Weathering and Sediment Transport

Complete the table of definitions.

[blank_start]Burrowing[blank_end] = The action of holes being dug by invertebrate and [blank_start]vertebrate[blank_end] animals that mixes and [blank_start]brings[blank_end] to the surface rock and [blank_start]soil[blank_end] particles. This [blank_start]facilitates[blank_end] weathering at greater depth by providing access for [blank_start]atmospheric[blank_end] gases and [blank_start]water[blank_end].

[blank_start]Root action[blank_end] = The [blank_start]mechanical[blank_end] and chemical weathering of rocks by the wedging action of [blank_start]roots[blank_end].

Complete the table on climate and weathering below.

Complete the table on weathering and climate below.

Frost shattering: Water enters [blank_start]cracks[blank_end], joints and bedding planes. In climates where daily [blank_start]temperature[blank_end] fluctuate above and below [blank_start]0oC[blank_end], water freezes and expands by [blank_start]9%[blank_end]. This exerts [blank_start]pressure[blank_end] on rocks, producing a residue of angular fragments called [blank_start]scree[blank_end].

[blank_start]Exfoliation[blank_end]: - Aka. onion-skin weathering. - Different [blank_start]minerals[blank_end] expand and contract by different [blank_start]amounts[blank_end] during heating and cooling, causing the rock to [blank_start]disintegrate[blank_end]. - [blank_start]Curved[blank_end] sheets [blank_start]peel[blank_end] off from the rock.

Pressure Release: Atmospheric [blank_start]pressure[blank_end] at the Earth's surface is much lower than pressures within the Earth. Pressure is released from rock due to [blank_start]erosion[blank_end] of the rocks above them. Rocks expand, producing [blank_start]fractures[blank_end] which are more widely [blank_start]spaced[blank_end] the [blank_start]further[blank_end] they are from the surface. Rocks that are well [blank_start]jointed[blank_end] or have many bedding planes are [blank_start]less[blank_end] affected.

Carbonation: [blank_start]Carbon dioxide[blank_end] gas in the atmosphere reacts with rainwater and [blank_start]pore[blank_end] water in the soil to form [blank_start]carbonic[blank_end] acid. The air in pore spaces is rich in carbon dioxide due to decomposing [blank_start]plant[blank_end] litter. This makes groundwater more acidic than rainwater which then reacts with [blank_start]carbonate[blank_end] minerals in the rock.

Carbonation Equation: [blank_start]CaCO3[blank_end] + H2CO3 --> [blank_start]Ca2+[blank_end] + 2HCO3- Calcite + [blank_start]Carbonic acid[blank_end] --> Calcium + [blank_start]Hydrogen carbonate[blank_end] ions in solution.

Carbonation is important in the weathering of [blank_start]limestone[blank_end]. [blank_start]Limestone[blank_end] generally contains insoluble [blank_start]impurities[blank_end] which are left behind as clay [blank_start]residues[blank_end].

Name the three methods of sediment transport in water: S[blank_start]uspension[blank_end] S[blank_start]altation[blank_end] T[blank_start]raction[blank_end]

How does ice transport sediment?

Select the 2 correct facts about traction.

Which medium of transport moves loose weathered material down slopes?

Which medium of transport can carry large amounts of rock debris?

Which medium of transport lifts and transports finer grained sediment?

[blank_start]Attrition[blank_end] = the wearing down of sedimentary grains due to [blank_start]collisions[blank_end] with other grains during transport. [blank_start]Abrasion[blank_end] = the wearing away of the Earth's surface by the action of the wind, water or ice [blank_start]dragging[blank_end] sediment over it or hurling it at the surface.

Erosion = the wearing away of the land surface and the removal of sediment by means of transport.

Saltation = the transport of the smaller grains in the [blank_start]bed load[blank_end] by [blank_start]bouncing[blank_end] the along the [blank_start]bed[blank_end]. Suspension = the transport of material in the [blank_start]suspended[blank_end] load of a water based transport medium, [blank_start]without[blank_end] it touching the Earth's surface.

Solution = the transport of [blank_start]ions[blank_end] dissolved in [blank_start]water[blank_end]. - Particularly K, [blank_start]Ca[blank_end], Na - this method of transportation is [blank_start]invisible[blank_end] so can not be shown on a diagram

Clay particles require high velocities for erosion because they are [blank_start]flat[blank_end], [blank_start]platy[blank_end] and [blank_start]cohesive[blank_end] so tend to stick together. Clay particles remain in [blank_start]suspension[blank_end] even at low current velocities because they are [blank_start]small[blank_end], have a [blank_start]low[blank_end] mass and are [blank_start]buoyant[blank_end].

Grains get rounder the longer they have been transported.