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.
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)