Relationship of benthic foraminiferal diversity to paleoproductivity in the Neogene Caribbean

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doi: 10.1016/j.palaeo.2007.05.017
Author(s): Jain, Sreepat; Collins, Laurel S.; Hayek, Lee-Ann C.
Author Affiliation(s): Primary:
Smithsonian Institution, National Museum of Natural History, Washington, DC, United States
Florida International University, United States
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, 255(3-4), p.223-245. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 112 refs.; illus., incl. 11 tables, sketch map
Summary: Diversity trends 8.3-2.5 Ma in Caribbean deep-sea foraminifera, as interpreted from the indices Fisher's α and the Information Index [H(S)] parallel paleoproductivity proxies (benthic foraminiferal infaunal/epifaunal species ratio, benthic foraminifer accumulation rates and flux of organic carbon to the seafloor). Paleoproductivity never reached a eutrophic threshold value above which we would predict opposite trends of high paleoproductivity and low diversity, consistent with stressful conditions. Instead, results are similar to those from other studies of oligotrophic settings that show a positive and statistically significant correlation between paleoproductivity and diversity. The correlations between current intensity and watermass oxygenation with diversity are negative and statistically significant. These results are also borne out by Principal Component Analysis (PCA). Intervals of increased relative abundance of Epistominella exigua, a proxy for seasonality of phytodetrital input to the seafloor, coincide with increased diversity, suggesting that pulsed paleoproductivity enhanced the diversity signal in the Caribbean. Diversity and paleoproductivity peaked in the Caribbean at 7.9 Ma, and declined thereafter due to the cut off of the nutrient-rich Pacific deep waters (<1000 m) into the Caribbean. From 7.6 to 4.2 Ma, both diversity and paleoproductivity increased. With the complete closure of the Caribbean-Pacific seaway at 4.2 Ma, both diversity and paleoproductivity gradually decreased from a high at 4.2 Ma to moderate values until the end of the study interval at 2.5 Ma. Major intervals of significant shifts in Caribbean diversity and paleoproductivity were also confirmed with SHEBI analysis that displays a diverging trend between the Pacific and Caribbean sites since 7.9 Ma, with the Caribbean displaying decreasing values. In summary, in the Caribbean, decreased paleoproductivity due to the gradual constriction and the final closure of the Central American Seaway (CAS) led to decreased deep-sea benthic foraminiferal diversity and that both benthic foraminiferal diversity and paleoproductivity maintained a positive relationship. Abstract Copyright (2007) Elsevier, B.V.
Year of Publication: 2007
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Benthic taxa; Biochemical sedimentation; Bioclastic sedimentation; Biodiversity; Biofacies; Caribbean Sea; Cenozoic; Correlation; DSDP Site 502; DSDP Site 503; Deep Sea Drilling Project; Deep-sea environment; East Pacific; Equatorial Pacific; Foraminifera; IPOD; Invertebrata; Leg 165; Leg 68; Marine environment; Microfossils; Neogene; North Atlantic; Nutrients; ODP Site 999; Ocean Drilling Program; Pacific Ocean; Paleo-oceanography; Paleoecology; Paleogeography; Principal components analysis; Productivity; Protista; Seasonal variations; Sedimentation; Sedimentation rates; Statistical analysis; Tertiary; Trophic analysis
Coordinates: N112925 N112925 W0792247 W0792247
N040303 N040303 W0953813 W0953813
N124437 N124437 W0784422 W0784422
Record ID: 2008024125
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands