Research Information System
8. Geochemistry Symposium, Antalya, Turkey, 2 - 05 May 2018, pp.293-294
Travertines occur along fractures in the
crust and are formed by the deposition of calcium and bicarbonate from cold to
hot mineral-rich waters. The fluid/rock interaction is an important process in
the formation of calcitic or aragonitic travertines and tufa (CATT). In most
situations the formation of CATT is related to dissolution of limestone from
any location along the hydrogeological pathway. The formation of the
travertines outcropping in Yaprakhisar village (Güzelyurt-Aksaray) which are
the topic of the study is controversial. Geochemistry and dating studies with
the 230Th/234,238U imbalance method were
performed to determine the source of the travertines.
It is known that the link between base and
the CATT (epigean and hypogean systems) can be revealed with evaluation of
potential geochemical tracers such as Ba and Sr, which are used in geochemical
evaluations and trace elements. In addition, CATT deposited from hypogenous
sources with high Be content indicates granitic source, while high Cr values show
the source may be fed from Cr-rich ultramafic rocks in the basement. According
to the Ba-Sr diagram, travertines are sourced in hypogenous fluids from
limestone-evaporite-dolomite, while the Be and Cr content were determined to
present variations depending on the different travertine masses. When the NTE
content of samples is noted, there were low values for total NTE and clear
negative Ce and Eu anomalies in nearly all samples. Additionally, though not
very clear, a positive Ho anomaly was determined.
Investigation and dating of travertines is
very important in terms of determining the activity of faults and crustal
deformation in tectonically active regions. With the U-series dating method,
the Yaprakhisar travertines were identified to have ages ranging from 3500 to
146,000 years.
In conclusion, when all data are assessed,
the travertines are concluded to have been deposited under oxic conditions from
relatively low temperature water, with low acidity and hypogenous source in
limestone-evaporite-dolomite. Additionally, considering the morphologies/ages
of the Yaprakhisar travertines located in the region between the Tuzgölü Fault
Zone Keçiboyunduran-Melendiz Fault, it may be considered that these travertines
are related to these faults or formed in paleodiscontinuities occurring due to
the interaction of these faults.