Metabasalts from the Troodos Massif, Cyprus: Genetic implication deduced from petrography and trace element geochemistry

Smewing, J. D.; Simonian, K. O.; Gass, I. G.

doi:10.1007/bf00403512

Cited by 98 publications

(34 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The ranges of Ti and V from the upper pillow lavas are restricted to ratios close to 10, suggesting that these rocks at least were formed in a high volatile environment such as an island arc or intra-arc basin. This conclusion is consistent with Pearce [7,8], Cameron et al [42], and Dick et al [56], but at odds with older interpretations [57,58].…”

Section: Application Of Ti/v Plots To Ophiolite Voicanicssupporting

confidence: 89%

Ti-V plots and the petrogenesis of modern and ophiolitic lavas

Shervais

1982

Earth and Planetary Science Letters

2,050

960

View full text Add to dashboard Cite

Plots of Ti vs. V for many modern volcanic rock associations are diagnostic of tectonic setting and can be used to determine possible tectonic settings of ophiolites as well. The basis of this plot is the variation in the crystal/liquid partition coefficients for vanadium, which range with increasing oxygen fugacity from > 1 to << 1. Since the partition coefficients for Ti are almost always << 1, the depletion of V relative to Ti is a function of the fo2 of the magma and its source, the degree of partial melting, and subsequent fractional crystallization. Volcanic rocks from modern island arcs have Ti/V ratios of ~20, except for calc-alkaline volcanics which show the effects of magnetite fractionation. MORB and continental flood basalts have Ti/V ratios of about 20-50 and alkaline rocks have Ti/V generally >50. Back-arc basin basalts may have either arc-like or MORB-like Ti/V ratios, and sample suites from single back-arc basins may have Ti/V ratios ranging from 10 to 50. This range in Ti/V ratios in samples from a restricted geographical area may be diagnostic of the back-arc setting. The Ti/V plot is applied here to published data on ophiolites from a variety of postulated settings and in general supports the conclusions of previous investigators. Ophiolites from the western Mediterranean (Corsica, northern Apennines) and the "lower" Karmoy volcanics have Ti/V trends similar to MORB; the "upper" Karmo'y volcanics have alkaline Ti/V ratios. Lavas and tonalites in the Papuan ultramafic belt, the high-Mg andesites of Cape Vogel, and the upper pillow lavas at Troodos all have Ti/V ratios < 20, consistent with formation in an island arc setting. More specific evaluation of the tectonic setting of these and other ophiolites requires application of detailed geologic and petrologic data as well as geochemistry. The Ti/V discrimination diagram, however, is a potentially powerful adjunct to these techniques.

show abstract

Section: Application Of Ti/v Plots To Ophiolite Voicanicssupporting

confidence: 89%

Ti-V plots and the petrogenesis of modern and ophiolitic lavas

Shervais

1982

Earth and Planetary Science Letters

2,050

960

View full text Add to dashboard Cite

show abstract

“…The literature on ophiolites is extensive and varied; we shall use the Troodos complex, Cyprus and the Othris complex, Greece, for our test. Reference to the work of Moores & Vine (1971), Smewing, Simonian & Gass (1975) and especially Menzies & Allen (1974) and the important work of Allen (1975) shows that most of the features seen in these two complexes can be duplicated in our model. Crude MgO balance calculations between basaltic liquid, mantle source and peridotitic residue based on data in Menzies & Allen (1974) suggest partial melts between 10-20 per cent or more for Troodos.…”

Section: O M P a R I S O N W I T H O P H I O L I T E C O M P L E X E Smentioning

confidence: 85%

The Mid-Atlantic Ridge at 37 and 45� N: some geophysical and petrological constraints

