R3102 Feb ‘17
Q1. a) Name ONE sedimentary rock found in the UK 1 mark
b) Describe TWO processes involving water which weather parent rock 6 marks
c) Brown earth is one soil type found in the UK. Name THREE other soil types found in the UK. 3 marks
This question relates to the following part of the syllabus:
1.1 Explain the process of soil formation and development.
Explain the natural processes of soil formation:
types of parent rock (igneous, sedimentary & metamorphic);
weathering processes of parent rock (physical, chemical and biological), addition of organic matter;
formation of soil types: alluvial, loess, sedentary;
to include the influence of the underlying rock types (limestone/chalk, sandstone, granite); development and characteristics of main horizons: organic layer, A, E, B, C horizons, parent rock.
the following UK soil types and their effects on plant growth: iron pan podzol,
brown earth, rendzina and gleys.
Two parts of this question require very short answers. For part a) just the name of one suitable rock should be written, such as sandstone or limestone.
For part c), three names are required. The number of names is in bold and capitals to make it clear. Suitable examples are listed on the syllabus – rendzina, podzol and gley.
Part b) requires longer answers as you are asked to ‘describe’. It is a good idea to structure an answer for this type of question with clear headings for each of the two types of weathering. It is also important to read the question properly to make sure you pick processes that involve water.
The examiner’s comments suggest the following as good answers:
Examples included rivers as the weathering agent and then described how water abraded the rock as it flowed over it, removal of rock particles, exposure of lower layers and continual abrasion. Another example was the process of water freezing and thawing in rock fissures; expanding on freezing and pushing rock apart, then thawing, and this continuous process eventually breaks rocks apart and exposes lower layers to water infiltration. Other weathering agents included wetting and drying and acid rain.
These examples of processes come under physical and chemical weathering.