Applied Geology and Field/Lab Skills
What the exam tests
Applied Geology and Field/Lab Skills tests the practical toolkit: field mapping, measuring structural attitude, sampling, hand-specimen identification, sieve analysis and data presentation.
Core rules
- A Brunton compass measures strike and dip; a clinometer measures vertical angles. Record strike, dip amount and dip direction, plus location and rock type.
- Field kit: hand lens, hardness kit, dilute HCl, hammer, GPS, notebook, camera and sample bags. Label samples with number, coordinates, rock type and date.
- Laboratory: thin sections under a polarising microscope for mineral identification; sieve analysis for grain-size distribution; heavy-liquid separation for placer minerals; rose diagrams for fracture and lineament trends.
- Maps: use the scale bar and grid references, plot traverses and sample points, and read the legend before interpreting.
Worked example
Sieve results for a sandstone: 10% coarser than 1 mm, 30% between 0.5 and 1 mm, 45% between 0.25 and 0.5 mm, 15% finer than 0.25 mm. The modal class is 0.25–0.5 mm, so the rock is medium-grained sandstone by the Wentworth scale. Cumulative curves are plotted against a logarithmic size axis, and the median is read where 50% passes.
Traps
Recording dip without dip direction. Using a compass beside a hammer or magnet. Giving a grain-size class without the Wentworth boundaries. Forgetting to orient and label samples in the notebook.