1. (2) 2. (1) 3. (3) 4. (3) 5. (1) 6. (3) 7. (3) 8. (4) 9. (1) 10. (1) 11. (4)
Sedimentary Rocks Answers Explained
1. (2) Looking at the Scheme for Sedimentary Rock Identification on Page 7 of the ESRT
under grain size, particles less than 0.006 would be both silt and clay, which turn into the
sedimentary rocks siltstone and shale.
2. (1) Fragments held together by natural cement only occurs with sedimentary rocks.
Looking at the Scheme for Sedimentary Rock Identification on Page 7 of the ESRT under
the comments section, breccia is composed of angular fragments.
3. (3) Sediments that are 1.5 cm in size are pebble sized which when compacted and
compressed turn into the sedimentary rock conglomerate.
4. (3) Sediments that are 0.05 cm in size are sand sized which when compacted and
compressed turn into the sedimentary rock sandstone.
5. (1) Some of the major characteristics of sedimentary rocks include layering of
sediments, fossils, mud-cracks, and ripple marks.
6. (3) Looking at the Scheme for Sedimentary Rock Identification on Page 7 of the ESRT
under the comments sections “Cemented shell fragments . . . ” is found in the rock
limestone.
7. (3) Clastic sedimentary rocks (conglomerate, sandstone, siltstone and shale) are
classified based on their grain size or particle size.
8. (4) One way in which sedimentary rocks form are from the cementation of sediments.
This can be seen on the Rock Cycle chart on page 6 of the ESRT.
9. (1) Rock Gypsum is formed when sea water rich in the mineral gypsum evaporates
and the mineral comes out of the sea water solution (precipitates). Chemically formed
sedimentary rocks from “crystals from chemical precipitates and evaporates”.
10. (1) The smallest sediment size is clay (less than 0.0004 cm) the map symbol for
shale (forms from clay) is shown on page 7 of the ESRT.
11. (4) Rock salt is formed from the evaporation of salt-water seas. When the water
evaporates it leaves behind the salt.