Heavy minerals and grain size distribution inYukon Coast and Herschel Island sediments

• Main Author: Hohberg, Stefanie
• Format: Dataset
• Language: English
• Published: PANGAEA 2017
• Subjects: AWI_PerDyn; Permafrost Research (Periglacial Dynamics) @ AWI; Yukon; Mackenzie River; Kay; Inuvik; Herschel Island; Roland; Mackay; Komakuk Beach; British Mountains; Inuvik Region; Roland Bay; Herschel; Ice; Ice Sheet; Mackenzie river; permafrost; Alaska
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.883546; https://doi.org/10.1594/PANGAEA.883546

Herschel Island and the Yukon Coastal Plain are an important research area as they geographically lie at the northwestern limit of the Laurentide glaciation (Mackay,1959). Quaternary geological maps show that sedimentary deposits are found in the study area around Komakuk Beach, Herschel Island, Roland Bay and Kay Point. These were found to be predominantly fluvial and glacial. In this work, glaciated and nonglaciated areas are compared in order to improve the distinction between the two. Four parageneses were identified from three heavy mineral provinces by means of heavy mineral analyses. The minerals from a proximal sediment source are predominant in the British Mountains. The greenschist fragments,zoisite and epidote originate from stone of the greenshist facies of the Neruopuk Formation. The clinopyroxenes derive from the basalt areas at the border to Alaska. In the region east of the Mackenzie River, in the vicinity of Inuvik, larger deposits of dolomitestone are found, from which dolomites and ankerites were derived. The most remote area is located in the Canadian Shield. There, several rock deposits of granulite facies are present. From these, garnets and to some extent amphibols, zircon, rutile and tourmaline were transported by the Laurentide Ice Sheet to the study area. Grainsize data and grain morphoscopic studies on quartz grains show that there is no spatial relationship between the sample areas. Instead the transport process is primarily dependent on the deposition environment. Most quartz grains show fluvial transport features. Some grains indicate signs of glacial transport. Summarized, the most important findings are: 1. Three heavy mineral provinces were identified: British Mountains (proximal), Inuvik region (distal), and Canadian Shield (distal). 2. In the samples from Herschel Island, Roland Bay and Kay Point, garnet and ZTR-index-minerals (less unambiguously) are strongly represented and show a glacial signal via their origin from the Canadian Shield 3. Some samples have a similar heavy ...