicates
-
nesosilicates
-
zircon group
-
zircon (8)
-
-
-
-
sheet silicates
-
mica group
-
biotite (1)
-
muscovite (1)
-
-
-
-
-
Primary terms
-
absolute age (8)
-
Atlantic Ocean
-
North Atlantic (1)
-
-
Canada
-
Eastern Canada
-
Maritime Provinces
-
New Brunswick (1)
-
Nova Scotia (1)
-
-
Newfoundland and Labrador
-
Newfoundland (1)
-
-
-
-
crust (1)
-
deformation (2)
-
Europe
-
Alps
-
Prealps (1)
-
-
-
faults (10)
-
folds (3)
-
geochemistry (4)
-
geochronology (3)
-
geophysical methods (1)
-
Graptolithina (2)
-
igneous rocks
-
plutonic rocks
-
diorites
-
tonalite (3)
-
trondhjemite (2)
-
-
granites (2)
-
granodiorites (1)
-
-
volcanic rocks (4)
-
-
intrusions (3)
-
Invertebrata (2)
-
isostasy (1)
-
isotopes
-
radioactive isotopes
-
Pb-206/Pb-204 (1)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
Rb-87/Sr-86 (1)
-
Sm-147/Nd-144 (1)
-
-
stable isotopes
-
Nd-144/Nd-143 (2)
-
Pb-206/Pb-204 (1)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
Rb-87/Sr-86 (1)
-
Sm-147/Nd-144 (1)
-
Sr-87/Sr-86 (1)
-
-
-
magmas (1)
-
Mesozoic
-
Cretaceous
-
Lower Cretaceous (1)
-
-
Jurassic
-
Middle Jurassic (1)
-
Upper Jurassic (1)
-
-
-
metals
-
alkali metals
-
rubidium
-
Rb-87/Sr-86 (1)
-
-
-
alkaline earth metals
-
strontium
-
Rb-87/Sr-86 (1)
-
Sr-87/Sr-86 (1)
-
-
-
lead
-
Pb-206/Pb-204 (1)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
-
rare earths
-
neodymium
-
Nd-144/Nd-143 (2)
-
Sm-147/Nd-144 (1)
-
-
samarium
-
Sm-147/Nd-144 (1)
-
-
-
-
metamorphic rocks
-
gneisses
-
granite gneiss (1)
-
paragneiss (1)
-
tonalite gneiss (1)
-
-
metaigneous rocks
-
metatuff (1)
-
-
metaplutonic rocks (1)
-
metasedimentary rocks
-
paragneiss (1)
-
-
metavolcanic rocks (2)
-
-
metamorphism (6)
-
North America
-
Appalachians
-
Northern Appalachians (6)
-
-
-
orogeny (7)
-
paleogeography (1)
-
Paleozoic
-
Devonian
-
Lower Devonian (1)
-
-
middle Paleozoic (1)
-
Ordovician
-
Martinsburg Formation (1)
-
Middle Ordovician
-
Ammonoosuc Volcanics (5)
-
Partridge Formation (1)
-
Schenectady Formation (1)
-
-
Upper Ordovician (1)
-
Utica Shale (1)
-
-
Permian (1)
-
Silurian (1)
-
-
plate tectonics (6)
-
Precambrian
-
upper Precambrian
-
Proterozoic
-
Neoproterozoic (1)
-
-
-
-
sedimentary rocks
-
clastic rocks (3)
-
-
sedimentary structures
-
soft sediment deformation
-
olistostromes (1)
-
-
-
sedimentation (2)
-
structural analysis (1)
-
structural geology (4)
-
tectonics (8)
-
tectonophysics (1)
-
United States
-
Bronson Hill Anticlinorium (19)
-
Connecticut
-
Litchfield County Connecticut (1)
-
Middlesex County Connecticut (1)
-
New Haven County Connecticut (1)
-
-
Connecticut Valley (2)
-
Hudson Valley (1)
-
Maine (2)
-
Massachusetts
-
Franklin County Massachusetts (5)
-
Hampden County Massachusetts (1)
-
Hampshire County Massachusetts (1)
-
Worcester County Massachusetts (1)
-
-
Merrimack Synclinorium (2)
-
New England (11)
-
New Hampshire
-
Cheshire County New Hampshire (4)
-
Coos County New Hampshire (2)
-
Grafton County New Hampshire (3)
-
Sullivan County New Hampshire (1)
-
-
New York
-
Adirondack Mountains (1)
-
Essex County New York (1)
-
-
Tennessee (1)
-
Vermont
-
Windham County Vermont (3)
-
-
Virginia (1)
-
-
-
sedimentary rocks
-
flysch (2)
-
sedimentary rocks
-
clastic rocks (3)
-
-
-
sedimentary structures
-
sedimentary structures
-
soft sediment deformation
-
olistostromes (1)
-
-
-
GeoRef Categories
Era and Period
Epoch and Age
Book Series
Date
Availability
Bronson Hill Anticlinorium
Evolution of the Bronson Hill arc and Central Maine basin, northern New Hampshire to western Maine: U-Pb zircon constraints on the timing of magmatism, sedimentation, and tectonism Available to Purchase
ABSTRACT The Ordovician Bronson Hill arc and Silurian–Devonian Central Maine basin are integral tectonic elements of the northern Appalachian Mountains (USA). However, understanding the evolution of, and the relationship between, these two domains has been challenging due to complex field relationships, overprinting associated with multiple phases of Paleozoic orogenesis, and a paucity of geochronologic dates. To constrain the nature of this boundary, and the tectonic evolution of the northern Appalachians, we present U-Pb zircon dates from 24 samples in the context of detailed mapping in northern New Hampshire and western Maine. Collectively, the new geochronology and mapping results constrain the timing of magmatism, sedimentation, metamorphism, and deformation. The Bronson Hill arc formed