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Post-tectonic landscape evolution in NE Iberia using staircase terraces: Combined effects of uplift and climate

Authors :
Lewis, Claudia J.
Sancho, Carlos
McDonald, Eric V.
Peña-Monné, José Luis
Pueyo Morer, Emilio Luis
Rhodes, Edward
Calle, Mikel
Soto Marín, Ruth Lourdes
Lewis, Claudia J.
Sancho, Carlos
McDonald, Eric V.
Peña-Monné, José Luis
Pueyo Morer, Emilio Luis
Rhodes, Edward
Calle, Mikel
Soto Marín, Ruth Lourdes
Publication Year :
2017

Abstract

River incision into bedrock resulting from the combined effects of tectonic uplift and climate governs long-term regional landscape evolution. We determined spatial and temporal patterns of post-orogenic stream incision from a sequence of well-preserved staircase terraces developed over the last 1 Ma in the Central Pyrenees and its southern foreland Ebro basin (NE Spain). Extensive remnants of ten vertically separated terraces (Qt1 to Qt10, from oldest to youngest) were mapped along 170 km of the Cinca River valley, transverse to the Pyrenean mountain belt. Multiple outcrops appear in the upper reach of the valley (Ainsa sector, 50 km from headwaters) as well as in the lower reach (Albalate sector, 125 km from headwaters). Fluvial incision into bedrock was calculated using (i) differentially corrected GPS measurements of the altitude of straths and (ii) numerical dating of alluvial sediments from the lower terraces (Qt5 to Qt9) by Optically Stimulated Luminescence, previously reported by Lewis et al. (2009), and supplemented with new dates for the upper terraces (Qt1, Qt2 and Qt3) based on paleomagnetism and supported by soil development. Considering altitude differences and the elapsed time between successive well preserved terrace couples (Qt3–Qt7, Qt7–Qt9 and Qt9-Active channel), mean bedrock incision rates ranged from 0.76 to 0.38 m ka− 1, at the upper reach of the valley (Ainsa section), and from 0.61 to 0.20 m ka− 1, at the lower reach (Albalate section). River incision along the valley produced vertically separated, near-parallel longitudinal terrace profiles evidencing a rapid near-uniform regional uplift as response to (i) the tectonic lithospheric thickening in NE Iberia and (ii) the erosional download rebound related to the Ebro basin exorheism. Moreover, a subtle upstream divergence of strath profiles may have been a consequence of an increase in uplift rate toward the head of the valley. Additionally, incision rates changed over time as indicate results

Details

Database :
OAIster
Notes :
Península Ibérica, English
Publication Type :
Electronic Resource
Accession number :
edsoai.on1342484327
Document Type :
Electronic Resource