Author: Ann Elizabeth Walker
Publisher:
ISBN:
Category : Geology, Structural
Languages : en
Pages : 94
Book Description
The Tablerock thrust sheet is exposed along the southwestern margin of Grandfather Mountain window in northwestern North Carolina, where it separates basement and cover rocks inside the window from basement thrust sheets of the overriding Blue Ridge-Piedmont megathrust sheet. It is a complex of footwall-derived horses of rifted-margin metasedimentary rocks, including Neoproterozoic to Early Cambrian Chilhowee Group quartzite and phyllite, and Shady Dolomite. Penetrative deformation throughout the Tablerock thrust sheet is defined by an extensively transposed foliation, and strong colinearity between well developed transport lineations and SE/NW-trending tight, isoclinal, and sheath folds. Centimeter- to meter-scale sheath folds are common throughout the interior of the thrust sheet, and not just within fault zones. NE-trending/NW-vergent crenulations and mesoscale open folds overprint these fabric elements, and represent one to two later phases of deformation. The strong colinearity between transport lineations and the hinges of tight to isoclinal folds, prevalence of mesoscale sheath folds, and outcrop patterns on Bryant and Reed’s 1970 map suggest SE/NW-trending megascopic folds at Linville Falls waterfall, Woodlawn quarry, and in the Linville Gorge Wilderness Area are map-scale sheath folds. Deformation temperatures estimated from metamorphic mineral assemblages, quartz lattice-preferred orientations, dynamic recrystallization microstructures, feldspar deformation microstructures, and the opening angles of quartz [c]-axis fabrics indicate the Tablerock thrust sheet reached 550–595 °C during lower–middle amphibolite facies conditions, and was later overprinted by upper greenschist to lower amphibolite facies conditions at 465–550 °C. These estimates are at least 120 °C higher than all previously reported temperatures, and are consistent with a model in which the Tablerock thrust sheet was significantly deformed during coupled transport with the Blue Ridge-Piedmont megathrust sheet prior to being emplaced at its present location.
Structural Analysis of the Tablerock Thrust Sheet, Grandfather Mountain Window, Northwestern North Carolina
Author: Ann Elizabeth Walker
Publisher:
ISBN:
Category : Geology, Structural
Languages : en
Pages : 94
Book Description
The Tablerock thrust sheet is exposed along the southwestern margin of Grandfather Mountain window in northwestern North Carolina, where it separates basement and cover rocks inside the window from basement thrust sheets of the overriding Blue Ridge-Piedmont megathrust sheet. It is a complex of footwall-derived horses of rifted-margin metasedimentary rocks, including Neoproterozoic to Early Cambrian Chilhowee Group quartzite and phyllite, and Shady Dolomite. Penetrative deformation throughout the Tablerock thrust sheet is defined by an extensively transposed foliation, and strong colinearity between well developed transport lineations and SE/NW-trending tight, isoclinal, and sheath folds. Centimeter- to meter-scale sheath folds are common throughout the interior of the thrust sheet, and not just within fault zones. NE-trending/NW-vergent crenulations and mesoscale open folds overprint these fabric elements, and represent one to two later phases of deformation. The strong colinearity between transport lineations and the hinges of tight to isoclinal folds, prevalence of mesoscale sheath folds, and outcrop patterns on Bryant and Reed’s 1970 map suggest SE/NW-trending megascopic folds at Linville Falls waterfall, Woodlawn quarry, and in the Linville Gorge Wilderness Area are map-scale sheath folds. Deformation temperatures estimated from metamorphic mineral assemblages, quartz lattice-preferred orientations, dynamic recrystallization microstructures, feldspar deformation microstructures, and the opening angles of quartz [c]-axis fabrics indicate the Tablerock thrust sheet reached 550–595 °C during lower–middle amphibolite facies conditions, and was later overprinted by upper greenschist to lower amphibolite facies conditions at 465–550 °C. These estimates are at least 120 °C higher than all previously reported temperatures, and are consistent with a model in which the Tablerock thrust sheet was significantly deformed during coupled transport with the Blue Ridge-Piedmont megathrust sheet prior to being emplaced at its present location.
