Balıkesir – Gönen (Mancılık – Tütüncü – Sebepli)çevresi kömür oluşumlarının jeokimyasal ve petrolojik incelenmesi
The geochemical and petrological investigation of balikesi̇r – gönen (Mancılık – Tütüncü – Sebepli̇) region
Yazar: MEHMET MARAL
Danışman: PROF. DR. MACİD FİKRET SUNER
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Jeoloji Mühendisliği Ana Bilim Dalı
Derece: Doktora, 2013
Konu: Jeoloji Mühendisliği = Geological Engineering

Özet:
Bu çalışmada, Biga Yarımadası'nın doğusunda yer alan Gönen çevresi linyit kömürü
oluşumlarının jeokimyasal ve petrografik açıdan incelenmesi, ilişkilerinin
irdelenmesi ve oluşum ortamının karakteristiklerinin belirlenmesi hedeflenmiştir.
Çalışma sahasının bulunduğu Biga Yarımadası'nda gnays, amfibolit, mermer ve
metaofiyolitten oluşan Kazdağ Masifi ve Triyas yaşlı Karakaya Kompleksi bölgenin
temelini oluşturmaktadır. Bölgede yayılım gösteren Karakaya Kompleksi dört
tektonik birime ayrılmıştır. Bu birimler Permo-Karbonifer yaşlı Kazdağ Masifi
kayaçları üzerine tektonik dokanakla gelirler. Bu birimleri Jura yaşlı kırıntılı bir istif
olan Bayırköy Formasyonu üzerler ve bir diskordans ile Bilecik Kireçtaşı tarafından
örtülür. Bu formasyonların üzerine Eosen yaşlı Ceylan Formasyonu gelir. Ceylan
Formasyonu üzerine bölgedeki volkanik faaliyetlerin ürünü olan Çan Volkanitleri ve
bu birim ile eş zamanlı olarak kırıntılı, tüf, kömür seviyeli Miyosen yaşlı Bigadiç
Formasyonu diskordan olarak çökelmiştir. Bölgedeki linyit yatakları bu formasyon
içersinde yer alır. Kuzey Anadolu Fay Zonu'nun etkisinde kalan bölge, tektonik
açıdan aktiftir ve kırıklı, çatlaklı, kıvrımlı yapılar sergiler. Bu tektonik aktiviteler
linyitlerin killerle birlikte çökeldiği basenleri kontrol etmektedir.
Çalışma sahasından alınan örnekler üzerinde gerçekleştirilen laboratuar çalışmaları,
kimyasal analizler ve mikroskop incelemeleri University of Kentucky, Center for
Applied Research (ABD) laboratuarlarında, literatürde tanımlanan ve standartlarda
belirtilen işlemler uygulanarak tamamlanmıştır. Elde edilen mikrolitotip ve maseral
verileri, belirli formüller ile sayısallaştırılarak grafikler yardımıyla kömürün oluşum
ortamı hakkında bilgilere ulaşılmıştır. Palinolojik çalışmalar ile bu bilgiler
desteklenmiştir. Kimyasal analiz sonuçları istatistiksel olarak değerlendirilerek
ilişkiler saptanmaya çalışılmıştır.
Kömürlerin kül içerikleri ile nem içerikleri arasında her zaman anlamlı bir ilişki
kurulamazken, bağlı karbon ve uçucu madde içerikleri genelde birlikte hareket eder
ve kül yüzdesiyle negatif korelasyona sahiptir. Karbon, hidrojen, azot ve oksijen
oranları da genelde paralellik gösterir.
Makro ve mikro gözlemlerde kömürde piritin varlığı ile kil ve silis oluşumları
saptanmıştır. Vitrinit yansıtma değerleri linyit – alt bitümlü kömür aralığında yer
almaktadır. Kömürlerin maseral dağılımlarında hüminit grubunun egemenliği söz
konusudur. Mikrolitotip bakımından da hüminitten oluşmuş olan vitrit baskındır.
