GL 107 Earth Systems Science

K. Hannula

Discussion questions for 9/19/07

1.  What the the important characteristics of each of the following types of sedimentary rock?

• conglomerate:  detrital sedimentary rock made of gravel (rock fragments larger than 2 mm)

• sandstone: detrital sedimentary rock made of sand (rock fragments between 1/16 and 2 mm)

• shale: detrital sedimentary rock made of mud, breaks into thin sheets

• limestone: sedimentary rock made of calcite

• rock salt: sedimentary rock made of halite

• gypsum:  sedimentary rock made of gypsum

• coal: sedimentary rock made of altered plant fragments

2.  How does sediment become sedimentary rock?

Sediment (loose particles of rock) becomes sedimentary rock by compaction (particles being pressed together) and cementation (chemical precipitation of minerals such as quartz or calcite from water; the new minerals form a sort of glue that holds the particles together)