The nature and extent of past glaciations are depicted on the glacial limits map of Yukon.

Glacial limits and ice-flow map (1:250,000 scale) of Mayo area, central Yukon (parts of NTS 115P northeast, 116A southeast, 105M northwest and 106D southwest).

Includes glacial limits and ice-flow direction, inset maps of the Mayo and Dawson areas and descriptive notes on Yukon placer deposits.

Yukon Territory has been glaciated by Cordilleran and montane glaciers at various times throughout the Pleistocene, as well as by continental ice, the Laurentine Ice Sheet in the Late Pleistocene. Throughout the Late Cenozoic, each successive glaciation appears to have been less extensive than the previous one. In west-central Yukon the earliest glaciation occurred between 2.6 and 2.9 Ma. ago (Duk-Rodkin and Barendregt, 1997). This glaciation was the most extensive and formed a continuous carapace of ice covering all the mountain ranges, except for a small area of Dawson Range and a more extensive area in northern Yukon. The Mid Pleistocene Cordilleran glaciation was less extensive than older glaciations but it formed an extensive ice sheet covering most of the northern Cordillera. The Late Pleistocene glaciation was the most restrictive and formed a continuous carapace of ice from the continental divide to the Saint Elias Mountains, but only restricted ice caps formed on the Ogilvie Mountains. During the last glaciation, the Laurentide Ice Sheet, flowing from the east, reached the northeast part of the Yukon Territory ca. 30 ka ago. Distributed from [GeoYukon](https://yukon.ca/geoyukon) by the [Government of Yukon](https://yukon.ca/maps) . Discover more digital map data and interactive maps from Yukon's digital map data collection. For more information: [geomatics.help@yukon.ca](mailto:geomatics.help@yukon.ca)

Preliminary investigation of surficial geology in northern Kluane Range has resulted in new interpretations of Pleistocene ice cover including extensive unglaciated terrain and restricted glaciation during the Last Glacial Maximum. Two glacial limits are identified: a higher limit recording the most extensive glaciation of the area; and a lower limit that records younger, less extensive glaciation. This paper describes Pleistocene limits of the Donjek Glacier and the distribution of surficial materials in the upper Quill, Maple, and Wade creek drainages. The source and transport mechanism of surface materials has particular significance for surficial geochemistry sampling programs and implications for mineral exploration are addressed.

Icefields captured at 1:1,000,000 scale from Digital Chart of the World data for the Yukon and surrounding area. Distributed from [GeoYukon](https://yukon.ca/geoyukon) by the [Government of Yukon](https://yukon.ca/maps) . Discover more digital map data and interactive maps from Yukon's digital map data collection. For more information: [geomatics.help@yukon.ca](mailto:geomatics.help@yukon.ca)

Throughout the Pleistocene epoch, Yukon was repeatedly influenced by glacial ice originating from the Cordilleran Ice Sheet and independent alpine glaciers. The penultimate limit in Yukon has garnered controversy in recent years, as moraines in the central region of the territory were found to be older (MIS 6) than moraines in the southwest part of the territory and Alaska (MIS 4). The Ogilvie Mountains, located east of Dawson City, have proven especially problematic for chronological studies. This study will attempt to test a relatively new dating method on penultimate surfaces in the Ogilvie Mountains; Chapman Lake is the primary study area. Using a vertical sampling method to construct a cosmogenic depth versus concentration profile in outwash gravel, this research will determine whether Marine Isotope Stage 4 or 6 provided the conditions necessary for ice nucleation to build the penultimate glacial surface. The age calculated by the depth profile is supported by radiocarbon ages and macrofossil samples, optically stimulated luminescence ages, TCN boulder dating, as well as detailed stratigraphy of significant sites near the Chapman Lake moraine. The results will help determine the effects of climate forcing in this region and its relationship to the existing glacial framework of the territory.

A regional till geochemistry project was completed in conjunction with bedrock mapping across rocks of Yukon-Tanana Terrane and North American affinity in central Yukon. The high mineral potential of the area is based on recent discoveries in the Finlayson Lake area to the southeast, an area thought to juxtapose the Glenlyon area prior to displacement on the Tintina Fault. The study area lies at the limit of the Late Wisconsinan McConnell glaciation. Ice flow was largely directed by topography. Soil profiles reveal a veneer of White River ash and loess over most till deposits. Geochemical results from 285 till samples highlight new anomalies in gold, gold/arsenic (intrusive- and fault-related), copper (veins), copper/nickel (ultramafic rocks) and zinc (sedimentary-exhalative (SEDEX) and epithermal). An orientation survey was completed at the Clear Lake SEDEX deposit to evaluate the extent of glacial dispersion down-ice from mineralization.

Includes glacial limits, glacial deposits, ice-flow direction and descriptive notes on placer gold and glaciation in the Dawson area.