Late Tertiary Faults Research Articles

Faulting along the Southeastern Margin of the Reelfoot Rift in Northwestern Tennessee Revealed in Deep Seismic-reflection Profiles

Other| November 01, 2004 Faulting along the Southeastern Margin of the Reelfoot Rift in Northwestern Tennessee Revealed in Deep Seismic-reflection Profiles Shane Parrish; Shane Parrish Department of Earth Sciences University of Memphis Memphis, TN 38152 rvonrsdl@memphis.edu Search for other works by this author on: GSW Google Scholar Roy Van Arsdale Roy Van Arsdale Department of Earth Sciences University of Memphis Memphis, TN 38152 rvonrsdl@memphis.edu Search for other works by this author on: GSW Google Scholar Seismological Research Letters (2004) 75 (6): 784–793. https://doi.org/10.1785/gssrl.75.6.784 Article history first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Shane Parrish, Roy Van Arsdale; Faulting along the Southeastern Margin of the Reelfoot Rift in Northwestern Tennessee Revealed in Deep Seismic-reflection Profiles. Seismological Research Letters 2004;; 75 (6): 784–793. doi: https://doi.org/10.1785/gssrl.75.6.784 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentBy SocietySeismological Research Letters Search Advanced Search Abstract Approximately 320 km of deep seismic-reflection profiles in northwestern Tennessee reveal the structure of a major portion of the southeastern margin of the Reelfoot Rift. This rift margin consists of at least two major down-to-the-west late Precambrian to Cambrian normal faults. Maximum fault displacement at one location is 3 km. These two faults strike N50°E, in their northern portions; over their southern extent they trend N30°E however.Numerous faults in these reflection lines displace Paleozoic, Cretaceous, and Tertiary reflectors. The dominantly reverse faulting, folding, and positive flower structures in the shallower section indicate Eocene or younger transpression. We believe the late Tertiary faulting is due to reactivation of the basement faults, because on some of the reflection lines basement normal faults can be traced into Tertiary reverse faults, the Tertiary faults parallel the basement faults, and the Tertiary faults overlie or are adjacent to the basement faults. Numerous faults displace the highest (youngest) reflectors and therefore we do not know how recently faulting has occurred. Previous studies have identified Quaternary faulting within the southeastern Reelfoot Rift margin of western Tennessee, however. Thus, we believe all of the late Tertiary faults identified in this research should be evaluated for possible Quaternary movement. You do not currently have access to this article.

Late Tertiary faults and their paleostress along the boundary between the Kuqa Basin and the Tianshan Mountains

Field investigation shows that the boundary between the Kuqa Basin and the Tianshan Mountains can be divided into two sections with the Yanbulak area as the di-viding point. In the western section, the Mesozoic strata overlie unconformably on the Paleozoic rocks. The ba-sin-dipping faults developed in both Mesozoic and Paleozoic rocks. The eastern section is characterized by basin-dipping normal faults separating the Paleozoic strata and Tertiary. The brittle structural analysis was carried out along the ba-sin-range boundary. 360 measurements of striations have been obtained at a total of 25 sites. Paleostress reconstruction indicates that the basin-range boundary was in an exten-sional condition, with some superimposed strike-slip, during the Late Tertiary. The extension could be explained by the vertical block uplift of the Tianshan Mountains.

Late Tertiary faults and their paleostress along the boundary between the Kuqa Basin and the Tianshan Mountains

Late Tertiary faults and their paleostress along the boundary between the Kuqa Basin and the Tianshan Mountains

Structure and kinematics of oblique continental convergence in northern Fiordland, New Zealand

