Geophysical and Geological Evidence for Quaternary Displacement on the Caborn Fault, Wabash Valley Fault System, Southwestern Indiana

Author(s):  
Edward W. Woolery ◽  
James W. Whitt ◽  
Roy B. Van Arsdale ◽  
Ali Almayahi
1997 ◽  
Vol 68 (4) ◽  
pp. 567-585 ◽  
Author(s):  
T. G. Hildenbrand ◽  
D. Ravat

Geophysics ◽  
1986 ◽  
Vol 51 (3) ◽  
pp. 640-660 ◽  
Author(s):  
John L. Sexton ◽  
L. W. Braile ◽  
W. J. Hinze ◽  
M. J. Campbell

Sixty‐eight kilometers of 12-fold seismic reflection data were collected in the Wabash River Valley of southwestern Indiana and southeastern Illinois to investigate the configuration of a basement structure inferred from regional gravity and magnetic anomaly data. The seismic profiles were also positioned to cross faults of the Wabash Valley fault system in a number of locations. Interpretation of the seismic reflection profiles and detailed gravity and magnetic profile data provides evidence for a series of northeasterly trending grabens in the basement. These grabens are filled with pre‐Mt. Simon layered rocks and are overlain by Paleozoic sedimentary rocks of the Illinois basin. Beneath the Wabash River near Grayville, Illinois, an interpreted graben (the Grayville graben) is approximately 15 km wide and contains about 3 km of fill. Individual boundary faults for the graben cut prominent reflectors within pre‐Mt. Simon rocks and display offsets of up to 500 m. The interpreted configuration of basement faults and thickness of pre‐Mt. Simon layered rocks provide evidence of a late Precambrian rift inferred to be one arm of the New Madrid rift complex. Post‐Pennsylvanian faulting of the Wabash Valley fault system is visible on the seismic reflection record sections as small offsets (less than 100 m) on steeply dipping normal faults. The downward projection of these faults intersects the older large‐offset faults within the pre‐Mt. Simon rocks suggesting that the Wabash Valley faults represent a post‐Pennsylvanian reactivation of the rift system.


2011 ◽  
Vol 82 (5) ◽  
pp. 735-747 ◽  
Author(s):  
M. W. Hamburger ◽  
K. Shoemaker ◽  
S. Horton ◽  
H. DeShon ◽  
M. Withers ◽  
...  

Solid Earth ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1967-1986
Author(s):  
Dario Zampieri ◽  
Paola Vannoli ◽  
Pierfrancesco Burrato

Abstract. We make a thorough review of geological and seismological data on the long-lived Schio-Vicenza Fault System (SVFS) in northern Italy and present for it a geodynamic and seismotectonic interpretation. The SVFS is a major and high-angle structure transverse to the mean trend of the eastern Southern Alps fold-and-thrust belt, and the knowledge of this structure is deeply rooted in the geological literature and spans more than a century and a half. The main fault of the SVFS is the Schio-Vicenza Fault (SVF), which has a significant imprint in the landscape across the eastern Southern Alps and the Veneto-Friuli foreland. The SVF can be divided into a northern segment, extending into the chain north of Schio and mapped up to the Adige Valley, and a southern one, coinciding with the SVF proper. The latter segment borders to the east the Lessini Mountains, Berici Mountains and Euganei Hills block, separating this foreland structural high from the Veneto-Friuli foreland, and continues southeastward beneath the recent sediments of the plain via the blind Conselve–Pomposa fault. The structures forming the SVFS have been active with different tectonic phases and different styles of faulting at least since the Mesozoic, with a long-term dip-slip component of faulting well defined and, on the contrary, the horizontal component of the movement not being well constrained. The SVFS interrupts the continuity of the eastern Southern Alps thrust fronts in the Veneto sector, suggesting that it played a passive role in controlling the geometry of the active thrust belt and possibly the current distribution of seismic release. As a whole, apart from moderate seismicity along the northern segment and few geological observations along the southern one, there is little evidence to constrain the recent activity of the SVFS. In this context, the SVFS, and specifically its SVF strand, has accommodated a different amount of shortening of adjacent domains of the Adriatic (Dolomites) indenter by internal deformation produced by lateral variation in strength, related to Permian–Mesozoic tectonic structures and paleogeographic domains. The review of the historical and instrumental seismicity along the SVFS shows that it does not appear to have generated large earthquakes during the last few hundred years. The moderate seismicity points to a dextral strike-slip activity, which is also corroborated by the field analysis of antithetic Riedel structures of the fault cropping out along the northern segment. Conversely, the southern segment shows geological evidence of sinistral strike-slip activity. The apparently conflicting geological and seismological data can be reconciled considering the faulting style of the southern segment as driven by the indentation of the Adriatic plate, while the opposite style along the northern segment can be explained in a sinistral opening “zipper” model, where intersecting pairs of simultaneously active faults with a different sense of shear merge into a single fault system.


