P lio‐ P leistocene landscape and vegetation reconstruction of the coastal area of the T jörnes P eninsula, N orthern I celand

Marine and continental deposits from the T jörnes area in northern I celand were studied to obtain their pollen/spore content. Six P ollen Z ones ( PZ ) were defined in the E arly P liocene T jörnes beds and the E arly P leistocene B reidavík G roup. The pollen is most diverse during the deposition of the lowest T apes Z one ( PZ 1) and the lower part of the overlying M actra Z one ( PZ 2). Local pollen from marshland, levee and foothill forests was deposited on a large coastal plain. The pollen spectrum reflects transgression and deepening during the second part of the M actra Z one ( PZ 3) and the lower part of the S erripes Z one ( PZ 4). Gymnosperm pollen derived from the higher inland plateau increases in PZ 3. This background pollen was of minor importance during periods with an extensive coastal plain ( PZ 1, 2, 4, 6). PZ 5 did not yield sufficient pollen for analysis. The pollen analysis allowed refinement of the sea‐level variations based on sedimentology and molluscs. Pollen of warmth‐demanding plants is recorded throughout the T jörnes beds and the E arly P leistocene interglacial deposits. Warmth‐loving species indicate summers 8° C warmer than today during deposition of the T apes Z one, and at least 5° C warmer during the rest of the T jörnes beds. The Pliocene vegetation of I celand matches well that of the present‐day western E uropean maritime temperate climate. The drastic cooling at the onset of the Q uaternary led to a marked vegetation impoverishment, already noticeable in the E arly P leistocene B reidavík G roup.