WJEC Geology GL5 Natural Resources — Papers & Mark Schemes

Ore deposit classification questions test understanding of the geological processes that concentrate metals. For each deposit type, know the formation mechanism: magmatic segregation (chromite in layered intrusions), hydrothermal veins (gold, tin, copper from hot fluids), porphyry deposits (disseminated copper-molybdenum associated with subduction-related intrusions), and sedimentary deposits (banded iron formations, placer gold). Link each to its tectonic setting. Petroleum geology questions focus on the petroleum system concept. Know the five essential elements: source rock (organic-rich shale or limestone), maturation (burial to the oil or gas window), migration (primary and secondary), reservoir rock (porous and permeable sandstone or limestone), and trap-and-seal (structural or stratigraphic traps capped by impermeable rock). Practise drawing annotated cross-sections of anticlinal traps, fault traps, and stratigraphic traps. Water resource questions overlap with hydrogeology from GL3 but emphasise resource management. Understand the concept of sustainable yield, the risks of over-abstraction (land subsidence, saltwater intrusion), and the geological factors controlling aquifer recharge rates.