Late neogene history of the Pacific-Caribbean gateway

Gerta Keller, C. E. Zenker, S. M. Stone

Research output: Contribution to journalArticle

92 Scopus citations

Abstract

Planktic foraminiferal provinces of Caribbean DSDP Hole 502A and East Pacific DSDP Hole 503A have been analyzed and compared with benthic and planktic isotope records, carbonate, hiatus events, and sea level changes. Four major events are evident in the closure history of the Pacific-Caribbean gateway, at 6.2, 4.2, 2.4 and 1.8 Ma. The faunal change at 6.2 Ma coincides with the δ13C shift and is primarily caused by upwelling in the western Caribbean. This suggests restricted circulation of intermediate water and deflection northeastward, strengthening the Gulf Stream as reflected in the first major erosion on Blake Plateau. The second faunal change, at 4.2 Ma, coincides with increased surface water salinity evident in δ18O data and indicates increasingly restricted surface water exchange. Divergence of faunal provinces beginning at 2.4 Ma is marked by increasing abundance of high salinity tolerant species (Globigerinoides ruber) in the Caribbean. This suggests that initial closure of the Pacific-Caribbean gateway and cessation of sustained surface current flow between the Pacific and Caribbean occurred as late as 2.4 Ma. Maximum divergence of faunal provinces begins at 1.8 Ma and continues to the present. This implies that at least incipient littoral-neritic leakage occurred across the Pacific-Caribbean gateway between 2.4 and 1.8 Ma, with final closure by 1.8 Ma.

Original languageEnglish (US)
Pages (from-to)73-108
Number of pages36
JournalJournal of South American Earth Sciences
Volume2
Issue number1
DOIs
StatePublished - 1989

All Science Journal Classification (ASJC) codes

  • Geology
  • Earth-Surface Processes

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