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 Chemical - precipitation out of solution – like salt, gypsum, some limestone Organic - accumulation of parts of plants and animals - swamps (coal), shells (limestone)

Sandstone

Conglomerate

Breccia

Coquina (kō-KĒ-na)

Chemical Sediments

Sedimentary Structures

Graded bedding

Kaibab Limestone million years old, forms the surface of the Colorado Plateaus. Toroweap Formation million years old, mostly limestone. Coconino Sandstone million years old, pure quartz sand, petrified sand dunes. Hermit Shale million years old, soft, easily eroded shales Supai Formation million years old, shale intermixed w/ limestone and sandstone. Fossilized muddy river delta that fed into an ancient sea.

Unconformity Redwall Limestone million years old ocean limestones. Temple Butte Limestone million years old, freshwater limestone. Unconformity Muav Limestone million years old, limestone that is separated by beds of sandstone and shale. Bright Angel Shale million years old, mudstone shale with thin layers of sandstone and sandy limestone.

Tapeats Sandstone million years old; Ripple marks suggest formation in shallow seas. Great Unconformity – almost 300 m.y. gap! Chuar Group 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)

Salt mine:

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)