Mancılık ve Sebepli çevresinde genel olarak bitki polen ve sporlarının egemendir.
Tütüncü sahasında mantar sporlarının oranı yüksektir. En yoğun rastlanılan tür
Taxodium sp.'dir. Alnus sp. izlenen ikinci hakim gruptur. Pineaceae ailesine üye
polenler (Pinus sp., Pityosporites microlatus, Pityosporites labdacus, Tsuga sp.), her
örnekte değişik oralarda bulunmaktadır. Polypodiaceae (Laevigatosporites sp.,
Tricolpopollenites sp., Tricolpopollenites henrici), Quercus sp., Ephedripites sp.,
Castanea sp., Momipites sp. bölgede düşük yüzdelerde karşılaşılan diğer bitki polen
ve spor türleridir.
Kimyasal analiz sonuçları istatistiksel olarak değerlendirilerek ilişkiler saptanmaya
çalışılmıştır. Kömürlerin major oksit ile iz element içerikleri arasında her zaman
anlamlı bir ilişki kurulamaz. Kömürlerin iz element içeriği başta As, Ga ve U olmak
üzere, Ba, Cr, Mn, Mo, Pb, V, Zn ve Zr değerleri çevresel etkiler ve sağlık açısından
problemlere neden olabilecek düzeydedir.
Sahadaki kömürler üzerinde deniz etkisini belirten nispeten yüksek CaO, V ve Cr
içeriklerine karşın, V-Cr arasında korelasyonun olmaması, düşük Na yüzdesi ve
yüksek Mn oranı açıksu (freshwater) ortamını işaret etmektedir.
Bölgedeki kömürler, oluşum koşulları açısıdan, otsu bitkilerin ve sazların yoğun
olarak bulunduğu, beslenme rejiminde reotropik-mesotropik koşullara hakim olduğu,
yer yer taşkınların gerçekleştiği, sazlık bataklığı ve orman bataklığı bir çevrede
geliştiği düşünülmektedir.

Abstract:
The aim of the study is the investigation of Gönen lignite occurrences, located in the
eastern part of Biga Peninsula, by geochemical and petrographic aspects, determined
their relations and formation conditions.
The basement of the study area is composed of Kazdağ Massif, which mainly consist
of gneisses, amphibolites, marbles and metaophiolites and Karakaya Complex, which
are classified in four tectonic units. Jurassic Bayırköy Formation, which is a clastic
sedimentary unit, overlied the former units, and it is overlie by Bilecik Limestone
with an unconformity. Eocene Ceylan Formation is on all of these formations.
Miocene is represented by Çan Volcanits and Bigadiç Formation where coal deposits
are being observed. North Anatolian Fault (NAF) Zone has controlled the region, so
the area is tectonically very active, and has numerous faults and crack systems had
been developed under this mechanism, which is responsible for coal and clay
formation and deposition within the continental basins.
The channel samples were collected certain grids from the fields. Laboratory studies,
chemical analysis and microscopic investigations were performed on the samples
according to the literature and the standarts at University of Kentucky, Center for
Applied Research (USA). The microlithotype and maceral data were calculated by
the formulas and plotted for interpretation of the coal deposition environment. There
were supported with the palynologic investigations. The results of chemical analysis
were statistically evaluated and found out their connections.
The relation between ash content and moisture of the coals are usually irrelevant.
Fixed carbon and volatile matter are moving together and have got a negative
correlation with ash percentage. Carbon, hydrogen, nitrogen and oxygen ratios show
parallelism each other.
The results of huminite random reflectance measurements ranged from 0.18% to
0.61% in Gonen region. Therefore, these coals are classified as both lignite and
subbituminous / high volatile C bituminous. Rr% of Mancilik coal samples is
between 0.23% and 0.58%, similarly, the measurements range in 0.34 – 0.61% in
Sebepli. Random reflectance of the Tutuncu coals, considered to lignite, ranges from
0.18% to 0.34%.