Publisher:
ISBN:
Category : Geology, Structural
Languages : en
Pages : 94
Book Description
The Tablerock thrust sheet is exposed along the southwestern margin of Grandfather Mountain window in northwestern North Carolina, where it separates basement and cover rocks inside the window from basement thrust sheets of the overriding Blue Ridge-Piedmont megathrust sheet. It is a complex of footwall-derived horses of rifted-margin metasedimentary rocks, including Neoproterozoic to Early Cambrian Chilhowee Group quartzite and phyllite, and Shady Dolomite. Penetrative deformation throughout the Tablerock thrust sheet is defined by an extensively transposed foliation, and strong colinearity between well developed transport lineations and SE/NW-trending tight, isoclinal, and sheath folds. Centimeter- to meter-scale sheath folds are common throughout the interior of the thrust sheet, and not just within fault zones. NE-trending/NW-vergent crenulations and mesoscale open folds overprint these fabric elements, and represent one to two later phases of deformation. The strong colinearity between transport lineations and the hinges of tight to isoclinal folds, prevalence of mesoscale sheath folds, and outcrop patterns on Bryant and Reed’s 1970 map suggest SE/NW-trending megascopic folds at Linville Falls waterfall, Woodlawn quarry, and in the Linville Gorge Wilderness Area are map-scale sheath folds. Deformation temperatures estimated from metamorphic mineral assemblages, quartz lattice-preferred orientations, dynamic recrystallization microstructures, feldspar deformation microstructures, and the opening angles of quartz [c]-axis fabrics indicate the Tablerock thrust sheet reached 550–595 °C during lower–middle amphibolite facies conditions, and was later overprinted by upper greenschist to lower amphibolite facies conditions at 465–550 °C. These estimates are at least 120 °C higher than all previously reported temperatures, and are consistent with a model in which the Tablerock thrust sheet was significantly deformed during coupled transport with the Blue Ridge-Piedmont megathrust sheet prior to being emplaced at its present location.
Geology of the Grandfather Mountain Window and Vicinity, North Carolina and Tennessee
Author: Bruce Bryant
Publisher:
ISBN:
Category : Blue Ridge Mountains
Languages : en
Pages : 220
Book Description
Structural and metamorphic history of rocks exposed in the largest window in the crystalline belt of the southern Appalachians, and a discussion of the significance of the window in interpretation of the tectonics of the region.
Publisher:
ISBN:
Category : Blue Ridge Mountains
Languages : en
Pages : 220
Book Description
Structural and metamorphic history of rocks exposed in the largest window in the crystalline belt of the southern Appalachians, and a discussion of the significance of the window in interpretation of the tectonics of the region.
Geological Survey Professional Paper
Author:
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 340
Book Description
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 340
Book Description
Geological Survey Professional Paper
Author: Geological Survey (U.S.)
Publisher:
ISBN:
Category :
Languages : en
Pages : 282
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 282
Book Description
U.S. Geological Survey Professional Paper
Author:
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 334
Book Description
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 334
Book Description
Depositional History of Paleozoic Sequences, Southern Appalachians
Author: Steven G. Driese
Publisher:
ISBN:
Category : Appalachian Region, Southern
Languages : en
Pages : 152
Book Description
Publisher:
ISBN:
Category : Appalachian Region, Southern
Languages : en
Pages : 152
Book Description
Studies in Geology
Author:
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 150
Book Description
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 150
Book Description
Diary of a Geological Tour by Dr. Elisha Mitchell in 1827 and 1828
Author: Elisha Mitchell
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 82
Book Description
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 82
Book Description
The Heart of the Alleghanies; Or, Western North Carolina
Author: Wilbur G. Zeigler
Publisher:
ISBN:
Category : Allegheny Mountains
Languages : en
Pages : 398
Book Description
Publisher:
ISBN:
Category : Allegheny Mountains
Languages : en
Pages : 398
Book Description
Fifty Years in the Northwest
Author: William Henry Carman Folsom
Publisher:
ISBN:
Category : Minnesota
Languages : en
Pages : 868
Book Description
Chapters start with historical information about a county or places within the county followed by biographies of people from those localities.
Publisher:
ISBN:
Category : Minnesota
Languages : en
Pages : 868
Book Description
Chapters start with historical information about a county or places within the county followed by biographies of people from those localities.