TY - JOUR
T1 - The interpretative value of transformed tephra sequences
AU - Dugmore, Andrew J.
AU - Thompson, Polly I. J.
AU - Streeter, Richard T.
AU - Cutler, Nick A.
AU - Newton, Anthony J.
AU - Kirkbride, Martin P.
N1 - Funding Information
Carnegie Trust for the Universities of Scotland. Grant Number: Richard Streeter
Natural Environment Research Council. Grant Number: NE/L002558/1
Division of Polar Programs. Grant Numbers: 1202692, 1249313
PY - 2020/1/29
Y1 - 2020/1/29
N2 - We explore developments in tephra science that consider more than chronology, using case studies of morphological transformations of tephra deposits. Volcanic processes and prevailing weather conditions determine the distribution of tephra deposits immediately after an eruption, but as these freshly fallen tephra become part of the stratigraphic record, the thickness, morphology and definition of the layers they form changes, reflecting the interplay of the tephra, climate, Earth surface processes, topography and vegetation structure, plus direct or indirect modification caused by people and animals. Once part of the stratigraphic record, there can be further diagnostic changes to the morphology of tephra layers, such as the creation of over folds by cryoturbation. Thus, tephra layers may contain proxy evidence of both past surface environments and subsurface processes. Transformations of tephra deposits can complicate the reconstruction of past volcanic processes and make the application of classical tephrochronology as pioneered by Thorarinsson (Sigurður Þórarinsson in Icelandic) challenging. However, as Thorarinsson also noted, novel sources of environmental data can exist within transformed tephra sequences that include the spread or removal of tephra, variations in layer thickness and internal structures, the nature of contact surfaces and the orientation of layers.
AB - We explore developments in tephra science that consider more than chronology, using case studies of morphological transformations of tephra deposits. Volcanic processes and prevailing weather conditions determine the distribution of tephra deposits immediately after an eruption, but as these freshly fallen tephra become part of the stratigraphic record, the thickness, morphology and definition of the layers they form changes, reflecting the interplay of the tephra, climate, Earth surface processes, topography and vegetation structure, plus direct or indirect modification caused by people and animals. Once part of the stratigraphic record, there can be further diagnostic changes to the morphology of tephra layers, such as the creation of over folds by cryoturbation. Thus, tephra layers may contain proxy evidence of both past surface environments and subsurface processes. Transformations of tephra deposits can complicate the reconstruction of past volcanic processes and make the application of classical tephrochronology as pioneered by Thorarinsson (Sigurður Þórarinsson in Icelandic) challenging. However, as Thorarinsson also noted, novel sources of environmental data can exist within transformed tephra sequences that include the spread or removal of tephra, variations in layer thickness and internal structures, the nature of contact surfaces and the orientation of layers.
KW - bioturbation
KW - cryoturbation
KW - isochron
KW - solifluction
KW - tephrochronology
UR - http://www.scopus.com/inward/record.url?scp=85076747902&partnerID=8YFLogxK
U2 - 10.1002/jqs.3174
DO - 10.1002/jqs.3174
M3 - Article
AN - SCOPUS:85076747902
VL - 35
SP - 23
EP - 38
JO - Journal of Quaternary Science
JF - Journal of Quaternary Science
SN - 0267-8179
IS - 1-2
ER -