Rectangular drainage pattern evolution controlled by pipe cave collapse along clastic dikes, the Dead Sea Basin, Israel

Abstract

Rectangular drainage networks are characterized by right‐angle bends and confluences. The formation of such drainage patterns is commonly associated with orthogonal sets of fractures, making them an outstanding example for structurally controlled landscape evolution. However, this association remains largely circumstantial because little is known about how rectangular drainages mechanistically link to orthogonal fractures. We investigated these linkages in the hyper‐arid Ami'az Plain located within the Dead Sea Basin in Israel. The Ami'az Plain is penetrated by hundreds of sub‐vertical clastic dikes (mode‐I fractures infilled with sediments) and is also incised by a rectangular canyon system. Numerous caves extend from the banks and heads of the canyon system. Based on field surveys and analysis of high‐resolution airborne LiDAR data, we mapped the Ami'az Plain drainage network and its associated landforms, including sinkholes. Our analysis revealed that the subaerial tributaries of the canyon system and the strike of the clastic dikes show similar orientations. In addition, subsurface mapping with a ground‐based scanning LiDAR, together with field experiments, demonstrated that the caves and sinkholes in the Ami'az Plain are spatially associated with clastic dikes and that the caves formed through piping erosion along dikes. Based on these findings, we suggest that clastic dikes act as efficient infiltration pathways to the subsurface, where flow along clastic dikes induces internal erosion that forms pipe caves. The sinkholes form by collapses of cave roofs. Coalescence of sinkholes and seepage erosion where dikes intersect canyon heads generate new tributaries and act to extend existing ones. Fluvial erosion and subsequent bank collapse modify the canyon network. Our findings emphasize the critical role of subsurface erosion, caves and sinkholes in linking fractures to drainage pattern evolution, and provide a new process‐based framework to interpret rectangular drainage networks on Earth and possibly other planetary surfaces.

Channel concavity controls plan-form complexity of branching drainage networks

“…These characteristics affect water runoff, sediment transport capacity, rate and pattern of erosion, and the distribution of ecological niches (Rodríguez-Iturbe and Valdés, 1979;Whipple and Tucker, 2002;Badgley et al, 2017;Pelletier et al, 2018;Khosh Bin Ghomash et al, 2019;Beeson et al, 2021;Stokes and Perron, 2020) Some of the variability in network complexity could be attributed to the level of heterogeneity in the environmental and boundary conditions affecting the landscape. Spatial gradients in tectonics (Castelltort et al, 2012;Goren et al, 2015Goren et al, , 2014Habousha et al, 2023;Cowie et al, 2006;Braun et al, 2013;Mudd et al, 2022), climate (Caylor et al, 2005;Thomas et al, 2011), and lithology (including fabric and fracture density) (Strong et al, 2019;Ward, 2019;Mudd et al, 2022) and discrete geologic structures (Hamawi et al, 2022;Scott and Wohl, 2019) are likely linked to more complex network geometry. However, numerical studies of landscape evolution (Shelef and Hilley, 2014;Tucker and Whipple, 2002;Howard, 1994;Rinaldo et al, 1992;Sun et al, 1994b;Howard, 1990) show that variabilities in complexity emerge even when environmental and boundary conditions are spatially uniform.…”

Time-varying drainage basin development and erosion on volcanic edifices

“…The formation of these other drainages often relate to the region's tectonic, volcanic, or glacial history, subsurface structure, or geometry of the primary landform that they erode (Zernitz, 1932). However, compared to dendritic basins, studies that explore the geometries and evolution of other drainage settings are scarce (e.g., Mejía and Niemann, 2008;Becerril et al, 2021;Hamawi et al, 2022).…”