scholarly journals Seismic-reflection profiles of the New Madrid seismic zone-data along the Mississippi River near Caruthersville, Missouri

1986 ◽  
Keyword(s):  
Mississippi River ◽  
Seismic Reflection ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Seismic Reflection Profiles ◽  
New Madrid

Structure of the Blytheville Arch in the New Madrid Seismic Zone

1988 ◽  
Vol 59 (4) ◽  
pp. 117-121 ◽  
Author(s):  
R.M. Hamilton ◽  
F.A. McKeown
Keyword(s):  
Seismic Hazard Assessment ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Middle Cambrian ◽  
Seismic Reflection Profiles ◽  
Paleozoic Rocks ◽  
Drill Holes ◽  
The Relationship ◽  
Strike Slip Movement ◽  
New Madrid

Abstract Seismic-reflection profiles across part of the New Madrid seismic zone in northeastern Arkansas and southeastern Missouri show a faulted and structurally complex zone, originally known as Charlie’s ridge but herein renamed Blytheville arch, which is about 10 to 15 km wide and about 110 km long. Several exploratory drill holes in the arch penetrate Upper and possibly Middle Cambrian formations directly below Cretaceous rocks, whereas drill holes off the arch penetrate the Cambrian and Ordovician Knox and Arbuckle Groups equivalents and possibly younger Paleozoic rocks below the Cretaceous; therefore, the pre-Cretaceous rocks in the arch are structurally high. Most earthquakes in the northeast-trending segment of the New Madrid seismic zone along the axis of the Reelfoot rift occur along the arch. Focal mechanisms of earthquakes in the trend show right-lateral, strike-slip movement. Epicenters in the northeastern part of the seismic trend between Caruthersville, MO, and Blytheville, AR, are spatially less dispersed than those to the southwest between Blytheville and Marked Tree, AR. Most of the hypocenters to the northeast cluster between 6 to 12 km deep, whereas those to the southwest range from near the surface to about 15 km deep. Earthquakes in the northeast part of the seismic trend are concentrated along a fault zone under the arch, whereas those to the southwest are more dispersed under the arch. A seismic trend that extends south-southwest from near Charleston, MO, projects to the northwest side of the ridge near Blytheville, where the seismicity changes character and the southeast boundary of the arch trends more easterly. The relationship between the structural boundaries of the arch and the seismicity may establish the extent of part of New Madrid seismicity and improve the basis for seismic hazard assessment.

Mini-Sosie High Resolution Seismic Reflection Profiles Along the Bootheel Lineament in the New Madrid Seismic Zone

1992 ◽  
Vol 63 (3) ◽  
pp. 297-307 ◽  
Author(s):  
John L. Sexton ◽  
Harvey Henson ◽  
Paul Dial ◽  
K. Shedlock
Keyword(s):  
High Resolution ◽  
Seismic Reflection ◽  
Aerial Photographs ◽  
Source Zone ◽  
Small Scale ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Geological Structures ◽  
Linear Features ◽  
New Madrid

Abstract Results of geological and geophysical research conducted in the New Madrid seismic zone since the early 1970’s indicate that much of the seismicity of the area is associated with late Precambrian age rift-related geological structures that have been reactivated by contemporary stresses. Deep seismic reflection surveys have been used to detect and delineate deeply buried geological structures thought to be associated with the seismicity. Satellite imagery and aerial photographs have recently been used to detect a linear feature named the Bootheel lineament inferred to be the surface expression of one of the faults responsible for the 1811–1812 earthquakes. To assess the seismogenic potential of these deep structures and linear features, high resolution seismic reflection and geomorphic studies are required. In July and August, 1990, Mini-Sosie high resolution reflection surveys were conducted in the New Madrid seismic zone. A total of 23 line-kilometers of high resolution reflection data were collected at nine locations. Specific targets for the new surveys include several locations on the Bootheel lineament in the New Madrid area, its northern projection near Sikeston, Missouri, and its southern projection near Blytheville, Arkansas at locations related to the Blytheville arch. A location several kilometers south of Charleston, Missouri, was also selected. Data presented in this paper consist of 7 line-kilometers recorded at locations on or close to the Bootheel lineament near New Madrid, Missouri, Hayti, Missouri, and Blytheville, Arkansas. Numerous small-offset faults, channels and other structures in Tertiary, Cretaceous and Paleozoic age rocks have been interpreted from the Mini-Sosie seismic sections. These structures, although generally not major features themselves, may be associated with deep seated rift-related reactivated structures. Many of the small-offset faults appear to deform or offset Quaternary age sediments. The spatial correlation of the observed faulting with sandblows and lineaments identified from aerial photographs, suggests the possibility that the observed faulting, sandblows, and linear features may be genetically related. If this is the case, then, because the origin of the sandblows has generally been attributed to the 1811–1812 seismic activity, the observed faulting may have been active at that time. It is not possible to directly link a single correlatable seismic signature with the Bootheel lineament, and thus we cannot state unequivocally that the lineament is continuous from Blytheville, Arkansas to New Madrid, Missouri. However, each seismic line has imaged similar small-offset faulting and gentle folding. If the faults and deformation observed are directly caused by reactivated deep structures associated with the Bootheel lineament, then, due to its great length, the total of which is yet undefined, this structure may be a source zone for major earthquakes, and therefore requires further investigations. The possibility exists, however, that the small scale faulting and deformation are ubiquitous throughout the New Madrid seismic zone. Additional high resolution seismic data are required to resolve this question.

Variable post-Paleozoic deformation detected by seismic reflection profiling across the northwestern “prong” of New Madrid seismic zone

2003 ◽  
Vol 368 (1-4) ◽  
pp. 171-191 ◽  
Author(s):  
J.H. McBride ◽  
A.J.M. Pugin ◽  
W.J. Nelson ◽  
T.H. Larson ◽  
S.L. Sargent ◽  
...  
Keyword(s):  
Seismic Reflection ◽  
New Madrid Seismic Zone ◽  
Seismic Zone ◽  
Seismic Reflection Profiling ◽  
New Madrid
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