Pyrite, clay and silica formations are defined both macro and micro observations.
Microscopic investigations reveal to enrich mineral matter in the coals. The Mancilik
mineral-matter ratio is lower than the other coal fields. Mineral-matter is generally
consisted of pyrite and clay minerals. Framboidal pyrite is mostly observed pyrite
form. This type pyrite enhanced in carbonate and sulfate-rich water that influenced
by sulfate-reducing bacteria, during peat formation. Framboidal pyrite occurrences
may be connected with sulfate-rich environment depending on local volcanism.
Huminite group is the dominant in the maceral distribution. Vitrit, which consists of
huminite, is the common microlithotype. Huminite ranging is abundance from 68.8%
to 98.6%. Gelinite is the prevailing maceral. Textinite, ulminite, densinite, attrinite
and corpohuminite are observed. Liptinite and inertinite group macerals occur in low
to moderate concentration.
The Mancilik humotelinite is almost mainly represented by ulminite; both textoulminite
and eu-ulminite types were observed. Textinite is present in the samples.
Gelinite has significant concentrations, while corpohuminite is found in low
concentrations. Densinite and attrinite are relatively minor macerals with some
exceptions. The Tutuncu humotelinite is primarly consisted of textinite, with textoulminite
and eu-ulminite types also observed. As with Mancilik, gelinite has high
concentration with lesser amounts of corpohuminite. Densinite and attrinite ratios are
almost equal in both Tutuncu and Mancilik coals. Unlike the other deposits,
humocollinite is the main component in Sebepli, with humotelinite and
humodetrinite are also present. Humotelinite consists of texto-ulminite, eu-ulminite,
and textinite. Gelinite can exceed more than 60%. Corpohuminite is observed in low
concentrations. Attrinite and densinite are minor macerals.
Liptinite macerals can be found up to 27.6% of the total organic matter in all of the
coal fields. Cutinite and resinite are the most abundant, accounting for more than half
of the liptinites in the samples. It is considered the other macerals of this group,
sporinite, suberinite, and liptodetrinite are observed in various amounts.
Inertinite display values less than 10% of the organic matter in the region with some
exception. Funginite, macrinite, and inertodetrinite are predominant macerals.
Fusinite and semifusinite are less common. Macrinite is in a fusinitized state
amorphous (gel-like) substance, which has been oxidized. Inertodetrinite consisted of
redeposited debris of fusinite, semifusinite, sclerotinite and macrinite and of small
plant remains, which decomposed and were fusinitized within the peat.
Inertinite macerals are mainly represented by funginite and inertodetrinite in the
Mancilik. Macrinite, fusinite, and semifusinite are uncommon in the samples.
Funginite and macrinite are abundant inertinite macerals in the Tutuncu.
Inertodetrinite is less common maceral, with fusinite and semifusinite. The Sebepli
inertinite mainly consists of inertodetrinite. Fusinite and macrinite are also observed.
Funginite and semifusinite are uncommon in the samples.
The paleoenvironment of peat formation can be classified as a function of the
hydrologic conditions in the peat mire and so obtain information on the supply of
nutrients and the effect of the water table.
Tissue preservation index (TPI) and gelification index (GI) are used for determining
the conditions during formation of the coal deposits. TPI describes the degree of
humification of the peat-forming materials and reflects a balance between the growth
and accumulation of plant materials, level of the water table and domination of tree
vegetation. A low TPI suggests either predominance of herbaceous plants in the mire
or large-scale destruction of plant tissues as a result of advanced humification. GI
mainly represents the ratio of gelified versus non-gelified macerals existing in the
peat. GI is an indication of the level of moisture in the peat-forming environment,
besides directly related to peat accumulation and basin subsidence.
Groundwater index (GWI) and vegetation index (VI) are used for reconstructing the
paleoenvironment conditions during peat deposition. GWI reflects the gelification
degree of the plant material and the pH conditions in the swamp, as well as the
vegetation type is related to VI and determines which maceral varieties will become
part of the peat existing in the swamp. VI is dependent on the type of peat-forming
plant communities, and is indicative of the type of vegetation (e.g., trees, bushes) that
determines the concentration ratios of coal macerals during coalification.
