SOURCE ROCK CHARACTERIZATION OF THE SHALES AND MUDSTONES OF THE CAMPANIAN–MAASTRICHTIAN HAYMANA FORMATION, HAYMANA BASIN, CENTRAL ANATOLIA, TURKEY

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Tezin Türü: Bütünleşik Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Jeoloji Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2022

Tezin Dili: Türkçe

Öğrenci: Özgür Yıldırım

Danışman: Ismail Ömer Yilmaz

Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu

Özet:

This study investigates the petroleum potential of the shales and mudstones of the

Campanian-Maastrichtian Haymana Formation in the Haymana Basin, Turkey.

Lithofacies, pore structure, and source rock potential of the shales and mudstones are

investigated using stratigraphical, sedimentological, petrophysical, and organic

geochemical studies along five stratigraphic sections and other sampling sites. The

depositional model presents a facies distribution within a set of turbidite fans,

including submarine canyon, inner fan, mid fan, and outer fan settings, in the

Haymana Formation. The shales and mudstones of the Haymana Formation are

subdivided into six lithofacies based on bulk mineralogy: mixed mudstone, mixed

siliceous mudstone, marl, mixed carbonate mudstone, argillaceous/siliceous

mudstone, and clay-rich siliceous mudstone. The decreasing ratio of coarse-grained

clastics towards south of the basin indicate increasing distance from sediment source

area. The observed pore volume of the shales and mudstones includes mesopores

and macropores. The macropores were created by dissolution of carbonate minerals,

while the fine mesopores were developed around clays and quartz/feldspar grains.

The effective porosity (avg. 5.66%) and absolute permeability (avg. < 0.1 md) show

a poor correlation with lithofacies type suggesting that the pores, mineral content,

and grain size of the shales and mudstones have strong heterogeneity. A few shale

and mudstone samples with relatively high total organic carbon and hydrogen index

values indicate mature source rocks in the north of the basin. Nevertheless, organic

geochemical measurements indicate that the analyzed shales and mudstones with

0.39% average total organic carbon values exhibit organic-poor source rock

characteristics in the basin.