Southeast of the Alpine Fault in Fiordland, New Zealand, Late Tertiary faults envelope exposures of Early Cretaceous high- P (12–16 kbar) granulite facies orthogneisses. These exposures allowed us to examine how pre-Cenozoic structures influenced variations in the degree and style of kinematic partitioning within a zone of oblique continental convergence. Fault-slip data and kinematic modelling show that oblique-slip and reverse displacements preferentially were partitioned east of the Alpine Fault onto curved NE-striking surfaces and moderately dipping (30–52°), N- and NW-striking surfaces, respectively. Approximately 3.0–5.5 km of exhumation and 6.5–7.0 km of oblique-dextral displacement occurred on faults that display palm tree-style geometries and subhorizontal detachments in profile. This heterogeneous style contrasts with the near horizontal slip on subvertical surfaces that define the Alpine Fault north of Milford Sound. The principal axes of instantaneous strain we determined using faults are compatible with principal stress axes derived from earthquakes. Our data indicate that mechanical anisotropies created by inherited structures controlled the locations and highly variable geometries of faulting since 7–9 Ma. The effects of these pre-existing structures and a focusing of contractional deformation along the northeast margin of Fiordland resulted in an unusually high degree of strike-slip partitioning across the southernmost onshore segment of the Alpine Fault.

Late Tertiary fault activity in the southwestern boundary fault system of the Roer Valley Graben: evidences from the Bree area (NE Belgium)

AbstractThe Bree Uplift is a particular structure in the direct footwall of the southwestern graben boundary fault system of the Roer Valley Graben, which has been firstly recognized at the base of the Cretaceous. To date fault activity around the Bree Uplift has been confined to the Subhercynian (late Cretaceous) inversion event or considered fading out during Tertiary times.The revision of the existing geological data reveals that the Bree Uplift can still be recognized on the top-Tertiary map. This infers at least a late Tertiary activity, suggesting continuous fault activity in the graben boundary fault system not only on the major boundary faults but also on different splay faults, bounding individual fault blocks.

Late Tertiary faulting, footwall uplift and topography in western Ireland

Abstract The Erriff Fault in south Mayo, Ireland, is a rare example within the British Isles and Ireland of a sizeable onshore fault (normal displacement >500 m) at which a correlatable stratigraphic horizon is preserved in both the footwall and the hanging wall. That this displacement probably accumulated during Late Tertiary time makes the Erriff Fault (and other similar faults in the area) all the more interesting. Structural forward modelling indicates that footwall uplift and hanging-wall subsidence accompanying faulting, followed by further isostatic uplift following glacial erosion during the Pleistocene glaciations, exercised a fundamental control on the overall form of present-day topography in western Ireland.

Models for relative motion of crustal blocks within the Carpathian region, based on restorations of the outer Carpathian thrust sheets

Details of the Oligocene‐present‐day motion of the Adriatic block with respect to Europe can be determined by palinspastic restorations of the outer Carpathians thrust sheets. The arcuate nature of the Carpathians poses problems for simple restorations of sections because they create converging restoration paths which require large amounts of strike‐parallel extension (40–50%). Such large amounts of extension are not seen on maps or in the field. A combination of thrust transport directions changing with time between and within thrust sheets and divergent transport directions helps minimise the arc‐parallel extension necessary (18–25%). The Pannonian basin can be treated either as an area dominated by strike‐slip motion (rigid block movements) or as an area of back arc extension. The differences in restoration geometry produced by these two scenarios help to indicate which of the two mechanisms was dominant. The consequences of the rigid block restoration indicate the model is inappropriate because it requires approximately 20° clockwise rotation of the Adriatic block during the late Tertiary. It also indicates at least 300 km strike‐slip motion distributed among the late Tertiary faults of the Dinaride‐Balkanide and Hellenide Mountain belts. The back arc extension model alleviates the the 20° clockwise rotation of the Adriatic block and requires about 200 km distributed strike‐slip motion in Yugoslavia and Bulgaria.

Neogene tectonics and volcanicity in the North Tanzania sector of the Gregory Rift Valley: contrasts with the Kenya sector

The Neogene tectonics and volcanism in the rift area of northern Tanzania are intimately related. A major phase of late Tertiary faulting, giving rise to a broad tectonic depression, was followed by extrusion of large amounts of basaltic to trachyte magmas from large shield volcanoes. This was separated by a second major phase of faulting at about 1.2 Ma from a Late Pleistocene-Recent phase of small volume, explosive nephelinite-phonolite-carbonatite volcanism that contrasts with the earlier phase in its volume, dominant magma type and eruptive style. In both its tectonic expression and contemporaneous magmatism, the northern Tanzania province contrasts with the southern Kenya sector of the Rift Valley. The area of tectonic disturbance is considerably broader in Tanzania where ultrabasic-basic magmatism predominates. The major episodes of basaltic magmatism. representing major thermal perturbations of the mantle, have moved southwards down the rift since the mid Tertiary.