1983 ◽  
Vol 20 (1) ◽  
pp. 135-159 ◽  
Author(s):  
C. J. Yorath ◽  
R. D. Hyndman

A tectonic model for the formation, subsidence, and thermal history of Queen Charlotte Basin is developed. Based upon regional geological and geophysical data, subsidence data from offshore wells in Hecate Strait and Queen Charlotte Sound, and thermal criteria derived from present heat flow and vitrinite reflectance information, Queen Charlotte Basin is seen to have resulted from two distinct mechanisms. (1) During a period of broad regional uplift, rifting and crustal extension occurred in Queen Charlotte Sound up to about 17 Ma ago and the Queen Charlotte Islands were displaced northwards toward their present position by transcurrent motion along the Louscoone Inlet – Sandspit fault system. The rifting generated a significant thermal anomaly and a restricted deep basin as a consequence of crustal thinning and subsequent thermal cooling. (2) Beginning about 6 Ma ago, oblique underthrusting commenced along the margin, resulting in flexural uplift of the western part of the Queen Charlotte Islands and companion subsidence in Hecate Strait and Queen Charlotte Sound. The underthrusting caused rapid cooling of the old rift basins. This phase of subsidence has continued at a decreasing rate until the present.The tectonically generated subsidence in the basin has been estimated by correcting the well data for sediment compaction, paleo water depth, and sediment loading effects. At the site of the Harlequin well in the Queen Charlotte Sound rift, with the termination of extension and associated volcanism, the basin was 1500–2000 m deep and contained little sediment. Model calculations show that this depth is consistent with the estimated extension of about 70 km and a resulting crustal thinning to 8–10 km.Models for the lithosphere flexure generated by underthrusting are constrained by the geological evidence for uplift and erosion of over 5 km of material from the western portion of the Queen Charlotte Islands and the exponentially slowing subsidence to a present regional basement depth of 2 km in Hecate Strait. An excellent fit to the pre-erosion surface profile onshore and pre-Skonun basement surface offshore is obtained with a model having underthrusting on a 30° thrust at a 10 mm year−1 orthogonal component of convergence. The flexure generated by underthrusting, which is particularly well documented in the Queen Charlotte region, appears to be a feature of most subduction zones.Vitrinite reflectance data, present heat flow estimates from the wells, and thermal modelling indicate that the heat flux in Queen Charlotte Basin was much higher in the past than at present, particularly in Queen Charlotte Sound. A model is proposed with high heat flow generated by rifting prior to 17 Ma ago, followed by cooling from the underthrust oceanic lithosphere.


2021 ◽  
Author(s):  
Dario Zampieri ◽  
Paola Vannoli ◽  
Pierfrancesco Burrato

Abstract. We make a thorough review of geological and seismological data on the long-lived Schio-Vicenza Fault System (SVFS) in northern Italy and present for it a geodynamic and seismotectonic interpretation. The SVFS is a major and high angle structure transverse to the mean trend of the Eastern Southern Alps fold-and-thrust belt, and the knowledge of this structure is deeply rooted in the geological literature and spans for more than a century and a half. The main fault of the SVFS is the Schio-Vicenza Fault (SVF), which has a significant imprint in the landscape across the Eastern Southern Alps and the Veneto-Friuli foreland. The SVF can be divided into a northern segment, extending into the chain north of Schio and mapped up to the Adige Valley, and a southern one, coinciding with the SVF proper. The latter segment borders to the east the Lessini, Berici Mts. and Euganei Hills block, separating this foreland structural high from the Veneto-Friuli foreland, and continues southeastward beneath the recent sediments of the plain via the blind Conselve-Pomposa fault. The structures forming the SVFS have been active with different tectonic phases and different style of faulting at least since the Mesozoic, with a long-term dip-slip component of faulting well defined and, on the contrary, the horizontal component of the movement not well constrained. The SVFS interrupts the continuity of the Eastern Southern Alps thrust fronts in the Veneto sector, suggesting that it played a passive role in controlling the geometry of the active thrust belt and possibly the current distribution of seismic release. As a whole, apart from moderate seismicity along the northern segment and few geological observations along the southern one, there is little evidence to constrain the recent activity of the SVFS. In this context, the SVFS, and specifically its SVF strand, has been referred to as a sinistral strike-slip boundary of the northeastern Adriatic indenter. The review of the historical and instrumental seismicity along the SVFS shows that it does not appear to have generated large earthquakes during the last few hundred years. The moderate seismicity point to a dextral strike-slip activity, which is also corroborated by the field analysis of antithetic Riedel structures of the fault cropping out along the northern segment. Conversely, the southern segment shows geological evidence of sinistral strike-slip activity. The geological and seismological apparently conflicting data can be reconciled considering the faulting style of the southern segment as driven by the indentation of the Adriatic plate, while the opposite style along the northern segment can be explained in a sinistral opening "zipper" model, where intersecting pairs of simultaneously active faults with different sense of shear merge into a single fault system via a zippered section.


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