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Structure and tectonics of subophiolitic mélanges in the western Hellenides(Greece): implications for ophiolite emplacement tectonicsConstandina Ghikas a; Yildirim Dilek a; Anne E. Rassios b

a Department of Geology, Miami University, Oxford, OH, USA b Institute of Geology and MineralExploration, Kozani, Greece

First published on: 03 June 2009

To cite this Article Ghikas, Constandina, Dilek, Yildirim and Rassios, Anne E.(2010) 'Structure and tectonics ofsubophiolitic mélanges in the western Hellenides (Greece): implications for ophiolite emplacement tectonics',International Geology Review, 52: 4, 423 — 453, First published on: 03 June 2009 (iFirst)To link to this Article: DOI: 10.1080/00206810902951106URL: http://dx.doi.org/10.1080/00206810902951106

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Structure and tectonics of subophiolitic melanges in the westernHellenides (Greece): implications for ophiolite emplacement tectonics

Constandina Ghikasa, Yildirim Dileka* and Anne E. Rassiosb

aDepartment of Geology, Miami University, Oxford, OH 45056, USA; bInstitute of Geology andMineral Exploration, Lefkovrisi, 50100 Kozani, Greece

(Accepted 3 April 2009)

The Jurassic Vourinos ophiolite is part of the Western Hellenide ophiolite belt inGreece and rests tectonically on the Pelagonian microcontinent. The Vourinos andcoeval Pindos ophiolite to the west display suprasubduction-zone geochemicalaffinities, and represent remnants of oceanic lithosphere formed in a rifted incipientarc–forearc setting within the Pindos Basin. In structurally descending order, and fromwest to east, the subophiolitic melange beneath the Vourinos ophiolite contains theAgios Nikolaos Formation (ANF) and a rift assemblage, both of which display ENE-vergent thrust faults, shear zones, and folds. The ANF comprises schistose mudstonewith pebbles, cobbles, and boulders of arenite and wacke derived from the crystallinebasement of Pelagonia. Imbricated along ENE-directed thrust faults and metamor-phosed up to lower amphibolite facies, the ANF represents continental rise deposits ofthe rifted Pelagonian margin. The rift assemblage includes blocks of basaltic lavas,ribbon chert, micritic cherty limestone, metagabbro, dolerite dikes, and serpentinitebreccia that are commonly in thrust contact with each other and are tectonicallyimbricated with the Pelagonian carbonates; however, primary intrusive anddepositional contacts are locally well preserved. Gabbro and dolerite dikes are locallyintrusive into the recrystallized carbonates and metapelitic rocks of the Pelagonianmicrocontinent. Lavas display mid-ocean ridge basalt within plate basalt affinities andrepresent Upper Triassic rift units that erupted during the separation of Pelagonia fromApulia. Gabbro, dolerite, and serpentinite breccia are the products of a magmatic riftingepisode prior to the onset of seafloor spreading in the Pindos Basin. The Vourinossubophiolitic melange thus consists of passive margin and rift assemblages that weretectonically overridden by the Vourinos ophiolite in the Middle Jurassic. The Avdellamelange beneath the Pindos ophiolite to the west includes a chaotic matrix includingophiolitic clasts and blocks, reefal to pelagic limestones, and olistostromal turbiditesthat range in age from Triassic to Jurassic–Cretaceous. The Avdella melange reststectonically on a Cretaceous–Eocene flysch unit and the Cretaceous–Eocene shelf andslope deposits of the Apulian margin along west-directed thrust faults. Theevolutionary history of the Vourinos and Avdella subophiolitic melanges indicatesdiachronous tectonic emplacement of the Mesohellenic oceanic slab, first in the east asa result of a trench-continent (Pelagonia) collision in the Middle Jurassic, then in thewest due to the Eocene collision of Apulia with Eurasia.

Keywords: subophiolitic melange; Western Hellenides of Greece; Pindos Basin;Pelagonian microcontinent; passive margin sequence; rift lavas; suprasubduction-zoneophiolite

ISSN 0020-6814 print/ISSN 1938-2839 online

q 2010 Taylor & Francis

DOI: 10.1080/00206810902951106

http://www.informaworld.com

*Corresponding author. Email: [email protected]

International Geology Review

Vol. 52, Nos. 4–6, April–June 2010, 423–453

Downloaded By: [Dilek, Yildirim] At: 17:21 15 February 2010

Introduction

Jurassic to Cretaceous ophiolites in the Alpine orogenic belt (Figure 1) represent

fragments of oceanic lithosphere generated during the Wilson cycle evolution of Tethyan

basins (Dilek and Flower 2003). These ocean basins developed in response to successive

episodes of the break-up of Gondwana and evolved as latitudinal, east–west-oriented

basins separated by discrete continental fragments. Most eastern Mediterranean ophiolites

are spatially associated with both Triassic–Jurassic volcanic rocks and subophiolitic

melanges that rest tectonically on passive margin sequences of ribbon continents

(i.e. Pelagonia in the Balkans and Tauride platform in southern Turkey; Figure 1). These

extrusive rocks display within-plate-type alkaline basalt (WPB) to transitional and

mid-ocean ridge basalt (MORB) chemistry and are intercalated with hemipelagic to

pelagic sedimentary rocks. They appear to represent rift-related magmatic pulses along

Figure 1. Simplified geological map of the Balkan Peninsula and the Aegean region, showing thedistribution of Tethyan ophiolites (in green) and active plate boundaries (modified from Dilek andFlower 2003). AC, Antalya Complex; IA, Isparta Angle; IAESZ, Izmir–Ankara–Erzincan SutureZone; IPO, Intra-Pontide ophiolites; KF, Kefalonia Fault; NAFZ, North Anatolian Fault Zone; MO,Mirdita ophiolite; PO, Pindos ophiolite; VO, Vourinos ophiolite. Black arrow shows theconvergence direction of the African lithosphere at the Hellenic Trench.

C. Ghikas et al.424


the northern periphery of Gondwana (Juteau 1980; Pe-Piper 1982, 1998; Pamic 1984;

Shallo et al. 1990; Jones and Robertson 1991; Dilek and Rowland 1993; Malpas et al.

1993; Saccani et al. 2003), prior to the onset of seafloor spreading and oceanic crust

formation in the Tethyan basins (Dilek and Flower 2003).

Subophiolitic melange units form thin (several hundred metres) slivers of thrust sheets

sandwiched between the metamorphic soles or upper mantle peridotites in the upper plate

and the continental margin units in the lower plate along Tethyan suture zones (Shallo

1990; Wakabayashi and Dilek 2003; Dilek et al. 2005, and references therein). Oceanic

rocks within the melanges include ophiolitic material, fragments of seamounts, rift lavas,

and high-grade metamorphic rocks (mainly metamorphic sole rocks), whereas detrital

material and blocks in the melange are generally derived from continental margin units

(shelf, slope, and rise sedimentary rocks) as well as continental rocks (Hsu 1968; 1974,

1988; Liou et al. 1977; Cloos and Shreve 1988a, 1988b). The melange matrix may consist

of mudstone, sandstone, or serpentinite depending on the melange-forming processes

(Phipps 1984; Raymond 1984; Yilmaz and Maxwell 1984; Dilek 1989; Shallo 1990; Polat

et al. 1996; Dilek et al. 1999; Scherreiks 2000). In most cases, subophiolitic melange units,

continental margin rocks, and ophiolitic peridotites are tectonically imbricated in the

direction of ophiolite emplacement. Subophiolitic melanges provide crucial information

about the tectonic, metamorphic, and sedimentary processes and their P–T conditions

during advancement of ophiolitic thrust sheets onto continental margins; they can also

constrain the maximum age of the timing of ophiolite emplacement. Because they contain

material from the rift–drift tectonics of the basins prior to their terminal closure, these

subophiolitic melanges can also give us significant clues about the tectonic, sedimentary,

and magmatic processes and events involved in the early stages of the geodynamic

evolution of the basins and their continental margins.

In this paper, we document the internal stratigraphy and structure of a subophiolitic

melange associated with the Jurassic Vourinos ophiolite in the Western Hellenides in

northern Greece. We then analyse our data and interpretations in a regional tectonic

framework to derive some conclusions about the tectonic processes involved in the

formation of the Vourinos ophiolite and its subophiolitic melange and in the emplacement

of the ophiolite–melange units onto the Pelagonian continental margin. The Vourinos

subophiolitic melange is typical of most melanges associated with the Tethyan ophiolites

in the eastern Mediterranean region, and therefore represents a case study of melange

formation that involves rift–drift–collision tectonics of restricted marginal basins in the

Tethyan realm and beyond.

Ophiolite geology of the Hellenides

The NW-trending Neotethyan ophiolites in the Hellenides occur in two distinct zones

bounding the Pelagonian ribbon continent (Figure 2(a)). The Vardar Zone ophiolites, also

known as the ‘Innermost Hellenic ophiolites’ (Smith 1993) or the ‘Eastern Hellenic

ophiolites’, are located east of Pelagonia and are Jurassic–Early Cretaceous in age

(Bebien et al. 1986; Mussallam and Jung 1986; Robertson 2002). The ophiolites to the

west of the Pelagonian microcontinent, called the ‘Western Hellenic ophiolites’, are nearly

coeval or slightly older than those in the Vardar Zone and are spatially associated with

Triassic–Jurassic volcano-sedimentary units and melanges (Smith 1993; Robertson and

Karamata 1994; Bortolotti et al. 2005; Dilek et al. 2005; Saccani and Photiades 2005).

