**Abstract**

Pseudoleucite syenite is a magmatic rock, which is rarely found in the foidolite rock group. With respect to the compositions of similar alkali feldspars as sodium potassium aluminosilicates, feldspathoid minerals are normally characterized by silica deficiency. Pseudoleucite syenite formed from alkaline (sodium and potassium)-rich and silica-poor magmas. In this study, intrusion-related distributions, mineralogical and petrographical properties, and mineral chemistry of pseudoleucites in İsahocalı (Kırşehir) alkali syenites from Central Anatolia Granitoids have been investigated, and magnetic enrichment processes have been carried out on their crushed and grinded samples. As a result of the enrichment of pseudoleucite syenites with a high amount of K2O + Na2O (12.25 + 5.61 wt.%), via dry magnetic separator, the obtained data demonstrated that pseudoleucites in İsahocalı Alkali syenites can be used as industrial raw material in sectors such as ceramics, agriculture, cement industries, etc.

**Keywords:** usability of pseudoleucite, industrial raw material, ceramics, İsahocalı alkali syenites, Kırşehir, Central Anatolia

## **1. Introduction**

Leucite is a rock-forming mineral composed of potassium and aluminum tectosilicate K[AlSi2O6]. Its crystals have the form of tetragonal but it is isotropic, because of its pseudocubic system [1]. Pseudoleucites are intergrowths of two or more minerals: leucite, nepheline, and K-feldspar; nepheline and feldspar; or analcite, nepheline, and feldspar; or alteration products of these, thought to be pseudomorphing leucite in igneous rocks [2].

In the Central Anatolia Granitoids, studied pseudoleucite syenites, which are feldspathoid igneous rocks, appear as light colored, coarse crystalline, and compositionally silica-poor. They can also be classified as foid syenite, consisting of pseudoleucite (leucite + nepheline + orthoclase) and aegerine-augite minerals.

Recent studies have shown that foid syenitic rocks containing feldspathoid minerals can be used as starting materials for the production of glass, ceramics, and paint. The lack of free silica, high alkaline and alumina content, high melting power, and narrow melting range of foid syenites are the properties that are desired in the glass industry. In addition, they provide high resistance to weather conditions, as well as the use of roof particles, road materials, stone pavements, as well as concrete aggregate and asphalt production. Other potential use areas are artificial fertilizer, refractory, cement mortar, and paper [3, 4].

The İsahocalı (Kırşehir) area in Central Anatolia includes pseudoleucite syenites. Such alkaline syenite intrusions in the region, which is the main objective of this study, offer irregularly shaped outcrops reaching up to 1 km2 . In the vicinity of the study area, there are also nephelite syenites, which are produced by B & S Invest CO. B & S Invest CO, via magnetic enrichment operations. After the magnetic enrichment, the iron-containing minerals are removed and the sodium and potassium-rich industrial raw materials are marketed to the ceramic industry.

The aim of this study is to investigate the usability of sodium- and potassiumrich pseudoleucites in İsahocalı (Kırşehir) alkali syenites from the Central Anatolia Granitoids.

## **2. Materials and methods**

In this study, the spread of pseudoleucite syenites in the İsahocalı (Kırşehir) area has been mapped. Then samples were taken from these intrusions for laboratory studies. In order to determine the mineralogical and petrographic properties of the pseudoleucite syenites samples obtained from the field, thin sections were prepared in the Thin Section Laboratory of the Department of Geological Engineering of the Engineering Faculty of the University of Ahi Evran.

Pseudoleucite syenite samples were grinded by a crusher and ball mill at B&S Yatırım AŞ laboratory. As the enrichment method, magnetic enrichment was carried out to remove the iron-bearing minerals in the grinded samples. The chemical analyses of the samples were carried out by the XRF-method before and after enrichment studies. As a result of chemical analysis, their sodium, potassium, and iron values were compared.

### **3. Geology**

The Central Anatolia, in which the study area is located, consists of several continental blocks separated from each other by ophiolitic suture zones (**Figure 2**). These tectonic belts are, from the north to the south, Pontid Continent, Intra-Pontide suture, Sakarya Continent, Ankara-Yozgat-Erzincan suture (Central Anatolian Metamorphites), and the Kırşehir Continent (Central Anatolian Metamorphics) (**Figure 1**), and the continental blocks developed as a result of Pan-African, Hercynian, and Cimmerian orogenies and remained as the continental basement during the Neo-Tethyan evolution [5]. The Neo-Tethys Ocean was opened by rifting of these continental bases along two lines in Lias, so that the Intra-Pontid and Ankara-Yozgat-Erzincan Ocean branches developed [6]. At the beginning of the Late Cretaceous, a subduction started along the entire Pontide belt [6]; in other words, the northern branch of Neo-Tethys began to subduct under the Pontide. During this period, the greatest ophiolitic nappes including Refahiye Complex, which is the oldest unit of the study area, was settled on Anatolide-Tauride continent [6, 7]. In the Paleocene-Early Eocene, the northern branch of the Neo-Tethys was completely closed and the continent-continent collision [6] took place [8].

The oldest level in the study area consists of Paleozoic Middle Anatolian Metamorphics consisting of schist, gneiss, amphibolite, and marbles. Seymen (1981)

**55**

**Figure 1.**

*The regional geological map of the study area [7–11].*

*Investigation of the Usability of Pseudoleucites in Central Anatolia Alkali Syenites as Industrial…*

divided the unit into three formations in his study [12]. These are from the old to the young, Kalkanlıdağ, Tamadağ, and Bozçaldağ formations. In the Upper Cretaceous, the Central Anatolian Volcanites with dacite-rhyolite-rhyodacite composition and the Upper Cretaceous-Paleocene granite-syenite-monzonite composition of the Central Anatolian Granitoids were cut by coeval units. All these units are unconformably overlain by Lower-Middle Eocene-Quaternary sedimentary units (**Figure 2**).

