The Northeastward Termination of the Appalachian Orogen

1974 ◽  
pp. 79-123 ◽  
Author(s):  
Harold Williams ◽  
M. J. Kennedy ◽  
E. R. W. Neale
Keyword(s):  
Appalachian Orogen

scholarly journals Application of Foreland Basin Detrital‐Zircon Geochronology to the Reconstruction of the Southern and Central Appalachian Orogen

2010 ◽  
Vol 118 (1) ◽  
pp. 23-44 ◽  
Author(s):  
Hyunmee Park ◽  
David L. Barbeau Jr. ◽  
Alan Rickenbaker ◽  
Denise Bachmann‐Krug ◽  
George Gehrels
Keyword(s):  
Detrital Zircon ◽  
Foreland Basin ◽  
Zircon Geochronology ◽  
Detrital Zircon Geochronology ◽  
Appalachian Orogen

scholarly journals ERRATUM: Suprasubduction zone ophiolite fragments in the central Appalachian orogen: Evidence for mantle and Moho in the Baltimore Mafic Complex (Maryland, USA)

Geosphere ◽  
2021 ◽  
Author(s):  
George L. Guice ◽  
Michael R. Ackerson ◽  
Robert M. Holder ◽  
Freya R. George ◽  
Joseph F. Browning-Hanson ◽  
...  
Keyword(s):  
Suprasubduction Zone ◽  
Mafic Complex ◽  
Appalachian Orogen

In the Table 3 note and captions of Figures 8 and 9, the equation Fe2+# = molar Fe2+/[Mg+Fe2++Fe3+] is incorrect. It should instead be Fe2+# = molar Fe2+/[Mg+Fe2+].

scholarly journals The Mid Atlantic Appalachian Orogen Traverse: a comparison of virtual and on-location field-based capstone experiences

Solid Earth ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 2803-2820
Author(s):  
Steven Whitmeyer ◽  
Lynn Fichter ◽  
Anita Marshall ◽  
Hannah Liddle
Keyword(s):  
Students With Disabilities ◽  
Online Survey ◽  
Field Experiences ◽  
Google Earth ◽  
Field Trips ◽  
Virtual Field Trips ◽  
James Madison ◽  
Virtual Field ◽  
Appalachian Orogen ◽  
Potential Benefits

Abstract. The Stratigraphy, Structure, Tectonics (SST) course at James Madison University incorporates a capstone project that traverses the Mid Atlantic region of the Appalachian Orogen and includes several all-day field trips. In the Fall 2020 semester, the SST field trips transitioned to a virtual format, due to restrictions from the COVID pandemic. The virtual field trip projects were developed in web-based Google Earth and incorporated other supplemental PowerPoint and PDF files. In order to evaluate the effectiveness of the virtual field experiences in comparison with traditional on-location field trips, an online survey was sent to SST students that took the course virtually in Fall 2020 and to students that took the course in person in previous years. Instructors and students alike recognized that some aspects of on-location field learning, especially those with a tactile component, were not possible or effective in virtual field experiences. However, students recognized the value of virtual field experiences for reviewing and revisiting outcrops as well as noting the improved access to virtual outcrops for students with disabilities and the generally more inclusive experience of virtual field trips. Students highlighted the potential benefits for hybrid field experiences that incorporate both on-location outcrop investigations and virtual field trips, which is the preferred model for SST field experiences in Fall 2021 and into the future.

Petrologic and thermal constraints on the origin of leucogranites in collisional orogens

2004 ◽  
Vol 95 (1-2) ◽  
pp. 73-85 ◽  
Author(s):  
Peter I. Nabelek ◽  
Mian Liu
Keyword(s):  
Partial Melting ◽  
Shear Zones ◽  
Source Rocks ◽  
Radioactive Isotopes ◽  
The Usa ◽  
Appalachian Orogen ◽  
Shear Heating ◽  
Heating Model ◽  
Orogenic Belts ◽  
Collisional Orogens

ABSTRACTLeucogranites are typical products of collisional orogenies. They are found in orogenic terranes of different ages, including the Proterozoic Trans-Hudson orogen, as exemplified in the Black Hills, South Dakota, and the Appalachian orogen in Maine, both in the USA, and the ongoing Himalayan orogen. Characteristics of these collisional leucogranites show that they were derived from predominantly pelitic sources at the veining stages of deformation and metamorphism in upper plates of thickened crusts. Once generated, the leucogranite magmas ascended as dykes and were emplaced within shallower parts of their source sequences. In these orogenic belts, there was a strong connection between deformation, metamorphism and granite generation. However, the heat sources needed for partial melting of the source rocks remain controversial. Lack of evidence for significant intrusion of mafic magmas necessary to cause melting of upper plate source rocks suggests that leucogranite generation in collisional orogens is mainly a crustal process.The present authors evaluate five types of thermal models which have previously been proposed for generating leucogranites in collisional orogens. The first, a thickened crust with exponentially decaying distribution of heat-producing radioactive isotopes with depth, has been shown to be insufficient for heating the upper crust to melting conditions. Four other models capable of raising the crustal temperatures sufficiently to initiate partial melting of metapelites in thickened crust include: (1) thick sequences of sedimentary rocks with high amounts of internal radioactive heat production; (2) decompression melting; (3) thinning of mantle lithosphere; and (4) shear-heating. The authors show that, for reasonable boundary conditions, shear-heating along crustal-scale shear zones is the most viable process to induce melting in upper plates of collisional orogens where pelitic source lithologies are usually located. The shear-heating model directly links partial melting to the deformation and metamorphism that typically precede leucogranite genera

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