A Late Cretaceous Adnidtic intrusion from Northern Haiti: additional evidence for slap melting and implicaions for migration of ridge-trench-trench triple junction during the Cretaceous in the Greater Antilles

We present a new U-Pb zircon age and geochemical data from an intermediate talc-alkaline pluton with adakitic affinity from NW Hispaniola (Haiti). The data provide important constraints and offer new insight on the Late Cretaceous (similar to 90 Ma) development and geological evolution of the Greater Antilles Arc (GAA). The pluton intrudes Cretaceous basalts and mafic basic tuffs of the volcanic arc domain in the Massif du Nord (northern Haiti), equivalent to the Tireo Fm (Cordillera Central) in the Dominican Republic. The talc-alkaline, low-K tonalite shows LREE enrichment, and HREE depletion and have geochemical features similar to adakites, including 67.11 wt.% SiO2, high Na2O contents (3.69 wt.%), and high Sr/Y (38.6). U-Pb SHRIMP zircon dating yielded a concordant Pb-206/U-238 emplacement age of 88.9 +/- 1.1 Ma, similar to other talc-alkaline intrusions in Hispaniola and Cuba related to the Cretaceous GAA. We link the presence of rocks with adakitic affinities in Eastern Cuba (La Corea and Sierra del Convento Melanges), Haiti (Massif du Nord; present study), and Dominican Republic (Cordillera Central) with subduction of the Proto-Caribbean ridge and eastward (present coordinates) migration of the corresponding ridge-trench-trench triple junction since at least similar to 120 Ma in eastern Cuba to the mid-Cretaceous (similar to 90 Ma) in Hispaniola. Here we show that this migration is not consistent with left-lateral oblique subduction and propose that it was not characterized by steady motion but by sudden jumps resulting from the segmentation of the proto-Caribbean ridge by transform faults. Ridge subduction and jumping triple point migration should have been active during the Late Cretaceous to early Tertiary, when the activity of the Proto-Caribbean ridge vanished.

Automated summary

This study presents new U-Pb zircon age and geochemical data from an intermediate talc-alkaline pluton in NW Hispaniola, shedding light on the Late Cretaceous development and geological evolution of the Greater Antilles Arc. The data suggest a connection between rocks with adakitic affinities in Eastern Cuba, Haiti, and Dominican Republic, and reveal potential ridge subduction and triple point migration during the Late Cretaceous to early Tertiary period.