The Silurian Salinic Disturbance — newly discovered orogenic event in the northern Appalachians

Pages: 
pp. 97-102
Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
Abstract: 

In northern New Brunswick the Silurian and Ordovician rocks have been affected by two regional deformation events. The first deformation is attributed to the Salinic orogeny. It took place during the late Wenlockian — early Ludlow (426—421 Ma) and produced tectonic folds with northwest striking axial surfaces. Evidence for cleavage and faulting coeval to this event is rare. The second regional deformation took place during the lower to middle Devonian (407—390 Ma) and is know as Acadian orogeny. The Acadian deformation overprinted the Salinic structures in the lower Silurian rocks but produced single fold generation in the upper Silurian rocks. Intensive cleavage and widespread faulting are related to the Acadian revolution. The refolds in the lower Silurian rocks are steeply plunging. The refolds are overprinted by the Acadian cleavage, while the Acadian folds are dextrally transected by the same cleavage. The kinematics of the Salinic deformation is not understood but it is known that the Acadian deformation was achieved during intensive dextral shear, which resulted in transecting cleavage and an echelon arrangement of Acadian folds with respect to the high-strain shear zones. Most of the faults in the northern Appalachians appear to be synchronous or to postdate the Acadian folding. The dextral shear was penetrative on a regional scale and resulted in numerous bedding parallel faults with hidden separation.

Ив. Димитров. Силурийский орогенез Салиник — новоустановленное орогеническое событие в северных отделах Аппалачских гор. Силурийские и ордовикские породы северных отделов Ню Брунсуика испытали воздействие двух региональных деформационных событий. Первая деформация связана с орогенезом Салиник (поздний уенлок — ранний лудлоу — 426—421 Ma). Он привел к образованию складок с северо-западным простиранием осевых плоскостей, а также — редкого кливажа и редких синхронных разломов. Вторая региональная деформация (Акадский орогенез) произошла в нижнем — среднем девоне (407—390 Ma). В нижнесилурийских породах Акадские деформации наложены на структуры Салиника, а в верхнесилурийских породах они представлены только одним этапом складчатости. С Акадской революцией связано образовение интенсивного кливажа и многочисленных разломов. В нижнесилурийских породах наложенные складки отличаются пологим погружением и пересекаются Акадским кливажом. Тот-же кливаж проходит и через Акадские складки. Кинематика деформации Салиник не изучена, но установлено, что Акадская деформация осуществилась во время интенсивных правосдвиговых движений. Это привело к образованию разломного кливажа и к кулисному расположению Акадских складок по отношению к сильно напряженным сдвиговым зонам. Становление большей части разломов в северных отделах Аппалачских гор очевидно произошло или синхронно с Акадским складкообразованием, или непосредствено после него. С региональной точки зрения правосдвиговые сколы имели проникающий характер. С ними связано образование нечетко выявляющихся разломов, параллельных слоистости.

Keywords: 

Silurian, Salinic, deformation, stratigraphy, folds, faults

VOLUME 36 (3-4)/December 2007

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, G. Bonchev Str., Block 24

Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev str., bl. 24, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev str., bl. 24, 1113 Sofia, Bulgaria

Geological Institute, Bulgarian Academy of Sciences, Bulgaria, 1113 Sofia, Acad. G. Bonchev Str., Bl. 24

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Acad. G. Bonchev St., Bl. 24
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Acad. G. Bonchev St., Bl. 24

Geological Institute of the Bulgarian Academy of Sciences, 1113 Sofia, Acad. G. Bonchev St., 24

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Instituto Andaluz de Ciencias de la Tierra, CSIC, Granada, Spain
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University of Granada, Granada, Spain
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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University of Granada, Granada, Spain
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia

Geological Institute, Bulgarian Academy of Sciences, 24 Acad G. Bonchev Str., 1113 Sofia

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia

Geological Institute, Bulgarian academy of Scienses, 1113 Sofia, 24 G. Bonchev Str.
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Geological Institute, Bulgarian academy of Scienses, 1113 Sofia, 24 G. Bonchev Str.

Sofia University “St. Kliment Ohridsky”, 1000 Sofia, 15 Tsar Osvoboditel Blvd.
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Geological Institute Bulgarian Academy of Sciences, 1113 Sofia, 24 G. Bonchev Str.
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Geological Institute Bulgarian Academy of Sciences, 1113 Sofia, 24 G. Bonchev Str.
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Ministry of Environment and Water, 1000 Sofia, 22 Maria Louisa Blvd.

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria

Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 24, 1113 Sofia, Bulgaria

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria

Bulgarian Academy of Sciences, Geological Institute, Acad. G. Bonchev St. Bl. 24, 1113 Sofia, Bulgaria
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Middle East Technical University, Department of Geological Engineering, 06531 Ankara, Turkey
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General Directorate of Mineral Research and Exploration, Department of Geological Research, 06520 Ankara, Turkey
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General Directorate of Mineral Research and Exploration, Department of Geological Research, 06520 Ankara, Turkey

Geophysical Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia

Geological Institute, Bulgarian Academy of Sciences
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Geological Institute, Bulgarian Academy of Sciences
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Geological Institute, Bulgarian Academy of Sciences