Origin and evolution of the Havran Unit, Western Sakarya basement (NW Turkey): new LA-ICP-MS U-Pb dating of the metasedimentary-metagranitic rocks and possible affiliation to Avalonian microcontinent

Abstract

One of the pre-Jurassic metamorphic basements of the Western Sakarya Zone (NW Turkey) is the Havran Unit which contains metasedimentary (i.e. the Kalabak formation) and metaintrusive rocks of Devonian age. An LA-ICP-MS U-Pb zircon dating study was conducted on 125 zircon grains obtained from a metasedimentary rock to better understand the origin and evolution of the Kalabak formation. Around 107 of 175 spot analyses are concordant with rates 90–110% and the zircon ages vary between 426 ± 5.2 and 3406.9 ± 195.7 Ma. Zircon populations cluster in ranges: 426 ± 5.2–535 ± 13 Ma (8.4%, Palaeozoic), 549 ± 14–999 ± 11 Ma (54.21%, Neoproterozoic), 1012 ± 200–1543 ± 50 Ma (6.54%, Mesoproterozoic), 1736 ± 123–2414 ± 58 Ma (18.7%, Palaeoproterozoic), and 2512 ± 30–3406.9 ± 195.7 Ma (12.15%, Archean). Dominating Neoproterozoic ages notate Cadomian-Avalonian terrains and Mesoproterozoic ages should mainly be related to Avalon terrains. The Karacabey metagranite consists of coarse-grained, equigranular, hypidiomorphic, and rarely foliated monzogranite and granodiorite. It is located to the north of the town of Karacabey in the eastern part of the Biga Peninsula. Main mineral assemblage is quartz, K-feldspar, plagioclase, and biotite. Zircon, apatite, monazite, magnetite, and sphene occur as accessory phases. Aluminum Saturation Index (ASI) values vary between 0.91 and 1.63, indicating the pluton as a metaluminous-peraluminous, I-type granite. The metagranite samples are plotted in the high-K-calcalkaline field on the SiO₂ vs. K₂O diagram. N-MORB-normalised spidergrams display a profound enrichment in the large-ion lithophile elements (LILE), light rare earth elements (LREE), and depletion in high field strength elements, suggesting that its genesis relates to hydrous melting of a mantle wedge in a subduction zone and/or melting of subduction zone-influenced source areas. Chondrite-normalised rare earth element spidergrams are indicative of the importance of plagioclase and amphibole fractionation. In tectonic discrimination diagrams, all of the metagranite samples fall into the volcanic arc granite and late post-collisional granite fields. U/Pb LA-ICP-MS zircon dating of the metagranite yielded an age of 400.3 ± 1.4 Ma (Early Devonian), interpreted as the age of igneous crystallisation. These age data show that the Karacabey metagranite is a member of the lower to mid Devonian granites, recently described from the Biga Peninsula. In light of these findings, we argue that the Havran Unit was an exotic terrain which possibly was once a part of far-travelled Avalon terrains and was attached to Sakarya Zone.

Keywords:

• Western Sakarya Zone
• Avalon terrain
• detrital zircon
• Devonian magmatism
• NW Turkey

1. Introduction

Detrital zircon ages obtained from metasedimentary rocks provide important clues for the determination of potential source regions of exotic terrains in orogenic belts such as Western Anatolia where many discrete continental blocks once located far away from each other and divided by the oceans joined together. In addition, detrital zircon ages are very useful tools for understanding the origins of metamorphosed and fossil-free rocks. Moreover, dating of cross-cutting plutonic rocks can be combined with the ages of detrital zircons to provide additional information on the timing of deposition (Condie, Belousova, Griffin, & Sircombe, 2009; Kolodner et al., 2006; Linnemann et al., 2011; Morag, Avigad, Gerdes, Belousova, & Harlavan, 2011; Strachan et al., 2007; Talavera, Montero, Martínez Poyatos, & Williams, 2012; Ustaömer, Ustaömer, & Robertson, 2012).

The Havran Unit is composed of metasedimentary rocks (i.e. the Kalabak formation) intercalated with ultramafic and metavolcanic rocks, and cross-cutting Devonian metagranites (i.e. the Yolindi, Çamlık, and Karacabey metagranites; Aysal et al., 2012 and references therein; Aysal & Peytcheva, 2012). In the Biga Peninsula, basement rocks (Havran Unit) are mapped as the Kalabak or Torasan formations (or units) in different areas by several researchers (Duru, Pehlivan, Dönmez, Ilgar, & Akçay, 2007; Duru, Pehlivan, Okay, Şentürk, & Kar, 2012; Krushensky, Akçay, & Karaeğe, 1980; Okay, Siyako, & Bürkan, 1991; Pickett & Robertson, 1996; Robertson & Ustaömer, 2011). Although the Havran Unit is exposed in a large area from Havran (western Biga Peninsula) to the town of Karacabey (located in the east of the Biga Peninsula), its origin and relationship with other units remained ambiguous until now within the Central Sakarya basement.

For the first time, we obtained LA-ICP-MS U-Pb zircon ages from both the metasedimentary rock sample (i.e. detrital zircon ages from the Kalabak formation) and cross-cutting metaintrusive rocks (i.e. the Karacabey metagranite). In this paper, we evaluate the detrital zircon ages obtained from the Kalabak formation with special reference to potential source regions of the Havran Unit and discuss their relationships with other continental blocks (e.g. Central and Eastern Sakarya, Istanbul, and Istranca zones) in Turkey and in the eastern Mediterranean region. Geochemistry and petrology of the Devonian Karacabey metagranite is presented and compared with other two metagranites of the Havran Unit (i.e. the Çamlık and Yolindi metagranites) described previously by Aysal et al. (2012) in Biga Peninsula.

Cadomian–Avalonian belts were formed along the northern margin of Gondwana and represent an over 5.000-km-long continental margin arc, comparable in size with that of the modern Andes (Ustaömer, Collins, & Robertson, 2009). Cadomian–Avalonian terrains have recently been described from Western Pontide in the basement complexes of the Istanbul Zone (Ayda Ustaömer, Mundil, & Renne, 2005; Ustaömer, 1999), in the Zonguldak – Karadere area (Chen, Siebel, Satır, Terzioğlu, & Saka, 2002), in the Armutlu metamorphics, NW Turkey (Akbayram, Okay, & Satır, 2012; Okay et al., 2008a).

2. Geological settings

Turkey resembles a geological puzzle where various microcontinental blocks were attached to each other during geological times (Figure 1). Among these, the most important piece of this puzzle is the northwestern Anatolia sector which is composed of numerous distinct tectonic units derived from different continental and oceanic crustal fragments (Ketin, 1966; Okay & Tüysüz, 1999).

Figure 1. Tectonic map of Turkey and surrounding area with major suture zones (Okay & Tüysüz, 1999; http://giseurope.brgm.fr/Tethyan/WTethysideMed2.gif). IPS: Intra Pontide suture, IAES: Izmir-Ankara-Erzincan suture, ITS: Inner Tauride suture.

The Izmir-Ankara-Erzincan-Suture (IAES) belt is the main suture zone between the continental blocks that separates the Pontides in the north from the Anatolide–Tauride platforms in the south (Şengör & Yılmaz, 1981). The Pontides are made up of three significant continental blocks which are named the Istranca (Strandja) Massif, Istanbul, and Sakarya zones (Ketin, 1966; Okay, 1989, 2000; Okay & Tüysüz, 1999) in NW Turkey. The Istranca Massif consists of Upper Precambrian to Lower Cretaceous intrusives and sedimentary rocks metamorphosed in greenschist and amphibolite facies, and Istanbul Zone is composed of Precambrian metamorphic rocks overlain by Lower Ordovician–Lower Carboniferous sedimentary rocks (Chen et al., 2002; Okay, Satır, Tüysüz, Akyüz, & Chen, 2001; Sunal, Natal’in, Satır, & Toraman, 2006; Sunal, Satır, Natal’in, & Toraman, 2008; Yılmaz-Şahin, Aysal, Güngör, Peytcheva, & Neubauer, in press). Remaining part of Pontides is described as Sakarya Zone (Ketin, 1966; Okay & Tüysüz, 1999) and/or Sakarya composite terrain (Göncüoğlu, Dirik, & Kozlu, 1997). Sakarya Zone includes Liassic to Upper Cretaceous sedimentary rocks and a pre-Jurassic metamorphic basement (Okay & Tüysüz, 1999). Sakarya Zone is bounded by the Ezine Zone in western Biga peninsula. Ezine Zone is made up of Upper Cretaceous ophiolitic mélange (i.e. Çetmi mélange, Beccaletto, Bonev, Bosch, & Bruguier, 2007; Okay, Siyako, & Burkan, 1991), metasedimentary rocks including blueschist and eclogite lenses (the Çamlıca Metamorphics; Okay, 2000; Okay et al., 1991).

Pre-Jurassic basement of Sakarya Zone is formed by a series of metamorphic massifs and enigmatic continental blocks (i.e. Pulur Massif, Topuz et al., 2010; and Karadağ Metamorphics, Ustaömer, Robertson, Ustaömer, Gerdes, & Peytcheva, 2012 in Eastern Pontides; Kazdağ and Uludağ massifs; Cavazza, Okay, & Zattin, 2008; Duru et al., 2007, 2012; Okay et al., 2008a in Western Pontides).

Ages obtained from Central Sakarya and Eastern Pontides indicate that Peri-Gondwanan terrains were accreted to southern Eurasia and cross-cut by Carboniferous granites bearing arc signature (Topuz et al., 2010; Ustaömer, Robertson, et al., 2012; Ustaömer, Ustaömer, et al., 2012).

