TRAVERTINE ROCKS
Travertine
is a form of massive calcium carbonate, CaCO 3 , resulting from
deposition by springs or rivers. It is often beautifully coloured
and banded as a result of the presence of iron compounds or other
(e.g., organic) impurities. This material is variously known as
calc-sinter and calcareous tufa (when used for decorative purposes),
in fact Travertine is actually a dense closely compacted form
of limestone.
Travertine
is an excellent product for residential and commercial use and
is becoming increasingly popular because not only does it have
the elegant look of marble, but also once sealed Travertine tiles
require very little maintenance, which allows for a timeless &
beautiful appearance.
Travertine
is available in a number of finishes ranging from polish, cross-cut,
regular-cut, honed & filled, honed & unfilled, tumbled,
distressed-edge, patinato and unpolished to name a few.
Travertine
tile possess a wide range of colors, and cover the spectrum from
pure white to deep mahogany. The various hues of Travertine tile
can sometimes be constant throughout large pieces and at times
are blended. Travertine tile displays distinct veins at times
and is a very sturdy natural stone.
Onyx
marble, Mexican onyx, and Egyptian or Oriental alabaster are terms
applied to travertine. Travertine is generally less coarse-grained
and takes a higher polish than stalactite and stalagmite, which
are similar in chemical composition and origin.
SEDIMENTARY ROCKS GENERAL
Sedimentary rock is one of the three main rock groups (along with igneous and metamorphic rocks) and is formed in three main ways—by the deposition of the weathered remains of other rocks (known as clastic sedimentary rocks); by the deposition of the results of biogenic activity; and by precipitation from solution. Sedimentary rocks include common types such as chalk, limestone, sandstone, and shale.
Sedimentary
rocks are formed from overburden pressure as particles of sediment
are deposited out of air, ice, or water flows carrying the particles
in suspension. As sediment deposition builds up, the overburden
(or lithostatic) pressure squeezes the sediment into layered solids
in a process known as lithification ("rock formation")
and the original connate fluids are expelled.
Sedimentary
rocks are composed largely of silica (i.e. quartz), with other
common minerals including feldspars, amphiboles, clay minerals
and sometimes more exotic igneous minerals. Sedimentary rocks
are classified as clastic, that is, they are composed of discrete
clasts of material (rather than being composed of organic material
as is the case for a limestone).
Carbonate
minerals precipitating out of the ocean cover the ocean floor
with layers of calcite which can later form limestone.
Sedimentary
rocks are economically important in that they can be used as construction
material. In addition, sedimentary rocks often form porous and
permeable reservoirs in sedimentary basins in which petroleum
and other hydrocarbons can be found.
It
is believed that the relatively low levels of carbon dioxide in
the Earth's atmosphere, in comparison to that of Venus, is due
to large amounts of carbon being trapped in limestone and dolomite
sedimentary layers. The flux of carbon from eroded sediments to
marine deposits is known as the carbon-cycle.
The
shape of the particles in sedimentary rocks has an important effect
on the ability of micro-organisms to colonize them. This interaction
is studied in the science of geomicrobiology. One measure of the
shape of these particles is the roundness factor, also known as
the Krumbein number after the geologist W. C. Krumbein.
Sedimentary
rock is one of the three main rock groups. See also igneous and
metamorphic.
Sedimentary
rock is formed from the weathered remains of other rocks.
CLASSIFICATION OF ROCKS
