Sr and Nd Isotopic Characteristics of Some S-, I- and A-type Granitoids from Central Anatolia

Serhat Köksal & M. Cemal GÖNCÜOĞLU; SERHAT KÖKSAL

Makale detayları

Sr and Nd Isotopic Characteristics of Some S-, I- and A-type Granitoids from Central Anatolia

Yazarlar:

Serhat Köksal & M. Cemal GÖNCÜOĞLU | SERHAT KÖKSAL

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Earth Sciences 2008 Vol.17 Issue 1, pp.111-127

Belge Tipi:

Makale

Yayın Tarihi:

12/2007

Belge Dili:

Türkçe

Document ID (Org No.):

2000732551

Sıklık:

İki Aylık

eISSN:

1303-619X

pISSN:

1300-0985

Özet:

 

The petrogenesis of some Late Cretaceous S-, I- and A-type granitoids in the Aksaray and Kırşehir regions of Central Anatolia is investigated by means of whole-rock Sr and Nd isotope data with supplementary field, petrographic, and whole-rock geochemical studies.  The S-type Central Anatolian granitoids (Sinandı and Namlıkışla) have calc-alkaline peraluminous characteristics and show LILE and LREE enrichment. The I-type Central Anatolian granitoids (Borucu, Terlemez, Hisarkaya, Baranadağ), on the other hand, are calc-alkaline (excepting the alkaline Baranadağ sample) and metaluminous or slightly peraluminous with LILE and LREE enriched patterns and variable Eu-anomalies. Additionally, the A-type Çamsarı granitoid is alkaline and metaluminous with the highest LREE contents.  Isotope data from the I-type Central Anatolian granitoids (87Sr/86Sr(i): 0.7078-0.7109; eNd: -5.4 to -7.9), and the A-type Çamsarı granitoid (87Sr/86Sr(i): 0.7082; eNd: -7.1) are similar. The S-type Central Anatolian granitoids, on the other hand, have more radiogenic initial Sr isotopic ratios (87Sr/86Sr(i): 0.7128-0.7152) and lower eNd values (-9.1 to -9.7) than the I- and A-type granitoids from Central Anatolia.  When combined with the available petrological and age data, the isotope data presented in this study support the suggestion of collisional S-type granitic associations, and younger post-collisional and subsequent extensional I- and A-type magmatism in Central Anatolia. Sr and Nd isotope data infer that the I- and A-type Central Anatolian granitoids have hybrid and heterogeneous sources, while in the A-type granitoids a mantle component is likely to be dominant. Moreover, the S-type Central Anatolian granitoids were possibly derived from crustal, or crustal-dominated sources. Furthermore, the increase of 87Sr/86Sr(i) and decrease of  eNd values observed from S-type granitoids to I- and A-type magmatic rocks is either related to distinct source characteristics or to isotopic mixing between mantle and crustal sources through time.

 

The petrogenesis of some Late Cretaceous S-, I- and A-type granitoids in the Aksaray and Kırşehir regions of Central Anatolia is investigated by means of whole-rock Sr and Nd isotope data with supplementary field, petrographic, and whole-rock geochemical studies.  The S-type Central Anatolian granitoids (Sinandı and Namlıkışla) have calc-alkaline peraluminous characteristics and show LILE and LREE enrichment. The I-type Central Anatolian granitoids (Borucu, Terlemez, Hisarkaya, Baranadağ), on the other hand, are calc-alkaline (excepting the alkaline Baranadağ sample) and metaluminous or slightly peraluminous with LILE and LREE enriched patterns and variable Eu-anomalies. Additionally, the A-type Çamsarı granitoid is alkaline and metaluminous with the highest LREE contents.  Isotope data from the I-type Central Anatolian granitoids (87Sr/86Sr(i): 0.7078-0.7109; eNd: -5.4 to -7.9), and the A-type Çamsarı granitoid (87Sr/86Sr(i): 0.7082; eNd: -7.1) are similar. The S-type Central Anatolian granitoids, on the other hand, have more radiogenic initial Sr isotopic ratios (87Sr/86Sr(i): 0.7128-0.7152) and lower eNd values (-9.1 to -9.7) than the I- and A-type granitoids from Central Anatolia.  When combined with the available petrological and age data, the isotope data presented in this study support the suggestion of collisional S-type granitic associations, and younger post-collisional and subsequent extensional I- and A-type magmatism in Central Anatolia. Sr and Nd isotope data infer that the I- and A-type Central Anatolian granitoids have hybrid and heterogeneous sources, while in the A-type granitoids a mantle component is likely to be dominant. Moreover, the S-type Central Anatolian granitoids were possibly derived from crustal, or crustal-dominated sources. Furthermore, the increase of 87Sr/86Sr(i) and decrease of  eNd values observed from S-type granitoids to I- and A-type magmatic rocks is either related to distinct source characteristics or to isotopic mixing between mantle and crustal sources through time.

Makale detayları

Sr and Nd Isotopic Characteristics of Some S-, I- and A-type Granitoids from Central Anatolia

Yazarlar: Serhat Köksal & M. Cemal GÖNCÜOĞLU | SERHAT KÖKSAL

Yayıncı: TUBITAK

Dergi: Turkish Journal of Earth Sciences 2008 Vol.17 Issue 1, pp.111-127

Belge Tipi: Makale

Yayın Tarihi: 12/2007

Belge Dili: Türkçe

Document ID (Org No.): 2000732551

Sıklık: İki Aylık

eISSN: 1303-619X

pISSN: 1300-0985

Sayı

Yazarlar:

Serhat Köksal & M. Cemal GÖNCÜOĞLU | SERHAT KÖKSAL

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Earth Sciences 2008 Vol.17 Issue 1, pp.111-127

Belge Tipi:

Makale

Yayın Tarihi:

12/2007

Belge Dili:

Türkçe

Document ID (Org No.):

2000732551

Sıklık:

İki Aylık

eISSN:

1303-619X

pISSN:

1300-0985