The most common rocks in Sakarya Zone are the subduction accretion complexes of Permian–Triassic age, which were formed by north-dipping subduction of the Palaeotethys under the southern Eurasia (i.e. the Karakaya Complex: Okay, 2000; Okay & Göncüoğlu, 2004; Pickett & Robertson, 1996, 2004; Robertson & Ustaömer, 2011; Robertson et al., 2004). The Karakaya Complex is observed throughout the whole length of northern Turkey from the Biga Peninsula in the west to Artvin (eastern border of Turkey) in the east (Figure 1). The Karakaya Complex consists of two units: (1) the Lower Karakaya which is represented by high-grade metamorphics and (2) the Upper Karakaya which is made up of lower-grade metamorphics (Okay & Göncüoğlu, 2004). The Lower Karakaya Unit corresponds to the Nilüfer Unit which is represented by metabasites and metacarbonates. Upper Karakaya Unit is divided into three subunits: (i) MORB-type pillow lavas, metachert, and turbiditic sandstones (Ortaoba Unit), (ii) Devonian radiolarian ribbon cherts as olistoliths and as thin (<100 m) tectonic slices, Carbonifeous limestones blocks and sediments representing debris flows (Orhanlar graywacke), (iii) within plate volcanics (Çal Unit) and arkosic sandstone conglomerates including Carboniferous–Permian limestones (Hodul Unit; Okay & Göncüoğlu, 2004; Pickett & Robertson, 2004; Robertson & Ustaömer, 2011).

The fourth basic unit of Sakarya Zone is the Havran Unit which is made up of lower to middle-grade metasedimentary rocks (i.e. the Kalabak formation) and cross-cutting Devonian plutonic rocks (Aysal et al., 2012; Okay, Satır, & Siebel, 2006; Okay et al., 1991; Figure 2(A)). The Kalabak formation and the Devonian metagranites (i.e. Yolindi and Çamlık metagranites) were described previously in detail by Aysal et al. (2012). This study basically focuses on the Havran Unit, extending to the NE, and being cross-cut by the Devonian Karacabey metagranite in the north of the town of Karacabey (Aysal & Peytcheva, 2012; Pehlivan, Duru, Kanar, & Kandemir, 2011).

Figure 2. (A) Simplified geological map of the Biga Peninsula and surroundings showing the distribution of tectonic zones discussed in the paper (after Duru et al., 2007, 2012; Pehlivan et al., 2011). (B) Geological map of the study area (in the eastern Karacabey Town, continuation of the contacts of Havran Unit is taken from Pehlivan et al., 2011; tectonic contact between the Havran and Nilufer units in the north of the Karacabey pluton is taken from Sunal, in press).

There are a number of Eocene to Oligo–Miocene volcanic and plutonic rocks across the Biga Peninsula which reflect post-collisional magmatic activity resulting from the collision of the Sakarya Zone with the Anatolide–Tauride Platform during the Late Palaeocene–Early Eocene period (Aldanmaz, Pearce, Thirlwall, & Mitchellal, 2000; Altunkaynak, 2007; Altunkaynak & Dilek, 2006).

2.1. Geology of Karacabey area

The oldest rocks of the Karacabey area are made up of regionally metamorphosed metaclastic successions with subordinate metacarbonate-metachert-metabasites, intercalated with tectonic slices of metaserpentinites which were named as the Fazlıkonağı formation (Ergül, Gözler, Akçaören, & Öztürk, 1986). These are correlated with the Kalabak formation and also considered as the continuation of the Kalabak formation across the NE part of the Biga Peninsula. This formation is composed mainly of dark-gray quartz-muscovite-albite schists, andalusite-bearing quartz-biotite schists, micaschist, and phyllite. Bands and lenses of marble are locally observed in this formation.

Okay (1988) described the overlaying basic metamorphic rocks as the Sazak formation and considered that these units are vertically and laterally transitional to the Kalabak formation (Duru et al., 2007, 2012; Pehlivan et al., 2011). Okay et al. (1991) renamed the Sazak formation as the Nilüfer Unit and this new name has been extensively used by most researchers. However, the inferred transitional contact relation of the Nilüfer Unit with the Kalabak formation was reinterpreted as tectonic contacts (Robertson & Ustaömer, 2011).

In the study area, the Kalabak formation is tectonically overlain by the Nilüfer Unit of Lower Karakaya Complex (Sunal, in press). Glaucophane-chlorite schists and glaucophane-epidote schists are exposed in the N-NW direction of the Karacabey pluton (Figure 2(A)). On the other hand, a 40-m-long tectonic eclogite lens, which is enveloped in serpentinite within a metabasite, phyllite-marble unit of the Lower Karakaya Complex, is exposed 25–30 km away from the town of Karacabey further northwest (Okay & Monié, 1997). Single-grain laser probe ⁴⁰Ar/³⁹Ar dating of phengites from the eclogite yielded ages of 203–208 Ma.

The Kalabak formation is cut by the Devonian Karacabey metagranite. The contact metamorphic zone in the adjacent Kalabak formation was overprinted later by regional metamorphism (Ergül et al., 1986). Epidote skarn and epidote-amphibolite hornfels type rocks are observed between marble lenses and granite within the Kalabak formation in the northern border of the Karacabey metagranite, around the southern slope of Bağdere hill. Hornfelses are observed in phyllites along the intrusive contact of the Karacabey metagranite. Similarly, compacted bands (dolomitic) are present in the marble succession of the host Kalabak formation.

The Karacabey metagranite is cropped out around the northern skirts of the town of Karacabey and Çavuşköy village in the west of the study area (Figure 2(B)). In some places it includes biotite-rich mafic microgranular enclaves. The Karacabey metagranite is a fine- to medium-grained metagranite, which has a brownish alteration colour. It displays a well-developed foliation in some places and it is partly weathered. It is cut by numerous aplite and pegmatite veins. The Karacabey metagranite was affected by intensive tectonism and low-grade metamorphism, but the magmatic texture has remained identifiable. Main mineral assemblage of the metagranite is represented by quartz (15–30%), K-feldspar (15–23%), plagioclase (22–45%), amphibole (5–10%), and biotite (10–15%). Accessory phases are zircon, apatite, monazite, and magnetite. Low-grade metamorphism and/or ductile shearing resulted in recrystallisation of some primary phases. Some hornblende crystals preserved their crystal shapes but changed in composition into actinolitic-hornblende. Epidote, chlorite, and calcite comprise secondary minerals as the pseudomorphs of biotite.

The Karacabey metagranite is unconformably overlain by the Jurassic Bilecik Limestone, which starts with a thin basal conglomerate at its base. In the west, the metagranite body is overlain by the terrigenous sedimentary rocks of Neogene age while in the east it is surrounded by the Quaternary alluvium deposits.

3. Analytical methods

3.1. LA-ICP-MS geochronology

Samples taken from the Kalabak formation and the Karacabey metagranite were separated by using mechanical crusher, magnetic separator, and heavy liquids at the Istanbul University. They were mounted in epoxy resin and imaged by cathodoluminescence (CL) at SEM laboratory, Belgrade University, using JEOL JSM-6610LV. Selected zircon grains are dated by U-Th-Pb LA-ICP-MS method at the Geological Institute, Bulgarian Academy of Science in Sofia, Bulgaria. The isotope analyses are carried out using a New Wave Research (NWR) 193 nm excimer laser UP-193FX attached to a Perkin-Elmer ELAN DRC-e quadrupole inductively coupled plasma mass spectrometer (LA-ICP-MS). An in-laboratory designed ablation cell with lowered position effects, “squid” smoothing device, energy density on sample ca. 8.8 J/cm⁻², and repetition rate of 8 are used. Ablation craters are of 35 μm size, but were changed to 25 μm for the small zircon samples (<60 μm size). The analyses were carried out in blocks of 22, using GJ1 zircon standard (Jackson, Pearson, Griffin, & Belousova, 2004) for fractionation corrections (two analyses at the beginning, two in the middle, and two at the end of the block) and Plešovice (Sláma et al., 2008) as “unknown” standard (to control the correct data reduction). The results were calculated offline using GLITTER 4.0 (Macquarie University).

Within the scope of geochronology, a sample taken from the Kalabak formation micaschist (KB-5) and a sample from the Karacabey metagranite (KR-9) were dated. Obtained ages were evaluated by using ISOPLOT/EX 3.0 (Ludwig, 2003) and 4.15.

3.2. Geochemistry

Ten fresh rock samples collected from the Karacabey metagranite were sent to Canada Acme Laboratory for geochemical analyses. The major element oxides were analysed by an ICP-AES, while the traces and rare earth elements were analysed by an ICP-MS. Analytical results are given in Table 1.

Table 1. The results of whole rock major (wt.%), trace (ppm), and rare earth elements (REE) (ppm) geochemical analysis of Karacabey metagranites.

