Sequential development of the Appalachian orogen above a master decollement — A hypothesis

Harris, Leonard D.; Bayer, Kenneth C.

doi:10.1130/0091-7613(1979)7<568:sdotao>2.0.co;2

Cited by 88 publications

(31 citation statements)

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“…Harris and Bayer (1979) also favored a thin-skinned model and pointed to several seismic sections as supporting evidence. A fundamental, and controversial, feature of the COCORP model is a master décollement that extends approximately 330 km from the Valley and Ridge province southeast ard to the Carolina slate belt and above which crystalline rocks are thrust an estimated 260 km northwestward.…”

Section: Introductionmentioning

confidence: 88%

“…A fundamental, and controversial, feature of the COCORP model is a master décollement that extends approximately 330 km from the Valley and Ridge province southeast ard to the Carolina slate belt and above which crystalline rocks are thrust an estimated 260 km northwestward. The thin-skinned model and its implications for the tectonic evolution and hydrocarbon potential of the Appalachian orogen have become a focus for vigorous debate (chronologically: Ellwood and others, 1980a;Williams, 1980;Cook and others, 1980a;Harris and Bayer, 1980;Reed and Bryant, 1980;Cook and others, 1980b;Moench, 1980;Cook and others, 1980c;Friedman and Reeckmann, 1980;Ellwood and others, 1980b). Throughout the debate, the prominent positive-negative Bouguer gravity anomaly pair that extends the length of the southern and central Appalachians ( Fig.…”

Section: Introductionmentioning

confidence: 97%

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Tectonic significance of paired gravity anomalies in the southern and central Appalachians

Thomas¹

1983

Geological Society of America Memoirs

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Extensive, positive-negative paired gravity anomalies occur along a number of Precambrian boundaries separating terranes with contrasting structural characteristics and radiometrically determined ages. Collective evidence from the boundaries supports an origin by plate collision following convergent plate movements operating in the style of modern day plate tectonics. The paleosubduction direction can be determined from the relative ages of the sutured terranes, the younger one being identified as a "reactivated" terrane formed in response to subduction beneath it. Because the positive-negative pattern of gravity anomalies is invariable with respect to the relative ages of the sutured terranes, the paleosubduction direction can be established with confidence on the basis of the gravity pattern alone; the latter also identifies the suture position.In the southern and central Appalachians, such utility of the basement is prevented by a widely-preserved cover of supracrustal rocks. Geological indicators of paleosubduction direction and suturing are present in these rocks, but because of the determined or possible allochthonous nature of some of the critical terranes, locating deeper, more fundamental sections of suture zones is problematical. However, the presence of paired gravity anomalies, strikingly similar to Precambrian examples, affords a novel method for identifying the location of a deep suture and the associated paleosubduction direction. Studies of these anomalies lead to the conclusion that a plate carrying a proto-American block subducted southeastward, leading to collision with an "accreted" block, in agreement with the general consensus that such a collision occurred in the Ordovician.Along the COCORP seismic profile, gravity modelling indicates that the suture dips southeastward beneath the Inner Piedmont and transects a master décollement outlined by the seismic studies. The presence of a suture in this locality suggests that any thin-skinned tectonic model for this part of the Appalachians should be restricted to the area northwest of the suture. 113

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Section: Introductionmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 97%

Tectonic significance of paired gravity anomalies in the southern and central Appalachians

Thomas¹

1983

Geological Society of America Memoirs

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“…The southern Appalachian Valley and Ridge is characterized by having more exposed major thrust faults than the central Appalachian Valley and Ridge, which exhibits more folds above zones of blind thrusts. On the basis of mapped geology, reflection seismic data, and borehole information, the Valley and Ridge province is interpreted to be the result of thin-skinned deformation above a major decollement in the lower Cambrian Rome/Waynesboro formations (Gwinn, 1964;Rodgers, 1970;Harris and Milici, 1977;Harris and Bayer 1979;Evans, 1989).…”

Section: Geologymentioning

confidence: 99%

Contrasts in Tectonic style of the Central and Southern Appalachians, United States: Insights from seismic reflection data

Peavy

Çoruh

Costain

et al. 2004

Journal of Geodynamics

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“…Geophysical studies (Cook and others, 1979;Harris and Bayer, 1979) have indicated that a major sub-horizontal interface underlies most of the Piedmont and. Coastal Plain at a depth of 5-15 km.…”

Section: Ii1 Carolina Slate Beltmentioning

confidence: 99%

Sequential development of the Appalachian orogen above a master decollement — A hypothesis

Cited by 88 publications

References 0 publications

Tectonic significance of paired gravity anomalies in the southern and central Appalachians

Tectonic significance of paired gravity anomalies in the southern and central Appalachians

Contrasts in Tectonic style of the Central and Southern Appalachians, United States: Insights from seismic reflection data

Geological studies in an area of induced seismicity at Monticello Reservoir, South Carolina

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