scholarly journals Spatial Variations of Tectonic Uplift - Subducting Plate Effects on the Guerrero Forearc, Mexico

2021 ◽  
Vol 8 ◽  
Author(s):  
María Teresa Ramírez-Herrera ◽  
Krzysztof Gaidzik ◽  
Steven L. Forman
Keyword(s):  
Subduction Zones ◽  
Spatial Variations ◽  
Tectonic Uplift ◽  
Tectonic Activity ◽  
Tectonic Deformation ◽  
Roughness Effects ◽  
Geomorphic Indices ◽  
River Incision ◽  
Uplift Rates ◽  
Differential Uplift

Uplift is the predominant factor controlling fluvial systems in tectonically deforming regions. Mountains along subduction zones force incision, aggradation, or sinuosity modifications, showing differential uplift and variations in erosion rates, in river incision, and in channel gradient produced by ongoing tectonic deformation. Thus, landscape can provide information on the tectonic activity of a defined region. Here, field studies, analysis of geomorphic indices using a digital elevation model, and dating of river terraces were undertaken to extract the following: (1) determine rates of ongoing tectonic deformation, (2) identify evidence of active faulting, and (3) explain the possible relation of ongoing differential uplift in the topography of the overriding plate with the geometry and roughness effects of subducting slab along the Mexican subduction within the Guerrero sector. Landscape analysis using geomorphic indices suggests segmentation along stream of the studied Tecpan River basin. Rates of tectonic uplift were derived from river incision rates computed with the combination of strath terrace heights and associated dating. Tectonic uplift rates vary from ∼1 ± 0.3 mm/yr up to ∼5 ± 0.6 mm/yr during the Holocene, consistent with inferred high tectonic activity in this zone. These results vary significantly spatially, i.e., increasing upstream. Possible explanations for spatial variations of tectonic uplift rates are most likely related to an effect of the geometry and the rugged seafloor of the oceanic Cocos plate subduction beneath a faulted continental lithosphere.

scholarly journals Distinct phases of eustatism and tectonics control the late Quaternary landscape evolution at the southern coastline of Crete

2016 ◽  
Author(s):  
Vasiliki Mouslopoulou ◽  
John Begg ◽  
Alexander Fülling ◽  
Daniel Moraetis ◽  
Panagiotis Partsinevelos ◽  
...  
Keyword(s):  
Landscape Evolution ◽  
Late Quaternary ◽  
Eastern Mediterranean ◽  
Vertical Movement ◽  
Tectonic Uplift ◽  
Alluvial Fan ◽  
Contributing Factors ◽  
River Incision ◽  
Coastal Landscapes ◽  
Uplift Rates

Abstract. The extent to which climate, eustacy and tectonics interact to shape the late Quaternary landscape is poorly known. Alluvial fans often provide useful indexes that allow decoding the information recorded on complex coastal landscapes, such as those of Eastern Mediterranean. In this paper we analyse and date (using optically stimulated luminescence – OSL) a double alluvial-fan system in Crete, an island straddling the forearc of the Hellenic subduction margin, in order to constrain the timing of, and quantify the contributing factors to, its landscape evolution. The studied alluvial system is unique because each of its two juxtaposed fans records individual phases of alluvial and marine incision, providing, thus, unprecedented resolution in the formation and evolution of its landscape. Specifically, our analysis shows that the fan sequence at Domata developed during the last glaciation (Marine Isotope Stage 3; 57–29 kyr) due to five distinct stages of marine transgressions and regressions and associated river incision, as a response to climatic changes and tectonic uplift at rates of ~ 2.2 mm/yr. Comparison of our results with published tectonic uplift rates from Crete shows, however, that vertical movement on Crete was minimal during 20–50 kyr BP and mot uplift was accrued during the last 20 kyr. This implies that eustacy and tectonism impacted on the landscape at Domata over mainly distinct time-intervals (e.g. sequentially and not synchronously), forming and preserving the coastal landforms, respectively.

