ROCKS THAT FORM FROM AN
ACCUMULATION OF SEDIMENTS
DERIVED FROM PREEXISTING ROCKS
AND/OR ORGANIC MATERIALS
Sediments that harden into rocks.
Here's a recipe for sedimentary rock:
You take a layer of sand and put
another hundred layers on top,
Then let it sit for years and years,
Let the pressure build You know, it may sound weird,
But that's how you make sedimentary
rock!
THREE KINDS OF
SEDIMENTARY ROCKS
What does a rock want to be
when it grows up?
A rock star!
FORM FROM SOLID FRAGMENTS
(SEDIMENTS) OF OTHER ROCKS.
EXAMPLES: SHALE, SANDSTONE,
CONGLOMERATE
SEDIMENTS COME FROM THE
WEATHERING OF EXISTING ROCKS.
->
->
-> ->
->
smallest
BOULDERS, PEBBLES, SAND, SILT, CLAY
FRAGMENTS ARE MOVED MOSTLY BY
RUNNING WATER.
WINDS, WAVES, AND GLACIERS ALSO
MOVE PARTICLES.
THE FARTHER A PARTICLE TRAVELS
THE ROUNDER IT BECOMES
ROCK FRAGMENTS SEPARATE
THROUGH HORIZONTAL AND
VERTICAL SORTING
What do you do to a baby rock?
Rock it!
IS THE COMPACTION AND CEMENTATION
OF ROCK FRAGMENTS THAT FORM
SEDIMENTARY ROCKS.
In coarse sediments (gravel and sand) sediments do not stick
together unless cemented. Dissolved minerals settle into
spaces between grains and bind them together.
- THE LARGER THE SEDIMENTS IN THE ROCK
THE MORE PERMEABLE (ABILITY TO LET
WATER PASS THROUGH) THE ROCK.
CONGLOMERATE IS A MIXTURE OF LARGE
ROUNDED PEBBLES CEMENTED
TOGETHER BY SMALLER SEDIMENTS
(BRECCIA HAS ANGULAR FRAGMENTS)
SANDSTONES ARE MADE LARGELY OF
QUARTZ GRAINS. (PERMEABLE)
SHALE FORMS FROM THE COMPACTION
OF TINY FLAKES OF CLAY.
(IMPERMEABLE)
Where is a rocks favorite golf
course?
Pebble Beach!
FORM FROM THE PRECIPITATION OF
MINERALS OUT OF SOLUTION
THE MAIN CAUSE FOR DISSOLVED MINERALS TO
PRECIPITATE, OR DROP OUT OF THE WATER, IS
EVAPORATION. (SHALLOW SEA ENVIRONMENT)
THIS RESULTS IN A CRYSTALLINE MASS OF
INTERGROWN MINERAL CRYSTALS
LIMESTONE - COMPOSED
PRIMARILY OF CALCITE;
FIZZES WITH HCL
DOLOSTONE – FIZZES IN
HCl WHEN POWEDERED
ROCK SALT - SAME
PROPERTIES OF
HALITE
ROCK GYPSUM SAME PROPERTIES
OF GYPSUM
What’s a rocks favorite cereal?
Cocoa Pebbles!
Organic (Bioclastic) Sedimentary Rocks
Form from the remains of living things or
rocks containing fossils
Limestones - calcite and
shells
Coal (sooty)- burial of
decayed plants; swamps
Fossiliferous shale – Shale
containing fossils
Sedimentary Features
Stratification – is the arrangement if different visible
layers of rock.
When the type of sediments found in an area change, a
new type of sedimentary rock forms Ex. Grand Canyon
Fossils - are the remains, impressions, or any other
evidence of plants and animals preserved in rock.
What’s a rocks favorite type of
music?
Rock n’ Roll!
Ripple marks - are formed by the
action of winds, streams, waves, and
currents on sand, and form on the
surface of bedding planes.
Mud cracks - develop when
deposits of wet clay dry up
and contract.
Geodes - are hollow spheres in
which groundwater has deposited
minerals (quartz or calcite crystals)