Geochemical characteristics of microgranular enclaves in Early Eocene adakitic andesites (Gümüşhane, NE Türkiye)

Mehmet Ali Gücer; Abdulkadir Murat Güner; Okay Çimen

Makale detayları

Geochemical characteristics of microgranular enclaves in Early Eocene adakitic andesites (Gümüşhane, NE Türkiye)

Yazarlar:

Mehmet Ali Gücer | Abdulkadir Murat Güner | Okay Çimen

Yayıncı:

Hacettepe University

Ana Başlıklar:

Mineraloji-Petrografi

Dergi:

Yerbilimleri Vol.45 Issue 2, pp.154-184

Belge Tipi:

Makale

Yayın Tarihi:

8/2024

Belge Dili:

Türkçe

Document ID (Org No.):

2001325472

pISSN:

1301-2894

Anahtar kelimeler:

Özet:

 The early Cenozoic magmatism in the Eastern Sakarya Zone NE Turkey provides significant insights into the regional tectonomagmatic evolution. Adakite-like intrusiveextrusive rocks have been widely observed from the Late Paleocene to the Plio-Quaternary period in the region. In the study area, Early Eocene adakitic andesites are observed in outcrop areas smaller than 10 km2 and they contain abundant microgranular enclaves. This study presents petrochemistry data of the enclaves and discusses petrological relationships with the host rock. The enclaves, with more basic composition compared to the parent rocks, are observed in ranging from a few to 20 cm in size. They are microlithic to porphyritic in texture and mainly composed of plagioclase, hornblende, clinopyroxene, orthoclase and opaques. Both petrographic and petrochemical characteristics indicate that they are of basaltic and basaltic andesite and may have derived from a sub-alkaline magma. Major and trace element variations indicate that fractional crystallization was effective, and plagioclase, pyroxene, hornblende, magnetite and apatite fractionation played an important role. Similar trace element distributions of enclaves and host rocks may indicate interaction processes while mixing of felsic and mafic magmas. Similarly, REE models of the rocks, indicated hornblende fractionation played an important role in their evolution, whereas plagioclase fractionation was less effective. Petrochemical data suggest that the parent magma of the enclaves was produced by the partial melting of oceanic basalts under amphibole-eclogite facies conditions during the initial stages of the extensional tectonic regime just after the complete closure of the northern Neotethys Ocean.

 The early Cenozoic magmatism in the Eastern Sakarya Zone NE Turkey provides significant insights into the regional tectonomagmatic evolution. Adakite-like intrusiveextrusive rocks have been widely observed from the Late Paleocene to the Plio-Quaternary period in the region. In the study area, Early Eocene adakitic andesites are observed in outcrop areas smaller than 10 km2 and they contain abundant microgranular enclaves. This study presents petrochemistry data of the enclaves and discusses petrological relationships with the host rock. The enclaves, with more basic composition compared to the parent rocks, are observed in ranging from a few to 20 cm in size. They are microlithic to porphyritic in texture and mainly composed of plagioclase, hornblende, clinopyroxene, orthoclase and opaques. Both petrographic and petrochemical characteristics indicate that they are of basaltic and basaltic andesite and may have derived from a sub-alkaline magma. Major and trace element variations indicate that fractional crystallization was effective, and plagioclase, pyroxene, hornblende, magnetite and apatite fractionation played an important role. Similar trace element distributions of enclaves and host rocks may indicate interaction processes while mixing of felsic and mafic magmas. Similarly, REE models of the rocks, indicated hornblende fractionation played an important role in their evolution, whereas plagioclase fractionation was less effective. Petrochemical data suggest that the parent magma of the enclaves was produced by the partial melting of oceanic basalts under amphibole-eclogite facies conditions during the initial stages of the extensional tectonic regime just after the complete closure of the northern Neotethys Ocean.

 The early Cenozoic magmatism in the Eastern Sakarya Zone NE Turkey provides significant insights into the regional tectonomagmatic evolution. Adakite-like intrusiveextrusive rocks have been widely observed from the Late Paleocene to the Plio-Quaternary period in the region. In the study area, Early Eocene adakitic andesites are observed in outcrop areas smaller than 10 km2 and they contain abundant microgranular enclaves. This study presents petrochemistry data of the enclaves and discusses petrological relationships with the host rock. The enclaves, with more basic composition compared to the parent rocks, are observed in ranging from a few to 20 cm in size. They are microlithic to porphyritic in texture and mainly composed of plagioclase, hornblende, clinopyroxene, orthoclase and opaques. Both petrographic and petrochemical characteristics indicate that they are of basaltic and basaltic andesite and may have derived from a sub-alkaline magma. Major and trace element variations indicate that fractional crystallization was effective, and plagioclase, pyroxene, hornblende, magnetite and apatite fractionation played an important role. Similar trace element distributions of enclaves and host rocks may indicate interaction processes while mixing of felsic and mafic magmas. Similarly, REE models of the rocks, indicated hornblende fractionation played an important role in their evolution, whereas plagioclase fractionation was less effective. Petrochemical data suggest that the parent magma of the enclaves was produced by the partial melting of oceanic basalts under amphibole-eclogite facies conditions during the initial stages of the extensional tectonic regime just after the complete closure of the northern Neotethys Ocean.

 Doğu Sakarya Zonundaki KD Türkiye erken Senozoyik magmatizması, bölgesel tektonomagmatik gelişime dair önemli veriler sağlamaktadır. Bölgede, adakit veya adakitik intrüzifekstrüzif kayaçlar Geç Paleosenden Pliyo-Kuvaterner döneme kadar yaygın olarak gözlenmektedir. Çalışma alanında, Erken Eosen adakitik andezitler, genellikle 10 km2den küçük mostralar halinde gözlenmektedir. Adakitik bileşimli bu andezitler bol miktarda mikrogranüler anklav içermekte olup bu çalışmada petrografikjeokimyasal özellikleri ve ana kayaç ile olan petrolojik ilişkileri irdelenmiştir. Ana kayaca kıyasla nispeten bazik bileşimli anklavlar, küreselden elipsoidala kadar değişen şekillerde ve birkaç cm ile 20 cm arasında değişen boyutlarda gözlenmektedir. Anklavlar mikrolitik yer yer porfirik dokulu olup başlıca plajiyoklas, hornblend, klinopiroksen, ortoklas ve opak minerallerden meydana gelmektedir. Gerek petrografik gerekse petrokimyasal özellikleri anklavların bazaltik andezit türünde olduğunu ve sub-alkalin bir magmadan türemiş olabileceğini göstermektedir. Ana ve iz element değişimleri, gelişimlerinde fraksiyonel kristallenmenin etkili olduğunu ve plajiyoklas, piroksen, hornblend, magnetit ve apatit ayrımlaşmasının büyük ölçüde rol oynadığını göstermiştir. Anklav ve ana kayaçların benzer iz element davranışları felsik ve mafik magmaların karışması esnasındaki etkileşim süreçlerini işaret edebilir. NTE dağılımları ise gelişimlerinde hornblend fraksiyonlaşmasının önemli rol oynadığını, buna karşılık plajiyoklas ayrımlaşmasının etkili olmadığını işaret etmektedir. Petrokimyasal veriler, anklavların ana magmasının, kuzey Neotetis Okyanusunun tamamen kapanmasından hemen sonra; genleşmeli tektonik rejimin başlangıç aşamalarında, amfibol-eklojit fasiyesi koşullarında okyanusal bazaltların kısmi erimesi ile üretildiğini göstermektedir.

Makale detayları

Geochemical characteristics of microgranular enclaves in Early Eocene adakitic andesites (Gümüşhane, NE Türkiye)

Yazarlar:

Mehmet Ali Gücer | Abdulkadir Murat Güner | Okay Çimen

Yayıncı:

Hacettepe University

Ana Başlıklar:

Mineraloji-Petrografi

Dergi:

Yerbilimleri Vol.45 Issue 2, pp.154-184

Belge Tipi:

Makale

Yayın Tarihi:

8/2024

Belge Dili:

Türkçe

Document ID (Org No.):

2001325472

pISSN:

1301-2894

Adakitic andesite

Eastern Sakarya Zone

Early Cenozoic

Microgranular enclaves

PetrochemistryAdakitik andezit

Doğu Sakarya Zonu

Erken Senozoyik

Mikrogranüler anklav

Petrokimya

Sayı

Makale detayları

Yazarlar: Mehmet Ali Gücer | Abdulkadir Murat Güner | Okay Çimen

Yayıncı: Hacettepe University

Ana Başlıklar: Mineraloji-Petrografi

Dergi: Yerbilimleri Vol.45 Issue 2, pp.154-184

Belge Tipi: Makale

Yayın Tarihi: 8/2024

Belge Dili: Türkçe

Document ID (Org No.): 2001325472

pISSN: 1301-2894

Sayı

Yazarlar:

Mehmet Ali Gücer | Abdulkadir Murat Güner | Okay Çimen

Yayıncı:

Hacettepe University

Ana Başlıklar:

Mineraloji-Petrografi

Dergi:

Yerbilimleri Vol.45 Issue 2, pp.154-184

Belge Tipi:

Makale

Yayın Tarihi:

8/2024

Belge Dili:

Türkçe

Document ID (Org No.):

2001325472

pISSN:

1301-2894