Edinburgh Research Archive logo

Edinburgh Research Archive

University of Edinburgh homecrest
View Item 
  •   ERA Home
  • Geosciences, School of
  • GeoSciences PhD thesis and dissertation collection
  • View Item
  •   ERA Home
  • Geosciences, School of
  • GeoSciences PhD thesis and dissertation collection
  • View Item
  • Login
JavaScript is disabled for your browser. Some features of this site may not work without it.

Pollen analysis and radiocarbon dating of lateglacial and early Flandrian deposits in southern Perthshire

View/Open
LoweJJ_1977redux.pdf (93.15Mb)
Date
1977
Author
Lowe, Joseph John
Metadata
Show full item record
Abstract
 
 
This thesis describes the results of pollen analysis and radiocarbon dating of mainly basal sediments from enclosed presently peat-filled hollows in southern Perthshire, and the environmental implications of the results are discussed with special emphasis on the glacial sequence and the development of vegetation and soils during the Lateglacial and early Flandrian in southern Perthshire. The pollen diagrams presented are all based on relative pollen percentages, and in interpreting such diagrams two approaches are considered to be fundamental. Firstly, a number of major problems that affect the interpretation of pollen assemblages in general but Lateglacial assemblages in particular are discussed in detail prior to the correlation and interpretation of the local pollen zones. Secondly, since for a variety of reasons the regional importance of particular taxa may be strongly misrepresented in any individual pollen diagram, interpretations of the local pollen zones are to a large extent influenced by the results of similar investigations for other parts of the country. Thus reviews of and comparisons with data from other parts of Scotland (and selectively from the British Isles as a whole) form an important part of this thesis. In addition, useful indications of palaeoenvironmental changes have resulted from the analysis of deteriorated pollen grains. This aspect of pollen analysis is usually ignored in routine pollen counting. The causes of the different kinds of deterioration as well as interpretations of their varying frequency are discussed in some detail.
 
Evidence from the Lateglacial deposits in southern Perthshire suggests that plant colonisation commenced shortly after 13,000 B.P. and that deglaciation was widespread by that time. Plant successions followed an uninterrupted sequence between about 13,000 and 11,000 B.P. (the Lateglacial Interstadial) from the predominantly open-habitat taxa of the colonisation period, to the closed grasslands with juniper, willow and copses of tree birch that characterised the lower-lying areas towards the end of the Interstadial. Moss heaths and poor grassland communities characterised the higher slopes. After 11,000 B.P. climatic conditions became much harsher, resulting in the Loch Lomond Readvance of glaciers, the break-up of existing soils, and revertence to openhabitat plant communities throughout southern Perthshire during the Loch Lomond Stadial (11 ,000 - 10,000 B.P.). A number of valley glaciers existed in southern Perthshire at this time, with the lowest and most southerly glacier terminus in this region near Callander. Rapid climatic amelioration shortly before 10,000 B.P. resulted in the cessation of solifluction processes, and a plant succession was then initiated that led to the immigration of birch woodland into parts of this area by about 9,500 B.P.
 
During the Flandrian a basically similar vegetational history is recorded at each site, with the following main phases: the expansion of juniper, the immigration and expansion of birch woodland, the development of a dominant birch-hazel woodland, and the decline of hazel following the immigration of elm and oak. At three sites the main Alnus rise is recognised, and the Elm Decline is positively identified at only one site. The climax forest of lowland Perthshire was a mixed oak-elmbirch association probably associated with brown forest soils. On upland sites woodlands were much lighter with birch the most important tree, the climax forest varying between birch-alder-hazel and birchalder- pine, with oak invading some of the higher valleys. At about 6,500 B.P. marked changes in mire stratigraphy, pollen assemblages and amounts and type of deteriorated pollen are recorded, probably related to a major transition from a relatively dry climate to a climate with markedly oceanic characteristics.
 
The Lateglacial and early Flandrian radiocarbon dates from sites in southern Perthshire are compared with other available dates from Scotland and the chronology and terminology of the Lateglacial are discussed. It is concluded that chronostratigraphic boundaries are at present poorly defined and that boundaries proposed in recent schemes may bear little relationship to times of major climatic change in Scotland. The thesis concludes by stressing the need for more detailed analyses for sites in southern Perthshire, employing absolute pollen counts, the analysis of deteriorated pollen and spores, and analysis of coleopteran remains in Lateglacial and early Flandrian sediments.
 
URI
http://hdl.handle.net/1842/34971
Collections
  • GeoSciences PhD thesis and dissertation collection

Library & University Collections HomeUniversity of Edinburgh Information Services Home
Privacy & Cookies | Takedown Policy | Accessibility | Contact
Privacy & Cookies
Takedown Policy
Accessibility
Contact
feed RSS Feeds

RSS Feed not available for this page

 

 

All of ERACommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsPublication TypeSponsorSupervisorsThis CollectionBy Issue DateAuthorsTitlesSubjectsPublication TypeSponsorSupervisors
LoginRegister

Library & University Collections HomeUniversity of Edinburgh Information Services Home
Privacy & Cookies | Takedown Policy | Accessibility | Contact
Privacy & Cookies
Takedown Policy
Accessibility
Contact
feed RSS Feeds

RSS Feed not available for this page