Paleoseismology of the Marquesado-La Rinconada thrust system, Eastern Precordillera of Argentina
Excavated trenches at two sites across the Marquesado–La Rinconada fault system along the eastern Precordilleran front south of San Juan, Argentina, reveal the earthquake history of this rapidly urbanizing region. Interpretation of earthquakes is based on both the generation of colluvial wedges and...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2022-12-01
|
| Series: | Frontiers in Earth Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2022.1032357/full |
| _version_ | 1828269620027457536 |
|---|---|
| author | Thomas K. Rockwell Carlos H. Costa Andrew J. Meigs Daniel Ragona Daniel Ragona Lewis A. Owen Madhav Krishna Murari Madhav Krishna Murari Eulalia Masana Andrés D. Richard |
| author_facet | Thomas K. Rockwell Carlos H. Costa Andrew J. Meigs Daniel Ragona Daniel Ragona Lewis A. Owen Madhav Krishna Murari Madhav Krishna Murari Eulalia Masana Andrés D. Richard |
| author_sort | Thomas K. Rockwell |
| collection | DOAJ |
| description | Excavated trenches at two sites across the Marquesado–La Rinconada fault system along the eastern Precordilleran front south of San Juan, Argentina, reveal the earthquake history of this rapidly urbanizing region. Interpretation of earthquakes is based on both the generation of colluvial wedges and upward fault terminations, as well as folding events in fine-grained alluvium ponded behind upslope-facing fault scarps. The ages of the past five interpreted earthquakes at the Loma Negra site are E1 at 2.8 ± 2.8 ka, E2 at 7.1 ± 1.5 ka, E3 at 9.6 ± 1.3 ka, E4 at 14.4 ± 2.1 ka, and E5 at 17.2 ± 3.1 ka. At the Jejenes sites, we documented event ages of 2.7 ± 0.1 ka, 3.9 ± 0.6 ka, 5.9 ± 1.3 ka, and 11.4 ± 4 ka. These results indicate that the recurrence interval along the Marquesado–La Rinconada fault zone averages several thousand years. The inferred displacements at the Jejenes site are about 1.1 m for E1, E3, and E4 and 2.1 m for event E2, whereas the displacements at Loma Negra averaged about 1 m, but the most recent event displays less slip. Notably, the older events seem to have been larger and emergent, whereas the youngest event appears to have been smaller and blind in the ponded sediment; this may partially explain the poor expression of classic colluvial wedges associated with some events. Despite the fact that active surface faulting has an uncertain relationship with the primary seismic sources at depth in the crust, past and future events of Mw ∼7.5 are consistent with the length scale of active deformation, the ∼1–2 m slip per event scale of these ruptures, and the size of historical earthquakes. |
| first_indexed | 2024-04-13T05:33:13Z |
| format | Article |
| id | doaj.art-7d6b6f1acd694f9f8ee9ec62b1191eac |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-04-13T05:33:13Z |
| publishDate | 2022-12-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-7d6b6f1acd694f9f8ee9ec62b1191eac2022-12-22T03:00:22ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632022-12-011010.3389/feart.2022.10323571032357Paleoseismology of the Marquesado-La Rinconada thrust system, Eastern Precordillera of ArgentinaThomas K. Rockwell0Carlos H. Costa1Andrew J. Meigs2Daniel Ragona3Daniel Ragona4Lewis A. Owen5Madhav Krishna Murari6Madhav Krishna Murari7Eulalia Masana8Andrés D. Richard9Department of Geological Sciences, San Diego State University, San Diego, CA, United StatesDepartamento de Geologia, Universidad Nacional de San Luis, San Luis, ArgentinaCollege of Earth, Ocean and Atmospheric Sciences, Oregon State University, Corvallis, OR, United StatesDepartment of Geological Sciences, San Diego State University, San Diego, CA, United StatesEcopetrol, Bogota, ColombiaDepartment of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC, United StatesDepartment of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC, United StatesInter-University Accelerator Center, New Delhi, IndiaDinàmica de la Terra i del Oceà, University of Barcelona, Barcelona, SpainDepartamento de Geologia, Universidad Nacional de San Luis, San Luis, ArgentinaExcavated trenches at