The Pannonian Sea was a shallow ancient sea located in the
area today known as the Pannonian Plain in Central Europe. The
Pannonian Sea existed during the Miocene and Pliocene epochs, when
three to four kilometres of marine sediments were deposited in the
Pannonian Basin. From that time in the most hills in Hungary are
covered with pannonian clay.
Clay is a naturally occurring material
composed primarily of fine-grained minerals, which show plasticity
through a variable range of water content, and which can be
hardened when dried and/or fired. Clay deposits are mostly composed
of clay minerals (phyllosilicate minerals), minerals which impart
plasticity and harden when fired and/or dried, and variable amounts
of water trapped in the mineral structure by polar attraction.
Organic materials which do not impart plasticity may also be a part
of clay deposits.
Clay minerals are typically formed over long periods of time by the
gradual chemical weathering of rocks, usually silicate-bearing, by
low concentrations of carbonic acid and other diluted solvents.
These solvents, usually acidic, migrate through the weathering rock
after leaching through upper weathered layers. In addition to the
weathering process, some clay minerals are formed by hydrothermal
activity. Clay deposits may be formed in place as residual deposits
in soil, but thick deposits usually are formed as the result of a
secondary sedimentary deposition process after they have been
eroded and transported from their original location of formation.
Clay deposits are typically associated with very low energy
depositional environments such as large lake and marine
deposits.
Primary clays, also known as kaolins, are located at the site of
formation. Secondary clay deposits have been moved by erosion and
water from their primary location
Depending on the academic source, there are three or four main
groups of clays: kaolinite, montmorillonite-smectite, illite, and
chlorite. Chlorites are not always considered a clay, sometimes
being classified as a separate group within the phyllosilicates.
There are approximately thirty different types of "pure" clays in
these categories, but most "natural" clays are mixtures of these
different types, along with other weathered minerals.
Clay minerals are hydrous aluminium phyllosilicates,
sometimes with variable amounts of iron, magnesium, alkali metals,
alkaline earths and other cations. Clays have structures similar to
the micas and therefore form flat hexagonal sheets. Clay minerals
are common weathering products (including weathering of feldspar)
and low temperature hydrothermal alteration products. Clay minerals
are very common in fine grained sedimentary rocks such as shale,
mudstone and siltstone and in fine grained metamorphic slate and
phyllite.
The pannonian clay is kaolinite type, it depends ont he minerals in
it can have different colours .
The Naszály is part of Cserhát hills in Hungary, but in
geological sence is different. Its major rocks are Dachstein
limestone, and you can find pannonian caly or vulcanic stones in it
as well. The highest paek is 652m.
The clay mining in Naszály is very old, there are vessels from the
paleoliticum as well.
To log this cache you have to find out
1. which is the type of pannonian clay
2. what are the clay minerals
3. what is the colour of the clay you see
4. take a photo at given coordinates with your GPSr and upload with
your log.
Send your answers via e-mail to me, if your
answer is correct you will get the log permission as fast as it
possible. You can find all the answears in the listing.
Please don’t log without permission and don’t give
answers in your log.
