Event Title
Origin of Chert Nodules within Dolomite of the Lower Silurian Brassfield Formation, Kentucky
Presentation Type
Poster/Portfolio
Presenter Major(s)
Geology, Natural Resource Management
Mentor Information
Patricia Videtich
Department
Geology
Location
Henry Hall Atrium 68
Start Date
10-4-2013 12:00 PM
End Date
10-4-2013 1:00 PM
Keywords
Physical Science
Abstract
The Lower Silurian Brassfield Formation (BF) is part of the Cincinnati Arch, which spans through northeast Kentucky as well as parts of Tennessee, Ohio, and Illinois. Samples were collected from the BF at an outcrop at the Tollesboro Roadcut, Kentucky. The BF was deposited as limestone and dolomitized after deposition. At this locality, the BF is composed primarily of dolomite, but also contains marine skeletals, pyrite, glauconite, and chert nodules. We will perform point counts (300 points per slide) of three thin sections in order to quantify the dolomite composition by determining percentages of the constituents listed above. Our goal is to determine the order in which the dolomitization and the formation of chert nodules occurred. Excellent preservation of skeletals within chert nodules may indicate the chert formed pre-dolomitization. On the contrary, presence of dolomite rhombs within chert may indicate the nodules formed post-dolomitization.
Origin of Chert Nodules within Dolomite of the Lower Silurian Brassfield Formation, Kentucky
Henry Hall Atrium 68
The Lower Silurian Brassfield Formation (BF) is part of the Cincinnati Arch, which spans through northeast Kentucky as well as parts of Tennessee, Ohio, and Illinois. Samples were collected from the BF at an outcrop at the Tollesboro Roadcut, Kentucky. The BF was deposited as limestone and dolomitized after deposition. At this locality, the BF is composed primarily of dolomite, but also contains marine skeletals, pyrite, glauconite, and chert nodules. We will perform point counts (300 points per slide) of three thin sections in order to quantify the dolomite composition by determining percentages of the constituents listed above. Our goal is to determine the order in which the dolomitization and the formation of chert nodules occurred. Excellent preservation of skeletals within chert nodules may indicate the chert formed pre-dolomitization. On the contrary, presence of dolomite rhombs within chert may indicate the nodules formed post-dolomitization.