Deciphering Anthropogenic VS. Natural Fulgurites
Faculty Mentor
Chad Pritchard
Document Type
Poster
Start Date
10-5-2023 11:15 AM
End Date
10-5-2023 1:00 PM
Location
PUB NCR
Department
Geology
Abstract
In July 2022, a copper electric distribution wire fell on sandy base-course and pulsed about for about an hour causing a line of artificial, or anthropogenic fulgurites - a type of rock formed from fusion of grains where electrical currents interact with sediments. As discussions around anthropogenic changes to the environment increase, so does the need to understand the extent of these changes. This is why research to better understand the similarities and differences between artificial/anthropogenic fulgurites and natural fulgurites was conducted. Differences in formation were hypothesized to demonstrate one way humans impact the surrounding geology of an area. These glass tubes were excavated, described, and analyzed using multiple methods to relate to fulgurites formed from lightning strikes (natural fulgurites). The clastic material that melted was about 60 percent basalt gravel to sand and 40 silica-dominated sand from local Pleistocene megaflood deposits, resulting in 60 wt% SiO2. Using a single crystal diffractometer the clear to white minerals correlates closest to alpha-quartz (a low-temperature variation of quartz) and solid state NMR resulted in a broad glass pattern with a minimal peak for 29Si. Thin section analyses showed quartz crystals surrounded by lighter colored glass, vesiculation, disequilibrium textures, and dissolution profiles with decreasing wt% SiO2 trending away from the minerals into the melt. The lack of high temperature/pressure crystal formation found in the artificial fulgurites (but present in natural fulgurites) is attributed to the pulsing of the downed electric line and an intermediate melt chemistry. Differences in crystal formation demonstrate how humans have an impact on the geological record. Research points to human’s electric grids on Earth (i.e., electric lines) potentially creating more alpha-quartz and amorphous silica on Earth’s surface directly correlated with human activity.
Recommended Citation
Reiner, Kai, "Deciphering Anthropogenic VS. Natural Fulgurites" (2023). 2023 Symposium. 47.
https://dc.ewu.edu/srcw_2023/res_2023/p2_2023/47
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Deciphering Anthropogenic VS. Natural Fulgurites
PUB NCR
In July 2022, a copper electric distribution wire fell on sandy base-course and pulsed about for about an hour causing a line of artificial, or anthropogenic fulgurites - a type of rock formed from fusion of grains where electrical currents interact with sediments. As discussions around anthropogenic changes to the environment increase, so does the need to understand the extent of these changes. This is why research to better understand the similarities and differences between artificial/anthropogenic fulgurites and natural fulgurites was conducted. Differences in formation were hypothesized to demonstrate one way humans impact the surrounding geology of an area. These glass tubes were excavated, described, and analyzed using multiple methods to relate to fulgurites formed from lightning strikes (natural fulgurites). The clastic material that melted was about 60 percent basalt gravel to sand and 40 silica-dominated sand from local Pleistocene megaflood deposits, resulting in 60 wt% SiO2. Using a single crystal diffractometer the clear to white minerals correlates closest to alpha-quartz (a low-temperature variation of quartz) and solid state NMR resulted in a broad glass pattern with a minimal peak for 29Si. Thin section analyses showed quartz crystals surrounded by lighter colored glass, vesiculation, disequilibrium textures, and dissolution profiles with decreasing wt% SiO2 trending away from the minerals into the melt. The lack of high temperature/pressure crystal formation found in the artificial fulgurites (but present in natural fulgurites) is attributed to the pulsing of the downed electric line and an intermediate melt chemistry. Differences in crystal formation demonstrate how humans have an impact on the geological record. Research points to human’s electric grids on Earth (i.e., electric lines) potentially creating more alpha-quartz and amorphous silica on Earth’s surface directly correlated with human activity.