Sample	KR-1	KR-2	KR-3	KR-4	KR-5	KR-6	KR-7	KR-8	KR-9	KR-10
SiO2	62.06	65.87	62.95	65.57	64.78	64.24	63.51	63.53	63.13	61.28
TiO2	.62	.47	.61	.39	.45	.47	.54	.48	.56	.59
Al2O3	14.85	15.21	16.42	13.93	15.59	15.45	14.77	15.67	14.74	16.91
Fe2O3	4.52	4.29	5.26	5.40	6.13	4.46	5.29	4.36	5.42	5.30
MnO	.09	.10	.10	.02	.09	.08	.10	.08	.11	.11
MgO	3.59	3.34	3.8	3.16	2.94	3.44	4.13	3.57	4.23	3.77
CaO	3.51	2.31	2.83	2.35	1.26	3.52	3.02	3.86	2.92	3.22
Na2O	3.52	2.85	2.69	4.36	1.95	3.12	2.55	3.15	2.52	2.35
K2O	3.85	2.79	3.15	3.1	3.78	2.92	3.81	2.48	3.89	3.16
P2O5	.15	.17	.15	.13	.16	.12	.12	.14	.11	.14
Cr2O3	.003	.002	.024	.002	.017	.026	.03	.026	.03	.024
LOI	2.2	1.7	1.8	.7	2.3	2.0	1.9	2.5	2.1	2.9
Total	98.96	99.10	99.78	99.11	99.45	99.85	99.77	99.85	99.76	99.75
Ni	39.1	32.1	43.6	24.1	50.2	34.1	52.8	43.9	44	38.9
Sc	7	6	15	3	14	15	17	12	17	17
Ba	371	317	904	337	749	591	655	467	665	601
Co	5.6	4.2	10	5.2	11.3	13.3	14.6	14.4	16.4	23.3
Cs	8.5	9.5	8.8	8.2	8.8	7.6	32.9	11.1	31.6	5.6
Ga	17.9	17.8	21.7	14.5	18.9	18.6	17.4	18.5	18.8	20.1
Hf	2.9	3.8	4	4.2	6	4.7	2.9	3.8	3	3.3
Nb	9.7	9.5	10.6	7.2	13.9	9.9	10.2	8.5	10.3	10
Rb	124.3	134.4	129.4	214.7	137.3	118.7	159.2	108.2	160	120.9
Sr	186.5	235.3	258.9	120.5	169.8	276.5	202.8	297.3	195.1	243.5
Ta	.6	.5	.8	1.1	.8	1.0	.9	.8	1.0	1.0
Th	9.1	9.2	9.8	7.2	13	6.3	22.9	20.8	12.5	11.2
U	3.8	3.8	3.5	4.5	2.4	1.2	1.5	1.7	1.5	3.5
V	94	72	120	80	122	94	108	93	107	124
W	21.6	50.7	9	15.2	17.6	15.3	9.3	13	6.4	1.8
Zr	119.5	129.3	135.4	131.2	217	132.4	113.9	145	94.5	118.5
Y	16.6	21.8	18	21.2	30.5	28.3	21.7	24.1	20.8	19.9
La	18.7	20.3	27.3	23.3	40.6	16.3	34.4	53.6	23.1	35.5
Ce	38.9	41.2	50.3	50.6	76.7	32.3	71.2	109	49.1	71
Pr	4.69	4.59	6.1	5.78	8.97	3.87	7.57	11.66	5.11	7.83
Nd	16.2	17.5	23.1	23.3	32.1	16.3	24.3	39.6	18.8	25.8
Sm	3.69	4.21	4.56	4.86	6.34	3.87	5.28	6.25	4.29	5.64
Eu	.99	1.0	1.1	1.3	1.13	.91	.99	.97	.84	1.16
Gd	4.13	3.84	3.9	4.04	5.69	4.44	4.45	4.89	4.05	5.01
Tb	.71	.66	.55	.65	.95	.76	.68	.72	.65	.72
Dy	3.75	3.82	3.06	3.36	5.32	4.69	3.94	4.12	3.22	3.82
Ho	.86	.84	.57	.46	1.13	1.06	.85	.89	.78	.69
Er	2.53	2.72	1.85	1.29	3.37	2.97	2.3	2.31	2.14	1.94
Tm	.42	.41	.24	.22	.52	.46	.32	.33	.31	.27
Yb	2.48	2.55	1.54	1.50	3.08	2.45	1.90	2.09	1.90	1.75
Lu	.41	.43	.26	.19	.49	.45	.32	.32	.27	.31
ASI	.91	1.28	1.27	.94	1.63	1.05	1.07	1.05	1.08	1.29
Eu/Eu*	.78	.76	.80	.90	.58	.67	.62	.54	.62	.67

4. Results

4.1. Dating of the metasedimentary rock sample

To constrain the age and provenance of basement rocks from the western Sakarya Zone, we collected one micaschist sample (KB-5) from the Kalabak formation for zircon geochronology. Sample locality is shown in Figure 2 and geographic coordinate is given in Table 2. The micaschist sample contains quartz, biotite, muscovite, chlorite, minor K-feldspar, and plagioclase as major minerals and zircon and oxides as accessory minerals. The main fabric of the sample is an almost flat-lying foliation (Figure 3(a)).

Table 2. Zircon La-ICP-MS data from sample KB-5 (Western Sakarya, Kalabak formation; Geographic coordinate: 40°1′38.71″N, 27°14′21.56″E).

