Deciphering the Shedroof Formation, a Proterozoic conglomerate structurally (?) overlying the Belt Supergroup in N Idaho and NE Washington
Faculty Mentor
Chad Pritchard
Presentation Type
Poster
Start Date
5-8-2024 9:00 AM
End Date
5-8-2024 10:45 AM
Location
PUB NCR
Primary Discipline of Presentation
Geosciences
Abstract
Nestled in northeastern Washington, the Shedroof Formation is very poorly constrained geologic unit. This project focuses on defining the unit, deciphering its structural history, and discover its connection to an inland temperate rainforest that grows within its fractures and soils. Additionally, it will assist in further constraining the age of the Neoproterozoic rifting event of Columbia, in which the Mawson Continent (now possibly southern Australia) presumably separated from western Laurentia (Box et al, 2020). Preliminary mapping has identified a pyrite rich metaconglomerate most closely corresponding with the Neoproterozoic Monk Formation based off of general rock descriptions. A two-meter-thick metaconglomerate to ultra mylonite cross-cutting a southerly dipping conglomerate follows the general contact of the Neoproterozoic Monk and Shedroof Formations, which may correlate to the severely understudied Newport fault (Harms and Price, 1992). The Newport fault is potentially a source of said massive mylonite zone and further age determination of these formations and structures will answer a number of basic stratigraphic and complex structural questions. The Shedroof Formation was previously presented as equivalent to the Deer Trail Group (Miller, 1994), however may now be a Buffalo Hump equivalent of the Windermere Supergroup(Box et al., 2020; Brennan et al. 2020).
Recommended Citation
Potter, Natalie and Pritchard, Chad, "Deciphering the Shedroof Formation, a Proterozoic conglomerate structurally (?) overlying the Belt Supergroup in N Idaho and NE Washington" (2024). 2024 Symposium. 21.
https://dc.ewu.edu/srcw_2024/ps_2024/p1_2024/21
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Deciphering the Shedroof Formation, a Proterozoic conglomerate structurally (?) overlying the Belt Supergroup in N Idaho and NE Washington
PUB NCR
Nestled in northeastern Washington, the Shedroof Formation is very poorly constrained geologic unit. This project focuses on defining the unit, deciphering its structural history, and discover its connection to an inland temperate rainforest that grows within its fractures and soils. Additionally, it will assist in further constraining the age of the Neoproterozoic rifting event of Columbia, in which the Mawson Continent (now possibly southern Australia) presumably separated from western Laurentia (Box et al, 2020). Preliminary mapping has identified a pyrite rich metaconglomerate most closely corresponding with the Neoproterozoic Monk Formation based off of general rock descriptions. A two-meter-thick metaconglomerate to ultra mylonite cross-cutting a southerly dipping conglomerate follows the general contact of the Neoproterozoic Monk and Shedroof Formations, which may correlate to the severely understudied Newport fault (Harms and Price, 1992). The Newport fault is potentially a source of said massive mylonite zone and further age determination of these formations and structures will answer a number of basic stratigraphic and complex structural questions. The Shedroof Formation was previously presented as equivalent to the Deer Trail Group (Miller, 1994), however may now be a Buffalo Hump equivalent of the Windermere Supergroup(Box et al., 2020; Brennan et al. 2020).
