The Caribbean and Farallon Plates Connected: Constraints From Stratigraphy and Paleomagnetism of the Nicoya Peninsula, Costa Rica

Abstract

Plate kinematic reconstructions play an essential role in our understanding of global geodynamics, but become increasingly difficult to constrain back in geological time due to the subduction of oceanic lithosphere. Here, we attempt to kinematically reconstruct the Cretaceous and older plate tectonic history of the Caribbean Plate within the Mesozoic Panthalassa (paleo-Pacific) Ocean. To this end, we present new paleomagnetic data from Jurassic and Cretaceous oceanic sedimentary and volcanic Large Igneous Province-related rocks of the Nicoya Peninsula and Murciélago Islands of northwestern Costa Rica. We use these data, in combination with constraints from marine magnetic anomalies to infer the age of the lithospheric basement, seismic tomography to locate deep-mantle plume generation zones, and general kinematic feasibility, to test different reconstruction scenarios connecting the Caribbean Plate to the Farallon Plate as restored from Pacific spreading records. Our resulting reconstruction implies that the western Caribbean subduction zone initiated around 100 Ma, in an intraoceanic setting, breaking up oceanic lithosphere of at least 70 Myr old.

Eocene intra-plate shortening responsible for the rise of a faunal pathway in the northeastern Caribbean realm

“…The Caribbean Plate consists mainly of Jurassic to Lower Cretaceous oceanic crust derived from the Farallon Plate [ 33 ]. Its lithosphere is partly covered by the ∼90 Ma Caribbean Large Igneous Province [ 14 , 34 ], which lies west of an extinct intra-oceanic arc represented by the Aves Ridge and an associated Jurassic back-arc basin to the east that currently underlies the Lesser Antilles islands [ 14 , 15 , 17 ] ( Fig 1C ).…”

Earth's Magnetic Field Strength and the Cretaceous Normal Superchron: New Data From Costa Rica

“…In order to compare our results from Costa Rica to all the worldwide data with similar ages, we calculated virtual axial dipole moments (VADMs), using paleolatitudes from both the study of Boshman et al (2019) (VADM; Table 2 and Figure 5) and the present-day latitudes (VADM1; Table 2 and Figure 5), between 9 and 10° N (Table 1). The paleolatitudes reported by Boshman et al (2019) range from 1° to 9° N (Table 2). The VADM values are systematically slightly higher than the VADM1 values but statistically indistinguishable (overlapping within the quoted 1σ errors).…”

Caribbean intra-plate deformation: Paleomagnetic evidence from St. Barthélemy Island for post-Oligocene rotation in the Lesser Antilles forearc

“…Plate reconstructions suggest that at least part of the modern curvature of the northern Caribbean region was inherited from Mesozoic plate boundary configurations, but part of it may be much younger, and is perhaps even actively forming today. The geometry of the Caribbean plate results from a long-term evolution that started with the split from the Farallon plate during the Late Cretaceous (Pindell and Kennan, 2009;Whattam and Stern, 2015;Boschman et al, 2019). The Caribbean plate was then captured between the North and South American continents and has been nearly mantle-stationary since ~50 Ma (Boschman et al, 2014;Montes et al, 2019a).…”