	Isotope ratios									Age, Ma								Concordance	Th/U
	^206Pb/^238U	1SE	^207Pb/^235U	1SE	^208Pb/^232Th	1SE	^207Pb/^206Pb	1 SE	Rho	^206Pb/^238U	1SE	^207Pb/^235U	1SE	^208Pb/^232Th	1SE	^207Pb/^206Pb	1 SE	%	ppm
1	.12963	.00156	1.3891	.0462	.04234	.00180	.0811	.0020	.65	786	8.9	884	19.6	838	35	1225	47	64.14
2	.46169	.00533	12.1402	.4119	.12599	.00553	.1892	.0036	.71	2447	23.5	2615	31.8	2399	99	2716	31	90.11
3r	.09163	.00104	.7530	.0205	.02651	.00121	.0600	.0013	.64	565	6.2	570	11.9	529	24	605	47	93.42
3rc	.08968	.00102	.7590	.0203	.02560	.00122	.0610	.0013	.64	554	6.0	573	11.7	511	24	640	46	86.45
4cr	.33813	.00396	5.7387	.2006	.09729	.00458	.1211	.0026	.69	1878	19.1	1937	30.2	1877	84	1973	37	95.18
4c	.33593	.00449	5.6963	.3121	.10176	.00507	.1276	.0035	.71	1867	21.7	1931	47.3	1959	93	2066	47	90.39
5c	.09945	.00155	.8295	.0527	.03198	.00199	.0625	.0031	.62	611	9.1	613	29.2	636	39	670	102	91.22
5r	.09913	.00122	.8786	.0330	.03045	.00180	.0645	.0019	.63	609	7.2	640	17.9	606	35	757	61	80.49
6c	.10129	.00118	.8432	.0262	.03141	.00190	.0628	.0016	.63	622	6.9	621	14.4	625	37	689	52	90.29
6r	.10122	.00118	.8107	.0252	.03081	.00195	.0615	.0015	.63	622	6.9	603	14.1	613	38	658	53	94.48
7c	.37038	.00449	8.6864	.3386	.10908	.00722	.1747	.0043	.67	2031	21.1	2306	35.5	2093	132	2603	41	78.04
7r	.09939	.00121	.9147	.0328	.03303	.00231	.0717	.0020	.63	611	7.1	660	17.4	657	45	976	57	62.58
8c	.36956	.00427	9.2567	.3366	.10420	.00373	.1747	.0033	.72	2027	20.1	2364	33.3	2004	68	2603	31	77.89
8r	.40781	.00443	10.5639	.2754	.11328	.00410	.1819	.0031	.69	2205	20.3	2486	24.2	2169	74	2670	28	82.57
8cr	.30698	.00349	7.7564	.2496	.11280	.00441	.1789	.0033	.70	1726	17.2	2203	28.9	2160	80	2642	31	65.31
9c	.42136	.00501	10.1898	.4127	.12070	.00491	.1801	.0036	.72	2267	22.7	2452	37.4	2303	89	2654	33	85.42
9r	.43788	.00472	11.6383	.2674	.22925	.00912	.1892	.0032	.66	2341	21.2	2576	21.5	4172	150	2735	28	85.60
9c	.46321	.00506	13.1021	.3345	.21322	.00886	.2054	.0036	.67	2454	22.3	2687	24.1	3907	148	2870	28	85.51
9r	.41481	.00465	10.6104	.3069	.13364	.00645	.1828	.0036	.67	2237	21.2	2490	26.8	2535	115	2679	32	83.51
10c	.12374	.00165	2.0108	.0860	.05607	.00301	.1206	.0035	.66	752	9.4	1119	29.0	1103	58	1965	51	38.27
10r	.10808	.00147	1.1549	.0540	.03883	.00219	.0785	.0027	.64	662	8.6	780	25.4	770	43	1160	67	57.02
11r	.22392	.00263	2.7804	.0925	.07009	.00411	.0872	.0021	.65	1303	13.8	1350	24.9	1369	78	1365	45	95.42
11cr	.24071	.00285	2.9197	.0994	.07393	.00454	.0899	.0022	.65	1390	14.8	1387	25.8	1442	85	1422	46	97.76
12cr	.15330	.00196	1.4361	.0621	.04671	.00213	.0695	.0021	.65	919	11.0	904	25.9	923	41	913	62	100.68
13c	.10956	.00223	1.0460	.0974	.03485	.00214	.0687	.0047	.63	670	13.0	727	48.3	692	42	890	134	75.29
13r	.11048	.00175	1.0101	.0670	.03448	.00188	.0648	.0032	.63	676	10.2	709	33.8	685	37	747	100	90.39
14c	.16117	.00215	1.7652	.0857	.05168	.00253	.0777	.0025	.66	963	12.0	1033	31.5	1019	49	1139	63	84.59
14r	.14784	.00170	1.5235	.0457	.04579	.00226	.0736	.0017	.65	889	9.6	940	18.4	905	44	1031	45	86.25
15	.50106	.00660	12.7039	.7499	.12986	.00652	.1772	.0044	.75	2618	28.3	2658	55.6	2468	117	2627	40	99.67
16c	.10566	.00134	.8990	.0368	.03205	.00181	.0630	.0020	.63	648	7.8	651	19.7	638	36	709	67	91.34
16r	.10096	.00128	.8911	.0376	.03091	.00185	.0609	.0020	.62	620	7.5	647	20.2	615	36	635	69	97.65
17c	.11012	.00157	.9494	.0518	.03225	.00216	.0630	.0026	.62	673	9.1	678	27.0	642	42	710	86	94.89
17r	.10642	.00156	.8621	.0500	.03355	.00242	.0610	.0028	.62	652	9.1	631	27.3	667	47	639	94	101.97
18r	.24392	.00288	3.7883	.1296	.08493	.00545	.1121	.0028	.64	1407	14.9	1590	27.5	1648	101	1834	45	76.74
18c	.32989	.00408	6.2324	.2643	.09663	.00642	.1266	.0035	.67	1838	19.8	2009	37.1	1864	118	2041	47	90.04
19r	.13939	.00167	1.2966	.0455	.04445	.00174	.0665	.0017	.65	841	9.5	844	20.1	879	34	823	53	102.26
19cr	.11477	.00131	1.0084	.0282	.02995	.00116	.0645	.0014	.64	700	7.6	708	14.3	596	23	758	45	92.39
19c	.11074	.00142	1.0486	.0437	.03227	.00132	.0663	.0021	.63	677	8.2	728	21.7	642	26	817	64	82.89
20c	.16403	.00218	1.7762	.0833	.05767	.00260	.0798	.0025	.66	979	12.1	1037	30.5	1133	50	1191	60	82.19
20r	.13278	.00164	1.3022	.0490	.04091	.00193	.0719	.0020	.65	804	9.3	847	21.6	810	37	983	55	81.79
21c	.16347	.00338	1.6167	.1662	.04597	.00249	.0725	.0049	.65	976	18.7	977	64.5	909	48	1000	131	97.60
22r	.25379	.00325	3.2120	.1441	.07220	.00362	.0958	.0026	.68	1458	16.7	1460	34.7	1409	68	1543	50	94.49
22c	.28188	.00360	3.7638	.1729	.07898	.00408	.0953	.0026	.68	1601	18.1	1585	36.9	1536	76	1534	50	104.39
23	.12116	.00149	1.0376	.0381	.03662	.00201	.0637	.0018	.64	737	8.6	723	19.0	727	39	730	58	101.00
24c	.11006	.00149	.9167	.0435	.03245	.00192	.0600	.0022	.63	673	8.6	661	23.0	646	38	604	77	111.46
25r	.10755	.00135	.9311	.0362	.03465	.00225	.0626	.0019	.63	659	7.9	668	19.0	689	44	694	63	94.88
26c	.14900	.00234	1.4258	.0945	.04416	.00286	.0702	.0032	.64	895	13.1	900	39.5	874	55	935	92	95.75
27r	.10730	.00137	1.0054	.0391	.11179	.00593	.0703	.0021	.64	657	8.0	707	19.8	2142	108	938	59	70.05
28r	.10947	.00129	.9591	.0298	.05281	.00276	.0642	.0016	.64	670	7.5	683	15.5	1040	53	744	50	90.03
29c	.12834	.00164	1.3023	.0525	.04340	.00191	.0750	.0022	.65	778	9.4	847	23.2	859	37	1068	58	72.89
30c	.12211	.00171	1.0751	.0547	.03925	.00192	.0679	.0026	.63	743	9.8	741	26.8	778	37	867	77	85.71
30r	.09432	.00158	.7734	.0534	.03734	.00218	.0618	.0033	.61	581	9.3	582	30.6	741	42	669	112	86.91
31c	.16764	.00217	1.5900	.0698	.05076	.00247	.0729	.0022	.65	999	12.0	966	27.4	1001	48	1012	61	98.74
32c	.13379	.00188	1.1916	.0632	.05455	.00331	.0647	.0025	.63	809	10.7	797	29.3	1074	63	763	79	106.08
32r	.16998	.00197	1.6648	.0495	.04751	.00254	.0722	.0016	.65	1012	10.8	995	18.9	938	49	991	45	102.09
33c	.46651	.00571	10.6644	.4457	.12924	.00725	.1702	.0040	.70	2468	25.1	2494	38.8	2457	130	2560	38	96.43
33r	.42655	.00733	8.8820	.7656	.12461	.00863	.1713	.0061	.74	2290	33.1	2326	78.7	2374	155	2541	58	90.14
34c	.11495	.00151	.9970	.0446	.03340	.00206	.0630	.0021	.63	701	8.7	702	22.7	664	40	708	71	99.12
34r	.10938	.00146	.9523	.0439	.03319	.00213	.0622	.0022	.63	669	8.5	679	22.8	660	42	682	74	98.12
35c	.34346	.00459	6.7415	.3743	.10713	.00440	.1408	.0037	.72	1903	22.0	2078	49.1	2057	80	2238	45	85.06
35r	.34362	.00415	6.1334	.2588	.10122	.00412	.1267	.0029	.71	1904	19.9	1995	36.8	1949	76	2053	39	92.76
36c	.47693	.00524	1.6277	.2893	.13352	.00579	.1655	.0030	.68	2514	22.9	2491	25.3	2533	103	2512	30	100.07
36r	.35400	.00389	6.1807	.1630	.09909	.00418	.1245	.0023	.67	1954	18.5	2002	23.1	1910	77	2021	33	96.65
36cr	.32460	.00360	5.5634	.1515	.09433	.00413	.1276	.0025	.67	1812	17.5	1910	23.4	1822	76	2065	33	87.76
37r	.33131	.00374	8.5406	.2548	.06727	.00310	.1821	.0036	.68	1845	18.1	2290	27.1	1316	59	2672	32	69.04
38c	.12349	.00172	1.1241	.0589	.03575	.00220	.0638	.0025	.63	751	9.9	765	28.1	710	43	734	80	102.22
38r	.11614	.00145	1.0429	.0409	.03734	.00212	.0672	.0020	.63	708	8.4	725	20.3	741	41	844	61	83.88
38cr	.11146	.00138	1.0255	.0396	.03289	.00196	.0650	.0019	.63	681	8.0	717	19.8	654	38	775	61	87.90
39c	.11315	.00143	.9976	.0402	.03427	.00208	.0658	.0020	.63	691	8.3	703	20.4	681	41	801	63	86.30
39r	.10454	.00133	.9118	.0377	.03359	.00211	.0599	.0019	.63	641	7.8	658	20.0	668	41	600	67	106.83
40	.13741	.00197	1.2253	.0676	.04354	.00314	.0654	.0026	.63	830	11.2	812	30.9	861	61	788	82	105.30
41	.44114	.00593	9.1316	.5309	.11440	.00477	.1561	.0038	.75	2356	26.5	2351	53.2	2189	87	2414	41	97.58
42c	.09382	.00146	.8621	.0515	.02921	.00146	.0667	.0031	.62	578	8.6	631	28.1	582	29	828	93	69.84
42cr	.09880	.00140	.8262	.0433	.02935	.00137	.0649	.0027	.62	607	8.2	612	24.1	585	27	771	84	78.82
43r	.09854	.00133	.9509	.0430	.03501	.00159	.0717	.0025	.63	606	7.8	679	22.4	696	31	978	68	61.97
44c	.17789	.00231	1.7280	.0796	.05245	.00247	.0711	.0022	.66	1055	12.6	1019	29.6	1033	47	960	62	109.96
44cr	.11476	.00135	.9960	.0323	.03112	.00139	.0643	.0016	.64	700	7.8	702	16.4	620	27	752	52	93.13
45r	.62868	.00700	24.6636	.6910	.12671	.00619	.2870	.0055	.67	3144	27.7	3295	27.3	2411	111	3401	30	92.44
46c	.11970	.00190	1.1258	.0757	.03165	.00177	.0630	.0031	.63	729	11.0	766	36.2	630	35	709	100	102.85
46r	.11965	.00185	1.1303	.0706	.03366	.00193	.0675	.0031	.63	729	10.7	768	33.6	669	38	854	91	85.31
47c	.11386	.00155	.9674	.0467	.03120	.00191	.0640	.0023	.63	695	9.0	687	24.1	621	37	740	75	93.89
47cr	.10795	.00141	1.1459	.0486	.03614	.00220	.0798	.0025	.64	661	8.2	775	23.0	718	43	1191	61	55.47
48r	.09412	.00107	.7693	.0228	.03486	.00224	.0581	.0014	.64	580	6.3	579	13.1	693	44	534	51	108.60
49c	.11752	.00174	1.0305	.0603	.03595	.00211	.0667	.0029	.63	716	10.1	719	30.1	714	41	828	89	86.47
49r	.11603	.00140	1.0278	.0379	.03523	.00190	.0647	.0018	.64	708	8.1	718	19.0	700	37	766	58	92.40
50r	.13487	.00172	1.2369	.0530	.04219	.00193	.0696	.0022	.64	816	9.8	818	24.1	835	37	905	63	90.16
51	.12942	.00170	1.2331	.0574	.03855	.00183	.0690	.0023	.64	785	9.7	816	26.1	765	36	898	68	87.36
52c	.14434	.00219	1.6592	.1022	.04191	.00233	.0814	.0033	.65	869	12.4	993	39.0	830	45	1232	78	70.55
52r	.15454	.00222	1.5693	.0904	.04564	.00251	.0734	.0029	.64	926	12.4	958	35.7	902	49	1025	78	90.35
53c	.61989	.00792	22.2658	1.2852	.16499	.00846	.2376	.0054	.76	3110	31.5	3195	56.1	3087	147	3104	36	100.18
