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Mid-Pleistocene climate transition drives net mass loss from rapidly uplifting St. Elias mountains, Alaska

DRS at CSIR-National Institute of Oceanography

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Title Mid-Pleistocene climate transition drives net mass loss from rapidly uplifting St. Elias mountains, Alaska
 
Creator Gulick, S.P.S.
Jaeger, J.M.
Mix, A.C.
Asahi, H.
Bahlburg, H.
Belanger, C.L.
Berbel, G.B.B.
Childress, L.
Cowan, E.
Drab, L.
Forwick, M.
Fukumura, A.
Ge, S.
Gupta, S.M.
Kioka, A.
Konno, S.
LeVay, L.J.
Marz, C.
Matsuzaki, K.M.
McClymont, E.L.
Moy, C.
Muller, J.
Nakamura, A.
Ojima, T.
Ribeiro, F.R.
Ridgway, K.D.
Romero, O.E.
Slagle, A.L.
Stoner, J.S.
St-Onge, G.
Suto, I.
Walczak, M.D.
Worthington, L.L.
Bailey, I.
Enkelmann, E.
Reece, R.
Swartz, J.M.
 
Subject PALAEO-STUDIES
GEOLOGY AND GEOPHYSICS
GEOLOGY AND GEOPHYSICS
PALAEO-STUDIES
 
Description Erosion, sediment production, and routing on a tectonically active continental margin reflect both tectonic and climatic processes; partitioning the relative importance of these processes remains controversial. Gulf of Alaska contains a preserved sedimentary record of the Yakutat Terrane collision with North America. Because tectonic convergence in the coastal St. Elias orogen has been roughly constant for 6 My, variations in its eroded sediments preserved in the offshore Surveyor Fan constrain a budget of tectonic material influx, erosion, and sediment output. Seismically imaged sediment volumes calibrated with chronologies derived from Integrated Ocean Drilling Program boreholes show that erosion accelerated in response to Northern Hemisphere glacial intensification (~2.7 Ma) and that the 900-km-long Surveyor Channel inception appears to correlate with this event. However, tectonic influx exceeded integrated sediment efflux over the interval 2.8–1.2 Ma. Volumetric erosion accelerated following the onset of quasi-periodic (~100-ky) glacial cycles in the mid-Pleistocene climate transition (1.2–0.7 Ma). Since then, erosion and transport of material out of the orogen has outpaced tectonic influx by 50–80%. Such a rapid net mass loss explains apparent increases in exhumation rates inferred onshore from exposure dates and mapped out-of-sequence fault patterns. The 1.2-My mass budget imbalance must relax back toward equilibrium in balance with tectonic influx over the timescale of orogenic wedge response (millions of years). The St. Elias Range provides a key example of how active orogenic systems respond to transient mass fluxes, and of the possible influence of climate-driven erosive processes that diverge from equilibrium on the million-year scale
 
Date 2016-01-08T06:48:58Z
2016-01-08T06:48:58Z
2015
 
Type Journal Article
 
Identifier Proceedings of the National Academy of Sciences of the United States of America, vol.112(49); 2015; 15042-15047
http://drs.nio.org/drs/handle/2264/4893
 
Language en
 
Rights Copyright [2015]. All efforts have been made to respect the copyright to the best of our knowledge. Inadvertent omissions, if brought to our notice, stand for correction and withdrawal of document from this repository.
 
Publisher National Academy of Sciences of the United States of America