chapter 6.3 sedimentary rocks
DESCRIPTION
SEDIMENTARY ROCKS 95% OF EARTHS CRUST IS IGNEOUS ROCK, AND 4-5% IS SEDIMENTARY AND METAMORPHIC ROCK SEDIMENTS – ANY SUBSTANCE THAT SETTLES OUT OF A FLUID Created by weathering and erosion WEATHERING – THE PROCESS BY WHICH ROCKS ARE BROKEN UP INTO FRAGMENTS MECHANICAL, CHEMICAL AND BIOLOGICAL EROSION – THE REMOVAL AND TRANSPORT OF EARTH MATERIALS BY NATURAL AGENTS LITHIFICATION – PROCESS BY WHICH MATERIALS BECOME ROCKTRANSCRIPT
CHAPTER 6.3 SEDIMENTARY ROCKS SEDIMENTARY ROCKS 95% OF EARTHS
CRUST IS IGNEOUS ROCK, AND 4-5% IS SEDIMENTARY AND METAMORPHIC ROCK
SEDIMENTS ANY SUBSTANCE THAT SETTLES OUT OF A FLUID Created by
weathering and erosion WEATHERING THE PROCESS BY WHICH ROCKS ARE
BROKEN UP INTO FRAGMENTS MECHANICAL, CHEMICAL AND BIOLOGICAL
EROSION THE REMOVAL AND TRANSPORT OF EARTH MATERIALS BY NATURAL
AGENTS LITHIFICATION PROCESS BY WHICH MATERIALS BECOME ROCK ORIGIN
OF SEDIMENTS: 1. CLASTIC ROCK FRAGMENTS FORMED BY
WEATHERING/EROSION OF EXISTING ROCK DEFINED BY SIZE - SMALLEST TO
LARGEST CLAY, SILT, SAND, GRAVEL Clastic sediments are often sorted
by water action before pressure and mineral cements turn them into
rock. LITHIFICATION OF CLASTICS:
a.) CEMENTATION DISSOLVED MINERALS THAT BIND PARTICLES TOGETHER
SILICA FROM QUARTZ. GRAY OR WHITE LIME FROM CALCITE. GRAY OR WHITE
IRON VARIOUS IRON MINERALS RED, BROWN, YELLOW b.) COMPACTION
PRESSURE OF OVERLYING MATERIALS LITHIFY DEPOSITS 1. A river moves
sediment into a lake.
2. Particles are sorted by size. The largest gravels are the first
to be deposited, followed by sands, and then silt and clay. Sands
and Gravels Sands Silt and Clay 3. Over time, the sediments are
buried, compacted, and may be cemented. Conglomerate Sandstone
Shale CLASTIC SEDIMENTARY ROCKS:
CONGLOMERATE CEMENTED MIXTURE OF ALL SIZES OF CLASTIC
MATERIALS.LARGEST PEBBLES (QUARTZ) SANDSTONE CEMENTED QUARTZ/
FELDSPAR GRAINS SILTSTONE SILT SIZED PARTICLES SHALE COMPACTED SILT
OR CLAY.OFTEN OCCUR IN FLAT SHEET LIKE LAYERS. SANDSTONE
CONGLOMERATE SILTSTONE SHALE 2. CHEMICAL SEDIMENTARY ROCKS
SEDIMENTS THAT FORM FROM EVAPORATION OR PRECIPITATES
LIMESTONE CHEMICAL DEPOSITION OF CALCITE ROCK SALT EVAPORATIVE
DEPOSITION OF HALITE ROCK GYPSUM EVAPORATIVE DEPOSITION OF GYPSUM
LIMESTONE ROCK GYPSUM ROCK SALT 3. ORGANIC SEDIMENTS FORMED FROM
THE REMAINS OF PLANTS AND ANIMALS
COQUINA LIMESTONE FORMED BY THE CALCUIM REMAINS OF MARINE ANIMALS
SHELL LIMESTONE SHELLS CEMENTED BY LIME OR CLAY MATRIX BITUMINOUS
COAL COMPACTION OF PLANT MATERIAL COQUINA SHELL LIMESTONE
BITUMINOUS COAL SEDIMENTARY ROCK FEATURES:
STRATIFICATION THE DEPOSITION OF SEDIMENTS INTO IN BEDS GIVES A
LAYERED APPEARANCE BEDDING PLANE THE LINE THAT SEPARATES ROCK
LAYERS
BEDDING PLANE THE LINE THAT SEPARATES ROCK LAYERS.ORIGINALLY
DEPOSITED IN NEARLY HORIZONTAL POSITION. CROSS BEDDING BEDS ARE
DEPOSITED IN INCLINED LAYERS
CROSS BEDDING BEDS ARE DEPOSITED IN INCLINED LAYERS.COMMON IN WIND
OR DELTAIC DEPOSITS. FOSSILS THE REMAINS OR IMPRESSIONS OF PLANTS
OR ANIMALS IN ROCK RIPPLE MARKS FEATURES FORMED BY THE ACTION OF
WIND OR WATER CURRENTS.
MUD CRACKS DEVELOP WHEN DEPOSITS WITH HIGH % OF CLAY DRY AND
CONTRACT. CONCRETION ROUND OR EGG SHAPED BODIES FOUND IN LIMESTONE
OR SHALEBEDS.