Presentation on theme: "Sedimentary rocks. A. Formation: COMPACTION & CEMENTATION 1. Sedimentary rocks form from the COMPACTION & CEMENTATION of rock fragments/sediments 2. Lithification:"— Presentation transcript:
Most sediment is carried by Running Water ROUNDER & SMOOTHER 2. The further water carries sediment, the ROUNDER & SMOOTHER the sediment becomes LARGEST SMALLEST (HORIZONTAL SORTING) 3. When a stream slows down, it drops the LARGEST particles first, & the SMALLEST last (HORIZONTAL SORTING)
Breccia Breccia – very large sediments that are angular, most likely deposited by gravity Conglomerate Conglomerate – large sediments that are rounded (have been transported by a stream!)
C. CRYSTALLINE seawater evaporates, 1. Formed when dissolved minerals in seawater are deposited (seawater evaporates, leaving the minerals behind to crystalize) 2. Also known as CHEMICAL
Salt “Mines” Salt “Mines” - Rock Salt is being formed as the salt water evaporates from the sea.
“Devil’s Golf Course” “Devil’s Golf Course” – millions of years ago this was a sea of salt water. It has been evaporating over time… …and has formed “pockets” of chemical limestone, rock salt, and rock gypsum!
D. BIOCLASTIC 1. Formed from the remains of plants & animals that are compacted –Fossil Limestone –Fossil Limestone – formed when shell remains of marine organisms are cemented in fragments Shells are made of CALCITE which reacts with acid
a. Long ago, huge trees grew in the warm, humid swamps. b. Trees died and decomposed into what is called PEAT c. Peat was buried under layers of mud. d. Pressure increased, slowly changing the plant remains into coal. Coal – note distinct layering of peat
Mud Cracks and Ripples Ripple Marks: A sand pattern formed by the action of winds, streams, waves or currents; preserved when sand becomes sandstone Mud Cracks: Develop when deposits of wet clay dry and contract. The cracks are filled with sediments and fossilize when the clay becomes shale
Ripple Marks in the Shale from running water as the rock was forming