scholarly journals TECTONIC GEOMORPHOLOGY OF ESCARPMENTS: THE CASES OF KOMPOTADES AND ΝΕΑ ANCHIALOS FAULTS

2004 ◽  
Vol 36 (4) ◽  
pp. 1716 ◽  
Author(s):  
E. Zovoili ◽  
E. Konstantinidi ◽  
I. K. Koukouvelas
Keyword(s):  
Active Tectonics ◽  
Tectonic Activity ◽  
Tectonic Geomorphology ◽  
Stream Length ◽  
Sinuosity Index ◽  
Geomorphic Indices ◽  
Tectonic Processes ◽  
Uplift Rates ◽  
Mountain Front ◽  
Active Processes

Most active processes on the surface imply that tectonics and geomorphology converge in a way that landscape change may be used as a tectonic signal, given that erosion and weathering have been taken into account. We selected two faults, the Kompotades and the Nea Anchialos faults in the Sperchios and South Thessaly rift zones respectively, and we performed a morphometric analysis. This analysis comprises geomorphic indices that have been used successfully in studies of active tectonics, as the mountain front sinuosity index (Smf), stream gradient index (SL) and valley floor width to valley height ratio (Vf). At both studied mountain fronts, the Vf index ranged between 0,4 to 1,2, implying high uplift rates, while the Smf «1 index revealed relatively high tectonic activity, which decreases towards the west. On the other hand, the SL index though more sensitive to non-tectonic processes, (i.e. the rock resistance, stream length) is less indicative of tectonic activity. Based on the distribution of the geomorphic indices a two-fault strand model is suggested forming the mountain front in the two examples with the range-ward fault strand to be more appropriate for Kompotades fault and the basinward fault strand for Nea Anchialos fault.

scholarly journals Assessment of tectonic control on the development of low mountains moderate relief in the Outer Carpathians (Southern Poland)

2020 ◽  
Vol 17 (10) ◽  
pp. 2297-2320
Author(s):  
Janusz Godziek ◽  
Krzysztof Gaidzik
Keyword(s):  
Landscape Analysis ◽  
Tectonic Activity ◽  
Tectonic Deformation ◽  
Gradient Index ◽  
Tectonic Structures ◽  
Stream Length ◽  
River Catchment ◽  
Hypsometric Integral ◽  
Uplift Rates ◽  
Outer Carpathians

Abstract Inherited tectonic structures, ongoing tectonic deformation, and variations in relative rock uplift rates play an important role in conditioning the processes of relief development. Their influence among other factors, such as climate and lithology, can be quantified using landscape analysis, and geomorphometric indices, in particular. The usage of landscape analysis in recent years is increasing systematically due to the constant improvement of the digital elevation models and GIS software that significantly facilitate this approach. In this study, we aim to recognize the influence of tectonic structures and processes on relief development in the low mountains with moderate relief of the Soła River catchment in the Western Outer Carpathians. To this end, we calculated geomorphometric indices (river longitudinal profile, stream-length gradient index, minimum bulk erosion, relief ratio, circulatory ratio, elongation ratio, and hypsometric integral) for the Sola River and its 47 sub-catchments using a 25-m spatial resolution Digital Terrain Elevation Data Level 2. Additionally, we identified lineaments and knickpoints and correlated the computed results with local and regional fault networks, variations in lithology, and climate fluctuations. Obtained results indicate a significant impact of inherited tectonic structures on the relief development of the Soła River catchment, i.e., directions of principal ridges and valleys follow the orientation of main folds and faults recorded in this area. Anomalously high values of minimum bulk erosion, river gradient, and stream-length gradient index allowed us to define two areas with higher relative uplift rates: 1) the Sola Gorge and 2) the Beskid Żywiecki Mts. Polish Outer Carpathians are generally considered as an area of low strain rate and low seismic activity. However, the possibility of neotectonic processes should be considered in geohazard estimations. Observed bends in the direction of river valleys that do not correspond with changes in lithology could be related to active strike-slip faults. These are probably the reactivated basement structures, copied in the thin-skinned nappe cover, as a result of the accommodation of the Mur-Žilina Fault Zone resulting from the tectonic push of the Alcapa (Alpine-Carpathian-Pannonian) microplate against the European plate. Thus, the role of recent tectonic activity in relief development of the Sola River catchment even though appears to be subsidiary at the most, should not be excluded.

