Evaporites/Siliceous

Question 1

Non-clastic sedimentary rocks formed through precipitating from solutions as ions within those become more concentrated as water evaporates.

Answer 1

Evaporites

Question 2

Most commonly encountered - evaporite minerals in sedimentary rocks that are composed of calcium sulphate. Precipitates once water has been evaporated to 19% of its original volume.

Answer 2

Gypsum and Anhydrite

Question 3

Precipitates as thick crystalline beds once water has been evaporated to 9.5% of its original volume.

Answer 3

Halite

Question 4

Sequence of evaporite deposition

Answer 4

1. Calcite
2. Gypsum
3. Anhydrite
4. Halite
5. Sylvite
6. Carnallite

Question 5

Non-clastic sedimentary rocks dominantly composed of silica. Forms through accumulation of siliceous skeletons of diatoms (phytoplankton) and radiolaria (zooplankton) as siliceous ooze.

Answer 5

Siliceous

Question 6

A non-clastic sedimentary rock made up of microcrystalline quartz.

Answer 6

Chert

Question 7

Enumerate different variants of chert

Answer 7

Flint, Jasper, Prase, Chalcedony

Question 8

Black Chert

Answer 8

Flint

Question 9

Red Chert

Answer 9

Jasper

Question 10

Green Chert

Answer 10

Prase

Question 11

Concentric Chert

Answer 11

Chalcedony

Question 12

Non-clastic sedimentary rocks dominantly composed of phosphate deposits that may form organically.

Answer 12

Phosphates

Question 13

Rocks with high concentrations of phosphates.

Answer 13

Phosphorites

Question 14

A calcium phosphate mineral.

Answer 14

Francolite

Question 15

Fossilized feces of animals that is high in phosphates.

Answer 15

Coprolite