North American glacial meltwater history for the past 2.3 m.y.; oxygen isotope evidence from the Gulf of Mexico

• Published in: Geology (Boulder) 1993-06, Vol.21 (6), p.483-486
• Main Authors: Joyce, J. Edward, Tjalsma, Leonard R. C, Prutzman, John M
• Format: Article
• Language: English
• Subjects: Atlantic Ocean; biochemistry; Cenozoic; deglaciation; Foraminifera; geochemical indicators; Geochemistry; Geology; glacial environment; glacial geology; glaciation; Glaciers; glaciomarine environment; Globigerinacea; Globigerinidae; Globigerinoides; Globigerinoides ruber; Globigerinoides sacculifer; Gulf of Mexico; high-resolution methods; Invertebrata; isotope ratios; isotopes; Leg 100; marine environment; meltwater; microfossils; Neogene; Neogloboquadrina; Neogloboquadrina dutertrei; North America; North American Atlantic; North Atlantic; O-18/O-16; Ocean Drilling Program; Oceanography; ODP Site 625; oxygen; paleo-oceanography; paleohydrology; planktonic taxa; Pliocene; Protista; Quaternary; Quaternary geology; Rotaliina; sea water; stable isotopes; Tertiary; upper Pliocene
• ISSN: 0091-7613; 1943-2682
• DOI: 10.1130/0091-7613(1993)021<0483:NAGMHF>2.3.CO;2

A high-resolution δ18O record from the northeastern Gulf of Mexico (Ocean Drilling Program Leg 100, hole 625B) provides a history of surface waters for the past 5.35 m.y. Negative δ18O anomalies between 0.3per mil and 3.0per mil in planktic foraminifera beginning at ∼2.30 Ma can only have resulted from the discharge of isotopically light glacial meltwater from the Mississippi River. Meltwater anomalies implicate either the periodic presence of North American, mid-latitude, glacial ice since the late Pliocene or a drainage system very different from that of the present.