Geochemistry and tectonic environment of basaltic rocks from the Misis ophiolitic mélange, south Turkey

Floyd, P. A.; Kelling, Gilbert; Gökçen, Sungu L.; Gökçen, Nuran

doi:10.1016/0009-2541(91)90020-r

Cited by 103 publications

(44 citation statements)

References 40 publications

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“…In discrimination of the tectonic setting, using V versus Ti/1000 reported by Shervais (1982) and Zr/Y versus Zr given by Pearce and Norry (1979), almost all Dehsard mafic volcanic rocks plot in the field of MORB + BABB and WPB, respectively (Figures 9c and 9d). It has been argued that La/Nb versus Y is a suitable discrimination diagram between ocean ridge and subduction related eruptive settings (Cameron et al, 1980;Floyd et al, 1991). The modest value of La/Nb ratios (in average 1.70) of the Dehsard mafic volcanic rocks show their back-arc basin characteristics (rather than an arc) that is recognizable from enriched MORB or intraplate oceanic lava flows with similar low Y contents (Figure 10a) (Floyd, 1989;Floyd et al, 1991).…”

Section: Tectonic Implicationmentioning

confidence: 99%

“…Furthermore, the island arc characteristic of Dehsard mafic volcanic rocks is shown in the La/Yb versus Th/Yb diagram given by Condie (1989) (Figure 9a). Moreover, in the Th-Ta-Hf/3 discrimination diagram nearly all the samples plot in the field of calc-alkaline volcanic arc basalts and back-arc basin basalts (BABBs) supplementary field (Figure 9b) (Wood, 1980;Floyd et al, 1991). It has been shown that some BABBs in the mature subduction zone can have transitional chemical aspect to calc-alkaline basalts and distinctive higher LILE/HFSE ratios (Saunders and Tarney, 1984;Floyd et al, 1991).…”

Section: Tectonic Implicationmentioning

confidence: 99%

“…Moreover, in the Th-Ta-Hf/3 discrimination diagram nearly all the samples plot in the field of calc-alkaline volcanic arc basalts and back-arc basin basalts (BABBs) supplementary field (Figure 9b) (Wood, 1980;Floyd et al, 1991). It has been shown that some BABBs in the mature subduction zone can have transitional chemical aspect to calc-alkaline basalts and distinctive higher LILE/HFSE ratios (Saunders and Tarney, 1984;Floyd et al, 1991). In discrimination of the tectonic setting, using V versus Ti/1000 reported by Shervais (1982) and Zr/Y versus Zr given by Pearce and Norry (1979), almost all Dehsard mafic volcanic rocks plot in the field of MORB + BABB and WPB, respectively (Figures 9c and 9d).…”

Section: Tectonic Implicationmentioning

confidence: 99%

“…It has been argued that La/Nb versus Y is a suitable discrimination diagram between ocean ridge and subduction related eruptive settings (Cameron et al, 1980;Floyd et al, 1991). The modest value of La/Nb ratios (in average 1.70) of the Dehsard mafic volcanic rocks show their back-arc basin characteristics (rather than an arc) that is recognizable from enriched MORB or intraplate oceanic lava flows with similar low Y contents (Figure 10a) (Floyd, 1989;Floyd et al, 1991). Furthermore, their back arc basin origin is evident in the Ti/Zr versus Zr diagram (Figure 10b) (Woodhead et al, 1993, Bagas et al, 2008.…”

Section: Tectonic Implicationmentioning

confidence: 99%

“…plagioclase played an insignificant role during magma evolution (Floyd et al, 1991;Slovenec et al, 2010;Qian et al, 2016). The Dehsard mafic volcanic rocks with ratios of Nb/La = 0.47-0.97 and Th/La = 0.09-0.34 and selective enrichment in LILEs (e.g., Ba) and depletion in HFSEs (e.g., Nb, Ta, Ti) on the primitive mantle-normalized multielement spider diagram (Figure 6) indicate an arc volcanic feature (Saunders and Tarney, 1979;Caulfield et al, 2008;Özdamar, 2016).…”

Section: Geochemical Characteristicsmentioning

confidence: 99%

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Geochemistry and source characteristics of Dehsard mafic volcanic rocks in the southeast of the Sanandaj–Sirjan zone, Iran: implications for the evolution of the Neo-Tethys Ocean

Nazemei¹,

Arvin²,

Dargahi³

2018

Turkish J Earth Sci

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The Late Jurassic-Early Cretaceous Dehsard mafic volcanic rocks crop out in the southeastern Sanandaj-Sirjan Zone (SSZ), composed primarily of basalts and basaltic andesite with subordinate dolerite. They are influenced to some degree by hydrothermal alteration under zeolite-greenschist facies. Using fairly immobile trace elements, the mafic volcanic rocks show subalkaline (tholeiitic) affinities. They commonly have similar designs with somewhat strong enrichment in light rare earth elements (LREEs) and large ion lithophile elements (LILEs) and depletion in high field strength elements (HFSEs; e.g., Nb, Ta, Ti) and nearly flat heavy rare earth element (HREE) patterns. The negligible or absence of negative Eu anomalies indicate that plagioclase played an insignificant role during magma evolution. The low La/Nb (1.03-2.31) and Nb/Y (0.12-0.46) ratios, relatively high Zr/Y (4.03-8.18) and Th/Ta (2.25-9.64) ratios, steady enhanced normalized patterns, and moderate La/Nb ratios hint at an island arc and most likely a back-arc basin environment for the formation of Dehsard mafic volcanic rocks. The arc magma resulted from partial melting of depleted mantle source that experienced assimilation and fractional crystallization and was enhanced by melts of subducted sediments or contribution of slabderived fluids in an intraoceanic subduction environment in the Neo-Tethyan Ocean. Therefore, the presence of an island arc setting (Dehsard island arc) must be investigated in the south of the SSZ prior to the Late Jurassic-Early Cretaceous as the Neo-Tethys oceanic crust was subducting north beneath the southern margin of the Central Iranian Microcontinents. The later collision of the arc with SSZ led to tectonic proximity of the Dehsard mafic volcanic rocks to SSZ components.

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