sedimentary rock classification
types of sedimentary rocks
Rock Conglomerate Breccia Sandstone Siltstone Shale Sediment Size Large Large Sand-sized Silt-sized, smaller than sand Clay-sized, smallest Other Features Rounded Angular When sediments settle out of calmer water, they form horizontal layers. One layer is deposited first, and another layer is deposited on top of it. So each layer is younger than the layer beneath it. When the sediments harden, the layers are preserved. Sedimentary rocks formed by the crystallization of chemical precipitates are called chemical sedimentary rocks. As discussed in the concepts on minerals, dissolved ions in fluids precipitate out of the fluid and settle out, just like the halite in Figure 1.1. The evaporite, halite, on a cobble from the Dead Sea, Israel. Biochemical sedimentary rocks form in the ocean or a salt lake. Living creatures remove ions, such as calcium, magnesium, and potassium, from the water to make shells or soft tissue. When the organism dies, it sinks to the ocean floor to become a biochemical sediment, which may then become compacted and cemented into solid rock (Figure 1.2). Table 1.2 shows some common types of sedimentary rocks. Breccia Clastic Sandstone Clastic Siltstone Clastic Shale Clastic Rock Salt Chemical precipitate Dolostone Chemical precipitate Limestone Bioclastic (sediments from organic materials, or plant or animal re- mains) Coal Organic Click image to the left or use the URL below. URL:
No diagram descriptions associated with this lesson
conglomerate rocks are made from
a) jagged, angular rocks --> b) round rocks c) sand d) clay
shale is made from
a) jagged, angular rocks b) round rocks c) sand --> d) clay
biochemical sedimentary rocks from in oceans or salt lakes.
--> a) true b) false
which of these rocks are not clastic?
a) conglomerate b) sandstone --> c) coal d) shale
sedimentary rocks in order of particle size from small to large is
a) conglomerate or breccia-sandstone-siltstone-shale. --> b) shale-siltstone-sandstone-conglomerate or breccia. c) sandstone-shale-breccia-siltstone-conglomerate. d) sandstone-siltstone-shale-conglomerate-breccia.
rock salt is a clastic rock.
a) true --> b) false
sediments are deposited
--> a) horizontally b) vertically c) as a coating on the land surface d) all of these
sedimentary rocks are made by
a) rock fragments b) precipitate from fluids c) precipitation from living organisms --> d) all of the above
which of these rocks forms from chemicals that precipitate from evaporating water?
a) rock salt b) coal --> c) gypsum d) conglomerate
sedimentary rocks are classified by
a) how they form. b) sediment size. c) whether they are made from living things. --> d) all of the above.
No diagram questions associated with this lesson