Modeling of wind gap formation and development of sedimentary basins during fold growth: application to the Zagros Fold Belt, Iran

Abstract

International audienceMountain building and landscape evolution are controlled by interactions between river dynamics and tectonic forces. Such interactions have been extensively studied, however a quantitative evaluation of tectonic/geomorphic feedbacks, which is imperative for understanding sediments routing within orogens and fold-and-thrust belts, remains to be undertaken. Here, we employ numerical simulations to assess the conditions of uplift and river incision necessary to deflect an antecedent drainage network during the growth of one, or several, folds. We propose that a partitioning of the river network into internal (endorheic) and longitudinal drainage arises as a result of lithological differences within the deforming crustal sedimentary cover. Using examples from the Zagros Fold Belt (ZFB), we show that drainage patterns can be linked to the non-dimensional incision ratio R between successive lithological layers, corresponding to the ratio between their relative erodibilities or incision coefficients. Transverse drainage networks develop for uplift rates smaller than 0.8 mm yr−1 and low incision ratios (−10 < R < 10). Intermediate drainage networks are obtained for uplift rates up to 2 mm yr−1 and large incision ratios (R > 20). Parallel drainage networks and the formation of sedimentary basins occur for large values of incision ratio (R > 20) and uplift rates between 1 and 2 mm yr−1. These results have implications for predicting the distribution of sediment depocenters in fold-and-thrust belts, which can be of direct economic interest for hydrocarbon exploration. They also put better constraints on the fluvial and geomorphic responses to fold growth induced by crustal-scale tectonics

Relative timing of uplift along the Zagros Mountain Front Flexure (Kurdistan Region of Iraq): Constrained by geomorphic indices and landscape evolution modeling

“…Most of these models include algorithms for bedrock fluvial incision and hillslope creep as input parameters. Several studies have constrained the landscape evolution with the involvement of the corresponding tectonics and structures elsewhere (Collignon et al, 2016;Cowie et al, 2006;Miller et al, 2007;Refice et al, 2012).…”

Short‐time (<10 ka) denudation rates as a marker of active folding in the Zagros Fold Belt (Iran)

“…In this study, we investigate the response of denudation rates to crustal deformation in the Fars Province of the Zagros Fold Belt (ZFB). The ZFB is a reference area to study the effects of fold growth on the drainage network morphology and sediment routing (Collignon, Yamato, Castelltort, & Kaus, ; Ramsey, Walker, & Jackson, ). The active deformation pattern has been documented by the seismicity and GPS data (Talebian & Jackson, ; Tatar et al., ; Vernant et al., ), which is coherent with the shortening rates derived from terraces incision rates integrated over the last 10 ka using fold kinematic models (Oveisi et al., ).…”

Relative Timing of Uplift along the Zagros Mountain Front Flexure Constrained by Geomorphic Indices and Landscape Modelling, Kurdistan Region of Iraq

“…Most of these models include algorithms for bedrock fluvial incision and hillslope creep as input parameters. Several studies have constrained the landscape evolution with the involvement of the corresponding tectonics and structures (Collignon et al, 2016;Cowie et al, 2006;10 Langston et al, 2015;Miller et al, 2007;Refice et al, 2012;Robl et al, 2008).…”