An investigation of two periglacial landforms on ignimbrite blockslopes in Kluane National Park and Reserve, Yukon Territory
Date
2024-05-14
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
An expedition to the subarctic mountain of Campsite Peak, Yukon Territory, within the Kluane National Park and Reserve (KNPR), was conducted during the summer of 2019 to investigate two undocumented periglacial forms identified in satellite imagery. The overall goal of this MSc research is to present and measure these two features spatially, morphologically, and sedimentologically, placing them within the periglacial literature and hypothesizing plausible formative processes. The first study documents a feature similar to stone-banked solifluction terraces, termed blockslope terraces (BSTs) within this research, and are found in large numbers on low- to mid-slopes of Campsite Peak above the treeline, mantling a blocky open matrix of ignimbrite cobble-to-boulder material. BSTs differ from expected solifluction characteristics by showing apparent periodicity, large sample sizes, oblique orientations relative to their slope, and material too coarse to support the formation of ice needed for active solifluction. In-field morphological measurements combined with spatial and remote sediment sieving using photography and structure from motion modelling provided the exploratory measurements needed to place BSTs within the literature. It is the hypothesis of this research that BSTs are either a relict gelifluction feature from deglaciation, or nivation features of uncommon size and occurrence. The second study documents a feature, termed banded lichen formations (BLFs) within this research, found on the upper slopes of Campsite Peak. BLFs exhibit an alternating dark-and-light pattern caused by the presence and absence of lichens on the lighter felsic tuff material of Campsite Peak. It is hypothesized that BLFs are attributed to periglacial processes such as solifluction and frost heave, the form and relief of which are influenced by slope gradient and availability of fine-grained sediment in the system, leading to diverse spatial patterns, even across the same slopes. This research introduces two novel forms of periglacial landforms, both occurring on ignimbrite material, and both occurring on other mountains in KNPR of the same geologic unit. Further, the results of these studies underline the knowledge gaps in the solifluction and nivation literature surrounding landforms occurring on coarse, blocky material.
Description
Keywords
geomorphology, landform, periglacial, solifluction, patterned ground, terrace, blockslope, blockfield
Citation
Boulding, A. D. (2024). An investigation of two periglacial landforms on blockslopes in Kluane National Park and Reserve, Yukon Territory (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.