DOI: 10.1016/j.epsl.2019.115864
论文题名: Late Cretaceous (99-69 Ma) basaltic intraplate volcanism on and around Zealandia: Tracing upper mantle geodynamics from Hikurangi Plateau collision to Gondwana breakup and beyond
作者: Hoernle K. ; Timm C. ; Hauff F. ; Tappenden V. ; Werner R. ; Jolis E.M. ; Mortimer N. ; Weaver S. ; Riefstahl F. ; Gohl K.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 529 语种: 英语
中文关键词: Gondwana subduction
; Hikurangi Plateau collision
; major & trace element & isotope geochemistry
; mantle plume
; St. Helena HIMU mantle end member
; Zealandia continental breakup
英文关键词: Basalt
; Exploratory geochemistry
; Hafnium alloys
; Isotopes
; Lead alloys
; Lithology
; Neodymium alloys
; Strontium alloys
; Tectonics
; Thermal plumes
; Trace elements
; Volcanoes
; Continental break-up
; Endmembers
; Gondwana subduction
; Hikurangi Plateau collision
; Isotope geochemistry
; Mantle plume
; Geodynamics
; basalt
; collision zone
; continental breakup
; Cretaceous
; geodynamics
; Gondwana
; intraplate process
; mantle plume
; plate convergence
; upper mantle
; volcanism
; Hikurangi Plateau
; Pacific Ocean
英文摘要: Margins resulting from continental breakup are generally classified as volcanic (related to flood basalt volcanism from a starting plume head) or non-volcanic (caused by tectonic processes), but many margins (breakups) may actually be hybrids caused by a combination of volcanic and tectonic processes. It has been postulated that the collision of the Hikurangi Plateau with the Gondwana margin ∼110 Ma ago caused subduction to cease, followed by large-scale extension and ultimately breakoff of the Zealandia micro-continent from West Antarctica through seafloor spreading which started at ∼85 Ma. Here we report new geochemical (major and trace element and Sr-Nd-Pb-Hf isotope) data for Late Cretaceous (99-69 Ma) volcanism from Zealandia, which include the calc-alkalic, subduction-related Mount Somers (99-96 Ma) and four intraplate igneous provinces: 1) Hikurangi Seamount Province (99-88 Ma), 2) Marlborough Igneous Province (98-94 Ma), 3) Westland Igneous Province (92-69 Ma), and 4) Eastern Chatham Igneous Province (86-79 Ma). Each of the intraplate provinces forms mixing arrays on incompatible-element and isotope ratio plots between HIMU (requiring long-term high μ=238U/204Pb) and either a depleted (MORB-source) upper mantle (DM) component or enriched continental (EM) type component (located in the crust and/or upper mantle) or a mixture of both. St. Helena end member HIMU could be the common component in all four provinces. Considering the uniformity in composition of the HIMU end member despite the type of lithosphere (continental, oceanic, oceanic plateau) beneath the igneous provinces, we attribute this component to a sublithospheric source, located beneath all volcanic provinces, and thus most likely a mantle plume. We propose that the plume material rose beneath the active Gondwana margin and flowed along the subducting lithosphere beneath the Hikurangi Plateau and neighboring seafloor and through slab tears/windows beneath the Gondwana (later to become Zealandia) continental lithosphere. We conclude that both plateau collision, resulting in subduction cessation, and the opening of slab tears/windows, allowing hot asthenosphere and/or plume material to upwell to shallow depths, were important in causing the breakup of Zealandia from West Antarctica. Combined tectonic-volcanic processes are also likely to be responsible for causing breakup and the formation of other hybrid type margins. © 2019 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165029
Appears in Collections: 气候变化与战略
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作者单位: GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, 24148, Germany; Kiel University, Institute of Geosciences, Kiel, 24118, Germany; GNS Science, Lower Hutt, 5040, New Zealand; University of Canterbury, Christchurch, 8140, New Zealand; GNS Science, Dunedin, 9054, New Zealand; Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27568, Germany
Recommended Citation:
Hoernle K.,Timm C.,Hauff F.,et al. Late Cretaceous (99-69 Ma) basaltic intraplate volcanism on and around Zealandia: Tracing upper mantle geodynamics from Hikurangi Plateau collision to Gondwana breakup and beyond[J]. Earth and Planetary Science Letters,2020-01-01,529