The Western Hellenic ophiolites in Greece and Albania, their northward continuation into

Kosovo and Serbia, and the Dinaric ophiolites in Bosnia and Croatia collectively form

International Geology Review 425


C. Ghikas et al.426


the Pindos Zone ophiolites in the western Balkan Peninsula (Robertson and Karamata

1994; Hoeck et al. 2002; Smith and Rassios 2003; Koller et al. 2006; Dilek et al. 2008).

These ophiolites show bidivergent emplacement onto Pelagonia in the east and Apulia in

the west (Figure 2(b)).

The root zones of the Pindos and Vardar Zone ophiolites and their possible genetic

relations have been a source of debate in discussions of Balkan geology. Some researchers

argue that both the Pindos and Vardar Zone ophiolites were derived from a Mesozoic

ocean basin located east of the Pelagonian microcontinent, and that the Jurassic ophiolites

in the Pindos Zone thus represent far-travelled nappe sheets with their roots in the Vardar

Zone (Collaku et al. 1990, 1991; Ricou et al. 1998; Bortolotti et al. 2005; Gawlick et al.

2007; Schmid et al. 2008). These interpretations imply that the Pelagonian microcontinent

was not rifted apart from Apulia, and that it was an outlier of the Apulian passive margin at

all times throughout the Mesozoic. The alternative and more widely accepted models

suggest that the Pelagonian block was an insular continental entity separating the Pindos

and Vardar (and/or Maliac) Basins within the Neotethyan realm during much of the

Mesozoic (Smith 1993; Robertson and Shallo 2000; Robertson 2002; Stampfli and Borel

2004; Dilek et al. 2005, 2007; Saccani and Photiades 2005). The structure and tectonic

evolution of the subophiolitic melanges in the Pindos Zone provide important constraints

on the validity of these different geodynamic models.

Vourinos and Pindos ophiolites: Mesohellenic oceanic slab

The Vourinos and Pindos ophiolites constitute the eastern and western edges, respectively,

of a larger Jurassic ophiolitic body, known as the Mesohellenic ophiolite (Rassios and

Dilek 2009) in the Western Hellenides (Figure 2(b)). These two ophiolites are exposed

.30 km apart, although magnetic and drilling data indicate that they are part of a single

mafic–ultramafic slab, which is continuous in the subsurface beneath the Palaeogene–

Neogene sedimentary cover of the Mesohellenic Trough (Saccani and Photiades 2004;

Rassios and Moores 2006; Rassios and Dilek 2009). This ophiolite belt continues to the

NW into Albania (SE Albanian and Mirdita ophiolites) and to the SE into Southern Greece

(Figure 1). Both the Vourinos and Pindos ophiolites overlie subophiolitic melanges

displaying some lithological similarities.

The Pindos and Vourinos ophiolites are coeval in age and display suprasubduction-

zone affinities (Kostopoulos 1989; Smith and Rassios 2003; Pe-Piper et al. 2004; Saccani

and Photiades 2004; Beccaluva et al. 2005; Rassios and Dilek 2009), although they also

show major differences in their internal structure and geochemical fingerprints. The Pindos

mantle section is harzburgitic to lherzolitic, indicating comparatively fertile mantle

compositions (Nicolas and Boudier 2003; Beccaluva et al. 2005; Rassios and Moores 2006).

Figure 2. (a) Simplified geological map of the west–central Balkan Peninsula and Adriatic Searegion, showing major tectonic zones and ophiolite occurrences. Key to lettering for differentJurassic ophiolites in the region (from north to south): Trp, Tropoja; Krb, Krrabi; Kuk, Kukesi; Puk,Puke; Skd, Skenderbeu; Blq, Bulqize; Shp, Shpati; She, Shebenik; Vo, Voskopoja; Pin, Pindos;Vou, Vourinos; Koz, Koziakas; Oth, Othris (modified after Dilek et al. 2007). (b) Tectoniccross-section depicting the crustal architecture of the Apulia–Pelagonia collision zone and the rootof the Mesohellenic ophiolite (Pindos (PO) to the west and Vourinos (VO) to the east with theirunderlying melange units). Palaeogene–Neogene sedimentary rocks of the Mesohellenic Trough(shown in yellow) cover the keel of the mafic–ultramafic slab that constitutes the root zone of theMesohellenic ophiolite. MHT, Mesohellenic Trough; VM, Vourinos melange (modified afterRassios and Dilek 2009).

R



A nearly 1-km-thick extrusive sequence in Pindos shows MORB to island arc tholeiite (IAT)

and boninitic compositions (Capedri et al. 1980; Kostopoulos 1989; Jones and Robertson

1991; Jones et al. 1991; Pe-Piper et al. 2004; Saccani and Photiades 2004; Beccaluva et al.

2005; Dilek and Furnes 2009). The Pindos ophiolite is underlain by the subophiolitic Avdella

melange (Kostopoulos 1989; Jones and Robertson 1991), which we describe in a later section.

The Vourinos ophiolite comprises a large mantle section of depleted harzburgite and

dunite with economically viable chromite bodies, a petrologic Moho, 4–5-km-thick mafic

and ultramafic cumulates, sheeted dikes, a thin extrusive sequence consisting mainly of

pillow lavas, and a Cretaceous pelagic limestone cover (Jackson et al. 1975; Harkins et al.

1980; Vrahatis and Grivas 1980; Rassios 1981; Rassios et al. 1983; Grivas et al. 1993;

Liati et al. 2004; Rassios and Moores 2006; Sharp and Robertson 2006). All lithological

units in the Vourinos ophiolite have been tilted or overturned to the west, so that the

structural progression of units from top to bottom is from west to east, with the upper

mantle peridotites occurring at the easternmost rim of the ophiolite nappe (Figure 3).

The Vourinos dikes and lavas are mainly IAT in composition, but boninitic dikes and lavas

occur as late-stage magmatic products both in the sheeted dike complex and the extrusive

rocks (Rassios and Dilek 2009, and references therein). Around the eastern rim of the

Figure 3. Geological map of the Vourinos ophiolite. Numbered boxes show subophiolitic melangelocalities that are investigated in detail in this study.

C. Ghikas et al.428


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ophiolite, the subophiolitic melange occurs as a discontinuous sliver between the ophiolite

and the Pelagonian microcontinent (Figure 3; Jones and Robertson 1991; Ghikas et al.

2007; Rassios and Dilek 2009).

Vourinos subophiolitic melange

A 300–500 m-thick melange unit occurs structurally underneath the Vourinos ophiolite

and on top of the Pelagonian microcontinent (Figure 4), and is exposed discontinuously

around the entire margin of the ophiolite. This study has focused on four major localities

around the rim of the Vourinos ophiolite, where the representative sections of the Vourinos

subophiolitic melange are exposed. These localities include: (1) the Agios Nikolaos Valley,

(2) North of Skoumtsa, (3) Frourio, and (4) the Aliakmonas River Valley (Figure 3).

The Vourinos subophiolitic melange locally contains numerous blocks and thrust sheets

of various rock types, ranging in size from several metres to several kilometres. These

subunits are typically less than 100 m thick, and thus the surface expression of the melange

resembles a collection of thin lensoidal blocks and thrust sheets with a strong preferred

alignment and imbrication in the direction of ophiolite emplacement to the NE (Figure 5).

Most melange subunits show an internal fabric (bedding, foliation, or shearing) and the

contacts between the subunits are most commonly defined by reverse and thrust faults.

Both the contacts and the internal fabric elements in the subunits approximately parallel

the dip of the bounding thrust faults of the melange. The general emplacement direction of

the Vourinos ophiolite is to the northeast (Figure 5; Rassios and Moores 2006; Rassios and

Dilek 2009), but locally the contractional deformation associated with this northeastward

movement has been overprinted by oblique-slip deformation. Along the north–

northwestern edge of the ophiolite (Mt. Vourinos, Agios Nikolaos Valley, and North of

Skoumtsa), the Vourinos subophiolitic melange shows mainly contractional deformation

with sinistral oblique-slip overprint and duplexing (Figure 6). In the central region

(Frourio), the deformation is manifested in major ENE-vergent thrust faults with

second-order, conjugate dextral and sinistral oblique-slip faults (Figure 7). Along the

southern edge of the ophiolite nappe (Aliakmonas River Valley), the southeast-vergent

thrust faults show strong dextral strike-slip components (Figure 8).

The Vourinos subophiolitic melange consists mainly of two major units, the Agios

Nikolaos Formation (ANF) and the Rift Assemblage. Below, we describe the internal

structure and stratigraphy of these two melange units.

Agios Nikolaos Formation (ANF)

The ANF, as originally named by Naylor and Harle (1976), is the most extensive subunit

of the melange and can be characterized as a ‘broken formation’. It is a brown, foliated to

Figure 5. Roadcut maps along the Zavordas Road traversing the basal thrust of the Vourinosophiolite in the Aliakmonas River Valley. Directly underneath the serpentinized and shearedharzburgite is a 0.5 m-thick amphibolite unit making up the metamorphic sole. The ANF beneath theamphibolite comprises mostly pervasively foliated mudstone, sandstone, and conglomerate that aremetamorphosed to greenschist facies. Sandstone clasts are elongated and mudstone displays pencilcleavage. Cleavage planes flow around greater than 1-m-long blocks and boulders in the sandstoneconglomerate. Both the sheared serpentinite and the ANF are imbricated along E–SE-directed thrustfaults and duplex structures. Panels A–C are continuous from WSW (top) to NE (bottom).

R



schistose mudstone containing pebble-, cobble-, and boulder-size clasts of sandstone

(arenite and wacke) mainly composed of quartz and plagioclase grains (Figure 9).

The provenance of the sandstone material is interpreted to be the Pelagonian hinterland

based on the presence of quartz, feldspars, muscovite, and detrital zircons (Mountrakis

1986; Lips et al. 1998; Most et al. 2001; Anders et al. 2006). The ANF has little or no

ophiolitic or Pelagonian carbonate blocks within it; however, the mudstone matrix is

locally tectonically mixed with reworked serpentinite mud and silt along shear zones.

Most blocks are lensoidal in shape and/or bounded by thrust faults. Both lithologically and

structurally, the ANF is analogous to the Lichi Melange associated with the East Taiwan

ophiolite in Taiwan (Liou et al. 1977).

In most areas, the ANF has undergone lower greenschist-facies metamorphism, as

evidenced by the presence of abundant quartz–sericite–calcite–chlorite in the matrix

rocks. Higher grades of metamorphism are seen lower in the structural section near the

contact with the Pelagonian platform carbonates, where the ANF becomes a phyllite with

a strongly developed foliation (Figure 10) and actinolite–albite–chlorite–epidote

mineral assemblages. Phyllitic foliation (cleavage) in the matrix generally dips to the west

(SW or NW) with quartz elongation and/or stretching lineation also plunging to the west

(Figure 10). Both transposed bedding and phyllitic cleavage are folded around NW–SE-

trending fold axes, which plunge at moderate to steep angles in these directions. Tight to

isoclinal folds and crenulation folds are commonly overturned to the NE. The sandstone

clasts are recrystallized to quartz veins, boudins, and lenses, and are commonly strongly

folded and elongated (Figure 9(c)). Adjacent to the Pelagonian micocontinent, the ANF

becomes a schist.

Rift assemblage

Discrete blocks and thrust sheets of igneous rock assemblages and associated sedimentary

rocks are locally abundant within the Vourinos subophiolitic melange (Figures 6 and 8).

The rock types include basaltic lavas, serpentinite breccia, gabbro, dolerite, jasper, ribbon

chert, cherty carbonate, metapelitic rocks, and mylonitized pelagic carbonate, as lensoidal

or phacoidal bodies typically bounded by thrust faults. However, these lithologies locally

have intrusive and/or depositional contacts and/or are interlayered with each other. These

blocks occur along the northern and southern margins of the ophiolite, such as North of

Skoumtsa, in the Agios Nikolaos Valley, and in the Aliakmonas River Valley, but are not

observed at the Frourio locale on the eastern margin of the Vourinos ophiolite (Figure 7).

They are tectonically intercalated with the ANF (Figures 6 and 8).

Volcanic units and associated sedimentary rocks

Volcanic rocks are widely distributed in the melange, particularly in the Aliakmonas River

Valley, the Agios Nikolaos Valley, and North of Skoumtsa. They occur as large blocks of

meta-tuff, pillow lavas, and hyaloclastites, varying in size from 10- to 100-m-long

(Figure 11(a,b); Zimmerman 1968; Ross and Zimmerman 1996). The basaltic lava

outcrops along the Aliakmonas River are strongly coloured in purple, dark red, pink,

and green, and are spatially associated with pink micritic limestone or cherty limestone

(Figure 11(c)). Calcite and chlorite fill brittle fractures as secondary minerals. The phyric

basaltic lavas contain acicular plagioclase microlites and granular clinopyroxene in a

vitrified glassy groundmass. Chlorite occurs as the replacement of olivine. Some of these

basaltic lava blocks contain hemipelagic cherty ribbon limestone (1–3 cm thick ribbons)

C. Ghikas et al.432


Figure 6. Geological map of the Agios Nikolaos Valley and structural cross-sections. See text fordiscussion.



interlayered with siltstone and tuffaceous sandstone (,0.5 cm thick layers). These rocks

are locally strongly folded and recrystallized.

Basaltic lava outcrops in the Agios Nikolaos Valley farther north occur as thin tectonic

wedges bounded by thrust faults (Figure 8), similar to the lava units along the Aliakmonas

River. However, they do not visually resemble the lavas to the south, and their associated

sedimentary units also differ from their counterparts to the south. These volcanic rocks in

the north are mostly massive lava flows and are brown to grey-green, aphanitic, and

Figure 7. Geological map of the Frourio region and a structural cross-section. See text fordiscussion.

C. Ghikas et al.434


commonly heavily weathered, although few pillow shapes are still locally discernable.

The sedimentary rocks associated with these northern volcanic units are metalliferous red

jasper and pelagic limestone. These sedimentary rocks occur either as continuous

interlayers or as large (0.5 m long) lenses within the volcanic units. The jasper interlayers

are highly folded and crenulated.

Intrusive units and associated sedimentary rocks

The intrusive rock units in the melange include gabbro stocks and dolerite dikes that are

commonly associated with a serpentinite breccia (Figure 12). They are intrusive into and/or

tectonically overlie the Pelagonian carbonate platform units, and are also tectonically

intercalated with metapelitic rocks, micritic limestone, and chert. They have been intensely

deformed via folding and thrust faulting, but their original contact relationships have

largely survived this contractional deformation. Some of the originally intrusive contacts

were partly reactivated as thrust faults during emplacement of the Vourinos ophiolite.

Gabbroic and doleritic intrusions are best seen along the Aliakmonas River (Figure 8).

They occur structurally at the bottom of the Vourinos subophiolitic melange, just above the

contact with the intensely deformed and recrystallized Pelagonian platform carbonates and

metapelites. This area of the melange does not contain the ANF. Gabbroic stocks

and doleritic dikes are intrusive into finely foliated phyllite and marble, psammitic schist,

and mylonitized micritic limestone that constitute the outermost units of the Pelagonian

microcontinent. Locally, the sedimentary and igneous contacts between these rock

Figure 8. Geological map of the Aliakmonas River–Zavordas Monastery region and structuralcross-sections. Serpentinite breccia, metagabbro intrusions, dolerite dikes, basaltic lavas, andassociated pelagic limestone collectively constitute the Triassic rift assemblage of the Pelagonianmargin. See text for discussion.



C. Ghikas et al.436


units are well preserved. The Pelagonian marble units contain dasycladacean algae,

algal oncolites, and loferites, suggesting a neritic to littoral environment of deposition

for their protoliths, which ranged in age from Middle Triassic to Upper Jurassic

(Zimmerman 1972).

The gabbroic intrusions here are typically less than 100 m thick, with weakly foliated

to submylonitic fabric parallel to the NE-oriented strike of the outcrop. They appear as

lozenge-shaped, highly sheared intrusive bodies with significant grain size change in short

distances. Mylonitic high-T foliation in the gabbros is folded and crosscut by discrete

narrow mylonitic shear zones. Strong mineral lineation and the fold axes of parasitic

z-folds in these local shear zones all plunge to the west (,2708). These gabbroic intrusions

are cut by numerous subparallel doleritic dikes (Figure 12(b)), which also extend into the

adjacent ultramafic breccia outcrops. Gabbro and dolerite rocks show pervasive secondary

alteration and lower amphibolite facies metamorphism evidenced by extensive

replacement of pyroxene by hornblende and actinolite. Some gabbro outcrops have

been completely altered to serpentinite, chlorite, and oxidized ferromagnesian minerals.

Epidosite is also common, occurring as thick bands parallel to the foliation, or as

disseminated individual grains.

Serpentinite

There are two types of reworked serpentinite types in the Vourinos melange. The first one

strongly resembles the serpentinized harzburgite in the upper mantle section of the

Vourinos ophiolite in terms of its mineralogical and textural features, and still contains

relict pyroxene and olivine crystals although highly sheared. This sheared serpentinite is

found directly beneath the ophiolite or as rare thrust sheets within the ANF. It was derived

mainly from the Vourinos ophiolite during its tectonic emplacement, which locally

incorporated blocks of highly sheared harzburgite into the melange.

The second type of reworked serpentinite bears no resemblance to peridotite rocks

from the ophiolite. It is black and contains rounded to angular clasts of serpentinite

cemented together by secondary serpentine and carbonate minerals. Outcrops of this

serpentinite are typically found in a structurally lower position in the melange (Figure 8),

near the contact with the mylonitized carbonates and metapelitic rocks of the Pelagonian

microcontinent. All these rocks are strongly deformed with refolded folds, thrust

imbrication, and z-type parasitic folds. Stretching lineations in the mylonitized metapelitic

schists trend ,808 with westerly plunges. Fold axes of the z-folds are locally subvertical

and the shear sense indicators suggest a component of dextral strike–slip deformation

(Figure 8).

Similar serpentinite breccia occurrences have been reported from the Godene Zone of

the Antalya Complex in SW Turkey (Figure 1), where foliated and reworked serpentinites

Figure 9. Outcrop photos of the ANF exposed in the Aliakmonas River Valley. (a) Serpentinizedbasal harzburgite (Hzb) of the Vourinos ophiolite (left) is thrust over the ANF (right), which in thislocality constitutes the structurally uppermost unit in the Vourinos melange. (b) General appearanceof the brown, scaly mudstone with numerous small to large clasts of quartzofeldspathic sandstone inthe ANF, here metamorphosed to lower greenschist facies. Hammer for scale. (c) A floating foldnose of an isoclinally folded sandstone–quartzite (QTZ) clast in a pervasively cleaved mudstone–phyllite within the ANF. Sharpie pen for scale. Bedding in the original mudstone has been transposedto phyllitic foliation.

R



Figure 10. Equal-area lower-hemisphere stereoplots of various fabric elements in the Vourinosmelange. (a) North of the Skoumtsa section: Black circles, poles to phyllitic foliation; open circles,poles to quartz elongation and/or stretching lineation; red arrows, poles to fold axes in the phyllite.(b) Frourio section: Black circles, poles to phyllitic foliation. (c) Aliakmon River Section: blackcircles, poles to phyllitic foliation; black stars, poles to doleritic dikes; black arrows, poles to quartzelongation and/or stretching lineation. See text for discussion.

C. Ghikas et al.438


Figure 11. Field occurrence of lava units within the Vourinos subophiolitic melange. (a) Basalticpillow lava block in a pebbly mudstone–phyllite of the ANF in Mt Vourinos northwest of the AgiosNikolaos Valley. Pillow lavas are mostly aphyric, green-brown in colour. (b) Pillow lava block fromthe Aliakmonas River Valley, with purple-pink coloured, visible pillows. (c) Close-up image of lavaflows in (b) showing thin beds of pink chert interlayers between the lava flows. ANF, Agios NikolaosFormation; CHRT, chert; LV, basaltic lava.



C. Ghikas et al.440


are tectonically intercalated with Upper Triassic volcanic–sedimentary passive margin

assemblages (Marcoux 1976; Robertson and Woodcock 1981; Dilek and Rowland 1993).

Anastomozing lenses of fault-bounded serpentinite bodies in the Godene Zone also

include lozenges of gabbro, dolerite, and harzburgite, and are spatially associated with

mafic pillow lavas, volcanic breccias, Upper Triassic pelagic limestones, and radiolarites.

Dilek and Rowland (1993) interpreted the Godene Zone as part of the rifted continental

margin of the Tauride carbonate platform (or microcontinent).

Metamorphic sole unit

Thin, discontinuous exposures of high-grade metamorphic rocks occur between the

subophiolitic melange and the overlying Vourinos ophiolite (Figures 7 and 8). Best

examples of these metamorphic thrust sheets are found on the Zavordas Road and Fruorio,

where a few metres- to 20-m-thick amphibolite, garnet-micaschist, and quartzite are

exposed structurally beneath the Vourinos peridotites (Zimmerman 1972; Ghikas 2007;

Myhill 2009). The contacts between these amphibolite and the melange units are

invariably faulted and sharp, but the crenulation cleavage, tight to isoclinal and overturned

folds, and microfaults all show east-directed tectonic transport similar to those in the

overlying peridotites and the underlying melange units.

Typical peak-metamorphic mineral assemblages in the Zavordas amphibolites include

hornblende–ferropargasite–plagioclase–garnet–sphene–ilmenite–quartz, with retro-

gressive chlorite, biotite, and phengite rimming hornblende and infilling fractures in

garnet (Myhill 2009). Peak temperatures of 6708C (^358C) for the Zavordas garnet–

hornblende pairs and 770 ^ 1008C for the Frourio garnet micaschists have been obtained

from the Vourinos subophiolitic metamorphic rocks (Myhill 2009). 40Ar/39Ar dating of the

Vourinos amphibolites has revealed a cooling age of 171 ^ 4 Ma (Spray 1984; Spray et al.

1984). Moores (1969) and Spray and Roddick (1980) interpreted the high-grade rocks

beneath the Vourinos ophiolite as a metamorphic sole. The geochemistry of the metabasic

rocks in the Vourinos sole indicates both MORB and WPB affinities (Spray and Roddick

1980; Jones and Robertson 1991), similar to the trace-element compositions of the

metalavas in the rift assemblage units within the structurally lowermost part of the

melange (see below).

Neogene cover of the Vourinos melange

Both the Vourinos ophiolite and the subophiolitic melange are unconformably overlain by

a lower Miocene conglomerate (Tsotyli Conglomerate) of the Palaeogene–Neogene

sedimentary sequence of the Mesohellenic Trough (Figure 13). This matrix-supported and

poorly sorted conglomerate consists almost entirely of ophiolitic material, and the clast

size ranges from greater than 1 m to cm scale (Figure 13) A regional compressional

episode in the late Miocene (Vamvaka et al. 2006) produced several SW-dipping thrust

faults, tectonically stacking the conglomerate, the ophiolite, and the melange along

Figure 12. Photos displaying original igneous structures within the rift assemblage outcrops in theAliakmonas River Valley. (a) Gabbro (upper half of photo, Gab) in intrusive contact withserpentinite breccia (lower half of photo, Srpt breccia). (b) Doleritic fine-grained dike (Dol)crosscutting the gabbro (Gab) and its internal fabric at an oblique angle. (c) Dolerite–microgabbrodike (Dol–Gab) intrusive into the recrystallized limestone (marble) of the Pelagonian margin.

R



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C. Ghikas et al.442


northeast-vergent thrust faults (Figure 13). These late Cenozoic thrust faults parallel

the orientation of the older emplacement faults and the foliation planes in sheared

peridotites and serpentinites in the ophiolite. Locally, the original depositional contact

between the conglomerates and the Vourinos melange was also activated as a thrust fault

(Figure 13).

Geochemistry of the rift lavas in the Vourinos melange

A detailed geochemistry and petrogenetic history of the rift lavas and dikes in the

Vourinos melange is presented elsewhere (Dilek et al. in preparation). We report here the

relevant geochemical features of these metabasic rocks. The metalavas in the melange

straddle the boundary between the tholeiitic and calc-alkaline fields on the AFM diagram,

and overlap compositionally with the Triassic lavas from Albania and southern mainland

Greece (Figure 14(a); Pe-Piper 1998; Saccani et al. 2003; Monjoie et al. 2008). Two main

groups of basaltic lavas, high-Ti and low-Ti, have been recognized within the rift

assemblage. The high-Ti group lavas show WPB to MORB geochemical signatures,

whereas low-Ti group lavas display an IAT affinity, suggesting a subduction zone

influence in their melt evolution (Figure 14(b,c)). The incompatible element-enriched

high-Ti group lavas are likely to have been derived from an E-MORB mantle source in a

rift tectonic environment (Dilek et al. in preparation). The geochemical features of the

low-Ti group lavas suggest that the enriched mantle source was influenced by subduction

zone-derived fluids (Dilek et al. in preparation). We interpret this subduction zone

influence as an inheritance from earlier Palaeotethyan subduction events in the region that

produced the late Palaeozoic continental arc magmatism in the Rhodope, Strandja, and

Sredna Gora zones in today’s eastern Greece and Bulgaria (Pe-Piper 1998; Bonev and

Dilek 2010).

Regional tectonics of the Vourinos melange

In order to understand the regional geology of the Vourinos subophiolitic melange within

the tectonic framework of the Western Hellenides and the Pindos Basin, it is important to

compare it with its counterpart on the west, the Avdella melange (Figure 2(b)).

The Avdella melange contains abundant clasts ranging in size from 1 cm to 2 km

(Kostopoulos 1989; Jones and Robertson 1991). Major components of this melange

include thick shallow turbidite and detrital sequences, and olistostromal blocks composed

of Triassic basaltic lavas (Pe-Piper 1982), Jurassic lavas, dolerite, gabbro, and

serpentinized peridotites of an ophiolitic origin, Upper Triassic ‘ammonitico rosso’,

pelagic limestone, Triassic and Jurassic radiolarian cherts, and metamorphic sole rocks

(i.e. amphibolite, greenschist, and micaschist). Volcanoclastic turbidites and debris flows,

composed in many localities of ophiolite-derived detritus, occur both as blocks within the

melange and make up relatively coherent sequences within the melange stratigraphy.

These lithologies range in age from Mid-Triassic to Upper Jurassic. The melange matrix is

heterogeneous (Kostopoulos 1989), and is composed of shale, mudstone, and terrigeneous

sandstone (Kostopoulos 1989; Ross and Zimmerman 1996). This polygenetic composition

is reminiscent of the lithological make-up of other subophiolitic melanges farther south in

the Hellenic ophiolite belt, such as the Pagondas and Komi Leibadi melanges of Crete

(Scherreiks 2000).

The Avdella and Vourinos subophiolitic melanges bear many lithological similarities

and occupy analogous tectonic positions beneath the western and eastern margins of the

Mesohellenic oceanic slab (respectively). However, they differ significantly regarding



their internal structural architecture and the processes involved in their formation.

The Avdella melange contains blocks of rocks associated with the initial rifting of

Pelagonia and Apulia, as well as with the development of a mature carbonate platform (pre-

Apulian platform), the deposition of thick shallow-marine turbidite and detrital sequences

(shelf and slope deposits of the pre-Apulian passive margin), and the emplacement of the

Pindos ophiolite (Jones and Robertson 1991; Rassios et al. 2009). With this association, the

Avdella melange can be characterized as a ‘block-in-matrix’ type, polygenetic melange,

the evolution of which involved both sedimentary and tectonic processes (Raymond 1984).

The Avdella melange was emplaced westwards onto the Cretaceous–Eocene shelf and

turbidite deposits of the pre-Apulian platform (Rassios et al. 2009).

The Vourinos melange, by contrast, is not a chaotic, ‘block-in-matrix’ melange.

It consists mainly of tectonic imbricates of a pebbly mudstone (ANF) with

Figure 14. (a) AFM diagram showing the geochemical affinity of the rift lavas in the Vourinosmelange (after Irvin and Baragar 1971). (b) Zr vs. Zr/Y diagram (after Pearce and Norry 1979).(c) MnO–P2O5–TiO2 diagram (after Mullen 1983). (d) Ti vs. V diagram (after Shervais 1982).Samples of rift-related basalts from the Albanides (data from Monjoie et al. 2008) and southernmainland Greece are also included for comparison (see text for discussion). Light green (left-facingblank) triangles, OIB samples (Triassic) from the Albanides (Monjoie et al. 2008); green (right-facing filled) triangles, BAB samples from Albanides and Othrys ophiolite in Greece (Monjoie et al.2008); purple blank rhombs, rift lavas from the Vourinos melange; purple filled triangles, Triassicbasaltic lavas from the Argolis Peninsula (Saccani et al. 2003); green (top-facing, blank) triangles,basaltic lavas from the Hellenides (Pe-Piper 1998).

C. Ghikas et al.444


Pelagonia-derived detrital material, and a Triassic rift assemblage including serpentinite

breccia, meta-gabbro, dolerite dikes, pillow lavas, and chert. Many of these tectonically

incorporated blocks show their own internal fabric features (i.e. bedding, foliation, and

pre-existing folding) overprinted by shearing and folding associated with the emplacement

of the Vourinos ophiolite and the subsequent eastward imbrication of the ophiolite,

melange, and the overlying Mesohellic sedimentary cover in the late Cenozoic

(Rassios and Dilek 2009; Vamvaka et al. 2010). The ANF is derived almost exclusively

from mudstone and sandstone formed in a depocentre that developed west of Pelagonia

following the early episode of continental rifting in the Mid-Triassic (Zimmerman 1968;

Naylor and Harle 1976; Ghikas et al. 2007). The rift assemblage represents the incipient

rift sequence of the western continental margin of the Pelagonian microcontinent.

We interpret these igneous lithologies and associated sedimentary units collectively as

‘rift assemblages’ that formed during the initial rifting of the Pelagonian microcontinent

from Apulia in the Late Triassic–Jurassic and prior to the onset of seafloor spreading in

the Pindos Basin. Olistostromal blocks or olistoliths are not present in the Vourinos

subophiolitic melange, and blocks of either the ophiolite or the Pelagonian carbonate

platform are rare to be absent within it. The Vourinos melange, therefore, can be best

described as a tectonic melange (Raymond 1984).

Origin of the Vourinos melange and implications for the Mesohellenic ophiolite

The internal structure and origin of the Vourinos melange are important not only for its

own provenance and tectonic history, but also for the root zone and the geodynamic

evolution of the overlying Vourinos ophiolite, which shares its geological history. Because

the Vourinos subophiolitic melange and all its subunits display lithologies and fabric

elements consistent with an origin within the Pindos Basin and with tectonic accretion

beneath an eastward-advancing ophiolite nappe, the Vourinos ophiolite itself must be

rooted in the Pindos Basin. This interpretation rules out the Vardar Zone origin of the

Vourinos ophiolite (and hence the Mesohellenic oceanic slab) and its underlying melange.

The ANF originated as a mudstone–sandstone unit deposited in a continental rise

setting west of the newly formed Pelagonian continental margin during the Late Triassic–

Early Jurassic. The sediment was derived from the interior of Pelagonia, where the

Palaeozoic and Precambrian schists and gneisses of its basement were exposed (Yarwood

and Dixon 1977; Mountrakis 1986; Koroneos et al. 1993; Schermer 1993; Lips et al. 1998;

Most et al. 2001; Mposkos et al. 2001; Anders et al. 2006). The lava blocks in the melange

have WPB to E-MORB geochemical signatures, consistent with their continental rift

origin (Pe-Piper 1998; Saccani et al. 2003; Dilek et al. in preparation). These extrusive

rocks are also in depositional contacts with marine sedimentary rocks including

hemipelagic chert and limestone.

Nearly, all blocks in the Vourinos melange are oriented with their long axis parallel to

the strike of faults bounding the melange between the ophiolite and the Pelagonian margin.

Ductile and brittle deformation structures observed within the melange, such as folds,

foliation, mylonitic and cataclastic shear zones, and brittle thrust faults, are all parallel to

the deformation structures within the lower sections of the overlying Vourinos ophiolite

(Figure 5). Mylonitic bands and shear zones within the melange blocks and the matrix are

generally parallel to each other and to the direction of NE thrusting. In all locales within

the Vourinos melange, the general direction of tectonic transport is eastwards.

Recrystallized limestone and metapelitic rocks of the Pelagonian microcontinent

structurally beneath the Vourinos ophiolite and melange show east-vergent, tight to



C. Ghikas et al.446


isoclinal folds that are commonly overturned to the east. Tectonic models for the root zone

and emplacement of the Vourinos ophiolite must, therefore, also include this information.

The Vourinos subophiolitic melange represents a parautochthonous oceanic

assemblage – it was formed in an ocean basin at the western edge of the Pelagonian

continent; it is now situated along a suture zone between the Vourinos ophiolite, which is a

remnant of the Pindos oceanic lithosphere, and the western edge of the Pelagonian

microcontinent. Hence, the Mesohellenic oceanic slab is also a parautochthonous unit.

Therefore, a far-travelled nappe origin of the Mesohellenic ophiolite rooted in the Vardar

Zone east of Pelagonia is not supported by our observations and tectonic model.

Tectonic history of the Pindos Basin and formation of the Vourinos melange

Apulia and Pelagonia were part of the northern edge of Gondwana in the latest Permian–

Early Triassic. Extension during the Late Triassic caused rifting of Apulia and Pelagonia

and formation of the rift assemblage now preserved in the structurally lower section of the

Vourinos melange (Figure 15(a,b)). Deposition of mudstone and sandstone, precursor to

the ANF, occurred in the rift basin at this time. Detrital sediments of this incipient rift

basin were derived from the crystalline basement of the Pelagonian microcontinent. As the

rift–drift tectonics of the Pindos Basin evolved and the passive margin of the Pelagonian

microcontinent fully developed, the ANF was deposited in the continental rise

environment of this Pelagonian passive margin (Figure 15(c)).

In the mid-Jurassic (175–165 Ma), the Pindos Basin started collapsing via intra-

oceanic subduction (Figure 15(d)) as a result of a collision-driven regional compressive

stress regime in the Tethyan realm farther east (Dilek et al. 2005, 2007). As subduction

continued and began to rollback to the east, suprasubduction-zone oceanic crust formation

in the Pindos Basin evolved in an east-facing infant arc–forearc environment (Saccani and

Photiades 2004; Beccaluva et al. 2005; Dilek et al. 2005, 2008). Mafic and ultramafic

rocks in the Mesohellenic ophiolite show, in general, a west-to-east MORB to SSZ to

boninitic progression in chemical affinity (Smith and Rassios 2003; Pe-Piper et al. 2004;

Beccaluva et al. 2005; Dilek et al. 2008), suggesting progressive depletion of the mantle

wedge peridotites through repeated melting episodes during SSZ oceanic crust evolution.

The arrival of the Pelagonian continental margin at the trench started an episode of arc–

continent collision in the Late Jurassic–Early Cretaceous that terminated the subduction

rollback cycle and magmatism (Figure 15(e)). The Vourinos ophiolite was then displaced

from its igneous environment of formation and was tectonically accreted onto the western

edge of Pelagonia along an ENE-directed lithospheric-scale thrust fault.

By the Early Cretaceous, the west-dipping subduction in the Pindos Basin was halted

by the collision and partial subduction of Pelagonia, and the Vourinos ophiolite (eastern

half of the Mesohellenic oceanic slab) was thrust over the Pelagonian microcontinent,

along with imbricate thrust sheets of the ANF (continental rise deposits) and the rift

assemblage units in this structurally descending order (Figure 15(f)). The western half of

the Pindos Basin remained open, and passive margin conditions along the Apulian margin

to the west persisted until early Tertiary time (Meco and Aliaj 2000; Dilek et al. 2005).

Figure 15. Tectonic model for the formation and evolution of the Pindos Basin. See text fordiscussion. A and P in continental blocks refer to Apulia and Pelagonia, respectively. X and o refer topost-collisional strike-slip components of deformation within the Mesohellenic Trough and in thePelagonian hinterland (x, away; o, towards). WPB, within-plate basalt.

R



Continued continental convergence between Apulia and Pelagonia caused underplating of

the Apulian continental margin beneath the Pindos Basin during the latest Mesozoic–

Early Palaeogene. The western half of the Mesohellenic ophiolite slab, the Pindos

ophiolite, was then detached and thrust over the Apulian margin, tectonically accreting

and overriding rift-related rocks and turbidite deposits along the western margin of the

basin (Figure 15(f)). This sequence of events along the eastern margin of Apulia during the

latest Cretaceous–Eocene developed the Avdella melange.

