Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-29T17:08:15.192Z Has data issue: false hasContentIssue false
  • English
  • Français

Jurassic to Early Cretaceous postaccretional sinistral transpression in north-central Chile (latitudes 31–32°S)

Published online by Cambridge University Press:  16 August 2011

UWE RING ,
ARNE P. WILLNER ,
PAUL W. LAYER  and
PETER P. RICHTER
UWE RING*
Affiliation:
Department of Geological Sciences, Canterbury University, Christchurch 8140, New Zealand
ARNE P. WILLNER
Affiliation:
Institut für Geologie, Mineralogie & Geophysik, Ruhr-Universität, D-44780 Bochum, Germany
PAUL W. LAYER
Affiliation:
Department of Geology & Geophysics, University of Alaska, Fairbanks, USA
PETER P. RICHTER
Affiliation:
Institut für Geologie, Christian-Albrechts Universität, 24118 Kiel, Germany
*
†Author for correspondence: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

We describe the geometry and kinematics of a Jurassic to Early Cretaceous transpressive sinistral strike-slip system within a metamorphic basement inlier of the Mesozoic magmatic arc near Bahia Agua Dulce at latitudes 31–32°S in north-central Chile and discuss possible relations with the Atacama Fault System further north. Sinistral transpression overprints structures of an accretionary system that is represented by the metamorphic basement. Sub-vertical semi-ductile NNW-striking strike-slip shear zones are the most conspicuous structures. Chlorite and sericite grew, and white mica and quartz dynamically recrystallized, suggesting low-grade metamorphic conditions during semi-ductile deformation. Folds at the 10–100 metre scale developed before and during strike-slip shearing. The folds are deforming a former sub-horizontal transposition foliation that originated during prior accretion processes. The folds have axes sub-parallel to the strike-slip shear zones and sub-vertical axial surfaces indicating a component of shortening parallel to the shear-zone boundaries, suggesting an overall transpressive deformation regime. Transpressive strike-slip deformation also affects Middle Triassic (Anisian) basal breccias of the El Quereo Formation. 40Ar–39Ar laser ablation ages of synkinematically recrystallized white mica in one of the shear zones provide an age of 174–165 Ma for the waning stages of semi-ductile strike-slip shearing. The semi-ductile shear zones are cut by mafic and rhyolite dykes. Two rhyolite dykes yield 40Ar–39Ar ages of 160.5 ± 1.7 Ma and 131.9 ± 1.7 Ma, respectively. The latter dyke has been affected by brittle faulting. Fault-slip analysis shows that the kinematics of the faulting event is similar to the one of the semi-ductile shearing event, suggesting that sinistral transpression continued after ~130 Ma. Timing, kinematics and geographic position suggest that the shear zones at Bahia Agua Dulce represent a southern continuation of the prominent Atacama Fault System that affected the Jurassic/Early Cretaceous arc over its ~1400 km length.

