Fault Throw and Regional Uplift Histories From Drainage Analysis: Evolution of Southern Italy

Abstract

Landscapes can record elevation changes caused by multiple tectonic processes. Here, we show how coeval histories of spatially coincident normal faulting and regional uplift can be deconvolved from river networks. We focus on Calabria, a tectonically active region incised by rivers containing knickpoints and knickzones. Marine fauna indicate that Calabria has been uplifted by >1 km since ∼0.8–1.2 Ma, which we used to calibrate parameters in a stream power erosional model. To deconvolve the local and regional uplift contributions to topography, we performed a spatiotemporal inversion of 994 fluvial longitudinal profiles. Uplift rates from fluvial inversion replicate the spatial trend of rates derived from dated Mid‐Late Pleistocene marine terraces, and the magnitude of predicted uplift rates matches the majority of marine terrace uplift rates. We used the predicted uplift history to analyze long‐term fault throw, and combined throw estimates with ratios of footwall uplift to hanging wall subsidence to isolate the nonfault related contribution to uplift. Increases in fault throw rate—which may suggest fault linkage and growth—have been identified on two major faults from fluvial inverse modeling, and total fault throw is consistent with independent estimates. The temporal evolution of nonfault related regional uplift is similar at three locations. Our results may be consistent with toroidal mantle flow generating uplift, perhaps if faulting reduces the strength of the overriding plate. In conclusion, fluvial inverse modeling can be an effective technique to quantify fault array evolution and can deconvolve different sources of uplift that are superimposed in space and time.

Rift kinematics preserved in deep‐time erosional landscape below the northern North Sea

“…Knickpoints in individual catchments can be generated by a range of processes including base level change, rock strength variations and landslide (e.g., Scheingross et al, 2021). However, the presence of large profile convexities (knickpoints) located consistently in footwall catchments upstream of active normal faults very often reflects the transient response of fluvial systems to relative base level change such as a change in fault slip rate (e.g., Whittaker et al, 2007; Kent et al, 2021; Quye‐Sawyer et al, 2021). In this scenario, the river reaches downstream of a knickpoint, but for instance upstream of an active fault, has steepened and incised in response to the tectonic perturbation, while upstream of the knickpoint has yet to respond to the fault‐driven uplift and retains its pre‐existing configuration (Kirby & Whipple, 2012).…”

“…This coupling of tectonics, erosion and sedimentation (e.g., Olive et al, 2022; Romans et al, 2016; Watkins et al, 2020) means that the transient erosional response of fluvial landscapes to rifting can be used to record the timescales, throw rates and kinematics of active faulting over a range of spatial scales (e.g., Goren et al, 2014; Kirby & Whipple, 2012; Whittaker & Boulton, 2012; Zondervan et al, 2020). In modern rifts, we can analyse digital elevation models (DEMs), together with independent tectonic and stratigraphic constraints, to estimate the patterns and rates of fault evolution (e.g., Pechlivanidou et al, 2017; Quye‐Sawyer et al, 2021; Watkins et al, 2020), but in many ancient rifts, similar rift‐related palaeo‐landscapes are absent. Consequently, time‐averaged patterns of faulting must be reconstructed indirectly from structural measurements and stratigraphic observations (e.g., Gawthorpe & Leeder, 2000; Kent et al, 2017).…”

Structure and Morphology of an Active Conjugate Relay Zone, Messina Strait, Southern Italy

“…2, 4) (Valensise and Pantosti, 1992;Westaway, 1993;Tortorici et al, 1995Tortorici et al, , 2003Monaco et al, 1997;Monaco and Tortorici, 2000;Jacques et al, 2001;Catalano et al, 2003Catalano et al, , 2008Palano et al, 2012Palano et al, , 2017Brutto et al, 2016;Presti et al, 2019;Pirrotta et al, 2021Pirrotta et al, , 2022. Well preserved normal fault scarps, marine terraces, and river channel profiles record fault offset and footwall uplift at rates of ~ 0.2 -2 mm/yr in Sicily (Tortorici et al, 1995;Catalano and De Guidi, 2003a;Catalano et al, 2008;Pavano et al, 2016;Meschis et al, 2022a) and southern Calabria (Montenat et al, 1991;Monaco et al, 1997;Catalano et al, 2003;Antonioli et al, 2006Antonioli et al, , 2021Roberts et al, 2013;Roda-Boluda and Whittaker, 2017;Quye-Sawyer et al, 2021;Meschis et al, 2022a;2022b). In southern Calabria the Cittanova, Calanna, Scilla, and Armo faults dip northwest and terminate to the northeast at the left-lateral Coccorino and Nicotera-Gioiosa strike-slip fault zones (Fig.…”

“…The age of initiation of normal faults in southern Calabria is poorly understood due to conflicting information about the age of marine deposits in the uplifted footwalls of the faults. Some studies (e.g., Roda-Boluda and Whittaker, 2017;Quye-Sawyer et al, 2021) conclude that normal faulting and uplift of raised SCA marine terraces started ~1.0 ± 0.2 Ma, based on the presence of "northern guest" faunas that are believed to have migrated into this region ca. 1 Ma (Dumas et al, 1981(Dumas et al, , 1987Ghisetti, 1981;Westaway, 1993;Miyauchi, 1994;Monaco et al, 1996;Catalano et al, 2008).…”

Rift kinematics preserved in deep-time erosional landscape below the northern North Sea

“…In modern rifts, we can analyse digital elevation models (DEMs), together with independent tectonic and stratigraphic constraints, to estimate the patterns and rates of fault evolution (e.g. Pechlivanidou et al, 2018;Watkins et al, 2020;Quye-Sawyer et al, 2021), but in many ancient rifts similar rift-related paleo-landscapes are absent. Consequently, time-averaged patterns of faulting must be reconstructed indirectly from structural measurements and stratigraphic observations (e.g.…”