The Cretaceous volcanic rocks, widely distributed throughout this area, are composed of basalt, trachyandesite
, andesite, tuff, rhyolite and rhyolitic tuff.
The rock sample used in the present work was the same as the one used in our previous study , that is, a Tertiary basaltic rock from the Balkan Peninsula, classified according to the TAS scheme as basaltic trachyandesite
A: andesite, BA: basaltic andesite, BTA: basaltic trachyandesite
, and D: dacite.
Subalkaline basalts to basaltic trachyandesite
(Ulrych et al., 2006) and rhyolitic ignimbrite predominate.
Shoshonite is an alkali-rich ([Na.sub.2]O + [K.sub.2]O > 6.5 wt %) trachyandesite
that occurs in continental rift, collisional and arc settings (Rogers and Setterfield 1994).
Six of the eight units consist of alkaline olivine basalt, while the other two are basaltic trachyandesite
Mineralogical, petrological and geochemical investigations were carried out on an only poorly known lava flow of zeolite-bearing trachyandesite
exposed in a deep valley of the Dobrnsky potok Creek (NE of Decin-Bfeziny).
The Sikhote Alin complex consists of small potassium-alkali-rich intrusions (shonkinite, essexite-diabase, trachyandesite
, leucitic trachyte) with high boron and titanium content.
In the Zr/Ti[O.sub.2]x0.0001 versus Nb/Y diagram (Winchester and Floyd, 1977), which uses only relatively for immobile elements, the studied volcanic rocks plot in the fields of basalt, andesite, trachyandesite
clinopyroxenes have a tendency to plot at volcanic arc rocks field in Ti + Cr versus Ca diagram, indicating an arc-related environment for the formation of Sabalan volcanic rocks.
According to the conducted studies, the following volcanic rocks have been observed in this belt: basalt, basaltic andesite, andesite, trachyte, latite, trachyandesite
, dacite and rhyodacite ignimbrite and acidic to intermediate tuffs.
Pardo et al., (2005) have identified trachyandesite
to alkaline rhyolitic ignimbrites, pyroclastic surge, block and ash flow deposits and volcaniclastic deposits, mapped as NgQv and related to Plio-Pleistocene, highly explosive volcanism.