Keywords

foldsshear zonestranspression40Ar–39Ar datingSouth AmericaChileAtacama Fault System
Type
Original Articles
Information
Geological Magazine , Volume 149 , Issue 2 , March 2012 , pp. 208 - 220
Copyright
Copyright © Cambridge University Press 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Aguirre, L., Hervé, F. & Godoy, E. 1972. Distribution of metamorphic facies in Chile: an outline. Krystallinikum 9, 7–19.Google Scholar
Arancibia, G. 2004. Mid-Cretaceous crustal shortening: evidence from a regional-scale ductile shear zone in the Coastal Range of central Chile (32°S). Journal of South American Earth Sciences 17, 209–26.CrossRefGoogle Scholar
Bolhar, R. & Ring, U. 2001. Deformation history of the Yolla Bolly terrane at Leech Lake Mountain, Eastern Belt, Franciscan Subduction Complex, Californian Coast Ranges. Geological Society of America Bulletin 181, 181–95.2.0.CO;2>CrossRefGoogle Scholar
Brandon, M. T. & Vance, J. A. 1992. Tectonic evolution of the Cenozoic Olympic subduction complex, Washington State, as deduced from fission track ages for detrital zircons. American Journal of Science 292, 565–636.CrossRefGoogle Scholar
Charrier, R., Pinto, L. & Rodríguez, M. P. 2008. Chapter 3 Tectonostratigraphic evolution of the Andean orogen in Chile. In The Geology of Chile (eds Moreno, T. & Gibbons, W.), pp. 21–114. London: The Geological Society.Google Scholar
Cecioni, G. & Westermann, G. 1968. The Triassic/Jurassic marine transition of coastal central Chile. Pacific Geology 1, 41–75.Google Scholar
Feehan, J. G. & Brandon, M. T. 1999. Contribution of ductile flow to exhumation of low-temperature, high-pressure metamorphic rocks: San Juan-Cascade nappes, NW Washington State. Journal of Geophysical Research B: Solid Earth 104, 10883–902.CrossRefGoogle Scholar
Glodny, J., Lohrmann, J., Echtler, H., Gräfe, K., Seifert, W., Collao, S. & Figueroa, O. 2005. Internal dynamics of a paleoaccretionary wedge: insights from combined isotope tectonochronology and sandbox modelling of the south-central Chilean forearc. Earth and Planetary Science Letters 231, 23–39.CrossRefGoogle Scholar
Glodny, J., Ring, U. & Kühn, A. 2008. Coeval high-pressure metamorphism, thrusting, strike-slip and extensional shearing in the Tauern Window, Eastern Alps. Tectonics 27, TC4004, doi:10.1029/2007TC002193, 27 pp.CrossRefGoogle Scholar
Grocott, J., Brown, M., Dallmeyer, R. D., Taylor, G. K. & Treloar, P. J. 1994. Mechanisms of continental growth in extensional arcs: an example from the Andean plate-boundary zone. Geology 22, 391–4.2.3.CO;2>CrossRefGoogle Scholar
Grocott, J. & Taylor, G. K. 2002. Magmatic arc fault systems, deformation partitioning and emplacement of granitic complexes in the Coastal Cordillera, north Chilean Andes (25°30′S to 27°00′S). Journal of the Geological Society, London 159, 425–42.CrossRefGoogle Scholar
Hervé, F. 1988. Late Paleozoic subduction and accretion in Southern Chile. Episodes 11, 183–8.CrossRefGoogle Scholar
Hervé, F., Faúndez, V., Calderón, M., Massonne, H.-J. & Willner, A. P. 2007. Metamorphic and plutonic basement complexes. In The Geology of Chile (eds Moreno, T. & Gibbons, W.), pp. 5–19. London: The Geological Society.CrossRefGoogle Scholar
Irwin, J. J., García, C., Hervé, F. & Brook, M. 1988. Geology of part of a long-lived dynamic plate margin: the coastal cordillera of north-central Chile, latitude 30°51′–31°–32°S. Canadian Journal of Earth Sciences 25, 603–24.CrossRefGoogle Scholar
Lanphere, M. A. & Dalrymple, G. B. 2000. First-principles calibration of 38Ar tracers: implications for the ages of 40Ar/39Ar fluence monitors. US Geological Survey Professional Paper 1621, 10 pp.Google Scholar
Layer, P. W. 2000. Argon-40/Argon-39 age of the El'gygytgyn impact event, Chukotka, Russia. Meteoritics and Planetary Science 35, 591–9.CrossRefGoogle Scholar
Layer, P. W., Hall, C. M. & York, D. 1987. The derivation of 40Ar/39Ar age spectra of single grains of hornblende and biotite by laser step heating. Geophysical Research Letters 14, 757–60.CrossRefGoogle Scholar
Marrett, R. & Allmendinger, R. W. 1990. Kinematic analysis of fault-slip data. Journal of Structural Geology 15, 973–86.CrossRefGoogle Scholar
McDougall, I. & Harrison, T. M. 1999. Geochronology and Thermochronology by the 40Ar/39Ar-Method. Oxford: Oxford University Press, 269 pp.CrossRefGoogle Scholar
Parada, M. A., Lopez-Escobar, L., Oliveros, V., Fuentes, F., Morata, D., Calderón, M., Aguirre, L., Féraud, G., Espinoza, F., Moreno, H., Figueroa, O., Munoz Bravo, J., Troncoso Vásquez, R. & Stern, C. R. 2008. Chapter 4 Andean magmatism. In The Geology of Chile (eds Moreno, T. & Gibbons, W.), pp. 115–46. London: The Geological Society.Google Scholar
Rebelledo, S. & Charrier, R. 1994. Evolución del basamento Paleozoico en el área de Punta Claditas, Región de Coquimbo, Chile (31–32°S). Revista Geológica de Chile 21, 55–69.Google Scholar
