HOLOCENE ALLUVIAL STRATIGRAPHY OF KITCHEN CORRAL WASH, SOUTHERN UTAH by William M. Huff1 and Tammy R. Rittenour1,2 ABSTRACT Kitchen Corral Wash (KCW), a tributary of the Paria River in southern Utah, has experienced episodes of historic and pre-historic (Holocene) arroyo cutting and filling. During the most recent arroyo-cutting event (about A.D. 1880–1920), KCW and other regional drainages were entrenched 5–30 meters into their fine-grained alluvial valley fills. While previous studies have attempted to constrain the timing of arroyo cut-fill events in KCW, poor age control has limited the results. In order to better understand the timing of arroyo cutting events, this study updates and improves the arroyo cut-fill chronostratigraphy from KCW by using alluvial stratigraphic descriptions and age control from optically stimulated luminescence and accelerator mass spectrometry radiocarbon dating. Results are based on 11 study sites, each exposing a number of unconformity-bounded alluvial packages in the arroyo-wall stratigraphy, and suggest at least six arroyo cut-fill episodes over the last approximately 7000 years. From oldest to youngest, the six episodes of alluvial fill aggradation are: an older fill from Hereford (2002), Qf1, Qf2, Qf3, Qf4, and Qf5. Although not discussed here, these chronostratigraphic results were used by Huff (2013) to test hypotheses related to climatic forcing of arroyo dynamics by comparing the chronology from KCW to regional alluvial chro- nologies and paleoclimate records. INTRODUCTION has experienced multiple periods of prehistoric arroyo en- trenchment and channel aggradation. The purpose of this Arroyos are an end-member geomorphic state of semi- study is to construct a detailed chronostratigraphy of KCW arid catchments with high sediment yields and are char- by expanding and updating the alluvial chronologies de- acterized by steep-walled channels entrenched into fine- veloped by Hereford (2002) and Harvey and others (2011). grained valley-fill alluvium (e.g. Bryan, 1925; Bull, 1997). This is achieved by combining detailed sedimentologic de- Historic observations suggest initiation of arroyo cutting scriptions and stratigraphic relationships at 11 study sites, from approximately A.D. 1880–1920 was accomplished by where buttress unconformities separate alluvial fills, with frequent, large-magnitude flood events (e.g. Bryan, 1925; age control derived from accelerator mass spectrometry Hack, 1942; Webb and others, 1991; Hereford, 2002). Ear- (AMS) radiocarbon dating of charcoal and optically stimu- ly hypotheses for the cause of this historic arroyo cutting lated luminescence (OSL) dating of quartz sand. include land mismanagement and overgrazing following pioneer settlement (Bailey, 1935; Thornthwaite and others, Background 1942; Antevs, 1952; Patton and Boison, 1986). However, evidence for prehistoric cut-fill events exposed in arroyo KCW is a tributary of the Paria River located in Kane walls suggests non-human related causes. Current hypoth- County, Utah, approximately 45 kilometers east of the town eses for prehistoric arroyo-cutting have been centered on of Kanab. It is the main trunk stream of a drainage that as- autogenic geomorphic adjustments (Schumm and Hadley, sumes several names from its headwaters to its confluence 1957; Patton and Schumm, 1981; Patton and Boison, 1986; with the Paria River (e.g. Park Wash, Deer Springs Wash, Tucker and others, 2006) and climate change to wetter or Kitchen Corral Wash, Kaibab Gulch, and Buckskin Gulch). drier conditions (Antevs, 1952; Karlstrom, 1988; Hereford, However, for the purpose of this study the name KCW will 2002; Mann and Meltzer, 2007). be used for the Park Wash (PW) and Deer Spring Wash This study examines the Holocene alluvial stratig- (DSW) reaches from the base of the White Cliffs and the raphy of Kitchen Corral Wash (KCW), a tributary of the main KCW alluvial valley that extends from the base of Paria River in southern Utah. Currently, KCW is in an the Vermillion Cliffs to the intersection with Kaibab Gulch incised state, and stratigraphic evidence indicates that it at U.S. Highway no. 89 (figure 1). From its headwaters in 1Utah State University Department of Geology, Logan, UT; [email protected] Huff, W.M., and Rittenour, T.R., 2014, Holocene alluvial stratigraphy of Kitchen Cor- 2USU Luminescence Laboratory, Logan, UT; [email protected] ral Wash, southern Utah, in MacLean, J.S., Biek, R.F., and Huntoon, J.E., edi- tors, Geology of Utah’s Far South: Utah Geological Association Publication 43, p. 77–96. Paunsaugunt Plateau UT Pink Clis 112°30'0"W 112°0'0"W 111°30'0"W Gray Clis Upper Escalante River 37°30'0"N 37°30'0"N Paria River Park Wash Deer Springs Wash White Clis KCW A B Huff, W.M., Rittenour, T.R. Rittenour, Huff, W.M., D C G F Highway-89 E Park Wash Wash Johnson 