scholarly journals Distinct phases of eustatic and tectonic forcing for late Quaternary landscape evolution in southwest Crete, Greece

2017 ◽  
Vol 5 (3) ◽  
pp. 511-527 ◽  
Author(s):  
Vasiliki Mouslopoulou ◽  
John Begg ◽  
Alexander Fülling ◽  
Daniel Moraetis ◽  
Panagiotis Partsinevelos ◽  
...  
Keyword(s):  
Landscape Evolution ◽  
Late Quaternary ◽  
Eastern Mediterranean ◽  
Tectonic Uplift ◽  
Alluvial Fan ◽  
Sea Level Fluctuations ◽  
River Incision ◽  
Infrared Stimulated Luminescence ◽  
Coastal Landscapes ◽  
Uplift Rates

Abstract. The extent to which climate, eustasy and tectonics interact to shape the late Quaternary landscape is poorly known. Alluvial fans often provide useful indexes that allow the decoding of information recorded on complex coastal landscapes, such as those of the eastern Mediterranean. In this paper we analyse and date (using infrared stimulated luminescence (IRSL) dating) a double alluvial fan system on southwest Crete, an island straddling the forearc of the Hellenic subduction margin, in order to constrain the timing and magnitude of its vertical deformation and discuss the factors contributing to its landscape evolution. The studied alluvial system is exceptional because each of its two juxtaposed fans records individual phases of alluvial and marine incision, thus providing unprecedented resolution in the formation and evolution of its landscape. Specifically, our analysis shows that the fan sequence at Domata developed during Marine Isotope Stage (MIS) 3 due to five distinct stages of marine transgressions and regressions and associated river incision, in response to sea-level fluctuations and tectonic uplift at averaged rates of  ∼ 2.2 mm yr−1. Interestingly, comparison of our results with published tectonic uplift rates from western Crete shows that uplift during 20–50 kyr BP was minimal (or even negative). Thus, most of the uplift recorded at Domata must have occurred in the last 20 kyr. This implies that eustasy and tectonism impacted the landscape at Domata over mainly distinct time intervals (e.g. sequentially and not synchronously), with eustasy forming and tectonism preserving the coastal landforms.

scholarly journals MORPHOTECTONIC ANALYSIS IN THE ELIKI FAULT ZONE (GULF OF CORINTH, GREECE)

2004 ◽  
Vol 36 (4) ◽  
pp. 1706 ◽  
Author(s):  
S. Verrios ◽  
V. Zygouri ◽  
S. Kokkalas
Keyword(s):  
Fault Zone ◽  
Active Tectonics ◽  
Specific Area ◽  
Aerial Photographs ◽  
Tectonic Activity ◽  
Tectonic Geomorphology ◽  
Tectonic Deformation ◽  
Width Ratio ◽  
Geomorphic Indices ◽  
Gulf Of Corinth

Morphotectonic analysis using geomorphic indices has been developed as a basic reconnaissance tool in order to identify areas experiencing rapid tectonic deformation or estimate relative variations of tectonic activity in a specific area. We applied this analysis in Eliki fault zone, which is located in the western part of the Gulf of Corinth. Eliki fault zone was selected because it displays a spectacular geomorphic expression and hosts historic and recent seismicity. The intensity of active tectonics is interpreted through a detailed geomorphic study of the fault-generated mountain fronts and fluvial systems. Tectonic geomorphology analysis of the Eliki footwall area includes the application of the most commonly used geomorphic indices, such as the mountain front sinuosity index (Smf), the valley floor / width ratio index (Vf), the stream gradient index (SL) and the transverse topographic symmetry factor (T). These indices were estimated on topographic maps and aerial photographs of the study area in order to correlate active tectonics and erosional processes. Our results imply that the Eliki fault zone can be assigned to a tectonic class of the higher tectonic activity. However, spatial variations of tectonic activity along the segmented studied fronts point to a general trend of increasing activity towards the east, which is gradually decreasing towards the west.