Rebelledo, S., Solari, M. & Contreras, J. P. 2003. Foliaciones S-C en rocas Paleozoicas y Triásicas del sector de Puerto Manso, IV Región de Coquimbo. Actas 10. Congreso Geológico Chileno 2003, 1–6.Google Scholar
Rivano, S. & Sepúlveda, P. 1983. Hallazgo de foraminíferos del Carbonífero Superior en la Formación Huentelauquén. Revista Geológica de Chile 19–20, 25–35.Google Scholar
Rivano, S. & Sepúlveda, P. 1985. Las calizas de la Formación Huenteauquén: Depósitos de aguas templadas a frías en el Carbonífero Superior-Pérmico Inferior. Revista Geológica de Chile 25–26, 29–38.Google Scholar
Richter, P., Ring, U., Willner, A. P. & Leiss, B. 2007. Structural contacts in subduction complexes and their tectonic significance: the late Palaeozoic coastal accretionary wedge of central Chile. Journal of the Geological Society, London 164, 203–14.CrossRefGoogle Scholar
Ring, U. 2008. The tectonic evolution of the Franciscan Subduction Complex: implications for the exhumation of high-pressure rocks in subduction-related accretionary wedges. Geological Society of America Special Paper 445, 1–91.Google Scholar
Ring, U. & Brandon, M. T. 1994. Kinematic data for the Coast Range fault and implications for exhumation of the Franciscan complex. Geology 22, 735–8.2.3.CO;2>CrossRefGoogle Scholar
Ring, U. & Brandon, M. T. 1999. Ductile strain, coaxial deformation and mass loss in the Franciscan complex: implications for exhumation processes in subduction zones. In Exhumation Processes: Normal faulting, ductile flow and erosion (eds Ring, U., Brandon, M. T., Lister, G. S. & Willett, S.), pp. 55–85. Geological Society of London, Special Publication no. 154.Google Scholar
Ring, U. & Brandon, M. T. 2008. Exhumation settings. Part I: relatively simple cases. International Geological Review 50, 97–120.CrossRefGoogle Scholar
Ring, U., Brandon, M. T. & Ramthun, A. 2001. Solution-mass-transfer deformation adjacent to the Glarus thrust, with implications for the tectonic evolution of the Alpine wedge in eastern Switzerland. Journal of Structural Geology 23, 1491–505.CrossRefGoogle Scholar
Robin, P.-Y. F. & Cruden, A. R. 1994. Strain and vorticity patterns in ideally ductile transpression zones. Journal of Structural Geology 16, 447–66.CrossRefGoogle Scholar
Samson, S. D. & Alexander, E. C. 1987. Calibration of the interlaboratory 40Ar/39Ar dating standard, MMhb1. Chemical Geology 66, 27–34.Google Scholar
Scheuber, E. & Andriessen, P. M. 1990. The kinematic significance of the Atacama Fault zone, northern, Chile. Journal of Structural Geology 21, 243–57.CrossRefGoogle Scholar
Scheuber, E. & Gonzalez, G. 1999. Tectonics of the Jurassic-Early Cretaceous magmatic arc of the north Chilean Coastal Cordillera (22°–26°S): a story of crustal deformation along a convergent plate boundary. Tectonics 18, 895–910.CrossRefGoogle Scholar
Steiger, R. H. & Jäger, E. 1977. Subcommission on geochronology: convention on the use of decay constants in geo and cosmochronology. Earth and Planetary Science Letters 36, 359–62.CrossRefGoogle Scholar
Thiele, R. & Hervé, F. 1984 Sedimentación y tectónica de antearco en los terrenos preandinos del Norte Chico, Chile. Revista Geológica de Chile 22, 61–75.Google Scholar
Thomson, S. N. & Hervé, F. 2002. New time constraints for metamorphism at the ancestral Pacific Gondwana margin of southern Chile (42°S–52°S). Revista Geológica de Chile 29, 255–71.CrossRefGoogle Scholar
Willner, A. P., Gerdes, A. & Massonne, H.-J. 2008. History of crustal growth and recycling at the Pacific convergent margin of South America at latitudes 29°–36°S revealed by a U-Pb and Lu-Hf isotope study of detrital zircon from late Paleozoic accretionary systems. Chemical Geology 253, 114–29.CrossRefGoogle Scholar
Willner, A. P., Massone, H.-J., Ring, U., Sudo, M. & Thomson, S. N. 2011. P–T evolution and timing of a late Palaeozoic fore-arc system and its heterogeneous Mesozoic overprint in north-central Chile (latitudes 31–32°S). Geological Magazine, 149, 177–207.CrossRefGoogle Scholar
Willner, A. P., Richter, P. & Ring, U. 2009. Structural overprint of a late Paleozoic accretionary system in north-central Chile (34°–35°S) during postaccretional deformation. Andean Geology 36, 17–36.CrossRefGoogle Scholar
Willner, A. P., Thomson, S. N., Kröner, A., Wartho, J. A., Wijbrans, J. & Hervé, F. 2005. Time markers for the evolution and exhumation history of a late Palaeozoic paired metamorphic belt in central Chile (34°–35°30´S). Journal of Petrology 46, 1835–58.CrossRefGoogle Scholar
York, D., Hall, C. M., Yanase, Y., Hanes, J. A. & Kenyon, W. J. 1981. 40Ar/39Ar dating of terrestrial minerals with a continuous laser. Geophysical Research Letters 8, 1136–8.CrossRefGoogle Scholar
Supplementary material: PDF

Ring Supplementary Appendix

Ring Supplementary Appendix

Download Ring Supplementary Appendix(PDF)
PDF 122.8 KB