Plate boundary readjustment in oblique convergence: Example of the Neogene of Hispaniola, Greater Antilles

Tectonics ◽  
2000 ◽  
Vol 19 (4) ◽  
pp. 630-648 ◽  
Author(s):  
Manuel Pubellier ◽  
Alain Mauffret ◽  
Sylvie Leroy ◽  
Jean Marie Vila ◽  
Helliot Amilcar
Keyword(s):  
Plate Boundary ◽  
Greater Antilles ◽  
Oblique Convergence

Seismotectonics of central and NW Himalaya: plate boundary–wedge thrust earthquakes in thin- and thick-skinned tectonic framework

2018 ◽  
Vol 481 (1) ◽  
pp. 41-63 ◽  
Author(s):  
V. C. Thakur ◽  
R. Jayangondaperumal ◽  
V. Joevivek
Keyword(s):  
Hanging Wall ◽  
Plate Boundary ◽  
Central Himalaya ◽  
Main Central Thrust ◽  
Nw Himalaya ◽  
Oblique Convergence ◽  
Normal Convergence ◽  
Tectonic Framework ◽  
Historical Accounts ◽  
Large Earthquakes

AbstractThe tectonic framework of NW Himalaya is different from that of the central Himalaya with respect to the position of the Main Central Thrust and Higher Himalayan Crystalline and the Lesser and Sub Himalayan structures. The former is characterized by thick-skinned tectonics, whereas the thin-skinned model explains the tectonic evolution of the central Himalaya. The boundary between the two segments of Himalaya is recognized along the Ropar–Manali lineament fault zone. The normal convergence rate within the Himalaya decreases from c. 18 mm a−1 in the central to c. 15 mm a−1 in the NW segments. In the last 800 years of historical accounts of large earthquakes of magnitude Mw ≥ 7, there are seven earthquakes clustered in the central Himalaya, whereas three reported earthquakes are widely separated in the NW Himalaya. The earthquakes in central Himalaya are inferred as occurring over the plate boundary fault, the Main Himalayan Thrust. The wedge thrust earthquakes in NW Himalaya originate over the faults on the hanging wall of the Main Himalayan Thrust. Palaeoseismic evidence recorded on the Himalayan front suggests the occurrence of giant earthquakes in the central Himalaya. The lack of such an event reported in the NW Himalaya may be due to oblique convergence.

Chapter 17 Accretionary orogens reworked in an overriding plate setting during protracted continent–continent collision, Sveconorwegian orogen, southwestern Sweden

2020 ◽  
Vol 50 (1) ◽  
pp. 435-448 ◽  
Author(s):  
Michael B. Stephens ◽  
Carl-Henric Wahlgren
Keyword(s):  
Plate Boundary ◽  
Crustal Thickening ◽  
Magmatic Activity ◽  
Continental Lithosphere ◽  
Extensional Deformation ◽  
Continental Plate ◽  
Oblique Convergence ◽  
Eastern Segment ◽  
Sveconorwegian Orogen ◽  
Subduction System

AbstractThe Eastern Segment in the Sveconorwegian orogen, southwestern Sweden, is dominated by 2.0–1.8, 1.7 and 1.5–1.4 Ga crust; and the overlying Idefjorden terrane by 1.6–1.5 Ga crust. Assuming reorganization of a subduction system prior to 1.5–1.4 Ga and applying a sinistral transpressive component of disruption during the subsequent Sveconorwegian orogeny (1.1–0.9 Ga), the Idefjorden terrane is inferred to be indigenous outboard rather than exotic with respect to the continental plate Fennoscandia (Baltica). The geological record then records successive westwards shift of accretionary orogens along a convergent plate boundary for at least 500 million years. Sveconorwegian foreland-younging tectonic cycles at c. 1.05 (or older)–1.02 Ga (Idefjorden terrane) and at c. 0.99–0.95 Ga (Eastern Segment) prevailed. Crustal thickening and exhumation during oblique convergence preceded migmatization, magmatic activity and a changeover to an extensional regime, possibly triggered by delamination of continental lithosphere, in each cycle. Convergence after 0.95 Ga involved antiformal doming with extensional deformation at higher crustal levels (Eastern Segment) and continued magmatic activity (Idefjorden terrane). An overriding plate setting is inferred during either accretionary orogeny or, more probably, protracted continent–continent collision. Continuity of the erosional fronts in the Grenville and Sveconorwegian orogens is questioned.

scholarly journals Evidence for a large strike-slip component during the 1960 Chilean earthquake

2019 ◽  
Vol 218 (1) ◽  
pp. 1-32 ◽  
Author(s):  
Hiroo Kanamori ◽  
Luis Rivera ◽  
Sophie Lambotte
Keyword(s):  
Subduction Zone ◽  
Plate Boundary ◽  
Strike Slip ◽  
Lateral Strain ◽  
Long Period ◽  
Great Earthquakes ◽  
Oblique Convergence ◽  
Maule Earthquake ◽  
Subduction Zone Earthquakes ◽  
Chilean Earthquake