scholarly journals Towards assessing the influence of sediment loading on Last Interglacial sea level

2019 ◽  
Vol 220 (1) ◽  
pp. 384-392
Author(s):  
T Pico
Keyword(s):  
Sea Level ◽  
Tectonic Uplift ◽  
Sediment Loading ◽  
Glacial Cycle ◽  
Last Interglacial ◽  
Isostatic Adjustment ◽  
Uplift Rates ◽  
History Of ◽  
The Impact ◽  
The Last Glacial

SUMMARY Locally, the elevation of last interglacial (LIG; ∼122 ka) sea level markers is modulated by processes of vertical displacement, such as tectonic uplift or glacial isostatic adjustment, and these processes must be accounted for in deriving estimates of global ice volumes from geological sea level records. The impact of sediment loading on LIG sea level markers is generally not accounted for in these corrections, as it is assumed that the impact is negligible except in extremely high depositional settings, such as the world's largest river deltas. Here we perform a generalized test to assess the extent to which sediment loading may impact global variability in the present-day elevation of LIG sea level markers. We numerically simulate river sediment deposition using a diffusive model that incorporates a migrating shoreline to construct a global history of sedimentation over the last glacial cycle. We then calculate sea level changes due to this sediment loading using a gravitationally self-consistent model of glacial isostatic adjustment, and compare these predictions to a global compilation of LIG sea level data. We perform a statistical analysis, which accounts for spatial autocorrelation, across a global compilation of 1287 LIG sea level markers. Though limited by uncertainties in the LIG sea level database and the precise history of river deposition, this analysis suggests there is not a statistically significant global signal of sediment loading in LIG sea level markers. Nevertheless, at sites where LIG sea level markers have been measured, local sea level predicted using our simulated sediment loading history is perturbed up to 16 m. More generally, these predictions establish the relative sensitivity of different regions to sediment loading. Finally, we consider the implications of our results for estimates of tectonic uplift rates derived from LIG marine terraces; we predict that sediment loading causes 5–10 m of subsidence over the last glacial cycle at specific locations along active margin regions such as California and Barbados, where deriving long-term tectonic uplift rates from LIG shorelines is a common practice.

How syn-rift sedimentation promotes the formation of hyper-extended margins

2020 ◽  
Author(s):  
Susanne Buiter
Keyword(s):  
Sedimentary Basins ◽  
Surface Processes ◽  
Tectonic Activity ◽  
Tectonic Deformation ◽  
Continental Margins ◽  
Rifted Margins ◽  
Continental Rifts ◽  
Break Up ◽  
Mountain Belts ◽  
Sediment Layers

<p>Seismic observations show that some rifted continental margins may have substantial amounts of offshore sediments. For example, sediment layers of several kilometres thick are found on the margins of Mid Norway, Namibia and Angola. Intriguingly, these margins are wide, being characterised by distances of several hundreds of kilometres from typical continental crustal thicknesses of 30-40 km to clearly identifiable oceanic crust. On the other hand, some margins that are sediment-starved, such as Goban Spur, Flemish Cap and Northern Norway, have short onshore-to-offshore transitions. Variations in the amount of sediments not only impact the development of offshore sedimentary basins, but the changes in mass balance by erosion and sedimentation can also interact with extensional tectonic processes. In convergent settings, such feedback relationships between erosion and tectonic deformation have long been highlighted: Erosion reduces the elevation and width of mountain belts and in turn tectonic activity and exhumation are focused at regions of enhanced erosion. But what is the role played by surface processes during formation of rifted continental margins?</p><p>I use geodynamic finite-element experiments to explore the response of continental rifts to erosion and sedimentation from initial rifting to continental break-up. The experiments predict that rifted margins with thick syn-rift sedimentary packages are more likely to form hyper-extended crust and require more stretching to achieve continental break-up than sediment-starved margins. These findings imply that surface processes can control the style of continental break-up and that the role of sedimentation in rifted margin evolution goes far beyond the simple exertion of a passive weight.</p>

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