two sites across the Marquesado–La Rinconada fault system along the eastern Precordilleran front south of San Juan, Argentina, reveal the earthquake history of this rapidly urbanizing region. Interpretation of earthquakes is based on both the generation of colluvial wedges and upward fault terminations, as well as folding events in fine-grained alluvium ponded behind upslope-facing fault scarps. The ages of the past five interpreted earthquakes at the Loma Negra site are E1 at 2.8 ± 2.8 ka, E2 at 7.1 ± 1.5 ka, E3 at 9.6 ± 1.3 ka, E4 at 14.4 ± 2.1 ka, and E5 at 17.2 ± 3.1 ka. At the Jejenes sites, we documented event ages of 2.7 ± 0.1 ka, 3.9 ± 0.6 ka, 5.9 ± 1.3 ka, and 11.4 ± 4 ka. These results indicate that the recurrence interval along the Marquesado–La Rinconada fault zone averages several thousand years. The inferred displacements at the Jejenes site are about 1.1 m for E1, E3, and E4 and 2.1 m for event E2, whereas the displacements at Loma Negra averaged about 1 m, but the most recent event displays less slip. Notably, the older events seem to have been larger and emergent, whereas the youngest event appears to have been smaller and blind in the ponded sediment; this may partially explain the poor expression of classic colluvial wedges associated with some events. Despite the fact that active surface faulting has an uncertain relationship with the primary seismic sources at depth in the crust, past and future events of Mw ∼7.5 are consistent with the length scale of active deformation, the ∼1–2 m slip per event scale of these ruptures, and the size of historical earthquakes.https://www.frontiersin.org/articles/10.3389/feart.2022.1032357/fullpaleoseismologySan Juan earthquake hazardMarquesado–La Rinconada faultEastern PrecordilleraArgentinaAndes |
| spellingShingle | Thomas K. Rockwell Carlos H. Costa Andrew J. Meigs Daniel Ragona Daniel Ragona Lewis A. Owen Madhav Krishna Murari Madhav Krishna Murari Eulalia Masana Andrés D. Richard Paleoseismology of the Marquesado-La Rinconada thrust system, Eastern Precordillera of Argentina Frontiers in Earth Science paleoseismology San Juan earthquake hazard Marquesado–La Rinconada fault Eastern Precordillera Argentina Andes |
| title | Paleoseismology of the Marquesado-La Rinconada thrust system, Eastern Precordillera of Argentina |
| title_full | Paleoseismology of the Marquesado-La Rinconada thrust system, Eastern Precordillera of Argentina |
| title_fullStr | Paleoseismology of the Marquesado-La Rinconada thrust system, Eastern Precordillera of Argentina |
| title_full_unstemmed | Paleoseismology of the Marquesado-La Rinconada thrust system, Eastern Precordillera of Argentina |
| title_short | Paleoseismology of the Marquesado-La Rinconada thrust system, Eastern Precordillera of Argentina |
| title_sort | paleoseismology of the marquesado la rinconada thrust system eastern precordillera of argentina |
| topic | paleoseismology San Juan earthquake hazard Marquesado–La Rinconada fault Eastern Precordillera Argentina Andes |
| url | https://www.frontiersin.org/articles/10.3389/feart.2022.1032357/full |
| work_keys_str_mv | AT thomaskrockwell paleoseismologyofthemarquesadolarinconadathrustsystemeasternprecordilleraofargentina AT carloshcosta paleoseismologyofthemarquesadolarinconadathrustsystemeasternprecordilleraofargentina AT andrewjmeigs paleoseismologyofthemarquesadolarinconadathrustsystemeasternprecordilleraofargentina AT danielragona paleoseismologyofthemarquesadolarinconadathrustsystemeasternprecordilleraofargentina AT danielragona paleoseismologyofthemarquesadolarinconadathrustsystemeasternprecordilleraofargentina AT lewisaowen paleoseismologyofthemarquesadolarinconadathrustsystemeasternprecordilleraofargentina AT madhavkrishnamurari paleoseismologyofthemarquesadolarinconadathrustsystemeasternprecordilleraofargentina AT madhavkrishnamurari paleoseismologyofthemarquesadolarinconadathrustsystemeasternprecordilleraofargentina AT eulaliamasana paleoseismologyofthemarquesadolarinconadathrustsystemeasternprecordilleraofargentina AT andresdrichard paleoseismologyofthemarquesadolarinconadathrustsystemeasternprecordilleraofargentina |