Quaternary faulting in Trans-Pecos Texas

Faults that displace Quaternary units can be observed in scarps in Trans-Pecos Texas and are restricted to two north-trending zones in contrast to late Tertiary faults that cover the region and strike north, northwest, and west. The western zone of Quaternary faults, near El Paso, is usually included as the southern part of the Rio Grande rift. The eastern zone of Quaternary faults extends for 300 km from southern New Mexico along the Salt Basin graben through Van Horn, Texas; its probable extensions and subparallel associates extend southward to Presidio, Texas. This belt of faults is parallel to the Rio Grande rift zone and should be considered a southeast extension of that zone. These fault zones die out southward into the edge of the Chihuahua tectonic belt, a region underlain by a thick Mesozoic carbonate and clastic section that in turn rests on a thick layer of evaporites. The evaporite zone may mask Cenozoic normal faulting and thus may define a zone of no data rather than a southern limit of basin-and-range or Rio Grande graben tectonics. All Quaternary and most Tertiary faults trend parallel to pre-existing structures. The map pattern of Quaternary scarps suggest a maximum extension oriented about S80°W; however, first-motion studies of the 1931 Valentine, Texas earthquake show a maximum elongation direction of S50° to 55° W. This difference may be unique to this one earthquake or may be due to the pre-existing lines of weakness that control the location of presently active faults.

Resurgent Volcano-Tectonic Depression of Oligocene Age, South-Central New Mexico

The Goodsight-Cedar Hills volcano-tectonic depression in south-central New Mexico formed concurrently with and following deposition of about 550 km 3 of Oligocene volcanic and volcaniclastic rocks. The depression is an asymmetric basin about 80 km long and 38 km wide. It is filled to a maximum depth of about 550 m by early rhyolitic ash-flow tuff, medial epiclastic strata derived partly from marginal raised rims (Bell Top Formation), and late basaltic andesite (Uvas Basalt). Much of the 295 km 3 of effusive rock was erupted from vents located near the center of the depression and from a major subsidence fracture zone along the eastern margin. Subsidence of the depression floor was noncatastrophic and approximately kept pace with basin filling, except along the eastern margin. Following eruption and broad, regional subsidence of the Uvas Basalt, the central floor of the depression was arched upward to form the Sierra de las Uvas dome and adjacent synclinal moat. The fault pattern of the dome and its association with known vents and the thickest part of the volcanic pile suggest that it formed by vertical movement of magma from an underlying chamber. Its development, following subsidence of the Uvas Basalt, suggests that it is essentially resurgent in origin. Although no postdoming volcanism is known, indirect evidence indicates that intrusion of silicic magma probably caused resurgence. It is clear that the Goodsight-Cedar Hills depression is not a resurgent cauldron of the classic Valles or Toba types. Rather, it appears to be a structure transitional in character between a cauldron and a fault trough. Subsidence apparently followed volcanism. Resurgence followed eruption of basaltic andesite rather than the usual ash-flow sequence, and the 10- to 12-m.y. history of the Goodsight-Cedar Hills depression is 5 to 6 times as long as other well-known resurgent cauldron cycles. Locally, deposition in the depression continued without interruption into early late Tertiary time, when extensional faulting occurred. The depression is elongated parallel to the late Tertiary Rio Grande Rift and may be a precursor of Basin and Range structure in the area. The late Tertiary fault pattern in the area indicates that earlier volcano-tectonic structures had important effects on the pattern of late Tertiary Basin and Range structures. Locally, late Tertiary faults were inherited from and duplicate the position of earlier subsidence faults or the synclinal moat. Elsewhere, the north-trending regional fault pattern was considerably modified by structural and litho-logic inhomogeneities of volcano-tectonic origin, particularly the Sierra de las Uvas dome and its buried intrusive masses.

