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Late cretaceous pelagic sediments, volcanic ASH and biotas from near the Louisville hotspot, Pacific Plate, paleolatitude ∼42°S

Palaeogeography, Palaeoclimatology, Palaeoecology

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, , , , , , , , , , , , , , and
DOI: 10.1016/0031-0182(89)90056-4

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Abstract

Dredging on the deep inner slope of the Tonga Trench, immediately north of the intersection between the Louisville Ridge hotspot chain and the trench, recovered some Late Cretaceous (Maestrichtian) slightly tuffaceous pelagic sediments. They are inferred to have been scraped off a recently subducted Late Cretaceous guyot of the Louisville chain. In the vicinity of the Louisville hotspot (present location 50°26′S, 139°09′W; Late Cretaceous location ∼42°S, longitude unknown) Late Cretaceous rich diatom, radiolarian, silicoflagellate, foraminiferal and coccolith biotas, accumulated on the flanks of the guyot and are described in this paper. Rich sponge faunas are not described. ?Inoceramus prisms are present. Volcanic ash is of within-plate alkalic character. Isotope ratios in bulk carbonate δ18O − 2.63 to + 0.85, δ13C + 2.98 to 3.83) are normal for Pacific Maestrichtian sediments. The local CCD may have been shallower than the regional CCD, because of high organic productivity. In some samples Late Cretaceous materials have been mixed with Neogene materials. Mixing may have taken place on the flanks of the guyot during transit across the western Pacific, or on the trench slope during or after subduction and offscraping about 0.5 Ma.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Late cretaceous pelagic sediments, volcanic ASH and biotas from near the Louisville hotspot, Pacific Plate, paleolatitude ∼42°S
Series title:
Palaeogeography, Palaeoclimatology, Palaeoecology
DOI:
10.1016/0031-0182(89)90056-4
Volume
71
Issue:
3-4
Year Published:
1989
Language:
English
Publisher:
Elsevier
Description:
19 p.
First page:
281
Last page:
299
Online Only (Y/N):
N
Additional Online Files(Y/N):
N