on Gondwana-derived basement and experienced prolonged magmatic activity before and after a ca. 460 Ma reversal in subduction polarity following its accretion to Laurentia in the Middle Ordovician Taconic orogeny. Local Silurian deformation between ca. 441 and 434 Ma may have been related to the last stages of the Taconic orogeny or the Late Ordovician to early Silurian Salinic orogeny. Silurian Central Maine basin units are dominated by local, arc-derived zircon grains, suggestive of a convergent margin setting. Devonian Central Maine basin units contain progressively larger proportions of older, outboard, and basement-derived zircon, associated with the onset of the collisional Early Devonian Acadian orogeny at ca. 410 Ma. Both the Early Devonian Acadian and Middle Devonian to early Carboniferous Neoacadian orogenies were associated with protracted amphibolite-facies metamorphism and magmatism, the latter potentially compatible with the hypothesized Acadian altiplano orogenic plateau. The final configuration of the Jefferson dome formed during the Carboniferous via normal faulting, possibly related to diapirism and/or ductile thinning and extrusion. We interpret the boundary between the Bronson Hill arc and the Central Maine basin to be a pre-Acadian normal fault on which dip was later reversed by dome-stage tectonism. This implies that the classic mantled gneiss domes of the Bronson Hill anticlinorium formed relatively late, during or after the Neoacadian orogeny, and that this process may have separated the once-contiguous Central Maine and Connecticut Valley basins.
Zircon and monazite geochronology in the Palmer zone of transpression, south-central New England, USA: Constraints on timing of deformation, high-grade metamorphism, and lithospheric foundering during late Paleozoic oblique collision in the Northern Appalachian orogen Available to Purchase
Geochronology of the Oliverian Plutonic Suite and the Ammonoosuc Volcanics in the Bronson Hill arc: Western New Hampshire, USA Open Access
Reevaluation of the Piermont-Frontenac allochthon in the Upper Connecticut Valley: Restoration of a coherent Boundary Mountains–Bronson Hill stratigraphic sequence Available to Purchase
Where is the Iapetus suture in northern New England? A study of the Ammonoosuc Volcanics, Bronson Hill terrane, New Hampshire 1 This article is one of a series of papers published in this CJES Special Issue: In honour of Ward Neale on the theme of Appalachian and Grenvillian geology. Available to Purchase
Regional-Scale Mid-Jurassic to Late Cretaceous Unroofing from the Adirondack Mountains through Central New England Based on Apatite Fission-Track and (U-Th)/He Thermochronology Available to Purchase
Early Cretaceous Normal Faulting in Southern New England: Evidence from Apatite and Zircon Fission-Track Ages Available to Purchase
Probing the depths of Oliverian magmas: Implications for Paleozoic tectonics in the northeastern United States Available to Purchase
Taconian orogeny in the New England Appalachians: Collision between Laurentia and the Shelburne Falls arc Available to Purchase
Temporal changes in Nd isotopic composition of sedimentary rocks in the Sevier and Taconic foreland basins: Increasing influence of juvenile sources Available to Purchase
Mid-Paleozoic orogenesis in the North Atlantic: The Acadian orogeny Available to Purchase
The Acadian orogeny in the North Atlantic region is assessed in this chapter in the light of mid-Paleozoic tectonics; throughout, plate tectonic nomenclature is used, and cycles are avoided. In North America nine regions bearing the imprint of the Acadian orogeny are recognized. In Newfoundland, in the Maritime Provinces of Canada, and in Vermont and New Hampshire a continuous sequence of lithotectonic belts correlates along the orogen. The Bronson Hill belt, although a continuous structure in southern New England, is not recognized as such but splits into two structures northeast of the Maine-New Hampshire border: the Boundary Mountain anticlinorium and the Lobster Mountain anticlinorium. Other lithotectonic belts are partly continuous from Canada into the United States; they include: (1) North-Central Maine belt, (2) Aroostook-Matapedia belt, (3) Miramichi belt, (4) Fredericton-Central Maine belt, (5) Richmond belt, (6) Casco Bay belt, (7) Benner Hill belt, (8) St. Croix-Ellsworth belt, (9) Mascarene belt, and (10) Avalon belt. The decision as to whether