Nisbet¹,

Fowler²

1978

Geophys J Int

128

View full text Add to dashboard Cite

At present there is a strong conflict between, on the one hand, seismological and thermal models of the Mid-Atlantic Ridge, which indicate that no large crustal magma chamber can exist, and on the other hand petrological models many of which stress the importance of such a chamber. We review the available geophysical and petrological information from the FAMOUS area and 45" N in an attempt to resolve this conflict and demonstrate that a model (the infinite leek) can be constructed which satisfies all the available seismological, thermal, petrographic, major element and traceelement information from these two areas. This mode is as follows: mantle rising from depth begins to melt at about 60 km, and rises in equilibrium with its melt to about 15-25 km below the sea surface. At this level melt segregates and rises rapidly to the base of the crust. Magma injection above this takes place by a process of crack propagation, or by the development of a narrow vertical magma chamber, but no large crustal chamber is present. This model successfully explains the marked petrographic zonation of the floor of the median valley (Hekinian, Moore ck. Bryan).

show abstract

“…[4,5,7,8]), but the discovery of glasses with compositions comparable to Cyprus lava whole rock compositions [6] has reduced the uncertainty associated with this question. Relative to their fresh precursors, the CY-1/ 1A lavas are enriched in K 2 O (up to 5 wt%) and depleted in Na 2 O (up to 1 wt%); depleted or enriched in CaO ( þ 6 wt%) (depending on carbonate content); and locally SiO 2 -depleted (up to 2 wt%) and MgO-enriched [26].…”

Section: Viscosity Of the Cy-1/1a Lavasmentioning

confidence: 99%

“…metamorphism of the Troodos lavas, Gass and Smewing [4] and Smewing et al [5] modi¢ed this early subdivision and de¢ned an axis sequence and an o¡-axis sequence (but not far enough o¡-axis for a sedimentary sequence to develop). The boundary between the two sequences was based on a relative lack of secondary mineralization in the younger, o¡-axis sequence.…”

Section: Introductionmentioning

confidence: 99%

Melt viscosity, temperature and transport processes, Troodos ophiolite, Cyprus

Schouten

Kelemen

2002

Earth and Planetary Science Letters

View full text Add to dashboard Cite

The lava section in the Troodos ophiolite, Cyprus, is chemically stratified and divided into a shallow lava sequence with low TiO 2 content and a deeper lava sequence with high TiO 2 content. We calculate the viscosity at magmatic temperature based on major element chemistry of lavas in Cyprus Crustal Study Project (CCSP) Holes CY-1 and 1A. We find that typical shallow low-Ti lavas have a magmatic viscosity that is two to three orders of magnitude lower than that of the deeper high-Ti lavas. This implies that, after eruption on-axis, Troodos low-Ti lavas would have been able to flow down the same slope faster and farther than high-Ti lavas. The calculated lava viscosity increases systematically from the lava^sediment interface to the bottom of the composite Hole CY-1/1A. This suggests that an efficient process of lava segregation by viscosity on the upper flanks of the paleo Troodos rise may have been responsible for the chemical stratification in the Troodos lava pile. Calculated magmatic temperature and molar Mg/ (Mg+Fe), or Mg#, decrease systematically down-section, while SiO 2 content increases. Correlation of Mg# in the lavas with Mg# in the underlying, lower crustal plutonic rocks sampled by CCSP Hole CY-4 shows that the shallow lavas came from a high-temperature, lower crustal magma reservoir which is now represented by high-Mg# pyroxenite cumulates, while the deeper lavas were erupted from a lower-temperature, mid-crustal reservoir which is now represented by gabbroic cumulates with lower Mg#. ß 2002 Published by Elsevier Science B.V.

show abstract

Metabasalts from the Troodos Massif, Cyprus: Genetic implication deduced from petrography and trace element geochemistry

Cited by 98 publications

References 23 publications

Ti-V plots and the petrogenesis of modern and ophiolitic lavas

Ti-V plots and the petrogenesis of modern and ophiolitic lavas

The Mid-Atlantic Ridge at 37 and 45� N: some geophysical and petrological constraints

Melt viscosity, temperature and transport processes, Troodos ophiolite, Cyprus

Contact Info

Product

Resources

About