54r	.48415	.00566	11.6738	.4429	.13683	.00714	.1777	.0039	.70	2545	24.6	2579	35.5	2592	127	2631	36	96.74
54c	.49734	.00577	13.0441	.4735	.14304	.00777	.1867	.0041	.69	2602	24.8	2683	34.2	2702	137	2713	36	95.92
55	.18115	.00205	1.8310	.0534	.05212	.00293	.0733	.0017	.64	1073	11.2	1057	19.1	1027	56	1021	45	105.12
56	.37405	.00431	6.7910	.2245	.10622	.00617	.1312	.0030	.66	2048	20.2	2085	29.3	2040	113	2114	40	96.88
57	.11429	.00172	1.0008	.0603	.03499	.00234	.0640	.0029	.63	698	10.0	704	30.6	695	46	741	93	94.16
58cr	.09913	.00167	.8126	.0582	.02796	.00173	.0609	.0034	.62	609	9.8	604	32.6	557	34	635	115	95.98
59r	.42138	.00508	10.7993	.4636	.11930	.00645	.1822	.0042	.71	2267	23.0	2506	39.9	2278	117	2673	37	84.80
59c	.48748	.00569	12.4169	.4698	.12381	.00699	.1771	.0040	.69	2560	24.6	2637	35.6	2359	126	2626	37	97.49
60r	.14493	.00168	1.3530	.0439	.04661	.00300	.0693	.0017	.64	873	9.5	869	19.0	921	58	908	51	96.07
61cr	.17659	.00214	1.9050	.0724	.05017	.00326	.0784	.0022	.64	1048	11.7	1083	25.3	989	63	1158	54	90.52
62rc	.38972	.00499	11.1816	.5342	.15665	.01092	.2007	.0056	.68	2122	23.2	2538	44.5	2942	191	2832	45	74.91
63cr	.10178	.00137	.9576	.0323	.0512	.0034	.0682	.0024	.58	624.8	8.0	682.0	16.5	1,009.4	64.3	875.7	142.6	71.35	.102
64cr	.17315	.00304	1.8902	.0933	.0541	.0035	.0792	.0040	.57	1029.5	16.7	1077.7	31.3	1,065.5	66.6	1120.0	200.4	91.92	.675
65r	.10438	.00151	.9339	.0377	.0428	.0032	.0649	.0027	.57	640.0	8.8	669.7	19.4	847.1	61.7	770.8	173.2	83.03	.104
66cr	.37223	.00485	6.3861	.1706	.1119	.0069	.1244	.0034	.59	2039.9	22.7	2030.4	21.7	2,143.6	125.4	2020.7	96.6	100.95	.570
67c	.10746	.00169	.9087	.0443	.0351	.0025	.0613	.0031	.56	658.0	9.8	656.4	23.0	697.3	49.1	651.0	214.2	101.07	.307
67cr	.10122	.00179	.8520	.0494	.0311	.0024	.0611	.0036	.56	621.5	10.5	625.8	26.4	619.2	47.6	641.1	255.7	96.95	.325
68cr	.32303	.00399	5.1032	.1370	.0937	.0068	.1146	.0032	.59	1804.5	19.4	1836.6	21.4	1,810.7	124.9	1873.3	99.1	96.33	.583
69r	.06831	.00087	.5288	.0172	.0305	.0034	.0561	.0019	.58	426.0	5.2	431.0	11.3	607.1	66.4	458.2	147.7	92.97	.011
70r	.13391	.00184	1.2290	.0455	.0509	.0048	.0666	.0025	.57	810.1	10.5	813.9	20.3	1,003.3	92.7	824.1	158.7	98.30	.050
71c	.09833	.00131	.8049	.0293	.0290	.0024	.0594	.0022	.57	604.6	7.7	599.6	16.2	577.0	47.7	580.7	162.4	104.11	.252
71r	.08477	.00120	.6751	.0281	.0257	.0023	.0578	.0025	.57	524.5	7.1	523.8	16.8	512.1	46.1	520.8	187.7	100.70	.164
72cr	.32391	.00548	5.0812	.2164	.0970	.0087	.1138	.0050	.57	1808.8	26.6	1833.0	32.7	1,870.7	158.9	1860.5	159.1	97.22	.904
73all	.16343	.00230	1.8703	.0696	.0540	.0050	.0830	.0032	.57	975.8	12.7	1070.6	23.8	1,062.4	94.9	1269.2	150.5	76.88	.380
74cr	.08433	.00099	.6746	.0177	.0276	.0016	.0580	.0016	.59	521.9	5.9	523.5	10.7	550.3	32.2	530.4	117.8	98.41	.556
75cr	.15357	.00208	1.4608	.0511	.0474	.0032	.0690	.0025	.58	920.9	11.6	914.3	20.6	936.6	61.5	898.5	147.7	102.50	.238
76c	.09175	.00131	.7435	.0314	.0305	.0020	.0588	.0025	.57	565.9	7.7	564.4	18.0	607.1	40.0	558.6	188.5	101.29	.353
77r	.09214	.00148	.7362	.0379	.0297	.0031	.0580	.0031	.56	568.2	8.7	560.2	21.7	591.4	61.5	528.0	230.7	107.61	.071
78cr	.30917	.00455	4.8746	.1591	.1002	.0068	.1144	.0038	.59	1736.6	22.4	1797.9	25.5	1,930.1	124.5	1869.7	121.2	92.88	.491
78cr	.33124	.00405	5.2400	.1306	.0973	.0065	.1147	.0029	.59	1844.4	19.6	1859.1	20.0	1,877.3	118.6	1875.7	91.4	98.33	.612
79a	.14767	.00189	1.9061	.0557	.0544	.0041	.0936	.0028	.59	887.9	10.6	1083.2	18.9	1,071.3	77.7	1500.4	112.3	59.18	.232
80cr	.10490	.00145	.8871	.0336	.0470	.0043	.0613	.0024	.57	643.1	8.5	644.8	17.8	928.3	82.1	650.9	165.2	98.79	.053
80r	.29039	.00408	4.2574	.1401	.0873	.0069	.1063	.0036	.58	1643.5	20.3	1685.2	25.3	1,692.5	127.8	1737.5	122.8	94.59	.581
81r	.09742	.00134	.8058	.0302	.0303	.0026	.0600	.0023	.57	599.3	7.9	600.1	16.8	603.5	51.7	603.3	164.5	99.33	.133
82c	.10766	.00256	.9144	.0782	.0338	.0031	.0616	.0054	.56	659.2	14.9	659.4	40.0	670.9	60.5	660.3	375.1	99.83	.852
83r	.10052	.00171	.8350	.0457	.0337	.0032	.0602	.0034	.56	617.4	10.0	616.4	24.7	668.9	61.9	612.5	241.0	100.81	.274
84rc	.20471	.00324	3.1262	.1248	.0756	.0070	.1108	.0045	.58	1200.6	17.3	1439.1	28.9	1,473.6	130.1	1811.9	147.6	66.26	.371
85r	.1154	.0017	1.038	.040	.0298	.0016	.065	.003	.57	704	9.5	723	19.6	593.6	30.92	780.8	81.07	90.13	.827
85c	.1102	.0015	.973	.034	.0297	.0018	.064	.002	.57	674	8.6	690	17.4	591.2	35.62	743	74.38	90.68	.209
86r	.0998	.0013	.827	.027	.0281	.0015	.060	.002	.58	613	7.6	612	15.0	559.9	29.83	607	71.43	101.00	.640
87r	.0852	.0011	.764	.023	.0223	.0012	.065	.002	.58	527	6.5	577	13.3	444.8	24.6	775.8	64.18	67.96	.528
88r	.4491	.0055	10.756	.234	.1078	.0061	.174	.004	.61	2,391	24.4	2,502	18.2	2069.7	111.21	2593.2	36.52	92.22	.513
89r	.0991	.0025	1.083	.088	.0277	.0024	.079	.007	.56	609	14.5	745	41.0	551.9	47.88	1178.5	157.04	51.68	.496
90c	.3486	.0046	6.113	.168	.0984	.0068	.127	.004	.59	1,928	21.9	1,992	22.2	1896.9	124.71	2059	48.94	93.64	.635
91a	.5003	.0071	12.996	.368	.1289	.0096	.188	.005	.59	2,615	30.3	2,679	22.7	2449.9	172.6	2728.1	47.15	95.86	.944
92r	.2325	.0029	3.723	.099	.0768	.0061	.116	.003	.59	1,347	15.0	1,576	20.3	1496.4	114.11	1897.9	48.31	70.99	.150
92c	.2739	.0033	4.351	.115	.0650	.0054	.115	.003	.59	1,561	16.9	1,703	20.6	1271.9	102.73	1883.1	47.98	82.87	.105
93r	.0784	.0012	.687	.033	.0251	.0022	.064	.003	.56	486	7.3	531	19.8	500.9	44.21	727.3	102.37	66.86	.394
94cr	.3762	.0056	6.595	.229	.1054	.0099	.127	.005	.58	2,058	26.0	2,059	27.6	2025.4	181.42	2058.9	61.94	99.97	.406
95r	.3104	.0044	4.872	.147	.0907	.0056	.114	.004	.59	1,743	21.7	1,797	23.7	1754.9	102.86	1861.4	54.8	93.62	.576
96c	.3606	.0048	6.436	.169	.1020	.0062	.129	.003	.60	1,985	22.8	2,037	21.3	1963.9	113.63	2090	46.39	94.98	.575
97cr	.0831	.0014	.672	.039	.0277	.0025	.059	.004	.56	514	8.3	522	23.5	552.7	49.22	553.6	125.37	92.92	.171
98cr	.0866	.0011	.694	.021	.0268	.0017	.058	.002	.58	535	6.5	535	12.7	533.9	33.19	535	67.68	100.09	.745
99r	.0750	.0014	.587	.043	.0230	.0020	.057	.004	.55	466	8.1	469	27.1	459.6	39.21	480.4	158.33	97.07	.321
100cr	.0811	.0013	.647	.034	.0242	.0020	.058	.003	.56	502	7.6	507	20.6	483.7	38.4	525.3	113.97	95.66	.327
101cr	.1042	.0021	.881	.062	.0309	.0024	.061	.004	.56	639	12.1	641	32.7	614.5	47.64	649	148.59	98.49	1.019
102cr	.1059	.0021	.896	.064	.0307	.0027	.061	.004	.56	649	12.2	650	33.2	611.1	52.45	652.7	149.09	99.45	.531
103c	.3450	.0043	5.810	.159	.0956	.0081	.122	.003	.59	1,910	20.4	1,948	22.0	1844.6	149.21	1988.6	49.01	96.07	.085
104c	.3249	.0043	6.715	.197	.0868	.0076	.150	.005	.58	1,814	20.6	2,075	23.7	1683.2	141.81	2345.1	50.72	77.34	.159
104r	.1044	.0016	.883	.048	.0307	.0027	.061	.003	.56	640	9.6	642	25.0	610.7	53.29	650.7	113.84	98.41	1.028
105r	.0816	.0013	.690	.037	.0277	.0024	.061	.003	.56	506	8.0	533	21.6	551.3	47.27	648.8	112.32	77.98	.349
106r	.1018	.0016	.904	.042	.0325	.0028	.064	.003	.57	625	9.2	654	22.2	646.2	54.71	756.4	98.31	82.59	.683
107r	.0901	.0013	.796	.031	.0277	.0025	.064	.003	.57	556	7.4	595	17.3	551.9	48.47	744	82.1	74.75	.984
108cr	.0840	.0012	.693	.030	.0274	.0028	.060	.003	.57	520	7.3	534	17.6	545.9	54.78	597.3	92.52	87.04	.197
109r	.0824	.0012	.654	.027	.0247	.0026	.058	.002	.57	510	6.8	511	16.1	493.7	50.48	514.2	88.81	99.24	.361
110r	.0889	.0012	.734	.027	.0293	.0032	.060	.002	.57	549	7.1	559	15.7	583.6	62.57	599	79.89	91.62	.460
111r	.0765	.0009	.622	.016	.0239	.0025	.059	.002	.59	475	5.4	491	10.0	477.3	49.93	566.4	55.73	83.86	.018
111c	.1408	.0019	1.497	.048	.0435	.0019	.077	.002	.58	849	10.4	929	18.9	860.6	36.36	1124.7	63.14	75.49	.518
112cr	.3153	.0035	5.166	.088	.0856	.0034	.119	.002	.63	1,767	17.2	1,847	13.9	1659.3	63.52	1938.6	29.84	91.13	.457
113r	.0906	.0013	.748	.031	.0270	.0015	.060	.003	.57	559	7.4	567	17.8	538.4	29.6	600.2	88.68	93.17	.196
113c	.0940	.0015	.809	.046	.0288	.0016	.062	.004	.56	579	9.0	602	25.2	573	31.28	688.1	118.57	84.20	.373
114c	.3405	.0042	6.421	.138	.0892	.0039	.137	.003	.61	1,889	20.2	2,035	17.7	1726.9	72.79	2186.7	37.27	86.38	.491
115c	.1075	.0014	.954	.032	.0312	.0017	.064	.002	.58	658	8.4	680	16.3	620.6	33.33	752.7	69.95	87.47	.255
116r	.0996	.0019	.930	.058	.0218	.0018	.068	.004	.56	612	10.8	668	29.8	436.5	36.26	858.6	127.44	71.32	.249
117rc	.0808	.0011	.667	.022	.0256	.0017	.060	.002	.58	501	6.3	519	13.2	511.5	33.53	599.2	70.39	83.56	.085
118cr	.1088	.0013	.925	.021	.0307	.0017	.062	.001	.60	666	7.6	665	11.2	611.8	33.74	662.6	48.68	100.50	.104
119cr	.1160	.0017	1.008	.043	.0322	.0021	.063	.003	.57	707	9.6	708	21.5	640.3	89.92	710.3	40.64	99.59	.516
120r	.0969	.0012	.831	.024	.0231	.0015	.062	.002	.59	596	7.3	614	13.1	460.6	60.54	682.4	29.53	87.33	.261
121r	.6607	.0082	26.228	.612	.1680	.0113	.288	.007	.61	3,270	31.6	3,355	17.8	3138	35.31	3406.9	195.71	95.98	.430
122r	.0729	.0011	.673	.027	.0301	.0027	.067	.003	.57	454	6.5	522	16.4	600.3	83.79	835.8	52.65	54.29	.065
123c	.0734	.0010	.569	.019	.0210	.0016	.056	.002	.58	457	5.9	457	12.3	420.6	73.52	461.6	31.46	98.95	.171
124cr	.1536	.0019	1.462	.039	.0453	.0033	.069	.002	.60	921	10.8	915	15.9	896.1	53.95	900.8	63.62	102.23	.761
125cr	.3765	.0050	6.861	.191	.1092	.0084	.132	.004	.60	2,060	23.5	2,094	22.6	2,094	48	2,128	152	96.80	.252

