Variable Quaternary Uplift Along the Southern Margin of the Central Anatolian Plateau Inferred From Modeling Marine Terrace Sequences

Abstract

The southern margin of the Central Anatolian Plateau (CAP) records a strong uplift phase after the early Middle Pleistocene, which has been related to the slab break-off of the subducting Arabian plate beneath the Anatolian microplate. During the last 450 kyr the area underwent an uplift phase at a mean rate of ~3.2 m/kyr, as suggested by Middle Pleistocene marine sediments exposed at ~1500 meters above sea level. These values are significantly higher than the 1.0-1.5 m/kyr estimated since the Late Pleistocene, suggesting temporal variations in uplift rate. To estimate changes in uplift rate during the Pleistocene we studied the marine terraces along the CAP southern margin, mapping the remnants of the platforms and their associated deposits in the field, and used the TerraceM software to identify the position and elevation of associated shoreline angles. We used shoreline angles and the timing of Quaternary marine sedimentation as constrains for a Landscape Evolution Model that simulates wave erosion of an uplifting coast. We applied random optimization algorithms and minimization statistics to find the input parameters that better reproduce the morphology of CAP marine terraces. The best-fitting uplift rate history suggests a significative increase from 1.9 to 3.5 m/kyr between 500 and 200 kyr, followed by an abrupt decrease to 1.4 m/kyr until the present. Our results agree with slab break-off models, which suggest a strong uplift pulse during slab rupture followed by a smoother decrease.

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

“…1). The mechanisms that created the modern CAP topography remain debated, but have primarily been attributed to crustal and upper-mantle dynamics related to interactions among the Eurasian, African and Arabian plates (Faccenna et al, 2006;Biryol et al, 2011;Cosentino et al, 2012;Schildgen et al, 2012a-b;Bartol & Govers, 2014;Goğuş et al, 2017;Meijers at al., 2018;Öğretmen et al, 2018a;McPhee et al, 2018;Fernández-Blanco et al, 2019;2020;Racano et al, 2020). Considering that the plateau margins rise high above the plateau interior in Central Anatolia, different mechanisms are likely responsible for surface uplift of the plateau margins and the plateau interior (Göğüş et al, 2017).…”

“…dated to 0.467 Ma based on analyses of benthic and planktonic foraminifers, ostracods, and calcareous nannofossils (Öğretmen et al, 2018a). The rock-uplift history since that time is inferred from modeling of a staircase sequence of coastal planation surfaces from the top of the margin toward the sea that have been interpreted as marine terraces (Racano et al, 2020).…”

“…middle Pleistocene (MIS7), with maximum rock-uplift rates estimated to have been 3.4 to 3.8 m/kyr (Racano et al, 2020).…”

“…For this estimate, we utilize the rock-uplift rates inferred from modeling of interpreted marine terraces on the eastern side of the CAP southern margin by Racano et al (2020). In that study, the creation and uplift of marine terraces were modelled with a landscape evolution model together with their inferred ages and an assumed sea-level history to derive a rock-uplift history.…”

“…this slope to K (Equation 18). The x and y errors used for the data points in the regression are one standard deviation of the mean of both ksn in each elevation band and the rock-uplift derived from marine terrace modeling (Racano et al, 2020). This approach enabled us to take into account x and y errors and respect the linearity in Equation ( 6) that is used to infer K.…”