Stream Response to Repeated Coseismic Folding, Tiptonville Dome, New Madrid Seismic Zone
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Geomorphology 43 (2002) 313–349 www.elsevier.com/locate/geomorph Stream response to repeated coseismic folding, Tiptonville dome, New Madrid seismic zone M.J. Guccione a,*, K. Mueller b, J. Champion b, S. Shepherd a, S.D. Carlson a, B. Odhiambo c, A. Tate b aDepartment of Geosciences, University of Arkansas, Fayetteville, AR 72701, USA bDepartment of Geological Sciences, University of Colorado, Boulder, CO 80309-0399, USA cEnvironmental Dynamics Program, University of Arkansas, Fayetteville, AR 72701, USA Received 12 January 2001; received in revised form 9 July 2001; accepted 16 August 2001 Abstract Fluvial response to tectonic deformation is dependent on the amount and style of surface deformation and the relative size of the stream. Active folding in the New Madrid seismic zone (NMSZ) forms the Tiptonville dome, a 15-km long and 5-km wide surface fold with up to 11 m of late Holocene structural relief. The fold is crossed by streams of varying size, from the Mississippi River to small flood-plain streams. Fluvial response of these streams to repeated coseismic folding has only been preserved for the past 2.3 ka, since the Tiptonville meander of the Mississippi River migrated across the area forming the present flood plain. This surface comprises a sandy point-bar deposit locally overlain by clayey overbank and silty sand crevasse-splay deposits, an abandoned chute channel infilled with laminated sandy silt and silty clay, and an abandoned neck cutoff filled with a sandy cutoff bar and silty clay oxbow lake deposits. Dating various stream responses to coseismic folding has more tightly constrained the timing of earthquake events in the central NMSZ and provides a means of partitioning the deformation amount into individual seismic events. Three earthquakes have been dated in the Reelfoot Lake area, ca. A.D. 900, 1470, and 1812. The latter two earthquakes had large local coseismic deformation. Both of these events were responsible for numerous stream responses such as shifting depocenters, modification of Mississippi River channel geometry, and derangement of small streams. Overbank sedimentation ceased on the dome as it was uplifted above the normal flood stage, and sedimentation of crevasse-splay deposits from the Mississippi River, colluvium from the scarp, and lacustrine sediment accumulated in the adjacent Reelfoot basin. The much larger Mississippi River channel responded to uplift by increasing its sinuosity across the uplift relative to both upstream and downstream, increasing its width/depth ratio across and downstream of the uplift, and decreasing the width/depth ratio upstream of the uplift. Despite the size of the Mississippi River, it has not yet attained equilibrium since the latest uplift 190 years ago. Small channels that could not downcut through the uplift were filled, locally reversed flow direction, or formed a lake where they were dammed. Uplift and stream response to folding along the Tiptonville dome is less dramatic between 2.3 and 0.53 ka. During this interval, abandoned channel fill and overbank deposition across the dome suggests that it was not a high-relief feature. One earthquake event occurred during this interval (ca. A.D. 900), but coseismic stream response was probably limited to a slight aggradation of a small flood-plain stream. D 2002 Elsevier Science B.V. All rights reserved. Keywords: Mississippi River; New Madrid seismic zone; Stream response; Folding * Corresponding author. E-mail address: [email protected] (M.J. Guccione). 0169-555X/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved. PII: S 0169-555X(01)00145-3 314 M.J. Guccione et al. / Geomorphology 43 (2002) 313–349 1. Introduction forms a single meander belt along the eastern valley margin in the NMSZ (Saucier, 1994; Guccione et al., Active faults and folds cut by stream valleys pro- 1999). vide an opportunity to examine the response of streams Deformation in the NMSZ during the Holocene and to earthquakes (Yielding et al., 1981; Philip and perhaps late Pleistocene formed a positive topographic Meghraoui, 1983; Philip et al., 1992) and date defor- feature, termed the Tiptonville dome of the Lake mation events. Stream response in seismically active County uplift (e.g., Russ, 1982; Schweig and Van areas is controlled by the amount and style of fault Arsdale, 1995; Mueller et al., 1999; Van Arsdale, surface rupture and folding, the style and scale of the 2000) (Figs. 1 and 2). The dome is the surface expres- drainage networks, and in some cases, other extrinsic sion of a fold formed at a compressive stepover in the factors such as climate change and geology. Intraplate dominantly strike–slip system of the NMSZ. Tipton- tectonic activity may be at a smaller scale than at plate ville dome was interpreted by Mueller et al. (1999) to margins, and therefore, stream response is commonly be a fault-bend fold formed in response to slip