Note: Abbreviations: c, core; r, rim.

Figure 3. Photomicrographs of (a) the dated micaschist sample from Kalabak formation (KB-5) and (b) Karacabey metagranite (KR-9, CPL).

Different types of zircon and zones (cores and rims) were defined in the zircon population from the Kalabak formation using the CL images (Figure 4). Zircons from the micaschist sample are generally transparent and colourless, sometimes brownish-yellow and rarely purple in colour. Most zircon crystals are subidiomorphic but a small subset is idiomorphic. Some of these have well-rounded shapes. The inner structures of zircons show variability but generally are dominated by magmatic zircons bearing oscillatory zoning. When zircon morphology is taken into consideration it is observed that some zircon grains were subjected to long-term weathering and/or transferring processes. Most of the grains are well rounded but some of them were carried apparently from closer distances, evident from their less-rounded and preserved prismatic crystal morphology. Measurements were performed on 175 points on the sample KB-5 from the Kalabak formation and 90–110% concordant ages were obtained on 107 points (Table 2). In the classification of zircon sets, ²⁰⁶Pb/²³⁸U ages were used for the ones younger than 1 Ga; in contrast ²⁰⁷Pb/²⁰⁶Pb ages were used for the ones older than 1 Ga. ²⁰⁷Pb/²⁰⁶Pb are generally considered as ages having minimum lead losses (Meinhold, Kostopoulos, Reischmann, Frei, & BouDagher-Fadel, 2009). The geological time scale of Walker, Geissman, Bowring, and Babcock (2012) is used as a stratigraphic reference for data interpretation.

Figure 4. Selected CL images of the zircon grains analysed from the Kalabak formation (KB-5). The zircons fall into three groups based on degree of roundness and crystal shapes. Locations of the LA-ICP-MS analysis in red spots and the corresponding ages are indicated.

The youngest 426 ± 5.2 (²⁰⁶Pb/²³⁸U, 92.97% concordant, Th/U = .011) and oldest 3406.9 ± 195.7 (²⁰⁶Pb/²⁰⁷Pb, 95.98% concordant, Th/U = .430) zircon ages were taken in KB-5 micaschist sample. Nine points at 535 ± 13–426 ± 5.2 Ma age interval (8.4% Palaeozoic), 58 zircon points at 999 ± 11–549 ± 14 Ma age interval (54.21% Neoproterozoic), seven points at 1543 ± 50–1012 ± 200 Ma age interval 6.54% Mezoproterozoic), twenty points at 14 ± 58–1736 ± 123 Ma age interval (18.7% Palaeoproterozoic), and 13 points at 3406.9 ± 195.7–2512 ± 30 Ma age interval (12.15% Archean) were measured at zircons. Therefore, it can be concluded that 54.21% of zircon populations is concentrated in Neoproterozoic eras. Distribution of 58 zircons that give Neoproterozoic age is as follows: 16 points at 622 ± 7–549 ± 14 Ma age intervals (27.58% Ediacaran), 33 points at 841 ± 9–639 ± 24 Ma age interval (56.9% Cryogenian), and nine points at 999 ± 11–873 ± 9 Ma age interval (15.52% Tonian; Figure 5). In addition, we found 17 zircon core ages from the Devonian metagranites cluster at 530.7–2281.8 Ma (Tables 3 and 4; Aysal et al., 2012).

Figure 5. Concordia diagram (upper) and probability density distributions (lower left 0–3500 Ma and lower right 400–1200 Ma) of the zircon ages obtained during this study from the Kalabak formation (KB-5). ²⁰⁶Pb/²³⁸U was used for ages < 1000 Ma and ²⁰⁷Pb/²⁰⁶Pb for ages > 1000 Ma in constructing the diagram. The inset in the upper diagram shows the enlarged portion of the Concordia diagram for the protolith ages from 426 to 841 Ma (Mid-Silurian to Cryogenian).

Table 3. Results of zircon LA-ICP-MS U-Pb age determinations of sample KR-9 from Karacabey metagranite (Geographic coordinate: 40°16′12.70″N, 28°20′40.33″E).

	Isotope ratios								Age (Ma)
	^206Pb/^238U	1SE	^207Pb/^235U	1SE	^208Pb/^232Th	1SE	^207Pb/^206Pb	1 SE	^206Pb/^238U	1SE	^207Pb/^235U	1SE
1c	.34319	.00418	5.9047	.1117	.1009	.0043	.1248	.0023	1902	20.1	1961.9	16.4
2r	.06297	.00082	.5169	.0141	.0226	.0011	.0596	.0016	393.7	5.0	423.1	9.5
3r	.05995	.00079	.4596	.0135	.0176	.0009	.0556	.0016	375.3	4.8	384	9.4
3c	.06396	.00086	.4825	.0151	.0210	.0011	.0547	.0017	399.7	5.2	399.8	10.4
4r	.06398	.00082	.4963	.0133	.0208	.0011	.0563	.0015	399.8	5.0	409.2	9.0
5r	.06665	.00091	.5459	.0170	.0215	.0013	.0594	.0019	416	5.5	442.3	11.2
6r	.06201	.00081	.4930	.0135	.0167	.0010	.0577	.0016	387.8	4.9	407	9.2
7c	.06132	.00081	.4926	.0139	.0199	.0013	.0583	.0016	383.7	4.9	406.7	9.5
8r	.06544	.00091	.5120	.0172	.0187	.0013	.0568	.0019	408.6	5.5	419.8	11.5
9r	.06664	.00087	.5069	.0135	.0203	.0011	.0552	.0015	415.9	5.2	416.3	9.1
9c	.13283	.00185	1.6435	.0483	.0571	.0035	.0898	.0027	804	10.5	987.1	18.6
10r	.06386	.00092	.4896	.0182	.0205	.0014	.0556	.0021	399.1	5.6	404.6	12.4
10c	.06305	.00089	.4831	.0171	.0208	.0015	.0556	.0020	394.1	5.4	400.2	11.7
11r	.06360	.00093	.4851	.0184	.0203	.0017	.0553	.0021	397.5	5.6	401.5	12.6
12c	.06312	.00103	.4919	.0242	.0210	.0019	.0565	.0028	394.6	6.3	406.2	16.5
13c	.06742	.00095	.5158	.0168	.0196	.0010	.0555	.0018	420.6	5.7	422.3	11.2
14r	.06505	.00087	.4924	.0131	.0178	.0009	.0549	.0015	406.3	5.3	406.5	8.9
15r	.06308	.00083	.4921	.0123	.0163	.0009	.0566	.0014	394.3	5.1	406.4	8.4
16cr	.06585	.00090	.5066	.0144	.0197	.0011	.0558	.0016	411.1	5.4	416.1	9.7
17c	.06871	.00097	.5194	.0166	.0209	.0013	.0548	.0018	428.4	5.8	424.7	11.1
18c	.06339	.00086	.5473	.0151	.0162	.0011	.0626	.0017	396.2	5.2	443.2	9.9
19r	.06323	.00089	.4819	.0152	.0169	.0012	.0553	.0018	395.3	5.4	399.4	10.4
19c	.06438	.00093	.5269	.0181	.0219	.0017	.0594	.0021	402.2	5.7	429.8	12.1
20r	.06406	.00090	.4972	.0160	.0193	.0016	.0563	.0018	400.3	5.5	409.8	10.9
21r	.06390	.00100	.4987	.0214	.0206	.0018	.0566	.0025	399.3	6.1	410.8	14.5

Table 4. Inherited zircon core ages from Devonian metagranites (Aysal et al., 2012).

