Chapter 6: Sedimentary Rocks

SEDIMENT - pieces of solid material that are deposited by wind, water, ice, gravity, and chemical precipitation

WEATHERING – a physical and chemical process that breaks things down, like rock. What are some examples of weathering you can think of?

How do you think these rocks wound up the way they did?

THERE ARE 2 TYPES OF WEATHERING CHEMICAL WEATHERING – when the chemical composition of the rock breaks down, allowing for the mineral to break and fall apart easier PHYSICAL WEATHERING – when water, wind, ice, gravity, and other non-chemical factors wear away at something Which do you think is an example of chemical weathering, and which is an example of physical weathering? Why do you think that?

CATEGORIZING SEDIMENT Pieces produced from weathering are called “clastic fragments” and are categorized by size. The chart is broken into 3 main categories, and each category is broken into several subcategories.

DEPOSITION As movement slows down, sediment begins to settle. It usually settles by size, larger ones dropping to the bottom first, then the finer ones settling on top of it. What are some examples of this happening? What are some situations where this might not be the case?

LITHIFICATION The two stages are COMPACTION and CEMENTATION. LITHIFICATION is the process by which factors like temperature and pressure come together to solidify sediment into sedimentary rock. The two stages are COMPACTION and CEMENTATION.

LITHIFICATION LITHIFICATION is the process by which factors like temperature and pressure come together to solidify sediment into sedimentary rock. COMPACTION happens first. All the weight from the layers of sediment pushes almost all of the water out of the sediment. The small gaps between the grains allow for some water, gas, and oil to remain behind.

LITHIFICATION LITHIFICATION is the process by which factors like temperature and pressure come together to solidify sediment into sedimentary rock. CEMENTATION is the process by which the grains are “glued” together. There are two types of cementation.

LITHIFICATION LITHIFICATION is the process by which factors like temperature and pressure come together to solidify sediment into sedimentary rock. The first type happens when a new mineral grows between the grains and “glues” them together. The second type happens when the same mineral grows between and over the same type of grains. This is called OVERGROWTH.