SUMMARY The strainmeter record observed at Isabella (ISA), California, for the 1960 Chilean earthquake (Mw = 9.5) is one of the most important historical records in seismology because it was one of the three records that provided the opportunity for the first definitive observations of free oscillations of the Earth. Because of the orientation of the strainmeter rod with respect to the back azimuth to Chile, the ISA strainmeter is relatively insensitive to G (Love) waves and higher order (order ≥ 6) toroidal modes, yet long-period G waves and toroidal modes were recorded with large amplitude on this record. This observation cannot be explained with the conventional low-angle thrust mechanism typical of great subduction-zone earthquakes and requires an oblique mechanism with half strike-slip and half thrust. The strain record at Ogdenburg, New Jersey, the Press–Ewing seismograms at Berkeley, California, and the ultra-long period displacement record at Pasadena, California, also support the oblique mechanism. We tested the performance of the ISA strainmeter using other events including the 1964 Alaskan earthquake and found no instrumental problems. Thus, the ISA observation of large G/R and toroidal/spheroidal ratios most likely reflects the real characteristics of the 1960 Chilean earthquake, rather than an observational artefact. The interpretation of the large strike-slip component is not unique, but it may represent release of the strike-slip strain that has accumulated along the plate boundary as a result of oblique convergence at the Nazca–South American plate boundary. The slip direction of the 2010 Chilean (Maule) earthquake ( Mw = 8.8) is rotated by about 10° clockwise from the plate convergence direction suggesting that right-lateral strain comparable to that of an Mw = 8.3 earthquake remained unreleased and accumulates near the plate boundary. One possible scenario is that the strike-slip strain accumulated over several great earthquakes like the 2010 Maule earthquake was released during the 1960 Chilean earthquake. If this is the case, we cannot always expect a similar behaviour for all the great earthquakes occurring in the same subduction zone and such variability needs to be considered in long-term hazard assessment of subduction-zone earthquakes.

The northern Caribbean Plate boundary in Hispaniola; tectonics and stratigraphy of the Dominican Cordillera septentrional, (Greater Antilles)

1983 ◽  
Vol S7-XXV (1) ◽  
pp. 83-89 ◽  
Author(s):  
J. Bourgois ◽  
Alphonse Blondeau ◽  
H. Feinberg ◽  
G. Glacon ◽  
J. M. Vila
Keyword(s):  
Plate Boundary ◽  
Greater Antilles ◽  
Caribbean Plate

Paleomagnetic and structural study of the NEastern Caribbean plate as mean to give paleogeographic constrains for fauna dispersal.

2021 ◽  
Author(s):  
Leny Montheil ◽  
Douwe Van Hinsbergen ◽  
Philippe Münch ◽  
Pierre Camps ◽  
Mélody Philippon
Keyword(s):  
Puerto Rico ◽  
Plate Boundary ◽  
Vertical Axis ◽  
Plate Motion ◽  
Lesser Antilles ◽  
Caribbean Region ◽  
Greater Antilles ◽  
Caribbean Plate ◽  
The Bahamas ◽  
The Caribbean

<p>Since the Eocene, the northeastern corner of the Caribbean plate is shaped by the indentation of the buoyant Bahamas platform with the Greater Caribbean Arc, the suture of a portion of the Antillean subduction zone along Cuba and Hispaniola and the subsequent relocation of the plate boundary along the strike slip Cayman Trough. Puzzlingly enough, these major re-arrangements followed a plate motion reorganization (Boschmann et al., 2014). During this kinematic reorganization, the Lesser Antilles trench initiated (or subduction intensified) along the eastern boundary of the Caribbean plate and progressively bent, resulting in an increase of subduction obliquity from south to north (Philippon et al., 2020a). This curvature has been, and still may be, associated with deformation within the Caribbean plate. Interestingly, in the 10-15 Ma following the plate reorganization, a hypothetical, now submerged “landbridge” allowed the dispersion of terrestrial fauna from South America to the Greater Antilles: the GAARlandia landbridge (land of Greater Antilles and Aves Ridge). Although it has been recently shown that Puerto Rico and the Northern Lesser Antilles where connected once forming a land mass called GrANoLA around 33-35 Ma (Philippon et al., 2020b), these rapids and drastics geodynamical changes may have impacted the regional paleogeography, which remains to be constrained. The intraplate deformation in the north-est Caribbean region associated with the plate reorganization, the Bahamas indentation, and the plate boundary curvature likely hold the key to (part of) the evolution of this landbridge.<br>At present day, the N-Eastern border of the Caribbean plate shows parallel to the trench faults dissecting the plate in a sliver-like manner. This “sliver” is cross cutted by perpendicular to the trench faults in four crustal blocks: Gonave, Hispaniola, Puerto Rico and the Northern Lesser Antilles. Present-day and past kinematics of these blocks, and even their existence, are still debated.</p><p>In this study, in the course of the French GAARAnti project, we focus on paleomagnetically determined vertical axis rotations that affected Puerto Rico and the Northern Lesser Antilles blocks since the Eocene, and use these to inform kinematic reconstructions constrained by regional structural analysis and Ar<sup>40</sup>-Ar<sup>39</sup> geochronology. These reconstructions will be used to refine the paleogeographic evolution of the NEastern edge of the Caribbean plate since the Eocene in order test the GAARlandia hypothesis.</p><p>A new set of paleomagnetic data (180 Oligo-Miocene specimens of sediments sampled in 18 sites) indicates that the Puerto Rico block underwent an early to mid-Miocene 10° counterclockwise (CCW) rotation. This result clearly differs from those of Reid et al., 1991 who concluded a Late Miocene 25° CCW rotation and that is currently used by the community to interpret the tectonic history of the northeastern Caribbean plate. The use of a larger dataset, that geographically covers the entire island, and of a more recent reference frame explain the difference observed between the two results. This new result will lead to a re-interpretation of the tectonic evolution of the region that will be integrated in a regional kinematic reconstruction.</p>

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