WJEC Geology GL5 Quaternary Geology — Resource Materials & Data Booklets

Oxygen isotope curves from ice cores require careful directional reading. In ice core records, more negative δ18O values correspond to colder glacial conditions (because lighter water molecules evaporate and precipitate as snow more readily during cold periods). This is the opposite convention to marine sediment records. Always check which type of record the resource booklet presents before interpreting the data. Pollen diagrams display the percentage abundance of different plant taxa at successive depths in a sediment core. When interpreting these, track the transitions: a shift from grass and sedge dominance (cold, open landscape) to birch and pine (early warming) to oak, elm, and lime (full interglacial warmth) records a classic post-glacial succession. Note any abrupt changes that might indicate rapid climate events. Geomorphological maps in the resource booklets show the distribution of glacial and periglacial features across a landscape. Identify moraine positions to reconstruct ice margins, use drumlin orientations to determine ice flow direction, and trace meltwater channels to understand drainage patterns during deglaciation.