Taconic allochthon and bordering deformed units of New York and Vermont: Structure and emplacement history
- SUNY, Albany, NY (United States). Geological Sciences
A laterally continuous system of thrust imbrication of the upper part of the carbonate shelf sequence and/or the overlying flysch/shale is mapped beneath the western boundary fault [Frontal Thrust] of the Taconic Allochthon. The more western of these faults much merge with Champlain Thrust to the north; this thrust system climbs section to the south so that carbonates are not seen on the thrusts in the south near Albany. The more easterly faults of this system, including the Taconic Frontal Thrust, project into the west and center of the Middlebury synclinorium; these faults are interpreted to join the Champlain Thrust at depth. Thrusts of this system in the south are marked by thick zones of melange, which become much narrower in the north where carbonate rocks are included in the thrust slices. The Taconic Frontal Thrust is an out-of -sequence structure that cuts the tight regional folds within the Taconic Allochthon, and the Taconic Basal Thrust, on which the Allochthon was initially emplaced over shelf rocks. Just east of the Taconic Allochthon, in the Vermont Valley, numerous thrusts imbricate the shelf carbonates and black phyllites. A major early thrust [Dorset Mtn. Thrust] separates the classic marble belts from less deformed carbonates, and a major out-of-sequence thrust [Green Mtn. Thrust] separates the carbonates from the Green Mountain Grenville basement and overlying Cambrian siliciclastics. The structure of the Vermont Valley carbonates is inferred to be a large antiformally folded duplex truncated on its eastern side by the Green Mtn. Thrust; this fold and thrust are also inferred to be part of the Champlain Thrust system. The bordering zones of the Taconic Allochthon contain much more deformation, especially thrust faults, than previously mapped; simple undisrupted stratigraphic sequences shown on previous maps are incorrect.
- OSTI ID:
- 5723027
- Report Number(s):
- CONF-9303211--
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Journal Name: Geological Society of America, Abstracts with Programs; (United States) Vol. 25:2; ISSN GAAPBC; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
Similar Records
Searching for the root zone(s) of the Taconic allochthons: Leaving no stone unturned
Structural style and tectonic evolution of the marathon thrust belt, west Texas