Zircon	Analysis	^206Pb/^238U	1σ error	^207Pb/^235U	1σ error	^208Pb/^232Th	1σ error	^207Pb/^206Pb	1σ error	Age, Ma
										^206Pb/^238U	1σ error
ÇMG-11 Karaaydın stock – LA-ICP-MS
25.1c	Ap21b14	.1036	.0024	.886	.094	.031	.005	.068	.005	635.4	13.9
26.1c	Ap21b15	.2562	.0054	3.782	.391	.086	.015	.117	.006	1470.4	27.7
28.1c	Ap21b18	.3568	.0079	6.783	.850	.127	.026	.134	.008	1966.9	37.6
28.3c	Ap21c03	.3106	.0064	5.270	.603	.086	.016	.122	.006	1743.9	31.7
ÇMG-4 Bayatlar stock – LA-ICP-MS
1.1	Ap22c04	.1024	.0022	.774	.072	.024	.004	.062	.004	628.6	12.7
1.3	Ap22c05	.0858	.0017	.852	.071	.018	.003	.068	.004	530.7	10.2
2.1c	Ap22c06	.0870	.0020	1.110	.106	.047	.005	.094	.007	537.5	11.8
10.3c	Ap22d03	.4169	.0105	13.682	2.345	.153	.019	.208	.011	2246.5	47.8
10.1c	Ap22d05	.4247	.0071	10.298	.772	.152	.017	.182	.006	2281.8	32.2
14.1c	Ap22d09	.1896	.0029	3.304	.156	.219	.026	.125	.004	1119.2	15.5
16.1c	Ap22d12	.2668	.0047	4.057	.311	.105	.014	.113	.005	1524.7	24.0
YI-18 Güveylerobası Stock – LA-ICP-MS
3.2c	Ap22a06	.0897	.0027	.897	.136	.032	.005	.071	.008	553.8	16.2
23.2c	Ap22b12	.1069	.0023	1.498	.133	.051	.007	.106	.006	654.4	13.2
41.1c	Ap22d21	.3239	.0064	4.960	.480	.103	.018	.121	.006	1808.6	31.4
NA-205 Yolindi Stock – SHRIMP-II
Zircon	^206Pb*	^204Pb^/206Pb	f206	^238U/^206Pb	2σ error	^207Pb/^206Pb	2σ error	^206Pb/^238U	2σ error	Age, Ma
										^206Pb/^238U	2σ error
4.1c	93.3	.000014	.37	3.010	.033	.1159	.0007	.3310	.0041	1843.3	20

The measured Th/U ratios range between .011 and 1.019 in 53 measurements which were performed in zircon rims and over growth zones, and were found in the range of 0.085–1.019 in 19 measurements which were performed in inherited cores. It is determined during the measurements that in the rim of eight zircon grains, Th/U ratios are > .1. Th/U ratios indicate that zircon grains are of felsic magmatic origin (Figure 6, Linnemann et al., 2011; Teipel et al., 2004).

Figure 6. Zircon Th/U ratio vs. age plot for the Kalabak formation (KB-5). The majority of the grains come from intermediate and magmatic sources; zircon fields are from Teipel et al. (2004) and Linnemann et al. (2011).

4.2. Dating of the Karacabey metagranite

Dated sample from the Karacabey metagranite (KR-9) is shown in Figure 2 and geographic coordinate is given in Table 3. This sample is a fine- to medium-grained metagranite which has a brownish alteration colour. It displays a weakly developed foliation. It contains quartz, alkali feldspar, plagioclase, amphibole, and biotite as primary phases. Accessory phase is represented by zircon, apatite, and opaque minerals (Figure 3(b)).

Zircons from the Karacabey metagranite displaying magmatic oscillatory zoning, unique, prismatic shapes, and amber colour were analysed by using the LA-ICP-MS method (Figure 7). Ages from 384 ± 9.4 to 443.2 ± 9.9 Ma were obtained on the magmatic oscillatory-zoned zircons/zircon rims, and 804 ± 10.5 Ma and 1961.9 ± 16.4 Ma ages were obtained in inherited cores (Table 3). A Concordia age of 400.3 ± 1.4 Ma (i.e. Early Devonian) was obtained for the Karacabey metagranite, coinciding with the weighted mean ²⁰⁶Pb/²³⁸U age 399.3 ± 5.2 Ma of the analysed zircon grains (Figure 8). Sunal (in press) reported similar ages of 393.8 ± 2.7–395.9 ± 4.09 Ma from the Karacabey metagranite (in this issue).

Figure 7. CL images of zircon grains from sample of the Karacabey metagranite (KR-9). Red circles show spots of LA-ICP-MS U-Pb analyses in zircon grains.

Figure 8. Concordia (a) and the weighted average diagrams (b) for the Karacabey metagranite.

4.3. Geochemistry of the Karacabey metagranite

The CIPW normative chemical classification scheme has been applied to the Karacabey metagranite, utilising the QAP diagram (Figure 9(a)) after Streckeisen (1974), where the Karacabey metagranite samples were plotted in the fields of monzogranite and granodiorite. One sample is scattered away in the field of quartzmonzodiorite. Based on Shand’s (1947) classification, it can be seen that two samples fall into metaluminous fields and all the rest are scattered in the peraluminous field (Figure 9(b)). Also, the ASI values vary between .91 and 1.63, and plot between I- and S-type granites. These samples have K₂O contents ranging from 2.48 to 3.89% (with an average of 3.3%). They plot in the high-K calc-alkaline field on the K₂O vs. SiO₂ classification diagram of Peccerillo and Taylor (1976) (Figure 9(c)). On one of the most commonly used tectonic discrimination diagrams for granitoids (i.e. Ta vs. Yb diagram of Pearce, Harrıs, & Tındle, 1984), the Karacabey metagranite samples clearly plot into the field of volcanic arc granites (Figure 9(d)).

Figure 9. (a) QAP nomenclature diagram (Streckeisen, 1974) with normative mineral compositions, (b) A/NK–A/CNK diagram (Shand, 1947) for the Karacabey metagranite, (c) K₂O–SiO₂ diagram (Peccerillo & Taylor, 1976), (d) Ta vs. Yb tectonic discrimation diagram of Pearce et al. (1984).

Multi-element spidergrams show results of Karacabey metagranite and the Devonian Çamlık and Yolindi metagranites (Aysal et al., 2012). N-MORB-normalised multi-element diagrams (Figure 10(a), (c), and (e)) indicate that all metagranitoid samples are enriched in LILEs (large ion lithophile elements; Sr, K, Rb, Ba, and Th) and, in a lesser extent, in LREEs (light rare earth elements; La, Ce, and Nd), but depleted in HFS elements (Tb, Ti, Y, and Yb). The decrease from Th to Ta and Nb is more profound than the decrease from La to Nd. On the other hand, Hf, Zr, and Sm form an almost horizontal trend. All Devonian metagranitoids in the region have similar patterns (Figure 10(a), (c), and (e)). In the Karacabey, Çamlık, and Yolindi metagranitoids, the aforementioned patterns represented by the distinct depletion in Ta and Nb with respect to the neighbouring LILE and LREEs can be interpreted as being the signature of either a volcanic arc or a post-collisional setting. In both cases, such a signature requires partial melting of the metasomatised mantle wedge in the stability field of rutile.

Figure 10. (a), (c), (e) N-MORB-normalised multi-element variation diagrams for the Karacabey, Yolindi and Çamlık metagranites. (b), (d), (f) Chondrite-normalised REE variation diagrams for the Karacabey, Yolindi, and Çamlık metagranites (normalisation values are from Sun & McDonough, 1989).

The Karacabey metagranite displays LREE-enriched patterns on the chondrite-normalised REE spidergrams (Figure 10(b, while HREE concentrations of most of the samples are one order higher than the chondrite values. All of the metagranite samples display upward concave patterns with slight but variable Eu anomalies with Eu/Eu* ranging from 0.54 to 0.89. Again, spider diagrams of the Karacabey, Yolindi, and Çamlık metagranites reveal similar chondrite-normalised patterns (Figure 10(b), (d), and (f)).

5. Discussion

5.1. Age and source regions of the Kalabak formation sample

The youngest ²⁰⁶Pb/²³⁸U detrital zircon age was measured as 426 ± 5.2 Ma (Middle Silurian), while younger ages vary between 457 ± 12 Ma (98.95% conc., Th/U = .171) and 466 ± 16 Ma (97.07% conc., Th/U = .018; Middle–Late Ordovician). Ordovician magmatic rocks are known to exist in the study area near Anatolide–Tauride platform and surrounding areas (Okay et al., 2008a; Okay, Satır, & Shang, 2008b; Özbey et al., 2012). Akbayram et al. (2012) obtained 428–486 Ma zircon ages from Pamukova Complex. Because 8.4% of the analysed zircons are Palaeozoic in age and present a distribution of ages between 535 ± 13 and 426 ± 5.2 Ma, the Kalabak formation was probably deposited during a period between Ordovician and Silurian. Because there is an intrusive contact between the Kalabak formation and the Devonian metagranites, the Kalabak formation should be older than Early Devonian and possibly metamorphosed later under the conditions of low–middle pressure (Aysal et al., 2012) together with the Devonian metagranites.

Zircon populations of the Kalabak formation are dominated by Neoproterozoic ages (54.21%) and are concentrated on an age interval between Ediacaran and Cryogenian (850–542 Ma). In general, this interval presents similarities with the peri-Gondwana originated terrains which can be observed throughout the eastern and western Mediterranean regions alongside the northern Gondwana (Figures 11 and 12; Kydonakis et al., in press; Meinhold et al., 2013; Ustaömer, Robertson, et al., 2012). Many Late Proterozoic–Early Palaeozoic-aged granitic rocks can be observed in near surroundings of study area in Menderes Massif (Bozkaya, Gürsu, & Cemal Göncüoglu, 2006; Bozkurt & Oberhänsli, 2001; Candan et al., 2011; Gessner, Collins, Ring, & Gungor, 2001, 2004; Koralay et al., 2004; Kröner & Şengör, 1990; Neubauer, 2002; Zlatkin, Avigad, & Gerdes, 2013), in Bolu Massif (Ayda Ustaömer et al., 2005), in Zonguldak – Karadere (Dean, Monod, Rickards, Demir, & Bultynck, 2000; Chen et al., 2002), in Bitlis Massif (Ustaömer P. A. et al., 2009, Ustaömer et al., 2011) and in Istranca Massif (Yılmaz-Şahin et al., in press). These granitic rocks might have been the potential source of the Kalabak formation. The first zircon population is concentrated around 426–728 Ma ages interval can be observed in the basement of the central and eastern Sakarya Zone (Figure 13(b)–(d)), Istranca Massif, and Istanbul Zone (Figure 13(e) and (f)). This type of pattern typically has great similarities with those of the Cadomian–Avalonian terrains (Figure 12).

Figure 11. Palaeogeographic reconstruction of the Cadomian–Avalonian active margin and related major peri-Gondwanan terranes at c. 570 Ma (Bahlburg et al., 2010; Linnemann et al., 2013 and references therein).

Figure 12. Detrital zircon age distributions of the analysed micaschist sample of the Kalabak formation (this study) and comparison with Avalonia, Cadomia, and other parts of Gondwana and potential source areas (data compilation from Linnemann et al., 2004; Ustaömer, Robertson, et al., 2012; and references therein).

Figure 13. Age distribution patterns of detrital zircons for the samples discussed in the text (a) Kalabak formation from this study and inherited core ages of Devonian metagranites from in this study and Aysal et al., 2012); (b) central Sakarya (Ustaömer, Ustaömer et al., 2012); (c) and (d) eastern Sakarya (Ustaömer, Robertson, et al., 2012); (e) Istranca Massif (Natal’in et al., 2012); (f) Istanbul Zone (Ustaömer, Ustaömer, et al., 2009).

The second zircon population after this major peak is concentrated around 800–1000 Ma years. Although zircons with 800–1000 Ma age interval are more numerous in the central Sakarya basement with respect to western Sakarya, central Sakarya basement presents similar patterns to the eastern Sakarya basement (Figure 12(a)–(d)). These ages have lesser population in the Istranca Massif and Istanbul Zone, and do not have similarities with western Sakarya (Figure 13(a), (e) and (f)).

The third zircon population is concentrated around 1100–1550 Ma age interval in the Kalabak formation and the Devonian metagranite inherited zircon cores. This age interval has a critical importance for the source area. Such a zircon population with this age stage is rarely seen in central and eastern Sakarya basement. There is an important peak in the Ordovician sandstones (Ustaömer et al., 2009) in the Istanbul Zone.

The most remarkable zircon population after the Neoproterozoic ages is the 1700–2100 Ma year interval. Although 1700–2100 Ma-aged zircons have been determined in central Sakarya, the Istranca Massif, and Istanbul Zone, this period is relatively quiet in eastern Sakarya basement and includes lesser amounts of zircon. Although, Neoproterprozoic ages can dominantly be observed in the Arabian shield (Stern & Johnson, 2010).

Another zircon concentration in the Kalabak formation is remarked at 2400–2800 Ma years, and rarely observed in central and eastern Sakarya and Istanbul Zone; a peak draws attention with 2500 Ma value in the Istranca Massif. Lastly, there are zircon ages with 3100–3400 Ma years at three points. Zircon grains with 3100–3200 Ma age interval are absent in other zones.

If we take all these findings into consideration, it becomes obvious that the Kalabak formation has more similarities with the Avalon terrains. Remnants of the Avalon terrain have been determined by a number of researchers in the Istanbul Zone, not far away from the study area in Western Anatolia (Bozkurt, Winchester, Yiğitbas, & Ottley, 2008; Chen et al., 2002; Dean et al., 2000; Okay et al., 2008a, 2011; Ustaömer, Ustaömer, Gerdes, & Zulauf, 2011). Aysal et al. (2012) argued that the Kalabak formation and the Devonian metagranites might be regarded as a part of a far-travelled exotic block, accreted to the basement of western Sakarya. Deformation and metamorphism of the Kalabak formation could have been developed in the Caledonian Zone after the collision of the Avalon terrains with the Baltica and Laurentia cratons, related to the closure of the Iapetus Ocean during the Ordovician–Silurian period (Aysal et al., 2012). Blueschist and eclogite blocks provide evidence for the often elusive Triassic subduction history of the Palaeotethys in the eastern Mediterranean area (Okay & Monié, 1997).

The Havran Unit in the western Sakarya Zone has been affected by a series of tectonic deformations that occurred in various periods including: closure of the Neotethyan Ocean during Late Cretaceous, collision of the Anatolide–Tauride platform with the Sakarya Zone (Şengör & Yılmaz, 1981) during Eocene, and the activity of the North Anatolian Transform Fault during Miocene (Şengör et al., 2005).

5.2. Petrogenesis of the metagranites

Devonian metagranites in the Havran Unit present same patterns on N-MORB-normalised multi-element diagrams. A significant enrichment can be observed in LILE (Sr, K, Rb, Ba, and Th) combined with a lesser enrichment in LREE (La, Ce, and Nd) on these diagrams and depletion in HFS elements (Tb, Ti, Y, and Yb) (Figure 9). It can be observed in the Karacabey, Yolindi, and Çamlık metagranites that Ta and Nb are more depleted in comparison with the neighbouring LILE and LRE elements. However, they are enriched relative to N-MORB values. Aysal et al. (2012) pointed out that this significant decrease in Ta and Nb recalls arc environment but inherited subduction components in collision zones cannot be ruled out. Besides, it should be noted that the exhaustion in HFS elements can also be explained by the mobility of these elements during the partial melting of mantle in the subduction zones (Figure 10(a), (c), and (e)). Similar patterns are also apparent on the chondrite-normalised spider diagrams of the Karacabey, Yolindi, and Çamlık metagranites. Although majority of the Karacabey metagranite samples present an upper concave pattern, they present Eu anomaly with variable rate. Eu/Eu* rates vary between .54 and .89. While these patterns can be explained by amphibole fractionation, negative Eu anomaly are linked to K-feldspar crystallisation (Figure 10(b), (d), and (f)).

Aysal et al. (2012) argued on the basis of Sr/Nd isotope variations that the Devonian metagranites might have been generated by melting of the lower continental crust. In that study, alternative geodynamic settings for magma generation of these granitoids have been discussed and evaluated. Aysal et al. (2012) put forward a model for the aforementioned metagranites (including the ones with a subduction component) that involves pounding of the mantle-derived basaltic magmas underneath the lower crust, resulting in a widespread partial crustal melting. On the basis of this evidence, Aysal et al. (2012) suggested that these granites displaying a distinct subduction component might have been generated either in an ensialic arc setting or post-collisional tectonic environment. We argue that the same interpretation also applies to the Karacabey metagranite, because it bears a great amount of geochemical similarities with the Yolindi and Çamlık metagranites.

Crystallisation ages for some series of the metagranites in the Havran Unit can be listed as follows: 389.1 ± 2.6–401.5 ± 4.8 Ma Çamlık metagranite: 397.5 ± 1.4 Ma; Yolindi stock: 389.1 ± 2.6 Ma, Karaaydın stock: 401.4 ± 3.7 Ma; Güveylerobası stock: 401.5 ± 4.8 Ma, and Bayatlar stock: 401 ± 7.8 Ma; Okay et al., 2006, 1991; Aysal et al., 2012). The Concordia age obtained for the Karacabey metagranite is 400.3 ± 1.4 Ma. When both age and geochemistry of the units are taken into account, the Karacabey metagranite appears to have the same origin as that of the other metagranites in the Havran Unit.

On the basis of detrital zircon ages obtained from the Kalabak formation and the presence of the Devonian-aged plutonic rocks we argue that the Havran Unit might represent a terrain originated possibly from Avalonia.

6. Conclusion

1. Detrital zircon ages of the Kalabak formation are concentrated around 535 ± 13–426 ± 5.2 Ma, 750–542 Ma, 800–1000 Ma, 1100–1550 Ma, 1700–2100 Ma, 2400–2800 Ma, and 3100–3400 Ma intervals.

2. LA-ICP-MS U–Pb zircon dating yields 400.3 ± 1.4 Ma (Early Devonian) age for the Karacabey metagranite. This finding indicates that the Karacabey metagranite has a relation with other Devonian metagranites across the Biga Peninsula.

3. On the basis of the youngest zircon ages obtained from the Kalabak formation and the presence of the intrusive contact with the Devonian granites, we argue that the deposition age of the Kalabak formation should be older than Ordovician and younger than Devonian.

4. The new data and results we presented in this paper, in combination with correlations between similar units across the eastern Mediterranean region, indicate that the Kalabak formation and the Devonian metagranites (i.e. the Havran Unit) might be regarded as a part of the Avalonian terrains.

Acknowledgements

This work was supported by the Research Fund of Istanbul University, project numbers YADOP-16129 and 6888. We thank Prof. Dr Timur Ustaömer for inspiring us to write this manuscript. We would also like to thank Prof. Dr Sabah Yılmaz-Şahin for her insightful comments on the preliminary version of this manuscript. We thank chief editor Prof. Dr Erdin Bozkurt and two anonymous referees for their constructive comments on the manuscript. We are grateful to Tuncer Çiltaş of Arson Engineering Co. (Bursa) for logistical support during our field work.