Southward shift of the Intertropical Convergence Zone in the western Pacific during the late Tertiary: Evidence from ferromanganese crusts on seamounts west of the Marshall Islands SCIE SCOPUS

Cited 15 time in WEB OF SCIENCE Cited 18 time in Scopus
Title
Southward shift of the Intertropical Convergence Zone in the western Pacific during the late Tertiary: Evidence from ferromanganese crusts on seamounts west of the Marshall Islands
Author(s)
Kim, Jonguk; Hyeong, Kiseong; Jung, Hoi-Soo; Moon, Jai-Woon; Kim, Ki-Hyune; Lee, Insung
KIOST Author(s)
Kim, Jong Uk(김종욱)Hyeong, Ki Seong(형기성)Jung, Hoi Soo(정회수)Moon, Jai Woon(문재운)
Alternative Author(s)
김종욱; 형기성; 정회수; 문재운; 김기현
Publication Year
2006-12-19
Abstract
[1] Hydrogenetic ferromanganese crusts were dredged from four seamounts in the western Pacific, OSM7, OSM2, Lomilik, and Lemkein, aligned in a NW-SE direction parallel to Pacific Plate movement. The crusts consist of four well-defined layers with distinct textural and geochemical properties. The topmost layer 1 is relatively enriched in Mn, Co, Ni, and Mo compared to the underlying layer 2, which is relatively enriched in Al, Ti, K, and Rb and Cu, Zn, and excess Ba. Textural and geochemical properties of layer 2 suggest growth conditions under high biogenic and detrital flux. Such conditions are met in the equatorial Pacific (i.e., between the Intertropical Convergence Zone (ITCZ) and equatorial high-productivity zone). Layer 2 likely formed when each seamount was beneath the equatorial Pacific along its back track path. On the other hand, layer 1 probably started to grow after seamounts moved northwest from the ITCZ. This interpretation is consistent with the thickness of layer 1 across the four crusts, which increases to the northwest. Ages of the layer 1 - layer 2 boundary in each crust, a potential proxy for northern margin of the ITCZ, also increase to the northwest at 17, 11, 8, and 5 Ma for OSM7, OSM2, Lomilik, and Lemkein, respectively. Assuming Pacific Plate motion of 0.3 degrees/Myr, the seamounts were located at 12 degrees N, 11 degrees N, 9 degrees N, and 8 degrees N at the time of boundary formation. This result suggests that the north edge of the ITCZ has shifted south since the middle Miocene in the western Pacific, which agrees with information from the eastern Pacific.
ISSN
0883-8305
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/4810
DOI
10.1029/2006PA001291
Bibliographic Citation
PALEOCEANOGRAPHY, v.21, no.4, 2006
Publisher
AMER GEOPHYSICAL UNION
Subject
HAWAIIAN ARCHIPELAGO; EQUATORIAL PACIFIC; EOLIAN DUST; OCEAN; ISOTOPES; ND; TRANSECT; SEAWATER; AGE; PB
Type
Article
Language
English
Document Type
Article
Publisher
AMER GEOPHYSICAL UNION
Related Researcher
Research Interests

Deep seabed exploration,Geochemistry,심해저자원탐사,지화학

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