37°0'0"N 0 5 10 20 East Kaibab Monocline Lake Powell KCW Kilometers 37°0'0"N Vermillion Clis VCKCW Creek Kanab 112°30'0"W 112°0'0"W 111°30'0"W H KCW1 I Study Site J Legend Locations KCW2 Elevation (m) Hereford (2002) K High : 2869 study sites 0 2.5 5 7.5 10 Kilometers KCW study area Kaibab Gulch at Highway-89 ¹ Low : 1611 Figure 1. Location map of KCW and surrounding drainages in southern Utah. the Paunsaugunt Plateau to the head of Kaibab Gulch, the The drainages continue through resistant Dakota Formation total drainage area of KCW is 511 square kilometers and sandstone at the base of the Gray Cliffs until transitioning ranges in elevation from about 2500 meters to just below into Late and Middle Jurassic Entrada Sandstone and Car- 1800 meters above sea level. KCW flows approximately mel Formation sediments. Below these two sedimentary north to south and occupies a continuous arroyo that is en- units, the White Cliffs of the Jurassic Navajo Sandstone trenched approximately 2–12 meters within its fine-grained are characterized by high-angle eolian crossbedding and alluvial valley fill. The total reach-length of the study area are primarily composed of white to tan-colored fine- and (combining PW, DSW, and KCW) is about 28 kilometers. medium-grained sand (Doelling and others, 2000). Exiting KCW heads in Tertiary (upper Paleocene to mid- the White Cliffs, the drainage headwaters converge into HOLOCENE ALLUVIAL STRATIGRAPHY OF KITCHEN CORRAL WASH, SOUTHERN UTAH – SOUTHERN UTAH WASH, OF KITCHEN CORRAL STRATIGRAPHY ALLUVIAL HOLOCENE dle Eocene) Claron Formation sandstones, siltstones, and PW and DSW and incise through Jurassic Kayenta For- mudstone of the Paunsaugunt Plateau (figure 2). The Clar- mation and the upper Vermillion Cliffs. The confluence of on Formation forms the Pink Cliffs that are exposed as the PW and DSW form the main channel of KCW, which exits uppermost unit of the Grand Staircase physiographic prov- through the Moenave Formation at the base of the Vermil- ince of the Colorado Plateau. From here the drainages con- lion Cliffs and then crosses Triassic Chinle and Moenkopi tinue incising through Cretaceous Kaiparowits Formation, Formations. The Chinle Formation is primarily composed Wahweap Formation, and Straight Cliffs Formation sedi- of interbedded mudstones, sandstone, and conglomerates ments as the lower Pink Cliffs change to the upper Gray and also contains fossilized wood of the Petrified Forest Cliffs. The Kaiparowits Formation lies unconformably be- Member. Finally, after exiting the disconformity-bounded neath the Claron Formation and is composed of subarkose Moenkopi Formation, KCW is renamed Buckskin Gulch as sandstone. The interbedded mudstone to sandstone of the it narrows and becomes entrenched within Permian lime- Wahweap Formation overlies the Straight Cliffs Formation, stones and sandstones of the Kaibab Formation. which is made of cliff-forming sandstones, slope-forming The modern channel of KCW in the study area is typi- mudstones, and coal interbeds (Doelling and others, 2000). fied by steep, arroyo walls ranging from 12 to <5 meters in 78 UGA Publication 43 (2014)—Geology of Utah's Far South B 2500 A Tc (Claron Fm) ~10 m Kk, Kw (Kaiparowits Fm, Wawheap Fm) 2400 Knickpoint 1 in Park Wash 2300 Ks Pink Clis (Straight 2200 Clis Fm) 6 m ~7 m Gray Clis HOLOCENE ALLUVIAL STRATIGRAPHY OF KITCHEN CORRAL WASH, SOUTHERN UTAH – SOUTHERN UTAH WASH, OF KITCHEN CORRAL STRATIGRAPHY ALLUVIAL HOLOCENE ) m 2100 Knickpoint 2 in Park Wash Knickpoint 3 in KCW ( Kt n (Tropic Shale) o ti a v e l (A-A’) Headwaters of Park Wash E 2000 (Dakota and Cedar to Intersection at Kaibab Gulch Kd Mountain Fm) (B-B’) Headwaters of Deer Springs Wash Je (Entrada Ss) to conuence with main KCW channel 1900 White Clis Jc (Carmel-Pages Fm) Knickpoint 1 Knickpoint 2 Vermillion Clis 1800 Study Area Knickpoint 3 KCW-B KCW-D KCW-A KCW-F Jn (Navajo Ss) KCW-G 1700 KCW-C KCW-H KCW-E KCW-I B’ KCW-J (Moenave Fm) TR (Chinle Fm) KCW-K Jk (Kayenta Fm) c Jmo TRm (Moenkopi Fm) A’ 1600 P (Kaibab Fm) 0 10 20 30 40 50 ~50x V.E. Distance (km) Figure 2. Longitudinal profile of KCW from the headwaters of Park Wash to the intersection of Kaibab Gulch (A-A') and from the head- waters of Deer Springs Wash to the confluence with the main KCW trunk stream (B-B'). Three bedrock knickpoints in Park Wash and KCW range from 6–10 meters in height. height, which were produced by the most recent arroyo cut- crosses KCW near the channel head of DSW. The East Kai- ting event between A.D. 1880 and 1920 (Hereford, 2002). bab monocline, expressed as the Cockscomb near KCW, The active channel is 20–100 meters wide and is inset into is a prominent, northeast-trending feature that is locally Huff, W.M., Rittenour, T.R. Rittenour, Huff, W.M., Holocene alluvium that lies within a broad (>1 kilometers faulted.