According to the VI and GWI, the type of the mire mainly developed under the
rheotrophic hydrological condition with few exceptions, which were mesotrophic.
Most of the samples are in a distinctive zone, VI is less than 3 and GWI is between
1and 5, representing swamp and limnic environments. Also, two determined minor
conditions were inundated marsh and swamp forest fields. The samples indicated
marginal aquatic/herbaceous type plant zones, possibly related to humification and
gelification degree of trees. Sebepli coals were progressed swamp, limnic and
inundated marsh conditions with rheotrophic regime. On the contrary, Mancilik and
Tutuncu fields were progressed in swamp, fen and swamp forest, which influenced
by rheotrophic-mesotrophic environment.
The TPI and GI shows the gelification index is greater than 1 and the tissue
preservation index is less than 2, with some exceptions. Therefore, the depositions of
organic materials were influenced strong gelification and wet conditions with
intensive humification. Cellulose-rich plant matter, such as that derived from
herbaceous plants, is more easily decomposed than lignin-rich wood. Thus, a low
TPI suggests either predominance of herbaceous plants in the mire or large-scale
destruction of wood because of extensive humification and. The values indicated the
deposition environments were varying marsh – fen – forest swamp and in linmotelmatic
zone. Mancilik coals were developed in marsh, fen, and forest swamp
conditions with limno-telmatic and telmatic zone. On the other hand, Sebepli and
Tutuncu coals were deposited in mainly marsh and fen, which influenced by limnotelmatic
environment.
Although, sulfur enrichment represents marine influenced; there is no other evidence.
Thus, the enrichment probably related to volcanic activity and alkaline conditions
with sulfide mineralization.
In generally, plant pollens and spores are dominant in Mancılık and Sebepli fields.
However, Tütüncü filed has plenty of fungal spores. Most abonduens one is
Taxodium sp., and fallowed by Alnus sp.. Pineaceae pollens (Pinus sp., Pityosporites
microlatus, Pityosporites labdacus, Tsuga sp.), may be observed in every sample with
various quantities. Also, Polypodiaceae (Laevigatosporites sp., Tricolpopollenites
sp., Tricolpopollenites henrici), Quercus sp., Ephedripites sp., Castanea sp.,
Momipites sp. are found in the region.
Pollens and spores which were identified with microscopic investigations and, plant
assemblages were grouped as swamp forest, shrubby peat-swamp, mixed mesophytic
forest, herbaceous plant. Taxodium, represents a swamp forest, is the most abundant
in the samples. It is followed by Alnus and Pinus. Alnus grown in periodically
flooded environments also may indicate riverside. Moreover, Acer, Fagacea,
Quercus, Carya, Castanea, and Ephedra are found. This group represents forest
swamp/wet forest swamp. Similar palynomorph associations were reported in the
west of the Biga.
The trace element analyses show that As, Ga, and U are significant enriched and
paramount in the samples. The contents of Ba, Cr, Mn, Mo, Pb, V, Zn and Zr are also
higher than world coals. The other trace elements exhibit a variety in a low range;
during Ge, Hg, Se and Th are below the detection limits of the equipment.
The abundance of the mentioned trace elements can lead to cause some
environmental problems and related disease. Therefore, usage potential of the coals
should be revised. By the way, some important elements like U and Ga are
considered to gain from the coals as by-products. Relatively high CaO, V and Cr
contents briefly indicate some marine influences on the coal deposition condition.
However, apparently lack of correlation of V-Cr, abundance of Mn, and low Na
percentage suggests freshwater environment.
According to the formation conditions, the coals accumulated and deposited in a
marsh and/or a wet forest swamp. There were controlled by rheotropic-mesotrophic
conditions and partly inundated environment. Herbals, fens and reeds were
abundance plant types.