DOI: 10.1016/j.marmicro.2019.101817
论文题名: Variation in the eastern North Pacific subtropical gyre (California Current system) during the Middle to Late Miocene as inferred from radiolarian assemblages
作者: Kamikuri S.-I. ; Motoyama I.
刊名: Marine Micropaleontology
ISSN: 3778398
出版年: 2020
卷: 155 语种: 英语
英文关键词: Biosiliceous sediments
; California Current
; Coastal upwelling
; High latitude cooling
; Tropical Pacific seaways
; Uplift of the Himalaya and Rocky Mountains
Scopus关键词: climate change
; deep water
; fossil assemblage
; fossil record
; gyre
; Miocene
; paleoclimate
; radiolaria
; California Current
; Himalayas
; Pacific Ocean
; Pacific Ocean (North)
; Rocky Mountains
英文摘要: The California Current has influenced the primary productivity along the California margin, which plays a significant role in global carbon cycles. Although previous studies have explored the response of the California Current to climate change since the Pliocene, comparatively little is known about that during the Middle and Late Miocene when the paleoclimate changed significantly. Here, we present variations of the California Current based on new data of radiolarian fossil assemblages integrated with previously published data from the Middle to Late Miocene, and show that the California Current was strengthened from 12.3 to 10.5 Ma, 9.0 to 8.2 Ma, and 7.2 to 6.9 Ma at ODP Site 1021. The biogenic opal declined during periods of increased strength of the California Current from the Middle to Late Miocene at Site 1021 in offshore area. These data suggest that the biogenic opal decreased at Site 1021 in offshore area due to the deep nutricline depth by the strengthened California Current. R-mode cluster analyses divided into three major assemblages; surface/warm, cool/surface to thermocline, and intermediate-deep water taxa. The pronounced faunal changes of radiolarian assemblages to the dominance of intermediate-deep water taxa might reflect an initiation of the modern-type California Current system since ca. 10.5 Ma in the early Late Miocene due to the tectonic changes (e.g. partial closing of tropical gateways and uplift of the Himalaya and the Rocky Mountains) and/or significant high latitude cooling. © 2019 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/158975
Appears in Collections: 气候变化与战略
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作者单位: Faculty of Education, Ibaraki University, Bunkyo 2-1-1, Mito, 310-8512, Japan; Faculty of Science, Yamagata University, Kojirakawa 1-4-12, Yamagata, 990-8560, Japan
Recommended Citation:
Kamikuri S.-I.,Motoyama I.. Variation in the eastern North Pacific subtropical gyre (California Current system) during the Middle to Late Miocene as inferred from radiolarian assemblages[J]. Marine Micropaleontology,2020-01-01,155