Architectural-landsystem analysis of a modern glacial landscape,Solheimajoekull, southern Iceland

摘要

Glacial terrains are commonly recorded using a landsystem approach, which allows detailed documentation of the geomorphological evolution of the landscape. However, landsystem analysis of Quaternary subsurface stratigraphies in which landforms are not apparent or preserved is problematic, making delineation of the sedimentary architecture of a glaciated basin infill difficult. The purpose of this study is to delineate the sedimentary architecture of the Solheimajokull (southern Iceland) glacial landsystem and to provide an architectural framework for allostratigraphy and modern analogue purposes. An integrated architectural-landsystem approach is applied here, which utilizes the principles from both architectural element analysis and landsystem analysis. A bounding surface hierarchy (fourth- to seventh-order surfaces) provides a framework within which the architecture is organized. Fieldwork was conducted at Solheimajokull glacier in 2012 and 2013; and 22 different surface features (bounded by the fourth-order surfaces) were mapped, which were grouped into four different landsystem tracts (glaciofluvial, ice-contact, joekulhlaup, and colluvial slope; bounded by the sixth-order surfaces). Landsystem tracts were deconstructed into smaller architectural units (components; bounded by the fifth-order surfaces), which allowed the delineation of eight allostratigraphic units that record the evolution of the glacial landsystem from～7000 YBP to A.D. 2013. The results of this study can provide insight to interpretation and delineation of the sedimentary architecture of other modern glacial landsystems and subsurface Quaternary deposits in North America and other formerly glaciated areas.