Paleo-Depositional Environment and Coalification Characteristics of Çilhoroz (Çayırlı - Erzincan) Coals

Abstract

This study has done by petrographic methods in order to determine the paleo-depositional features and coalification process characteristics of coal deposits around Çilhoroz in Erzincan basin. Coal bearing units consists of coal and alternating layers (mainly clay, carbonate shale, limestone) and it located at the Miocene aged Neftlik Formation at Çayırlı area. Çilhoroz coal seam demonstrate a dominance of dull and banded dull lithotypes. The coal is predominated by combined xylitic/attrital lithotypes and by huminite macerals with inertinite and minor liptinite macerals. Densinite, attrinite, ulminite and corpohuminite were the most abundant huminite group macerals, respectively. Inertodetrinite and macrinite were the dominant inertinite macerals, while sporinite and resinite were the predominant litpinite macerals. The content of mineral matter (such as clay, pyrit) is variable but generally low (varying from 1% to 7%), it consists mostly of quartz, calcite, clay minerals, and pyrite. According to the proximate and ultimate analyses data indicate that the coal is describe by and in proportion to low ash (avg. 27%), moisture ingredient (avg. 18%) and total sulphur content (avg. 7.7). The volatile matter yields and carbon contents are relatively high, while fixed carbon, sulphur and oxygen contents are average and hydrogen and nitrogen contents are low. The mean huminite reflectance values of samples (Ro, %) ranged from 0.42 to 0.50, and these coals are bituminous B/C coal according to ASTM classification. Based on the GI-TPI, VI-GWI facies diagrams, the Çilhoroz coal formed in the limnic environment, with the accumulation of dominated vegetable matter and conditions up to rheotrophic to mesotrophic.

Keywords

• Tertiary coals,paleo-environment,petrography,Çayırlı coal,Erzincan Basin

Çilhoroz (Çayırlı-Erzincan) Kömürlerinin Paleo-Çökelim Ortamı ve Kömürleşme Süreci Özellikleri

Öz

Bu çalışma Erzincan havzasında, Çilhoroz civarındaki kömürlü istiflerin paleo-ortam özellikleri ve kömürleşme süreçlerinin belirlenmesi amacıyla petrografik yöntemlerle gerçekleştirilmiştir. Kömürlü istif, kömür ve ardalanmalı tabakalardan (başlıca kil, karbonatlı şeyl, kireçtaşı) oluşur ve Çayırlı sahasında Miyosen yaşlı Neftlik Formasyonu taban seviyelerinde bulunur.  Çilhoroz kömür damarı egemen olarak mat, bantlı mat litotiplerini göstermektedir. Kömür ksilitik/detritik litotipler ve hüminit maseralleri, ikinci olarak da inertinit maseralleri ile çok düşük miktarda liptinitlerden oluşmaktadır. Densinit, attrinit, ulminit ve korpohuminit sırasıyla en bol bulunan huminit grubu maseralleridir. Inertodetrinit ve makrinit inertinit grubunda egemenken, liptinit grubunda da sporinit ve resinitler baskın maserallerdir. Mineral madde içeriği (kil ve pirit gibi) ise genellikle değişken ve düşük (%1-7 arasında) olup, çoğunlukla kuvars, kalsit, kil mineralleri ve piritten oluşur. Kısa ve elementer analiz verilerine göre kömür düşük kül (ort. %27), nem (ort. %18) ve kükürt içeriklidir (ort. % 7.7). Uçucu madde ve karbon bileşimi ortalama değerlerde iken, hidrojen ve azot içeriği düşüktür. Ortalama hüminit yansıma değerleri (Ro, %) 0.42-0.50 arasında değişmektedir ve ASTM sınıflamasına göre bitümlü B/C tipi kömürdür. GI-TPI, VI-GWI fasiyes diyagramlarına göre Çilhoroz kömür damarı limnik ortamda, başlıca bitkisel maddelerin birikimi ile retrofik-mesotrofik şartlarda oluşmuştur.

Anahtar Kelimeler

• Tersiyer kömürleri,paleo-ortam,petrografi,Çayırlı kömürü,Erzincan Havzası

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