Why learn about Sedimentary Rocks. Source of building materials Source of fossil fuels (oil,coal,etc) Fresh water source Evidence of past surface conditions Fossils. Sedimentary Rock: Clastic - particles deposited, cemented – like sandstone, shale
Clastic - particles deposited, cemented – like sandstone, shale
Chemical - precipitation out of solution – like salt, gypsum, some limestone
Organic - accumulation of parts of plants and animals - swamps (coal), shells (limestone)
Kaibab Limestone - 250 million years old, forms the surface of the Colorado Plateaus.
Toroweap Formation - 255 million years old, mostly limestone.
Coconino Sandstone - 260 million years old, pure quartz sand, petrified sand dunes.
Hermit Shale - 265 million years old, soft, easily eroded shales
Supai Formation - 285 million years old, shale intermixed w/ limestone and sandstone. Fossilized muddy river delta that fed into an ancient sea.
Redwall Limestone - 335 million years old ocean limestones.
Temple Butte Limestone - 350 million years old, freshwater limestone.
Muav Limestone - 515 million years old, limestone that is separated by beds of sandstone and shale.
Bright Angel Shale - 530 million years old, mudstone shale with thin layers of sandstone and sandy limestone.
Tapeats Sandstone - 545 million years old; Ripple marks suggest formation in shallow seas.
Great Unconformity – almost 300 m.y. gap!
Chuar Group - 825 to 1,000 million years old, mixture of sandstone, limestone and shale.
Nankoweap Formation - 1,050 million years old, coarse-grained sandstone.
Unkar Group - 1,100 to 1,250 million years old, contains lava flows & sedimentary rx
Unconformity – Gap from 1.25 to 1.7 b.y.
Vishnu Schist and Zoroaster Granite - 1,700 to 2,000 million years old. The Vishnu schist – used to be sandstone, limestone, and shale
This Vishnu Schist and Zoroaster Granite roots of an ancient mountain range, taller than Rockies.
Playa (“dry” basin salt flat)
Bonneville Salt Flats:
Q. Why is St. Louis covered with limestone and other ocean-formed sedimentary rocks?
A. Many reasons (need to talk about climate, plate tectonics, continental development)