Four billion years of ophiolites reveal secular trends in oceanic crust formation

Furnes, Harald; Wit, Maarten de; Dilek, Yıldırım

doi:10.1016/j.gsf.2014.02.002

Cited by 175 publications

(85 citation statements)

References 242 publications

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“…The WPCB extends along a great circle for more than 25000 km around the Pacific Ocean rim and includes the western Pacific islands (e.g., Japan, Ryukyu islands, Taiwan, Philippines, Indonesia, Papua New Guinea, eastern Australia, and New Zealand) and the Cordilleran belts of western North and South America (Ishiwatari 1991(Ishiwatari , 1994Dilek 2003;Dilek andFurnes 2011, 2014;Furnes et al 2014). The WPCB ophiolites (e.g., Josephine, Trinity, Smartville, Itogon, Papua New Guinea, Zambales, and Yakuno) typically show geochemical and structural characteristics of SSZ or volcanic-arc ophiolites and are found mostly on or among the accreted oceanic and trench sediments of active continental margins (Ishiwatari 1994;Dilek 2003;Dilek and Polat 2008;Dilek andFurnes 2011, 2014).…”

Section: Introductionmentioning

confidence: 99%

Mantle Potential Temperature Estimates of Basalt from the East Taiwan Ophiolite

Shellnutt¹,

Hsieh

2016

Terr. Atmos. Ocean. Sci.

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The East Taiwan Ophiolite (ETO) is a fragment of the eastern-most South China Sea that was accreted to the Eurasian margin during the Pliocene and is a member of the Western Pacific and Cordilleran belt ophiolite group. Ophiolites from the Western Pacific and Cordilleran belt are typically subduction-related (i.e., supra-subduction or volcanic-arc) but the ETO is compositionally, isotopically and mineralogically similar to subduction-unrelated ophiolites. The primary melt compositions of ETO basaltic rocks were calculated and range from high-Mg basalt to picrite (i.e., MgO = 10 to 14 wt%). The mantle potential temperature (T P ) estimates are within the range of ambient mantle (1300 -1400°C) and other mid-ocean ridge ophiolites (i.e., Macquarie Island and Masirah) indicating that it is consistent with a mid-ocean ridge setting. Mantle potential temperature estimates for rocks from a mantle-plume-type ophiolite (i.e., 1620 -1630°C) are anomalously high whereas rocks from supra-subduction zone ophiolites show a wider range that extends from ambient (i.e., Troodos and Semail) T P to very high (i.e., Betts Cove and Bay of Islands) T P .

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Section: Introductionmentioning

confidence: 99%

Mantle Potential Temperature Estimates of Basalt from the East Taiwan Ophiolite

Shellnutt¹,

Hsieh

2016

Terr. Atmos. Ocean. Sci.

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“…Ophiolites form in a variety of tectonic environments, from low degrees of partial melting (subduction-unrelated) to high degrees of partial melting (subduction-related) (e.g. Furnes et al 2014). The subduction-unrelated ophiolites represent a constructional stage of oceanic crust formation and contain predominantly mid ocean ridge basalts (MORB), whereas the subductionrelated ophiolites represent a destructive stage of ocean floor recycling (e.g.…”

Section: Introductionmentioning

confidence: 99%

The Neoproterozoic Abu Dahr ophiolite, South Eastern Desert, Egypt: petrological characteristics and tectonomagmatic evolution

2015

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The Neoproterozoic Abu Dahr ophiolite, South Eastern Desert, Egypt, is one of the best preserved and least dismembered ophiolite successions in the Arabian-Nubian Shield. It contains a Penrose-type ophiolite sequence from mantle section below mafic crust upward to oceanic sedimentary cover overlying mafic volcanics, although the original magmatic (stratigraphic) contact between the mantle and crustal sections is disrupted by tectonism. The Abu Dahr ophiolite is metamorphosed under greenschist facies conditions, and low-temperature alteration is widespread. Petrography reveals that: (i) the mantle is homogenous, serpentinized, and dominated by harzburgite and less abundant dunite; (ii) the cumulate ultramafics are represented by wehrlite and pyroxenite; and (iii) the crustal section is represented by metagabbros, meta-anorthosites and metabasalts. The Abu Dahr serpentinized peridotites show high Mg# (0.92-0.93), with enrichment of Ni, Cr and Co, and depletion of Al 2 O 3 and CaO, and nearly flat and unfractionated REE chondrite-normalized pattern. Major and trace element characteristics of the Abu Dahr metagabbro and metabasalt (crustal section) indicate a tholeiitic to calc-alkaline affinity. Units of the crustal section have low-Nb and Zr concentrations, low Dy/Yb and relatively elevated La/Yb ratios, high U/Yb and Th/Yb ratios, and LREE enriched chondrite-normalized pattern. All of the Abu Dahr ophiolite units have trace-element signatures characterized by enrichment of LILE over HFSE. Rare and trace element patterns indicate a genetic link between the Abu Dahr mantle, cumulate ultramafics, and crust. Chromian spinel has survived metamorphism and is used as a petrogenetic indicator in the Abu Dahr serpentinized peridotites. The spinel is homogeneous with a limited composition, and shows high-Cr# (>0.6) combined with low-TiO 2 character (mostly <0.1 wt.%). The Abu Dahr ophiolite is interpreted as a fragment of depleted oceanic lithosphere that experienced high degrees of partial melting (up to 35 %) and originated in a fore-arc setting. Such interpretation contributes to the body of evidence suggesting that tectonomagmatic processes of the Neoproterozoic were largely similar to those of the Phanerozoic, implying little, or no significant, change in the geothermal regime of Earth since the Neoproterozoic.

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“…13. Percentage lithology of komatiite and boninitic volcanism represented at given age intervals, relative to total of mafic and ultramafic magmatism in the Earth history, according to [Furnes et al, 2014]. Рис.…”

Section: Subduction Initiation In the Early Precambrianmentioning

confidence: 99%

“…13. Соотношения объемов коматиитового и бонинитового вулканизма в процентах от общего объема мафит-ультрамафитовых ассоциаций в истории Земли, по [Furnes et al, 2014].…”

Section: Subduction Initiation In the Early Precambrianunclassified

“…Согласно недавно опубликованным оценкам, объем бонинитового магма-тизма в архее примерно соответствует объемам коматиитов [Furnes et al, 2014]. Установление пород бонини-товой серии, ассоциирующих с фрагментами параллельных даек и метабазитами IAT-типа в древнейшем сохранившемся комплексе Исуа, по-видимому, указывает на то, что процессы субдукции имеют корни, про-стирающиеся к началу геологической истории Земли.…”

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