Low-Angle Gravity Glide Structures in the Northern Virgin Mountains, Nevada and Arizona

The Northern Virgin Mountains of northwestern Arizona and adjacent Nevada are an arc-shaped anticlinal uplift that contains marine Paleozoic shelf sedimentary rocks flanking a central core of Precambrian metamorphic rocks. Mesozoic and Tertiary rocks, including Upper Cretaceous beds previously unknown in northwestern Arizona, are present in downfaulted blocks around the edges of the range. Except for marine Lower Triassic beds and Tertiary lacustrine limestones, they consist largely of clastics of continental origin. Tertiary and Laramide uplift in the Virgin Range resulted in gravitative adjustments that took the form of major glide plates. Gravity structures of different styles originated from each of three major uplifts. The oldest uplift, the asymmetric Virgin Mountain Anticline, formed during the Laramide orogenic interval by draping of the sedimentary cover over a basement horst that shows evidence of recurrent activity from Precambrian through Recent time. The northeast-trending anticline produced a structural and topographical high from which the Paleozoic cover slid, by gravity, south-eastward down a slope formed by bedding. By moving across successively younger beds of the southeastern limb, older rocks in the upper plate came to rest on younger. Compression generated during movement created tight folds in the overridden strata and within the glide plate itself. Most important of these is an overturned syncline beneath the glide plate that extends for a distance of 12 mi parallel to the axis of the Virgin Mountain Anticline. Two younger uplifts were formed by the Virgin Mountain fault system on the west border of the range and by the State Line fault on the east border. The strikes of both faults apparently were partly controlled by the structural grain of the basement; the faults collectively produced the late Tertiary uplift of the Virgin Mountain Anticline as a wedge-shaped horst. Along the State Line fault, uplift and westward tilting created a structural high from which a 25-sq-mi plate of sedimentary cover became detached and moved westward down a slope, subparallel to bedding, thereby truncating all older structures in both upper and lower plates. A horst uplifted on two large faults belonging to the Virgin Mountain fault system formed the third structural high in the Virgin Range. Six glide plates, apparently originating from this high, moved westward on bowl- and scoop-shaped faults across steeply dipping strata of the northwestern limb of the Virgin Mountain Anticline. The glide plates both truncate and are cut by faults associated with the frontal Virgin Mountain fault, which suggests that sliding was concurrent with and in response to movements on them. The main distinction between the Laramide and late Tertiary gliding is the nature of the causal uplift and degree to which older rocks were emplaced above younger ones. Gliding from the crest of the Virgin Mountain Anticline under considerable cover resulted in plastic flow, which allowed tight drag folding, the formation of a sharp glide surface, and the emplacement of older rocks above younger ones. Shallower gliding from late Tertiary fault blocks permitted brecciation, minor folding, and resulted mainly in the movement of younger rocks to positions above older ones.

Stages and epochs of mineralization in the San Juan Mountains, Colorado, as shown at the Dunmore Mine, Ouray County, Colorado

The Dunmore lode is localized along a persistent fissure zone over two miles long and averaging nearly 100 feet in width along the length of the Dunmore claim. The fault in which the lode is located offset the pre-Cambrian quartzite and slate walls about 4,500 feet prior to deposition of the overlying thick San Juan tuff. Late Tertiary faulting extended the fissure into the San Juan tuff, dropping the south side about 80 feet. Although most of the lode crops out in the pre-Cambrian rocks, it extends upward across the profound unconformity into the tuff. The lode is complex, containing sharply marked fissure veins, sheared slate dragged into the fault zone, a sheared dike, breccia chimneys, and pebble dikes. An assemblage consisting of quartz, sericite, kaolin, and pyrite appears to be of early Tertiary age. The more productive part of the lode, however, is late Tertiary and consists of a hematite chimney inclosing a copper shoot, a tungsten chimney, and compound base-metal fissure veins. These chimneys and veins are mostly localized along early Tertiary structures, but their mineral sequences correlate them with the second stage of late Tertiary deposition recognized by Burbank in the adjoining Red Mountain and other districts. The Dunmore lode, however, is believed to have been deposited at greater depth and higher temperature and nearer to a source of supply than the lodes of these districts. In structure as well as mineral assemblages the Dunmore lode shows a connection between the chimneys and veins of the region.