Tectonics from fluvial topography using formal linear inversion: Theory and applications to the Inyo Mountains, California

Abstract

Key Points:• Analytic solution to the stream power model yields a linear inverse problem • A time-space record of uplift rate is inferred from fluvial profiles • Acceleration of relative uplift is inferred for the Inyo range, California, since 2-3Ma Abstract Tectonic activity generates topography, and the variability of tectonic forcing is responsible for topographic patterns and variability of relief in fluvial landscapes. Despite this basic relation, the inverse problem, by which features of the topography are used for inferring tectonic uplift rates, has proven challenging. Here we develop formal linear inversion schemes to infer a record of the rate of relative uplift as a function of space and time from the long profiles of rivers. The relative uplift rate is the difference between the rates of rock uplift and of the base level change. The inversion schemes are based on a closed-form analytic solution to the transient linear stream power model, and to increase model resolution they make use of the multiplicity of information made available by multiple rivers and their tributaries. The distribution of the fluvial response time to tectonic perturbations is a key component of the inversion scheme, as this determines which tectonic events are preserved in the topography. We develop two inversion parameterizations that differ in their assumptions about the tectonic forcing: space-invariant and time-space variability with an assumed spatial distribution. The inversion schemes are applied to the Inyo Mountains, an uplifted block along the western boundary of the Basin and Range Province in California.Inversion results indicate that the range has been experiencing an acceleration of the relative uplift in the past ∼2-3 Ma. We use the inversion results to constrain the paleotopography and paleo-erosion rate along the range and to recover the throw rate history along the fault that bounds the Inyo range.

Tectonic geomorphology at small catchment sizes – extensions of the stream-power approach and the <i>χ</i> method

“…The solutions of this equation and their potential for unraveling the uplift and erosion history have been discussed by Royden and Perron (2013), and a formal inversion procedure for the linear case (n = 1) has been presented by Goren et al (2014). The most striking property of the χ transformation is immediately recognized in Eq.…”

River profile response to normal fault growth and linkage: an example from the Hellenic forearc of south-central Crete, Greece

“…Transient landscapes, those landscapes in the process of adjusting to newly imposed boundary conditions, provide the opportunity to interrogate topography for information regarding the timing and magnitude of landscape adjustment to external forcing. As such, studies of transient landscapes have received considerable attention over the past 15 years and serve as a cornerstone of modern tectonic geomorphological studies Whipple, 2001, 2012;Wobus et al, 2006;Pritchard et al, 2009;Perron and Royden, 2013;Royden and Perron, 2013;Gallen et al, 2013;Goren et al, 2014). Most studies that seek to extract tectonic and climate signals from fluvial landscapes rely on river profile analysis; the interpretation of the geometry of river longitudinal profiles, mostly in the context of the detachment-limited river incision model (Howard, 1994;Whipple and Tucker, 1999).…”

Drainage reorganization during mountain building in the river system of the Eastern Cordillera of the Colombian Andes

“…Koons, 1995; Kooi and Beaumont, 1996;Willett et al, 2001; Goren et al, 2014). However, 30 during mountain building, active folds and thrusts can deviate rivers from the regional slope 31 (e.g., Van der Beek et al, 2002).…”