Details
| Original language | English |
|---|---|
| Pages (from-to) | 7-1 - 7-16 |
| Journal | TECTONICS |
| Volume | 22 |
| Issue number | 3 |
| Publication status | Published - Jun 2003 |
| Externally published | Yes |
Abstract
Subsidence of Lima Basin, part of the Peruvian forearc, is controlled by tectonic erosion by the subducting Nazca plate. Multichannel seismic reflection data coupled with age and paleowater depth constraints derived from Ocean Drilling Program (ODP) coring now allow the rates of erosion to be reconstructed through time. In trenchward locations the forearc has experienced limited recent relative uplift (700-850 m) likely due to preferential basal erosion under the center of Lima Basin. Long-term subsidence driven by basal tectonic erosion dominates and is fastest closest to the trench. Since 47 Ma (Eocene) up to 148 km of the plate margin have been lost at an average rate of up to 3.1 km myr-1. Appoximately 110 km of that total appears to be lost since 11 Ma, implying much faster average rates of trench retreat (10 km myr-1) since collision of the Nazca Ridge with the Lima Basin at 11 Ma. Although there is no clear subsidence event at ODP Site 679 during the time at which Nazca Ridge was subducting beneath this part of the forearc (4-11 Ma), the more trenchward ODP Sites 682 and 688 show significant deepening after 11 Ma indicating that subduction of the ridge accelerates tectonic erosion. Long-term rates of crustal erosion in the region of Lima Basin are greater than estimates of regional arc magmatic productivity, implying that such margins are net sinks of continental crust.
Keywords
- Peru, Subduction, Subsidence, Tectonics
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geophysics
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
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In: TECTONICS, Vol. 22, No. 3, 06.2003, p. 7-1 - 7-16.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Tectonic erosion of the Peruvian forearc, Lima Basin, by subduction and Nazca Ridge collision
AU - Clift, Peter D.
AU - Pecher, Ingo
AU - Kukowski, Nina
AU - Hampel, Andrea
N1 - Funding information: The study was founded by Assistance-Publique-Hopitaux-de-Paris, (Délégation à la Recherche Clinique), grant PHRC AOA94057 and EMUL 930902. We are indebted to Geneviève Barret (CIC) for sleep recordings, to Odile Maugenest, and to Anne-Marie César d'Ornano (Nutrition Department) for preparing the low-tryptophan diets.
PY - 2003/6
Y1 - 2003/6
N2 - Subsidence of Lima Basin, part of the Peruvian forearc, is controlled by tectonic erosion by the subducting Nazca plate. Multichannel seismic reflection data coupled with age and paleowater depth constraints derived from Ocean Drilling Program (ODP) coring now allow the rates of erosion to be reconstructed through time. In trenchward locations the forearc has experienced limited recent relative uplift (700-850 m) likely due to preferential basal erosion under the center of Lima Basin. Long-term subsidence driven by basal tectonic erosion dominates and is fastest closest to the trench. Since 47 Ma (Eocene) up to 148 km of the plate margin have been lost at an average rate of up to 3.1 km myr-1. Appoximately 110 km of that total appears to be lost since 11 Ma, implying much faster average rates of trench retreat (10 km myr-1) since collision of the Nazca Ridge with the Lima Basin at 11 Ma. Although there is no clear subsidence event at ODP Site 679 during the time at which Nazca Ridge was subducting beneath this part of the forearc (4-11 Ma), the more trenchward ODP Sites 682 and 688 show significant deepening after 11 Ma indicating that subduction of the ridge accelerates tectonic erosion. Long-term rates of crustal erosion in the region of Lima Basin are greater than estimates of regional arc magmatic productivity, implying that such margins are net sinks of continental crust.
AB - Subsidence of Lima Basin, part of the Peruvian forearc, is controlled by tectonic erosion by the subducting Nazca plate. Multichannel seismic reflection data coupled with age and paleowater depth constraints derived from Ocean Drilling Program (ODP) coring now allow the rates of erosion to be reconstructed through time. In trenchward locations the forearc has experienced limited recent relative uplift (700-850 m) likely due to preferential basal erosion under the center of Lima Basin. Long-term subsidence driven by basal tectonic erosion dominates and is fastest closest to the trench. Since 47 Ma (Eocene) up to 148 km of the plate margin have been lost at an average rate of up to 3.1 km myr-1. Appoximately 110 km of that total appears to be lost since 11 Ma, implying much faster average rates of trench retreat (10 km myr-1) since collision of the Nazca Ridge with the Lima Basin at 11 Ma. Although there is no clear subsidence event at ODP Site 679 during the time at which Nazca Ridge was subducting beneath this part of the forearc (4-11 Ma), the more trenchward ODP Sites 682 and 688 show significant deepening after 11 Ma indicating that subduction of the ridge accelerates tectonic erosion. Long-term rates of crustal erosion in the region of Lima Basin are greater than estimates of regional arc magmatic productivity, implying that such margins are net sinks of continental crust.
KW - Peru
KW - Subduction
KW - Subsidence
KW - Tectonics
UR - http://www.scopus.com/inward/record.url?scp=0141569360&partnerID=8YFLogxK
U2 - 10.1029/2002TC001386
DO - 10.1029/2002TC001386
M3 - Article
AN - SCOPUS:0141569360
VL - 22
SP - 7-1 - 7-16
JO - TECTONICS
JF - TECTONICS
SN - 0278-7407
IS - 3
ER -