Throughout the early Cenozoic, Pelagonia and Apulia underwent oblique continental

collision, creating regional E–W crustal-shortening and broad-dextral deformation in a

,NW–SE-trending zone in the Pelagonian hinterland (Dilek et al. 2005). As the Pindos

basin contracted due to this collision and the Pindos ophiolite overrode the Apulian

continental margin, west-directed thrust faults propagated through the Apulian carbonate

platform (Figure 15(g)), flysch deposits accumulated within foreland-migrating flexural

basins, and thin-skinned thrust packages developed over the Apulian basement during the

Eocene–Oligocene. The remnant Pindos Basin gradually transitioned from a marine-

dominated environment to a coastal, deltaic, and finally terrestrial alluvial depocentre –

the Mesohellenic Trough. The Mesohellenic Trough was bounded and compartmentalized

by oblique-slip normal faults that created sub-basins, which were subsequently filled by

Miocene–Pliocene sediments (Figure 15(g); Vamvaka et al. 2006).

Conclusions

The Triassic–Jurassic Vourinos subophiolitic melange consists of passive margin units

and rift assemblages that formed prior to the onset of seafloor spreading in the Pindos

Basin. The phyllitic matrix of the ANF was originally deposited as a pebbly mudstone and

sandstone on the continental rise setting of the rifted Pelagonian margin, and was then

deformed and metamorphosed during ophiolite emplacement. Clasts and blocks supported

by the phyllitic matrix were mostly derived from the crystalline basement of the

Pelagonian microcontinent. Igneous rocks of the rift assemblage are locally intrusive into

the recrystallized limestone and metapelites of the Pelagonian margin and have WPB to

MORB compositions. Original igneous and sedimentary contacts are well preserved in the

rift assemblage. The continental rise deposits and the rift assemblages were imbricated

along east-directed thrust sheets during the emplacement of the Vourinos ophiolite onto

the Pelagonian margin in the Middle–Late Jurassic. The internal structure and the

evolutionary history of the Vourinos melange represent a tectonic melange character.

The Triassic–Cretaceous Avdella melange beneath the Pindos ophiolite to the west has a

longer, polyphase history of development, and can be described as a block-in-matrix,

polygenetic melange, whose evolution involved both sedimentary and tectonic processes.

The shear sense indicators in the melange units, the lower structural sections of the

Vourinos ophiolite, and the Pelagonian continental margin rocks consistently show top-to-

the-ENE shearing associated with the ENE tectonic transport during the initial stages of

closure of the Pindos Basin. This tectonic phase was marked by ophiolite emplacement.

These structural observations, coupled with the existence of the parautochthonous igneous

and sedimentary rift units along the western margin of Pelagonia, rule out those

interpretations and models suggesting the westward tectonic transport of the Vourinos

ophiolite and its subophiolitic melange from the Vardar Zone to the east of Pelagonia.

The Pindos ophiolite and the Avdella melange beneath it were displaced westwards and

emplaced onto the pre-Apulian platform carbonates as a result of the oblique collision

between Eurasia and Apulia later in the Eocene.

C. Ghikas et al.448


Acknowledgements

This paper is part of Constandina Ghikas’ MS thesis work at Miami University and has been fundedin part by research grants from the Geological Society of America, Institute of Geology and MineralExploration of Greece (Kozani), and the Department of Geology at Miami. We have benefited fromour discussions on the geology of the Vourinos and Pindos ophiolites and their subophioliticmelanges with Alan G. Smith, Dimitrios Kostopoulos, Eldridge Moores, Bob Myhill, and JohnWakabayashi. Constructive and thorough reviews by Andrea Festa, Nancy Lindsley-Griffin, andKathleen Nicoll were helpful to improve the paper.

References

Anders, B., Reischmann, T., Kostopoulos, D., and Poller, U., 2006, The oldest rocks of Greece: Firstevidence for a Precambrian terrane within the Pelagonian Zone: Geological Magazine, v. 143,p. 41–58.

Bebien, J., Dubois, R., and Gauthier, A., 1986, Example of ensialic ophiolites emplaced in a wrenchzone: Innermost Hellenic ophiolite belt (Greek Macedonia): Geology, v. 14, p. 1016–1019.

Beccaluva, L., Coltorti, M., Saccani, E., and Siena, F., 2005, Magma generation and crustal accretionas evidenced by supra-subduction ophiolites of the Albanide–Hellenide subpelagonian zone:The Island Arc, v. 14, p. 551–563.

Bonev, N., and Dilek, Y., 2010, Geochemistry and tectonic significance of proto-ophioltic metamaficunits from the Serbo-Macedonian and western Rhodope massifs (Bulgaria-Greece):International Geology Review, v. 52, p. 298–335.

Bortolotti, V., Marroni, M., Pandolfi, L., and Principi, G., 2005, Mesozoic to Tertiary tectonichistory of the Mirdita ophiolites, northern Albania: The Island Arc, v. 14, p. 471–493.

Capedri, S., Venturelli, G., Bocchi, G., Dostal, J., Garuti, G., and Rossi, A., 1980, The geochemistryand petrogenesis of an ophiolite sequence from Pindos, Greece: Contributions to Mineralogy andPetrology, v. 74, p. 189–200.

Cloos, M., and Shrece, R.L., 1988a, Subduction-channel model of prism accretion, melangeformation, sediment subduction, and subduction erosion at convergent plate margins: 1.Background and description, in Ruff, L.J., and Kanamori, H., eds., Subduction zones, Part I:Basel: Birkhauser Verlag, p. 455–500.

Cloos, M., and Shrece, R.L., 1988b, Subduction-channel model of prism accretion, melangeformation, sediment subduction, and subduction erosion at convergent plate margins: 2.Implications and discussions, in Ruff, L.J., and Kanamori, H., eds., Subduction Zones, Part I:Basel-Boston-Berlin: Birkhauser Verlag, p. 501–545.

Collaku, A., Cadet, J.-P., Melo, V., Vranaj, A., and Bonneau, M., 1990, Sur l’allochtonie deszones internes albanais: Mise en evidence de fenetre a l’arriere de la nappe ophiolitiquede la Mirdita (Albanie): Comptes Rendus de L’Academie des Sciences de Paris, v. 311,p. 1251–1258.

Collaku, A., Bonneau, M., Cadet, J.-P., and Kienast, J.-R., 1991, La semelle metamorphique infra-ophiolitique de la nappe de Mirdita, son metamorphisme inverse et ses relations avec la serievolcano-sedimentaire (region de Lura, Albanie septentrionale): Les Comptes Rendus del’Academie des sciences de Paris, v. 313, p. 251–258.

Dilek, Y., 1989, Structure and tectonics of an Early Mesozoic oceanic basement in the northernSierra Nevada metamorphic belt, California: Evidence for transform faulting and ensimatic arcevolution: Tectonics, v. 8, p. 999–1014, doi: 10.1029/TC008i005p00999.

Dilek, Y., and Flower, M.F.J., 2003, Arc-trench rollback and forearc accretion: 2. Model template forAlbania, Cyprus, and Oman, in Dilek, Y., and Robinson, P.T., eds., Ophiolites in earth history,v. 218, London: Special Publication Geological Society, p. 43–68.

Dilek, Y., and Furnes, H., 2009, Structure and geochemistry of Tethyan ophiolites and theirpetrogenesis in subduction rollback systems (Lithos, in press).

Dilek, Y., and Rowland, J.C., 1993, Evolution of a conjugate passive margin pair in Mesozoicsouthern Turkey: Tectonics, v. 12, no. 4, p. 954–970, doi: 10.1029/93TC01060.

Dilek, Y., Thy, P., Hacker, B., and Grundvig, S., 1999, Structure and petrology of Taurideophiolites and mafic dike intrusions (Turkey): Implications for the Neo-Tethyan ocean:Bulletin of the Geological Society of America, v. 111, p. 1192–1216, doi: 10.1130/0016-7606(1999)111,1192:SAPOTO.2.3.CO;2.



Dilek, Y., Shallo, M., and Furnes, H., 2005, Rift-drift, seafloor spreading and subduction tectonics ofAlbanian ophiolites: International Geology Review, v. 46, p. 147–176, doi: 10.2747/0020-6814.47.2.147.

Dilek, Y., Furnes, H., and Shallo, M., 2007, Suprasubduction zone ophiolite formation alongthe periphery of Mesozoic Gondwana: Gondwana Research, v. 11, p. 453–475, doi: 10.1016/j.gr.2007.01.005.

Dilek, Y., Furnes, H., and Shallo, M., 2008, Geochemistry of the Jurassic Mirdita ophiolite (Albania)and the MORB to SSZ evolution of a marginal basin oceanic crust: Lithos, v. 100, nos. 1–4,p. 174–209, doi: 10.1016/j.lithos.2007.06.026.

Gawlick, H.J., Frisch, W., Hoxha, L., Dumitrica, P., Krystyn, L., Lein, R., Missoni, S., andSchlagintweit, F., 2007, Mirdita Zone ophiolites and associated sediments in Albania revealNeotethys Ocean origin: International Journal of Earth Sciences, doi: 10.1007/s00531-007-01193-z.

Ghikas, C., 2007, Structure and tectonics of a subophiolitic melange (Zavordhas Melange) of theVourinos Ophiolite (Greece) and kinematics of ophiolite emplacement [MSc thesis]: Ohio,Miami University.

Ghikas, C., Dilek, Y., and Rassios, A.E., 2007, Structure and tectonics of subophiolitic melanges inthe western Hellenides (Greece) and implications for ophiolite emplacement tectonics:Geological Society of America Abstracts with Programs, v. 39, no. 6, p. 454.

