Temporal and Spatial Variations in Rock Uplift From River‐Profile Inversions at the Central Anatolian Plateau Southern Margin

• Published in: Journal of geophysical research. Earth surface 2021-08, Vol.126 (8), p.n/a
• Main Authors: Racano, Simone, Schildgen, Taylor F., Cosentino, Domenico, Miller, Scott R.
• Format: Article
• Language: English
• Subjects: Central Anatolian Plateau; Crustal shortening; Fluvial sediments; Inversions; Lithosphere; Marine sediments; Mountains; Orogeny; Plate tectonics; Plateaus; Plates (tectonics); Pleistocene; Quaternary; quaternary rock uplift; River erosion; river linear inversion; Rivers; Rocks; Sediment; Sediments; slab break‐off; Slopes; Spatial variations; Subduction (geology); Tape recorders; Temporal variations; Terraces; Topography; Uplift
• ISSN: 2169-9003; 2169-9011
• DOI: 10.1029/2020JF006027

In geodynamically active areas, spatio‐temporal variations in rock uplift can provide key insights into the processes responsible for the evolution of topography. The Central Anatolian Plateau (CAP) southern margin experienced a rapid rock‐uplift pulse with maximum rates of 3.5 m/kyr during the Quaternary, based on marine sediments dated to the middle Pleistocene that are now located at 1,500 m.a.s.l. Fluvial landscapes record elements that reflect temporal and spatial variations in rock‐uplift rates, such as the normalized river steepness index, which is affected by rock‐uplift rate, the erodibility of the underlying rock, and climate. Following the calibration of river profiles for an erosion coefficient value, which can be done using independent data (in our case, uplifted marine terraces and dated marine sediments), river profiles can be inverted for the rock‐uplift histories that created them. Here, we demonstrate how it is possible to define the spatio‐temporal rock‐uplift history of the CAP southern margin by quantitative analysis of river profiles. Plain Language Summary The cause of mountain building can be enigmatic, particularly in locations where evidence for typical causes, such as horizontal crustal shortening, is absent. However, forces in the lithosphere can come about in other ways that also cause the land surface to rise. The pattern and history of topographic growth, reconstructed from geologic evidence, is one way to test among different potential mechanisms. Here, we explore the rapid rise of the Central Anatolian Plateau in southern Turkey. We use the shape of the rivers that drain the plateau to reconstruct the history of topographic growth. These rivers set their gradients to balance rates of rock uplift, and thus they preserve evidence of past rates of rock uplift along their lengths, much like a tape recorder. We find that the most rapid phase of uplift began about half a million years ago and was short‐lived everywhere, lasting only a few hundred thousand years, and occurred first in the west and later in the east. These results are similar to the effects predicted when one tectonic plate that is subducting beneath another breaks off, thus releasing a weight that allows the surface to rebound at rates that are among the fastest known on Earth. Key Points Linear inversion of longitudinal river profiles for the Central Anatolian Plateau southern margin uplift history Strong Quaternary uplift pulse that affected the margin of the pl