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| Sedimentary Rock |
Sediment is the loose particulate materials (clay, sand,
gravel, and) Sedimentary rocks are rocks formed on the surface of the
earth by the deposition of particles or precipitation of dissolved substances, derived
from the weathering and erosion of rocks existing (or organisms). Sediment into sedimentary rocks through lithification, which
involves: Compaction, Cementation and recrystallization (carbonate sediments).
Sedimentary rocks
Does a rock formed by deposition and compression of mineral
and rock particles, but often include materials of organic origin and exposed
by various agencies denudation *. Sedimentary rocks can be classified as
terrigenous (ie derived from the breakdown of preexisting rocks on the ground),
organic (that is produced either directly or indirectly with the production
process like organic shell or * the formation of peat), chemical (ie generated
by rainfall of water, such as carbonates and all evaporites * some *), or
volcanogenic (* pyroclastic, for example, * and * tufa Bentonites). They can
also be described according to the chemical properties and their behavior and
their environment deposition, and other complementary schemes (Oxford
Dictionary of Earth Sciences by Michael Allaby 2008).
Petrographic sediment Is the description and classification
of sedimentary rocks. The petrographic show according to the study conducted
using a petrographic microscope.
Sedimentary petrology is the study of the composition and
origin of sedimentary rocks.
Why sedimentary Important?
All deposits of oil, gas and coal and ore deposits occur in
sedimentary rocks.
Sedimentary rocks is an important building material.
Sedimentary rocks give us the best window into the past. The
past allows us to predict the future.
"Now is the key to the past".
Helps in knowing that depositional environments. marine (sea
deposits), fluvial (river deposits), Aeolian (wind deposits), glacial,
estuarine, lacustrine (lake deposits), etc.
Helps in knowing the origin (ie sediment source area);
changes in climatic conditions that is to know and understand the old climate
paleoclimate =.
Almost 90% of the Earth's crust is composed of igneous rock
Sedimentary rock is 75% of the earth's surface.
Shale 65%, 15-20% sandstone, limestone 10-15%, others%
Cover ~ 75% of the land area of the continent (including
the continental shelf). Average ~ 2 km thick on the continent
& Lt; crust Volume 5%
Marine sediments: the average thickness of ~ 0.5 km
sedimentary structure
External shape, internal structure, or other forms of
preserved on the surface of the bed, resulting in sedimentary rocks * by the
process of sedimentation and contemporary biogenic activity *. Internal
sedimentary structures include: they are formed by a physical deposition process
(* cross-stratification, flat bed (see air beds), * laminate, and *
heterolithic structure); due to post-depositional deformation (bed convolute, *
structural deterioration, dishes and mast structure, structure fire, * the ball
and pillow structures, etc.); caused by organic disorders (* bioturbation, *
trace fossils); or by post-depositional chemical disruption (* enterolithic
structure, collapse and structure solution, * concrete, etc.) pre-charge
structure at the top of the bed, among others: formed by the deposition process
(ripple marks *, lineations primary current); erosion structures (* flute and
explore the signs, see explored and underdeveloped); the structure caused by
the transport of an object above the bed (* tool marks), and other features
such as drying and cracking * * sineresis, volcanoes * sand, ripple adhesion
and warts, mold rain, and biogenic trace and track *. Preserved structure with
the base of the bed (* single sign) including loadcasts * obtained
castsofflutes, roads and tool marks, and filling of local scour erosion.
External shape of the sedimentary units (sheet-like, * channel-fill, * rock or
mound (see mounds of mud), lenticular, etc.) is a function of depositional
environments and sometimes post-deposition solidification (Oxford Dictionary of
Earth Sciences by Michael Allaby, 2008).
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