on the less dramatic (e.g., Burnett and Schumm, 1983; Mer- blind Reelfoot thrust fault. Alternatively, the dome has ritts and Hesterberg, 1994; Holbrook and Schumm, been interpreted as a fault-propagation fold where 1999; Guccione et al., 2000; Marple and Talwani, deformation in the hanging wall has been accommo- 2000) than along plate margins (e.g., Mulder and dated by shear above the west-dipping Reelfoot re- Burbank, 1993; Olsen and Larsen, 1993; Audemard, verse fault (Purser and Van Arsdale, 1998; Champion 1999; Friend et al., 1999; Snyder et al., 2000). et al., 2001) (Fig. 2). Although there are some large-scale fluvial responses The recurrence interval of great earthquakes in the to intraplate doming such as the incision of the Colo- NMSZ, approximately 300–600 years during the last rado River into the Colorado Plateau to form the Grand 1200 years (Tuttle et al., 1999b), is less than that of Canyon (Patton et al., 1991) and intraplate subsidence channel migration and flood plain renewal within the such as the position of the lower Mississippi River Mississippi River meander belt. Thus, the river has alluvial valley within the Mississippi Embayment responded to multiple seismic events during the late (Fisk, 1944; Autin et al., 1991; Saucier, 1994; Cox Holocene, and these responses are preserved in both and Van Arsdale, 1997), most intraplate tectonic the depositional record and the geomorphology of the deformation occurs at relatively small spatial scales. area. Vertical accretion on uplifted parts of flood plains The New Madrid seismic zone (NMSZ) is unique in is thin or absent and finer grained compared to the that it is an active seismic zone in an intraplate setting accumulation of relatively thicker and coarser grained developed across the alluvial valley of the third largest overbank sediment in downwarped areas (Ouchi, river in the world. The general character of the Mis- 1985). Channel width, depth, and pattern can respond sissippi Alluvial Valley, including its location and to the new gradients created by deformation (Burnett aggradation of deltaic and alluvial sediment through and Schumm, 1983; Jorgensen, 1990; Schumm and the Tertiary and Quaternary, is controlled by a failed Galay, 1994), but the size of the Mississippi River rift [initiated in the early Paleozoic (Hildebrand and precludes drainage derangement given the relatively Hendricks, 1995)] or passage of the Mississippi graben small amount of surface deformation from individual system over a hotspot (Cox and Van Arsdale, 1997). earthquakes in the seismic zone. Small streams also Evidence for recurrent faulting in the NMSZ is defined respond to the individual earthquake events and record by the growth strata across the Reelfoot scarp during their effects with changes in gradient that the stream is episodes in the late Cretaceous, early Tertiary, and late incapable of modifying during the interval between Quaternary (Van Arsdale, 2000). During the late Pleis- earthquakes. As in the case of the larger Mississippi tocene, thick widespread deposits of braided-stream River, longitudinal profiles along small streams may sand were deposited by glacial meltwater across the deviate from the estimated natural profiles for hundreds broad alluvial valley and the channel position moved of years in this setting (Merritts and Hesterberg, 1994). eastward (Van Arsdale et al., 1995b; Blum et al., Unlike the Mississippi River, small channels may fill 2000). In contrast, during the Holocene, the river has where the gradient is reduced, and channel patterns been a single-channel meandering stream. It currently may become deranged (e.g., Matmon et al., 1999). M.J. Guccione et al. / Geomorphology 43 (2002) 313–349 315 Fig. 1. Location map of geomorphic and structural features in the New Madrid seismic zone (NMSZ). Filled circles are the locations of historic earthquakes and dates of occurrence (modified from Rhea and Wheeler, 1995). Square is the outline of study area shown in Fig. 3. MO— Missouri; AR—Arkansas; KY—Kentucky; TN—Tennessee. Modified from Guccione et al. (2000). The purpose of this paper is threefold: first, to Reelfoot Lake area; second, to further constrain the determine the style and amount of response of small- style and timing of surface folding produced by these and large-scale rivers to well-dated earthquakes in the earthquakes; and third, to partition the amount of 316 M.J. Guccione et al. / Geomorphology 43 (2002) 313–349 Fig. 2. Topographic profile (upper) and cross-section (lower) of Tiptonville dome, oriented east–west through CT-2 boring transect shown in Fig. 3. Seismicity from Mueller and Pujol (in press) shown as white circles on cross-section, details of strata folded across Reelfoot monocline shown as insert from Champion et al. (2001). Area of insert (with no vertical exaggeration) is shown as small rectangle at uppermost fault tip, above 800-m depth on cross-section. Fault geometry is from Champion et al. (2001) and Mueller and Pujol (in press). deformation produced by individual events.