each of these belts represents a separate terrane is at present reserved. In the coastal Maine zone the situation is particularly complex, and belts 6 through 10 can be recognized there. In Massachusetts, we interpret the Merrimack Trough belt as in fault contact with both the Kearsarge-Central Maine and Bronson Hill belts to the northwest, and in Connecticut, with the Bronson Hill belt alone. Additionally, the Merrimack Trough belt is in fault contact with the Putnam-Nashoba belt to the southeast. The latter shows mainly a Taconian metamorphism and extensive intrusion of granites; clear evidence for Acadian orogenic effects in the Putnam-Nashoba belt is lacking. In Newfoundland the main orogeny appears to be Silurian in age, and the same is true of New Brunswick, whereas in the Meguma of Nova Scotia the Devonian deformation and intrusive activity continue from the Devonian to the Carboniferous. Correlations with the south-central Appalachians indicate a possibility of significant Acadian transpressional effects. The most recent evidence of a new microfossil find, however, implies that considerable Acadian deformation occurred in the Southern Appalachians, although it may have been directly continuous with earlier Taconian events. The Acadian metamorphism in the Northern Appalachians is associated with numerous granites, in general ranging in age from the Silurian to the Carboniferous. The earlier Silurian granites may have originated along the Iapetus suture or may be associated with transcurrent faults. The plate tectonic interpretation of the orogenic system is based on a model of successive blocks (terranes) approaching and colliding with North America and squeezing intervening sediments and volcanics. This took place over a fairly prolonged period of time.
The nappe theory in the Connecticut Valley region: Thirty-five years since Jim Thompson's first proposal Available to Purchase
Age and setting of the Bronson Hill magmatic arc: A re-evaluation based on U-Pb zircon ages in southern New England Available to Purchase
Geochronologic studies in central New England I: Evidence for pre-Acadian metamorphism in eastern Vermont Available to Purchase
Geochronologic studies in central New England II: Post-Acadian hinged and differential uplift Available to Purchase
Petrochemistry and origin of the Killingworth dome rocks, Bronson Hill anticlinorium, south-central Connecticut Available to Purchase
Trondhjemite and metamorphosed quartz keratophyre tuff of the Ammonoosuc Volcanics (Ordovician), western New Hampshire and adjacent Vermont and Massachusetts Available to Purchase
Crustal Profile of Mountain Belt: COCORP Deep Seismic Reflection Profiling in New England Appalachians and Implications for Architecture of Convergent Mountain Chains Available to Purchase
Formation of melange in a foreland basin overthrust setting: Example from the Taconic Orogen Available to Purchase
The Taconic melanges of eastern New York developed through the progressive deformation of a synorogenic flysch sequence deposited within a N-S elongate foreland basin. This basin formed in front of the Taconic Allochthon as it was emplaced onto the North American continental shelf during the medial Ordovician Taconic Orogeny. The flysch was derived from, and was subsequently overridden by the allochthon, resulting in the formation of belts of tectonic melange. An east to west decrease in deformation intensity allows interpretation of the structural history of the melange and study of the flysch-melange transition. The formation of the melange involved: isoclinal folding, boudinage and disruption of graywacke-shale sequences due to ductility contrasts; sub-aqueous slumping and deposition of olistoliths which were subsequently tectonized and incorporated into the melange; and imbrication of the overthrust and underthrust sedimentary sections into the melange. The characteristic microstructure of the melange is a phacoidal conjugate-shear cleavage, which is intimately associated with high strains and bedding disruption. Rootless isoclines within the melange have apparently been rotated into an east-west shear direction, consistent with fault, fold, and cleavage orientations within the flysch. The melange zones are best modeled as zones of high shear strain developed during the emplacement of the Taconic Allochthon. Total displacement across these melange zones is estimated to be in excess of 60 kilometers.