Morphology and Sedimentology of an Emergent Fjord-Head Gilbert-Type Delta: Alta Delta, Norway
- Albina Colella2 and
- David B. Prior3
Published Online: 2 APR 2009
Copyright © 1990 The International Association of Sedimentologists
How to Cite
Corner, G. D., Nordahl, E., Munch-Ellingsen, K. and Robertsen, K. R. (1990) Morphology and Sedimentology of an Emergent Fjord-Head Gilbert-Type Delta: Alta Delta, Norway, in Coarse-Grained Deltas (eds A. Colella and D. B. Prior), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303858.ch8
Universita della Calabria, Italy
Atlantic Geoscience Center, Nova Scotia, Canada
- Published Online: 2 APR 2009
- Published Print: 19 OCT 1990
Print ISBN: 9780632028948
Online ISBN: 9781444303858
- morphology and sedimentology;
- modern alluvial deltas;
- Alta delta;
- wave and tide dominated;
- sand-gravel facies;
- pro delta;
- channel (subtidal)
The Alta delta, in Finnmark, northern Norway (70° N, 23.5°E), is a Holocene, partially emergent, fan-shaped, sandy to sandy–gravelly Gilbert-type delta, set in a subarctic, fjord-head environment.
A study of the modern delta surface, subrecent subsurface and sections in older, raised terraces, shows that the delta comprises three major components: (1) a relatively thin (1–3 m), sandy–gravelly topset unit with erosional base, formed on an emerging, partly fluvial-, partly wave- and tide-dominated, intertidal delta plain; (2) a thick, sandy foreset unit comprising steeply dipping beds, deposited on a steep (5–35°), gravity-process-dominated delta slope; and (3) a muddy bottomset unit containing intermittent, turbidite sand beds, formed on a gently sloping (< 3–4°) prodelta area.
Radiocarbon dates and a regional sea-level curve have been used to reconstruct palaeodepths, sedimentation rates and average rate of delta progradation (c. 0.4 m yr−1 over the last 6000 years).