Grivas, E., Rassios, A., Konstantopoulou, G., Vacondios, I., and Vrahatis, G., 1993, Drilling for“blind” podiform chrome ore bodies at Voidolakkos in the Vourinos ophiolite complex, Greece:Economic Geology, v. 88, p. 461–468.

Harkins, M., Green, H., and Moores, E., 1980, Multiple intrusive events documented from theVourinos ophiolite complex, northern Greece: American Journal of Science, v. 280, p. 284–290.

Hoeck, V., Koller, F., Meisel, T., Onuzi, K., and Kneringer, E., 2002, The Jurassic South Albanianophiolites: MOR- vs. SSZ-type ophiolites: Lithos, v. 65, p. 143–164.

Hsu, K.J., 1968, Principles of melanges and their bearing on the Franciscan-Knoxville paradox:Geological Society of America Bulletin, v. 79, p. 1063–1074.

Hsu, K.J., 1974, Melanges and their distinction from olistostromes, in Dott, Jr, R.H., and Shaver,R.H., eds., Modern and Ancient Geosynclinal Sedimentation, v. 19, Society for EconomicPaleontologists and Mineralogists, Special Publication, p. 321–333.

Hsu, K.J., 1988, Melange and melange tectonics of Taiwan: Proceedings of the Geological Societyof China, v. 31, p. 87–91.

Irvine, T.H., and Baragar, W.R.A., 1971, A guide to the chemical classification of the commonvolcanic rocks: Canadian Journal of Earth Sciences, v. 8, p. 523–548.

Jackson, E., Green, H., and Moores, E., 1975, The Vourinos ophiolite,Greece: Cyclic units oflineated cumulates overlying harzburgite tectonite: Bulletin of the Geological Society ofAmerica, v. 86, p. 390–398.

Jones, G., and Robertson, A., 1991, Tectono-stratigraphy and evolution of the Mesozoic Pindosophiolite and related units, northwestern Greece: Journal of the Geological Society, London,v. 148, p. 267–288.

Jones, G., Robertson, A., and Cann, J., 1991, Genesis and emplacement of the supra-subduction zonePindos ophiolite, northwestern Greece, in Peters, T., Nicolas, A., and Coleman, G., eds.,Ophiolite genesis and the evolution of the oceanic lithosphere, 5: Petrology and structuralgeology: Amsterdam: Kluwer Academic Publishers, p. 771–800.

Juteau, T., 1980, Ophiolites of Turkey: Ofioliti, v. 2, p. 199–238.Koller, F., Hoeck, V., Meisel, T., Ionescu, C., Onuzi, K., and Ghega, D., 2006, Cumulates and

gabbros in southern Albanian ophiolites: their bearing on regional tectonic setting, in Robertson,A., and Mountrakis, D., eds., Tectonic Development of the Eastern Mediterranean Region:Geological Society, London: Special Publication, v. 260, p. 267–299.

Koroneos, A., Christofides, G., Del Moro, A., and Kilias, A., 1993, Rb–Sr geochronology andgeochemical aspects of the Eastern Varnountas plutonite (NW Macedonia, Greece): NeuesJahbuch fuur Mineralogie, Abhandlungen, v. 165, p. 297–315.

Kostopoulos, D., 1989, Petrogenesis and Tectonic Setting of the Pindos ophiolite, NW Greece [Ph.D.thesis]: Newcastle upon Tyne, University of Newcastle, 528 pp.

Liati, A., Gebauer, D., and Fanning, C., 2004, The age of ophiolitic rocks of the Hellenides(Vourinos, Pindos, Crete): First U-Pb ion microprobe (SHRIMP) zircon ages: ChemicalGeology, v. 207, p. 171–188.

C. Ghikas et al.450


Liou, J.G., Lan, C.-Y., Suppe, J., and Ernst, W.G., 1977, The East Taiwan Ophiolite: its occurrence,petrology, metamorphism and tectonic setting: Taipei, Taiwan: Mining Research and ServiceOrganization, Industrial Technology Research Institute, 212 pp.

Lips, A.L.W., White, S.H., and Wijbrans, J.R., 1998, 40Ar/39Ar laserprobe direct dating of discretedeformational events: A continuous record of early Alpine tectonics in the Pelagonianmicrocontinent, NW Aegean area, Greece: Tectonophysics, v. 298, p. 133–153.

Malpas, J., Calon, T., and Squires, G., 1993, The development of a Late Cretaceous microplatesuture zone in SW Cyprus, in Prichard, H.M., Alabaster, T., Harris, N.B.W., and Neary, C.R.,eds., Magmatic Processes and Plate Tectonics, v. 76, Geological Society, London: SpecialPublications, p. 177–195.

Marcoux, J., 1976, Les series traissiques des nappes a radiolarites et ophiolites d’Antalya (Turquie):Homologies et signification probable: Bulletin de la Societe Geologique de France, v. 18,p. 511–512.

Meco, S., and Aliaj, Sh., 2000, Geology of Albania: Beitrage zur Regionalen Geologie der Erde,Gebruder Borntraeger, Berlin, Stuttgart, Germany, 246 pp.

Monjoie, P., Lapierre, H., Tashko, A., Mascle, G.H., Dechamp, A., Muceku, B., and Brunet, P.,2008, Nature and origin of the Triassic volcanism in Albania and Othrys: A key to understandingthe Neotethys opening?: Bulletin de la Societe Geologique de France, v. 179, p. 411–425.

Moores, E., 1969, Petrology and structure of the Vourinos ophiolite complex, of Northern Greece,Geological Society of America Special Paper, v. 118, p. 1–74.

Most, Th., Frisch, W., Dunkl, I., Balogh, K., Boev, B., Avgerinas, A., and Kilias, A., 2001,Geochronological and structural investigations of the northern Pelagonian crystalline zone –Constraints from K/Ar and zircon and apatite fission track dating: Geological Society of GreeceBulletin, v. 34, p. 91–95.

Mountrakis, D., 1986, The Pelagonian microcontinent in Greece: a polyphase deformed fragment ofthe Cimmerian continent and its role in the geotectonic evolution of the Eastern Mediterranean:Journal of Geology, v. 94, p. 335–347.

Mposkos, E., Kostopoulos, D.K., and Krohe, A., 2001, Low-P/High-T pre-Alpine metamorphismand medium-P Alpine overprint of the Pelagonian Zone documented in high alumina metapelitesfrom the Vernon massif, Western Macedonia, Northern Greece: Geological Society of GreeceBulletin, v. 34, p. 949–958.

Mullen, E.D., 1983, MnO/TiO2/P2O5: a minor element discrimination for basaltic rocks of oceanicenvironments and its implications for petrogenesis: Earth and Planetary Science Letters, v. 62,p. 53–62.

Mussallam, K., and Jung, D., 1986, Petrology and geotectonic significance of sialic rocks preceedingophiolites in the eastern Vardar Zone, Greece: Tschermak’s Mineralogische und Petrogra-phische Mitteilungen, v. 35, p. 217–242.

Myhill, R., 2009, Constraints on the evolution of the Mesohellenic ophiolite from subophioliticmetamorphic rocks, in Wakabayashi, J., and Dilek, Y., eds., Melanges: Processes of Formationand Societal Significance: Geological Society of America Special Paper (in press).

Naylor, M., and Harle, T., 1976, Palaeogeographic significance of rocks and structures Beneath theVourinos ophiolite, northern Greece: Journal of the Geological Society, London, v. 132,p. 667–676.

Nicolas, A., and Boudier, F., 2003, Where ophiolites come from and what they tell us, in Dilek, Y.,and Newcomb, S., eds., Ophiolite Concept and the Evolution of Geological Thought: GeologicalSociety of America Special Paper, v. 373, p. 137–152.

Pamic, J., 1984, Triassic magmatism of the Dinarides in Yugoslavia: Tectonophysics, v. 109,p. 273–307.

Pearce, J.A., and Norry, M.J., 1979, Petrogenetic implications of Ti, Zr, Y, and Nb variations involcanc rocks: Contributions to Mineralogy and Petrology, v. 69, p. 33–47.

Pe-Piper, G., 1982, Geochemistry, tectonic setting and metamorphism of the mid-Triassic volcanicrocks of Greece: Tectonophysics, v. 85, p. 253–272.

Pe-Piper, G., 1998, The nature of Triassic extension-related magmatism in Greece: Evidence fromNd and Pb isotope geochemistry: Geological Magazine, v. 135, p. 331–348.

Pe-Piper, G., Tsikouras, B., and Hatzipanagiotou, K., 2004, Evolution of boninites and island-arctholeiites in the Pindos ophiolite, Greece: Geological Magazine, v. 141, p. 455–469.



Phipps, S.P., 1984, Ophiolitic olistostromes in the basal Great Valley sequence, Napa County,northern California Coast Ranges, in Raymond, L.A., ed., Melanges: Their nature, origin, andsignificance: Geological Society of America Special Paper, v. 198, p. 103–125.

Polat, A., Casey, J.F., and Kerrich, R., 1996, Geochemical characteristics of accreted materialbeneath the Pozanti–Karsanti ophiolite, Turkey: Intra-oceanic detachment, assembly andobduction: Tectonophysics, v. 263, p. 249–276.

