Role of Panama uplift on oceanic freshwater balance

Relationship of benthic foraminiferal diversity to paleoproductivity in the Neogene Caribbean

“…1982; Haug and Tiedemann, 1998;Driscoll and Haug, 1998;Haug et al, 2001). The main events listed in Table 6 are used to divide the 8.3-2.5 Ma study period into three intervals: a) Early shoaling (8.3-7.9 Ma), b) Pre-closure (7.9-4.2 Ma) and c) Post-closure (4.2-2.5 Ma) (see Jain and Collins for details).…”

“…The Post-closure interval (4.2-2.5 Ma) in the Caribbean is marked by an abrupt dip in diversity and Equitability that also coincides with the timing of establishment of the Atlantic-Pacific salinity contrast and the complete CAS closure (Keigwin, 1982;Haug et al, 2001; Fig. 3).…”

“…The rise of the Panamanian isthmus and the environmental changes linked with the closure of the Central American Seaway (CAS) provides an opportunity that allows for better understanding of the relationship between tectonic, climatic and oceanographic changes on one hand (Keigwin, 1982;Duque-Caro, 1990;Collins et al, 1996;Haug and Tiedemann, 1998;Haug et al, 2001;Bickert et al, 2004) and patterns of speciation, extinction and morphological evolution of organisms on Available online at www.sciencedirect.com Palaeogeography, Palaeoclimatology, Palaeoecology 255 (2007) 223 -245 www.elsevier.com/locate/palaeo the other (Vermeij and Petuch, 1986;Roopnarine, 1996;Collins et al, 1996;Jackson et al, 1999;Jackson and Johnson, 2000). Previous studies from the western Atlantic (Allmon et al, 1996) and Caribbean (Vermeij and Petuch, 1986;Collins, 1996;Collins et al, 1996) predicted that seaway constriction and closure led to decreased biologic productivity caused by decreased current velocity and coastal upwelling and conversely, increased seasonality and primary productivity in the Eastern Equatorial Pacific (Keigwin, 1982;Jones and Hasson, 1985;Teranes et al, 1996;Ibaraki, 1997).…”

History of upwelling in the Tropical Eastern Pacific and the paleogeography of the Isthmus of Panama

“…Uplift rates based on paleobathymetries of marine sediments from across the Isthmus suggest that the majority of the volcanic arc was submerged up until very recently with bathyal sediments of latest Miocene age present in the Caribbean and Pacific of western Panama, the Caribbean of central Panama and eastern Panama (Coates et al, 1992;Collins, 1992Collins, , 1993Collins, , 1996Coates, 1999;Coates et al, 2000Coates et al, , 2003Coates et al, , 2004Coates et al, , 2005. Strong similarities between Pacific and Caribbean Mio-Pliocene biota (Chaisson and Ravelo, 2000;O'Dea et al, 2007b) and near-identical environmental conditions on either side of the Isthmus (Keigwin, 1978(Keigwin, , 1982Keller et al, 1989;Haug and Tiedemann, 1998;Haug et al, 2001) in the Early Pliocene imply the CAS was maintained in some form until the mid-Pliocene. Nevertheless, well-studied and extensive lacustrine sediments, shallow water reefs and mangroves, plus a continental-like mammal fauna in the Canal Zone of Panama demonstrate the presence of substantial subaerial land(s) in the middle Miocene (Whitmore and Stewart, 1965;Kirby and MacFadden, 2005;Johnson and Kirby, 2006;Retallack and Kirby, 2007;Kirby et al, 2008).…”

“…Consequently, when the Isthmus severed the marine connection in the Neogene, oceanic circulation on a global scale was fundamentally altered with equally global effects. These included major shifts in the salinity patterns of equatorial waters (Haug et al, 2001), radical changes in latitudinal heat transport in the Atlantic, the initiation and intensification of northern hemisphere glaciation (Haug and Tiedemann, 1998) (but see subsequent interrogation of this theory by Klocker et al (2005)) and the desertification of Africa which may have been decisive in hominid evolution (Stanley, 1998).…”