Constraining early to middle Eocene climate evolution of the Southwest Pacific and Southern Ocean

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doi: 10.1016/j.epsl.2015.11.010
Author(s): Dallanave, Edoardo; Bachtadse, Valerian; Crouch, Erica M.; Tauxe, Lisa; Shepherd, Claire L.; Morgans, Hugh E. G.; Hollis, Christopher J.; Hines, Benjamin R.; Sugisaki, Saiko
Author Affiliation(s): Primary:
Ludwig-Maximilians University, Department of Earth and Environmental Science, Munich, Germany
GNS Science, New Zealand
Scripps Institution of Oceanography, United States
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, Vol.433, p.380-392. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. Includes appendices. 54 refs.; illus., incl. 1 table, geol. sketch map
Summary: Studies of early Paleogene climate suffer from the scarcity of well-dated sedimentary records from the southern Pacific Ocean, the largest ocean basin during this time. We present a new magnetostratigraphic record from marine sediments that outcrop along the mid-Waipara River, South Island, New Zealand. Fully oriented samples for paleomagnetic analyses were collected along 45 m of stratigraphic section, which encompasses magnetic polarity Chrons from C23n to C21n (∼ 51.5 - 47 Ma). These results are integrated with foraminiferal, calcareous nannofossil, and dinoflagellate cyst (dinocyst) biostratigraphy from samples collected in three different expeditions along a total of ∼80 m of section. Biostratigraphic data indicates relatively continuous sedimentation from the lower Waipawan to the upper Heretaungan New Zealand stages (i.e., lower Ypresian to lower Lutetian, 55.5 to 46 Ma). We provide the first magnetostratigraphically-calibrated age of 48.88 Ma for the base of the Heretaungan New Zealand stage (latest early Eocene). To improve the correlation of the climate record in this section with other Southern Ocean records, we reviewed the magnetostratigraphy of Ocean Drilling Program (ODP) Site 1172 (East Tasman Plateau) and Integrated Ocean Drilling Program (IODP) Site U1356 (Wilkes Land Margin, Antarctica). A paleomagnetic study of discrete samples could not confirm any reliable magnetic polarity reversals in the early Eocene at Site 1172. We use the robust magneto-biochronology of a succession of dinocyst bioevents that are common to mid-Waipara, Site 1172, and Site U1356 to assist correlation between the three records. A new integrated chronology offers new insights into the nature and completeness of the southern high-latitude climate histories derived from these sites. Abstract Copyright (2016) Elsevier, B.V.
Year of Publication: 2016
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Australasia; Biostratigraphy; Cenozoic; Correlation; Dinoflagellata; Eocene; Expedition 318; Foraminifera; IODP Site U1356; Integrated Ocean Drilling Program; Invertebrata; Leg 189; Lower Paleogene; Magnetostratigraphy; Marine sediments; Microfossils; Nannofossils; New Zealand; ODP Site 1172; Ocean Drilling Program; Pacific Ocean; Paleoclimatology; Paleogene; Paleomagnetism; Paleotemperature; Palynomorphs; Plantae; Protista; Reversals; Sediments; South Island; South Pacific; Southern Ocean; Southwest Pacific; Tasman Sea; Tertiary; Waipara River; West Pacific
Coordinates: S631837 S631837 E1355956 E1355956
S435800 S435700 E1495600 E1495500
Record ID: 2016040124
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands