Student:	Mehmet Ali GÜCER
Supervisor:	Yrd. Doç. Dr. Zafer ASLAN
Department:	Jeoloji Mühendisliği
Institution:	Graduate School of Natural and Applied Sciences
University:	Karadeniz Technical University, Turkey

Title of the Thesis:	Mineralogical, Petrographical and Geochemical Investigations of Yoncayolu Metamorphites (Üzümlü-Erzincan) and Their Surrounding Rocks
Level:	M.Sc.
Acceptance Date:	20/6/2008
Number of Pages:	123
Registration Number:	i1910

Summary:

Mineralogical, Petrographical and Geochemical Investigations of Yoncayolu

Metamorphites (Üzümlü-Erzincan) and Their Surrounding Rocks

Study area includes an area of 80 km2 around Üzümlü County, about 30 km east of

Erzincan, Turkey. Permian? aged Yoncayolu Metamorphites forms the basement of study

area. Yoncayolu Metamorphites is overlaid uncomformably by Dogger-Malm? aged

comes over both units below. Quaternary aged volcanic domes developed along North

Anatolian Fault Zone (NAFZ) and slope boulders, alluvial accumulation are the youngest

units observed in the study area.

Yoncayolu Metamorphites consisting of phyllite, greenschist, metadacite,

metabasic, metagranite, calcschist and quartzite is the product of regional metamorphism

within the facies of very-low and low-graded semi-greenschist and greenschist. General

mineral associations are as follow; albite+chlorite+calcite+quartz and

clinozoisite+epidote+chlorite +actinolite+albite+quartz. It mostly carries low sometimes

medium K calc-alkaline character. It resembles geochemically oceanic island-arc basalts,

compositionally volcanic-arc basalt and in distribution mid-ocean ridge basalts (MORB).

Metagranites located upper part of the Yoncayolu Metamorphites derived from

granodiorite/tonalitic granitoides and has character of metalumine, I-type representing

tectonically volcanic-arc granitoides. All the rocks of Yoncayolu Metamorphites show

enrichment in Large-ion Lithophile Elements (LILE) whereas they present an obvious

negative anomaly in Ta, Nb, Ti elements. While (La/Lu)N values changes between 0,28-

5,55, (Eu/Eu*)N values are in between 0,15-1,65. This unit is generally magmatic and

sometimes sedimentary in origin therefore pointing possible volcano-sedimentary genes.

chlorite crystallinity values changes between (ChC) Δ°2θ=0,146-0,298 and Árkai index

index pairs of KI- ÁI and IC-ChC. All samples points an environment of epizone

metamorphic conditions. When compared to chlorite thermometer index rocks of

greenschist facies is a formed temperature between 321-347 °C and about 4 kbar pressures.

Erzincan volcanics consisting of andesite, dacite and rhyolites have high-K calcalkaline

character. Fractional crystallization has possibly been affective in their formations

and geochemically carries volcanic-arc basalts character. In all samples Eu<1 and shows

light negative anomaly and (La/Lu)N values changes between 13,62-35,12.

Key Words: Uzumlu (Erzincan), Yoncayolu Metamorphites, Erzincan volcanics, Lowgrade

metamorphism, Greenschist facies, Chlorite thermometer, Illite