Sedimentary Rocks (F2 Key Idea 1)

Question 1

What are the some types of sediment transport?

Answer 1

• Traction
• Saltation
• Suspension
• Solution

Question 2

What is Hydrolysis?

Answer 2

The breakdown of rock by acidic water to produce clay and soluble salts

Question 3

What is Oxidation?

Answer 3

The breakdown of rock by oxygen and water, often gives iron-rich rocks a rusty-coloured weathered surface

Question 4

What is Carbonation?

Answer 4

The mixing of water with CO2 to make carbonic acid. It’s very important in the formation of caves.
Dissolved CO2 in rain water forms the acid, this acid reacts with minerals in rocks

Question 5

What is Solution?

Answer 5

Removal of rock in solution by acidic rain water. This combination removals minerals from solid bedrock and carries them away in liquid solution

• In particular, limestone is weathered by rain water containing dissolved CO2.

Question 6

What is Spheroidal Weathering?

Answer 6

It is a process of cracking and splitting off of curved layers from a generally spheroidal boulder.

• It occurs when a rectangular block is weathered from 3 sides at the corners and from two sides along its edges

Question 7

What are some factors controlling the rate and type of weathering?

Answer 7

• Acidity of water
• Water levels
• Water pH
• Rainfall amount/intensity
• Temperature
• Oxygen levels
• Lithology (rock type)

Question 8

Products of Weathering?

Answer 8

• Quartz
• Clay minerals
• Sand
• Iron oxides
• Aluminium oxides
• Rock fragments (known as regolith)
• Dissolved ions

Question 9

What is Traction?

Answer 9

The rolling/dragging of large grains along a river bed or shore

Question 10

What is Saltation?

Answer 10

The bouncing of sand grains as they are picked up, carried along and dropped repeatedly by flowing water

Question 11

What is Suspension?

Answer 11

Method of transporting very fine sediment in a river

• Very small sediments carried by river water

Question 12

What is Flocculation?

Answer 12

Most moving bodies of water carry in suspension or a certain amount of clayey material

• Clay sized particles are flat, plate shaped, small, buoyant

Question 13

What is Porosity?

Answer 13

The % of the space within a rock.

• The ability to hold a fluid

Question 14

What is Permeability?

Answer 14

Measurement of how easy it is for a fluid to flow through a rock

Question 15

What are some sedimentary environments?

Answer 15

• fluvial (rivers, deltas, alluvial fans and playa lakes)

• aeolian (wind dominated, e.g. desert dunes)

• shallow marine (lagoon/reef/beach systems)

• deep marine (submarine fan turbidites).

Question 16

What are some sedimentary structures?

Answer 16

bedding,
cross-bedding,
graded bedding,
laminations, desiccation features,
sole structures (load/flame,flute casts)
ripple marks (symmetrical/ asymmetrical)

Question 17

What are some common igneous rocks?

Answer 17

• Silicic (quartz-rich): granite (coarse crystals)
• Mafic (iron/magnesium-rich): gabbro (coarse crystals), dolerite (medium crystals) and basalt (fine crystals/glassy)
• Ultramafic (olivine, pyroxene-rich): peridotite
(coarse crystals)