Ice Peak Formation
| Ice Peak Formation | |
|---|---|
| Stratigraphic range: Pleistocene Approx. | |
East side of Mount Edziza; the two lateral exposures of rock in the upper left corner are part of the upper assemblage of the Ice Peak Formation. | |
| Type | Geological formation |
| Unit of | Mount Edziza volcanic complex |
| Sub-units | Upper assemblage Lower assemblage |
| Underlies | Pillow Ridge Formation, Edziza Formation, Kakiddi Formation, Big Raven Formation |
| Overlies | Armadillo Formation, Nido Formation, Pyramid Formation |
| Lithology | |
| Primary | Alkali basalt, hawaiite, mugearite, benmoreite, trachyte |
| Other | Trachybasalt, tristanite |
| Location | |
| Coordinates | 57°41′26″N 130°38′08″W / 57.69056°N 130.63556°W |
| Region | British Columbia |
| Country | Canada |
| Type section | |
| Named for | Ice Peak |
| Named by | Souther et al., 1984 |
Paleogeological map of the Ice Peak Formation at the end of the Ice Peak eruptive period | |
The Ice Peak Formation (IPF) is a stratigraphic unit of Pleistocene age in northwestern British Columbia, Canada. It is the seventh youngest and fifth most voluminous of the 13 recognized geological formations comprising the Mount Edziza volcanic complex (MEVC), which consists of late Cenozoic volcanic rocks. The IPF overlies the 6.3-million-year-old Armadillo Formation, the 4.4-million-year-old Nido Formation and the 1.1-million-year-old Pyramid Formation, all of which are older units of the MEVC. Overlying the IPF are the younger and much less voluminous Pillow Ridge, Edziza, Kakiddi and Big Raven formations of the MEVC; all of these formations were deposited by volcanic eruptions in the last 0.9 million years. The stratigraphic position of the Ice Peak Formation suggests that it is about 1 million years old.
The IPF is subdivided into two units informally called the upper and lower assemblages. The upper assemblage consists of randomly oriented alkali basalt, hawaiite, trachybasalt, tristanite, mugearite, benmoreite and trachyte that are in the form of lavas and pyroclastic rocks. This assemblage conprises the upper portion of Ice Peak, as well as Camp Hill, Cache Hill, Ornostay Bluff, Koosick Bluff, The Neck. The lower assemblage consists mainly of alkali basalt and hawaiite, but also includes small volumes of trachybasalt, mugearite and tristanite. It comprises the bulk of the Ice Peak volcanic pile and occurs on the surrounding Big Raven Plateau.