Event Title
Investigating Geologic Controls of Western Pennyroyal Karst Region, Kentucky
Session Type
Poster/Flash-talk Session
Start Date
19-8-2020 9:00 AM
Description
Investigating Geologic Controls of Western Pennyroyal Karst Region, Kentucky
Nahid, Gani¹, Evan Crowe¹, Kaily Scott¹, M. Royhan Gani¹, Megan Whittle²
¹Department of Earth, Environmental and Atmospheric Sciences, Western Kentucky University, Bowling Green, Kentucky USA ²Gatton Academy of Mathematics and Science in Kentucky, Western Kentucky University, Bowling Green, Kentucky USA
The Western Pennyroyal Karst region of Kentucky possesses the world’s longest karst network, the Mam- moth Cave. This landscape contains ~100 tributaries of the Green River watershed located within the Rough Creek Graben (RCG), a Cambrian age continental rift structure, where numerous fault-systems crisscross the Mammoth Cave and the tributaries. The RCG is dominated by macro-scale E-W trending rift border-faults. Numerous meso-scale structures also exist that are crucial to understand graben’s deformation history as well as karstification. These structures are largely underexplored due to the presence of thick succession of sedimentary rocks and Quaternary sediments (~8 km) above the basement. We integrate field and remote sensing based analysis of the meso-scale structures and the tributary profiles from nine Green River sub- watersheds using 30-meter-resolution ASTER Digital Elevation Model (DEM). Our results suggest presence of distinct meso-scale faults mostly NE-SW and NW-SE trending. While lithology is the primary control of cave formation, these meso-scale faults likely played an important role in karst-landform development. Our river- profile analysis shows the presence of higher values (25) of normalized steepness-index, and ~300 knick- points. A large number of these knickpoints, which are unassociated with lithology, likely formed due to the neo-tectonic activity in the region. A preliminary positive-correlation between our mapped meso-scale fault systems, geomorphic parameters, and the sinkhole locations suggest a likely relationship between these faults and the morphology of conduit systems. Our findings not only advance our understanding of a potential link between structures, karst, and geomorphic parameters but also help assess earthquake and landslide hazard risks.
Recommended Citation
Gani,, Nahid Presenter, "Investigating Geologic Controls of Western Pennyroyal Karst Region, Kentucky" (2020). Conservation of Fragile Karst Resources Proceedings. 4.
https://digitalcommons.wku.edu/con_karst_res_proc/con_karst_pro_2020/day_two/4
Investigating Geologic Controls of Western Pennyroyal Karst Region, Kentucky
Investigating Geologic Controls of Western Pennyroyal Karst Region, Kentucky
Nahid, Gani¹, Evan Crowe¹, Kaily Scott¹, M. Royhan Gani¹, Megan Whittle²
¹Department of Earth, Environmental and Atmospheric Sciences, Western Kentucky University, Bowling Green, Kentucky USA ²Gatton Academy of Mathematics and Science in Kentucky, Western Kentucky University, Bowling Green, Kentucky USA
The Western Pennyroyal Karst region of Kentucky possesses the world’s longest karst network, the Mam- moth Cave. This landscape contains ~100 tributaries of the Green River watershed located within the Rough Creek Graben (RCG), a Cambrian age continental rift structure, where numerous fault-systems crisscross the Mammoth Cave and the tributaries. The RCG is dominated by macro-scale E-W trending rift border-faults. Numerous meso-scale structures also exist that are crucial to understand graben’s deformation history as well as karstification. These structures are largely underexplored due to the presence of thick succession of sedimentary rocks and Quaternary sediments (~8 km) above the basement. We integrate field and remote sensing based analysis of the meso-scale structures and the tributary profiles from nine Green River sub- watersheds using 30-meter-resolution ASTER Digital Elevation Model (DEM). Our results suggest presence of distinct meso-scale faults mostly NE-SW and NW-SE trending. While lithology is the primary control of cave formation, these meso-scale faults likely played an important role in karst-landform development. Our river- profile analysis shows the presence of higher values (25) of normalized steepness-index, and ~300 knick- points. A large number of these knickpoints, which are unassociated with lithology, likely formed due to the neo-tectonic activity in the region. A preliminary positive-correlation between our mapped meso-scale fault systems, geomorphic parameters, and the sinkhole locations suggest a likely relationship between these faults and the morphology of conduit systems. Our findings not only advance our understanding of a potential link between structures, karst, and geomorphic parameters but also help assess earthquake and landslide hazard risks.
Comments
This presentation was part of the Poster/Flash-talk Session.