Rassios, A., 1981, Geology and Evolution of the Vourinos Complex, Northern Greece [Ph.D. thesis]:Davis, University of California, 499 pp.

Rassios, A.E., and Dilek, Y., 2009, Rotational deformation in the Jurassic Mesohellenic ophiolites,Greece, and its tectonic significance: Lithos, v. 108, p. 207–223, doi: 10.1016/j.lithos.2008.09.005.

Rassios, A., and Moores, E., 2006, Heterogeneous mantle complex, crustal processes, and Obductionkinematics in a unified Pindos–Vourinos ophiolitic slab (northern Greece), in Robertson, A., andMountrakis, D., eds., Tectonic Development of The Eastern Mediterranean Region: GeologicalSociety, London: Special Publications, v. 260, p. 237–266.

Rassios, A., Beccaluva, L., Bortolotti, V., Mavrides, A., and Moores, E.M., 1983, The Vourinosophiolitic complex: A field excursion guidebook: Ofioliti, v. 8, p. 275–292.

Rassios, A.E., Dilek, Y., Myhill, R., Ghikas, C., and Batsi, A., 2009, Melange formations beneath thePindos basin ophiolites, northern Greece, in Wakabayashi, J., and Dilek, Y., eds., Melanges:Processes of Formation and Societal Significance: Geological Society of America Special Paper(in press).

Raymond, L.A., 1984, Classification of melanges, in Raymond, L.A., ed., Melanges: Their nature,origin, and significance: Geological Society of America Special Paper, v. 198, p. 7–20.

Ricou, L.-E., Burg, J.-P., Godfriaux, I., and Ivanov, Z., 1998, The Rhodope and Vardar: Themetamorphic and olistostromic paired belts related to the Cretaceous subduction under Europe:Geodinamica Acta, v. 11, p. 503–511.

Robertson, A.H.F., 2002, Overview of the genesis and emplacement of Mesozoic ophiolites in theEastern Mediterranean Tethyan region: Lithos, v. 65, p. 1–67.

Robertson, A.H.F., and Karamata, S., 1994, The role of subduction-accretion processes in thetectonic evolution of the Mesozoic Tethys in Serbia: Tectonophysics, v. 234, p. 73–94.

Robertson, A.H.F., and Shallo, M., 2000, Mesozoic-Tertiary tectonic evolution of Albania in itsregional Eastern Mediterranean context: Tectonophysics, v. 316, p. 197–254.

Robertson, A.H.F., and Woodcock, N.H., 1981, Godene Zone, Antalya Complex: Volcanism andsedimentation along a Mesozoic continental margin, SW Turkey: Geologische Rundschau, v. 70,p. 1177–1214.

Ross, J., and Zimmerman, J., 1996, Comparison of evolution and tectonic significance of the Pindosand Vourinos ophiolite suites, northern Greece: Tectonophysics, v. 256, p. 1–15.

Saccani, E., and Photiades, A., 2004, Mid-ocean ridge and supra-subduction affinities in the Pindosophiolites (Greece): Implications for magma genesis in a forearc setting: Lithos, v. 73,p. 229–253.

Saccani, E., and Photiades, A., 2005, Petrogenesis and tectonomagmatic significance of volcanic andsubvolcanic rocks in the Albanide–Hellenide ophiolitic melanges: The Island Arc, v. 14,p. 494–516.

Saccani, E., Padoa, E., and Photiades, A., 2003, A Triassic mid-ocean ridge basalts from the ArgolisPeninsula (Greece): New constraints for the early oceanization phases of the Neo-TethyanPindos basin, in Dilek, Y., and Robinson, P.T., eds., Ophiolites in earth history, GeologicalSociety, London, Special Publications, v. 218, p. 109–127.

Scherreiks, R., 2000, Platform margin and oceanic sedimentation in a divergent and convergent platesetting (Jurassic, Pelagonian Zone, NE Evvoia, Greece): International Journal of Earth Science,v. 89, p. 90–107.

Schermer, E.R., 1993, Geometry and kinematics of continental basement deformation during theAlpine orogeny, Mt. Olympos region, Greece: Journal of Structural Geology, v. 15, p. 571–591.

Schmid, S.M., Bernoulli, D., Fugenschuh, B., Matenco, L., Schefer, S., Schuster, R., Tischler, M.,and Ustaszewski, K., 2008, The Alpine–Carpathian–Dinaridic orogenic system: Correlationand evolution of tectonic units: Swiss Journal of Geosciences, v. 101, p. 139–183.

Shallo, M., 1990, Ophiolitic melange and flyschoidal sediments of the Tithonian-Lower Cretaceousin Albania: Terra Nova, v. 2, p. 476–482.

C. Ghikas et al.452


Shallo, M., Kodra, A., and Gjata, K., 1990, Geotectonics of the Albanian ophiolites, in Malpas, J.,Moores, E.M., Panayiotou, A., and Xenophontos, C., eds., Ophiolites, Oceanic CrustalAnalogues, Proceedings of the Symposium “Troodos 1987”: Nicosia, Cyprus: The GeologicalSurvey Department, p. 165–170.

Sharp, I., and Robertson, A., 2006, Tectonic-sedimentary evolution of the western margin Of theMesozoic Vardar Ocean: Evidence from the Pelagonian and Almopias Zones, northern Greece,in Robertson, A., and Mountrakis, D., eds., Tectonic Development of The Eastern MediterraneanRegion, Geological Society: London, Special Publications, p. 373–412.

Shervais, J.W., 1982, Ti-V plots and the petrogenesis of modern ophiolitic lavas: Earth and PlanetaryScience Letters, v. 57, p. 101–118.

Smith, A.G., 1993, Tectonic significance of the Hellenic-Dinaric ophiolites, in Prichard, H.M.,Alabaster, T., Harris, N.B.W., and Neary, C.R., eds., Magmatic processes and plate tectonics:Geological Society of London Special Publications, v. 76, p. 213–243.

Smith, A., and Rassios, A., 2003, The evolution of idea for the origin and emplacement of thewestern Hellenic ophiolites, in Dilek, Y., and Newcomb, S., eds., Ophiolite Concept and theEvolution of Geological Thought: Geological Society of America Special Paper, v. 373,p. 337–350.

Spray, J.G., 1984, Possible causes and consequences of upper mantle decoupling and ophiolitedisplacement: Geological Society of London, Special Publications, v. 13, p. 255–268.

Spray, J.G., and Roddick, J.C., 1980, Petrology and 40Ar/39Ar geochronology of some Hellenicsubophiolitic metamorphic rocks: Contributions to Mineralogy and Petrology, v. 72, p. 43–55.

Spray, J.G., Bebien, J., Rex, D.C., and Roddick, J.C., 1984, Age constraints on the igneous andmetamorphic evolution of the Hellenic–Dinaric ophiolites, in Dixon, J.E., and Robertson,A.H.F., eds., The Geological Evolution of the Eastern Mediterranean: Geological Society,London, Special Publications , v. 17, p. 619–627.

Stampfli, G.M., and Borel, G., 2004, The TRANSMED transects in space and time: Constraints onthe paleotectonic evolution of the Mediterranean domain, in Cavazza, W., Roure, F.M.,Spakman, W., Stampfli, G.M., and Ziegler, P.A., eds., The TRANSMED Atlas, TheMediterranean region from crust to mantle: Springer-Verlag, Berlin-Heidelberg, p. 53–90.

Vamvaka, A., Kilias, A., Mountrakis, D., and Papaoikonomou, J., 2006, Geometry and structuralevolution of the Mesohellenic Trough (Greece): A new approach, in Robertson, A., andMountrakis, D., eds., Tectonic Development of the Eastern Mediterranean Region: GeologicalSociety, London, Special Publications , v. 260, p. 521–538.

Vamvaka, A., Spiegel, C., Frisch, W., Danisik, M., and Kilias, A., 2010, Fission track data from theMesohellenic Trough and the Pelagonian Zone in NW Greece: Cenozoic tectonics andexhumation of sources areas: International Geology Review, v. 52, p. 223–248.

Vrahatis, G., and Grivas, E., 1980, Geological mapping in Vourinos, 1:10,000 scale: Institute ofGeology and Mineral Exploration, Athens, 80 pp.

Wakabayashi, J., and Dilek, Y., 2003, What constitutes ‘emplacement’ of an ophiolite?: Mechanismsand relationship to subduction initiation and formation of metamorphic soles, in Dilek, Y., andRobinson, P., eds., Ophiolites in earth history: Geological Society, London, SpecialPublications, v. 218, p. 427–447.

Yarwood, G., and Dixon, J., 1977, Lower Cretaceous and younger thrusting in the Pelagonian rocksof the high Pieria, Greece, 6th Colloquim on the Geology of the Aegean region: Athens: Instituteof Geological and Mining Research, p. 269–280.

Yilmaz, P.O., and Maxwell, J.C., 1984, An example of an obduction melange: The Alakir Cay unit,Antalya Complex, southwest Turkey, in Raymond, L.A., ed., Melanges: Their nature, origin, andsignificance: Geological Society of America Special Paper, p. 139–152.

Zimmerman, J., 1968, Structure and Petrology of Rocks Underlying the Vourinos OphioliticComplex, Northern Greece [Ph.D. Thesis]: Princeton, Princeton University 98 pp.

Zimmerman, J., 1972, Emplacement of the Vourinos ophiolitic complex, northern Greece:Geological Society of America Memoir, v. 132, p. 225–239.



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