Holocene coastal change at Luce Bay, South West Scotland

David E Smith,Mathew Blackett,Richard M Tipping,Jason T Jordan

doi:10.1002/jqs.3227

David E Smith, Mathew Blackett + Show 2 more

Open Access

https://doi.org/10.1002/jqs.3227

Copy DOI

Abstract

ABSTRACTCoastal change during the Mid‐ to Late Holocene at Luce Bay, South West Scotland, is examined using morphological, stratigraphic and biostratigraphical techniques supported by radiocarbon dating. Deglaciation left extensive sediments, providing a source for depositional coastal landforms. Glacio‐isostatic uplift resulted in the registration of evidence for former relative sea levels (RSLs), which support the pattern of Holocene RSL change for the northern Irish Sea as determined by shoreline‐based Gaussian trend surface models. The rate of RSL rise was rapid from before ca. 8600 to ca. 7800 cal a bp, but then slowed, changing by <3 m over the next 3000 years, a pattern reflected in the convergence of shorelines predicted in the models. By ca. 4400 cal a bp RSL was falling towards present levels. As these changes were taking place, coastal barriers developed and dunes formed across them. In the West of the Bay, a lagoon forming to landward of the barriers and dunes acted as a sediment sink for dune sand. Changes in the coastal landscape influenced the occupation of the area by early human societies. This study illustrates the value of combining an understanding of process geomorphology, RSL and archaeology in studies of coastal change.

Highlights

Luce Bay is a 20‐km‐wide macro‐tidal marine embayment on the northern coast of the outer Solway Firth in SW Scotland (Fig. 1) with clear but complex inter‐relations between Holocene sediment bodies of contrasting depositional environments (Single and Hansom, 1994)
During the Last Glacial Maximum (LGM), the area was occupied by an ice sheet flowing broadly southward or south‐ south‐westward into the Irish Sea basin (e.g. McMillan et al, 2011)
Evidence from sites studied for relative sea levels (RSLs) in this paper show that the rise in RSL in the Early Holocene at Luce Bay reached its maximum at ca. 6300 cal a BP

Summary

Introduction

Luce Bay is a 20‐km‐wide macro‐tidal marine embayment on the northern coast of the outer Solway Firth in SW Scotland (Fig. 1) with clear but complex inter‐relations between Holocene sediment bodies of contrasting depositional environments (Single and Hansom, 1994). The objectives of the work were to (i) identify the nature, causes and rates of change of Holocene coastal processes using field and laboratory analyses, (ii) compare relative sea levels (RSLs) at Luce Bay with evidence from neighbouring areas and (iii) examine the intricate effect of coastal changes at Luce Bay on the early human occupation of the area

Objectives

Methods

Results

Conclusion