Contents lists available at ScienceDirect Catena journal homepage: www.elsevier.com/locate/catena Coevolution of soil and topography across a semiarid cinder cone chronosequence Craig Rasmussen a,⁎ , Luke McGuire b , Prakash Dhakal a , Jon D. Pelletier b a Department of Soil, Water and Environmental Science, The University of Arizona, United States b Department of Geosciences, The University of Arizona, United States ARTICLE INFO Keywords: Soil Pedogenesis Landscape evolution Cinder cone Chronosequence Toposequence Dust ABSTRACT Soil evolution and the development of surface and subsurface diagnostic horizons affects hydrologic partitioning of precipitation to infiltration and runoff, and the vegetative carrying capacity of landscapes, all of which affect rates of hillslope erosion. Rates of erosion, in turn, feedback on soil development by removing or preserving soil horizons. This coevolution is difficult to investigate because landscape age and initial conditions are often poorly constrained. In this paper we investigated the coevolution of the soils and hillslope topography by exploiting differences in vegetation type and density as a function of slope aspect across a semiarid basaltic cinder cone chronosequence, spanning cone ages from 1.065 to 1000 kyr, in the San Francisco volcanic field (SFVF) of northern Arizona, USA. We document that soils on south-facing hillslopes exhibit systematically more aeolian- derived dust despite having higher rates of erosion. We attribute this to the fact that south-facing slopes likely had more dust-trapping vegetation cover during the glacial climates that dominated the Quaternary. The higher dust contents of soils on south-facing slopes was associated with formation of argillic horizons, lower saturated hydrologic conductivity and increased water holding capacity. Greater water retention, in turn, likely increased rates of erosion by bioturbation and freeze-thaw-driven creep in a positive feedback. Over time, dust accumulation at the hillslope point of inflection increased with age up to several hundred thousand years, then decreased with time as the cones degraded by erosion. Data suggest that approximately 200 kyr of time was required before the soils developed sufficient water-holding capacity to drive in situ weathering of the basalt cinders. These results further demonstrate the importance of feedbacks among soil development, hydrology, and geomorphology in the evolution of hillslopes. 1. Introduction 1.1. Problem statement and motivation Understanding the coupled processes and state factors that control the coevolution of soils and landscapes is central to quantifying Earth surface change and the development of soil-landscape structure. A key knowledge gap to understanding this process is the complex interaction among pedogenic and sediment transport processes that often co-vary in time and space, making them difficult to disentangle. Here we address this knowledge gap across a chronosequence of semiarid cinder cones in northern Arizona, USA that provide a unique opportunity and well constrained framework to examine these factors simultaneously in actively eroding landscapes. Landscape evolution in coupled hillslope-fluvial systems involves feedbacks among hydrology, soil development, and rates of erosion and deposition. The partitioning of precipitation into infiltration and runoff controls the relative importance of colluvial processes, which are driven in part by soil moisture, versus slope-wash/fluvial processes which are driven by runoff. The relative rates of colluvial and slope-wash/fluvial sediment transport, in turn, influences drainage density (Perron et al., 2008). Pelletier et al. (2013) exploited the elevation/climate gradient of the Santa Catalina Mountains of Arizona to investigate the relationships among vegetation cover, soil development, relief, and drainage density. These authors found that the thicker soils associated with higher elevations and/or more humid climates tend to increase colluvial transport rates and decrease drainage density. Numerical models that explicitly model grain-size variations in soils due to in situ weathering and/or size-selective transport or deposition predict strong feedbacks among soil development, hydrology, and geomorphic process rates (e.g., Heng et al., 2011; Vanwalleghem et al., 2013). Chronosequences provide a means for investigating how pedogenic, hydrologic, and geomorphic properties vary through time by using younger landscapes within the chronosequence as a proxy for how older http://dx.doi.org/10.1016/j.catena.2017.04.025 Received 18 August 2016; Received in revised form 27 January 2017; Accepted 26 April 2017 ⁎ Corresponding author. E-mail address: crasmuss@email.arizona.edu (C. Rasmussen). Catena 156 (2017) 338–352 Available online 05 May 2017 0341-8162/ © 2017 Elsevier B.V. All rights reserved. MARK