Download Sedimentary rock

I-Surface Materials
A-Bedrock & Soil:
1-Crust outer layer of earth
consist of bedrock, rock
fragments, and soil.
a-Bedrock- solid rock. When exposed
to the surface it’s called an
outcrop. (range from boulders to grains of sand)
b-Soil- mixture of small rocks, organic
matter, air and water.
outcrop
Rock
Fragments
Soil
Rock fragments
Bedrock
Bedrock
B-Minerals
1-Rocks are composed of minerals,
which are naturally occurring solid
substances made of inorganic
(nonliving) material. Minerals have
certain physical and chemical
properties by which they can be
identified.
1. Physical properties of minerals
include streak color, hardness,
luster, cleavage, and color.
•Luster refers to how a mineral looks
when it reflects light. {metallic, glassy, greasy,
or earthy.}
•Streak color is the color of the
powdered form of the mineral.
•Hardness resistance of a mineral
to being scratched. Between I and
10, with I being softest and 10 the
hardest.
Mohls Hardness Scale
Hardness
1
2
3
Mineral
Talc
Gypsum
Calcite
Test
4
5
6
Fluorite
Apatite
K-felspar
Glass will
Scratch
Steel
7
8
9
10
Quartz
Topaz
Corundum
Diamond
knife
Will
Scratch
Finger Nail
Will Scratch
copper penny
will scratch
Will Scratch all
•Cleavage is a mineral's tendency to break
along smooth, flat surfaces. {Often causes a mineral
to break into characteristic shapes}.
•Color is not always a reliable guide to a
mineral's identity.
2. Minerals have chemical
properties, how they react
with an acid. {For example, calcite,
the chief mineral in limestone
and marble, fizzes when
hydrochloric acid is placed on it.}
C-Rocks natural, stony materials
composed of one or more
minerals. Like minerals, rocks
are identified by their physical
and chemical properties.
•Three groups of rocks:
1- Igneous rocks are produced
by the cooling and hardening
liquid rock.
a-Melted rock
~ Magma underground
~ Lava on surface
b-Types of Igneous rocks
Igneous rocks that form from rapid
cooling of lava, called volcanic rocks,
contain tiny crystals.
-Basalt dark-colored volcanic rock
composed of small crystals. The closer
the magma is to the surface, the smaller
the grain (crystal) size. Obsidian, a
glassy, no individual grains.
~Igneous rocks that cools slow
form large crystals.
~Granite is a light-colored
igneous rock that contains
large, easily visible mineral
grains.
2- Sedimentary rocks form from
particles called sediments that pile up
in layers. These sediments may be small
rock fragments or seashells.
Sedimentary rocks usually form
underwater.
Stream
carrying
sediment
Ocean
Sedimentary rock
Common Sedimentary Rocks
Rock
Name
Type of
Sediment
Place of Formation
Sandstone
Sand grains
Shallow waters near a
shore pounded by waves
Shale
Clay particles
Deep, calm ocean
waters; lake bottoms
Limestone
Tiny seashells
Warm, shallow seas
3- Metamorphic rocks are
produced when either igneous
or sedimentary rocks undergo
a change in form caused by
heat, pressure, or both.
The rock cycle: is an illustration that
explains how the three rock types are
related to each other, and how
processes change from one type to
another over time.
Igneous
Rock
Solidification
Erosion
Deposition
Melting
Metamorphic
Rock
Sediments
Metamorphism
Burial and
Cementing
Heat and/or
Pressure
Sedimentary
Rock
II Earth History
A- Interpreting Rocks= rocks contain
information about that
area's past.
1-Sedimentary rocks indicates
the area was once covered by
water.
2-Fossils in sedimentary rocks
tell of past life and the
environmental conditions
3- Horizontally layered sedimentary
rocks are easy to interpret. The
bottom layers are the oldest,
youngest layers are at the top
YOUNGEST
OLDEST
FAULT
PRESENT DAY
INASION
OF
IGNEOUS
ROCK
FOLDED
ROCK
INVASION OF IGNEOUS ROCK
B-Fossils remains or traces of
organisms that lived long ago.
1-Fossils form when a dead plant,
animal, or footprint in mud, is
covered by sediment that later
hardens into rock.
a-Almost all fossils are found in
sedimentary rock
Brachiopod
Trilobite
Cephalopod
Footprint
C-Dating Rocks To determine the
age of rocks, scientists use a
technique called
1~Radioactive dating.
a. Rocks contain small amounts of
radioactive substances that change
(decay) into non-radioactive
substances at a definite rate.
b. Using this technique, scientists have
been able to assign dates to the Earth.
c. Earth itself is about 4.5 billion years
old.
2-Relative Dating: Section of
sedimentary rock oldest sediment is
on the bottom and the youngest is on
the top.
a. It only tells us that one fossil is
older than another.
Trilobite is an index fossil tells
about the age of the rock layer .