WJEC Geology GL1 Foundation — Unit Papers & Mark Schemes

Mineral identification in GL1 tests systematic observation. For each mineral, record hardness (Mohs scale), lustre (metallic, vitreous, pearly, earthy), colour, streak, cleavage or fracture, and crystal system. Practise with a reference collection until you can distinguish quartz from feldspar, calcite from dolomite, and olivine from pyroxene without hesitation. Rock classification requires linking texture to origin. For igneous rocks, grain size indicates cooling rate: coarse (plutonic), fine (volcanic), glassy (rapid quenching). For sedimentary rocks, classify by origin: clastic (grain size from clay to boulders), chemical (evaporites, limestones), or organic (coal, chalk). Metamorphic rocks should be classified by texture (foliated versus non-foliated) and parent rock. Geological map reading at GL1 level focuses on recognising horizontal, dipping, and vertical strata from outcrop patterns. Practise drawing cross-sections from maps with V-shaped outcrops in valleys, and explain how the direction of the V reveals dip direction.