The igneous rocks in the region and its vicinity are defined as Central Anatolian

Granitoids by Erler and Bayhan (1995) [13]. These rocks with granite, syenite, and monzonite composition are Upper Cretaceous-Paleocene aged [14, 15]. Central Anatolian Metamorphics and Central Anatolian Granitoids are covered by Eocene—Quaternary aged, marine, and terrestrial rock units. These units consist of alternation of conglomerate, sandstone, siltstone, claystone, limestone, and occasionally tuff and gypsiferous levels, from old to young, formations defined as Baraklı Formation, Arzilar Limestone Member, Meşeköy Formation, Kozaklı Limestone Member, Kızılırmak Formation, travertine, and alluvium [15–17].

*DOI: http://dx.doi.org/10.5772/intechopen.89588*

*Investigation of the Usability of Pseudoleucites in Central Anatolia Alkali Syenites as Industrial… DOI: http://dx.doi.org/10.5772/intechopen.89588*

**Figure 1.**

*Mineralogy - Significance and Applications*

Granitoids.

**2. Materials and methods**

iron values were compared.

**3. Geology**

fertilizer, refractory, cement mortar, and paper [3, 4].

Engineering Faculty of the University of Ahi Evran.

study, offer irregularly shaped outcrops reaching up to 1 km2

in the glass industry. In addition, they provide high resistance to weather conditions, as well as the use of roof particles, road materials, stone pavements, as well as concrete aggregate and asphalt production. Other potential use areas are artificial

study area, there are also nephelite syenites, which are produced by B & S Invest CO. B & S Invest CO, via magnetic enrichment operations. After the magnetic enrichment, the iron-containing minerals are removed and the sodium and potassium-rich industrial raw materials are marketed to the ceramic industry. The aim of this study is to investigate the usability of sodium- and potassiumrich pseudoleucites in İsahocalı (Kırşehir) alkali syenites from the Central Anatolia

The İsahocalı (Kırşehir) area in Central Anatolia includes pseudoleucite syenites. Such alkaline syenite intrusions in the region, which is the main objective of this

In this study, the spread of pseudoleucite syenites in the İsahocalı (Kırşehir) area has been mapped. Then samples were taken from these intrusions for laboratory studies. In order to determine the mineralogical and petrographic properties of the pseudoleucite syenites samples obtained from the field, thin sections were prepared in the Thin Section Laboratory of the Department of Geological Engineering of the

Pseudoleucite syenite samples were grinded by a crusher and ball mill at B&S Yatırım AŞ laboratory. As the enrichment method, magnetic enrichment was carried out to remove the iron-bearing minerals in the grinded samples. The chemical analyses of the samples were carried out by the XRF-method before and after enrichment studies. As a result of chemical analysis, their sodium, potassium, and

The Central Anatolia, in which the study area is located, consists of several continental blocks separated from each other by ophiolitic suture zones (**Figure 2**). These tectonic belts are, from the north to the south, Pontid Continent, Intra-Pontide suture, Sakarya Continent, Ankara-Yozgat-Erzincan suture (Central Anatolian Metamorphites), and the Kırşehir Continent (Central Anatolian Metamorphics) (**Figure 1**), and the continental blocks developed as a result of Pan-African, Hercynian, and Cimmerian orogenies and remained as the continental basement during the Neo-Tethyan evolution [5]. The Neo-Tethys Ocean was opened by rifting of these continental bases along two lines in Lias, so that the Intra-Pontid and Ankara-Yozgat-Erzincan Ocean branches developed [6]. At the beginning of the Late Cretaceous, a subduction started along the entire Pontide belt [6]; in other words, the northern branch of Neo-Tethys began to subduct under the Pontide. During this period, the greatest ophiolitic nappes including Refahiye Complex, which is the oldest unit of the study area, was settled on Anatolide-Tauride continent [6, 7]. In the Paleocene-Early Eocene, the northern branch of the Neo-Tethys was completely closed and the continent-continent collision [6] took place [8]. The oldest level in the study area consists of Paleozoic Middle Anatolian Metamorphics consisting of schist, gneiss, amphibolite, and marbles. Seymen (1981)

. In the vicinity of the

**54**

*The regional geological map of the study area [7–11].*

divided the unit into three formations in his study [12]. These are from the old to the young, Kalkanlıdağ, Tamadağ, and Bozçaldağ formations. In the Upper Cretaceous, the Central Anatolian Volcanites with dacite-rhyolite-rhyodacite composition and the Upper Cretaceous-Paleocene granite-syenite-monzonite composition of the Central Anatolian Granitoids were cut by coeval units. All these units are unconformably overlain by Lower-Middle Eocene-Quaternary sedimentary units (**Figure 2**).

The igneous rocks in the region and its vicinity are defined as Central Anatolian Granitoids by Erler and Bayhan (1995) [13]. These rocks with granite, syenite, and monzonite composition are Upper Cretaceous-Paleocene aged [14, 15]. Central Anatolian Metamorphics and Central Anatolian Granitoids are covered by Eocene—Quaternary aged, marine, and terrestrial rock units. These units consist of alternation of conglomerate, sandstone, siltstone, claystone, limestone, and occasionally tuff and gypsiferous levels, from old to young, formations defined as Baraklı Formation, Arzilar Limestone Member, Meşeköy Formation, Kozaklı Limestone Member, Kızılırmak Formation, travertine, and alluvium [15–17].

**Figure 2.** *Geological map of the study area [16].*
