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Widespread chemical weathering of Tertiary alkaline volcanic rocks in the vicinity of Trabzon (NE Turkey) has led to the formation of well developed reddish-brown saprolite. These saprolites are dominated by kaolin minerals (predominantly kaolinite), with minor quantities of halloysite, pyrophyllite, chlorite, smectite, hematite and illite. Other common minerals are opal-CT, quartz and occasional feldspar, clinopyroxene, hematite and Fe-Mn-Ti oxides. The significant degree of fracturing and fragmentation of primary igneous minerals within the pyroclastic units, and subsequent penetration by reactive fluids, resulted in partial chloritization of clinopyroxene, albitization of plagioclase and precipitation of Fe-Mn-Ti-oxides within fractures and dissolution voids. Kaolin minerals occur as spongy fibrous meshes surrounding partly dissolved volcanic glass and devitrified sub-rounded grains that may be relict allophane. Field observations and mineralogical-chemical characteristics indicate that the alteration of the Tertiary volcanic units of the Black Sea region was controlled by chemical weathering during circulation of oxic meteoric or mixed meteoric and marine waters. Intense fracturing and fragmentation of the pyroclastic rocks resulted in the formation of clay minerals in the upper saprolite level under acidic and largely oxidizing conditions. Incongruent dissolution was associated with the leaching and downward transport of Si, Na, K and Ca and the concentration of Al. In such an environment, early precipitation of halloysite from allophane was probable, and it gradually transformed into kaolinite during aging and progressive weathering.

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Energy demand which has increased rapidly is estimated to increase also in the future. Coal and natural gas would continue to have primary role in electricity generation and industry. Turkey's energy consumption has been growing faster than its production. Natural gas is the greatest source in the energy consumption with a share of 32%. Lignite coal is major domestic energy source of Turkey and its reserves are 12.4 billion tons. Since most of the lignite reserves are low in quality, they are used mostly in electricity generation. On the other hand, Turkey has very limited natural gas reserves. Aim of this article is to evaluate the energy demand of Turkey based on hard coal, lignite and natural gas. As a result of the study it was determined that 70% of the primary energy consumption is met by imported energy sources. This figure shows that Turkey's dependency on foreign energy will continue to increase in following years in parallel with its economic growth. Turkey should increase the use of domestic sources, since foreign dependence of country can be minimized.