Meteor impacts can have subtle effects

LOWER HUTT, New Zealand, Jan. 23 (UPI) -- A New Zealand study suggests meteor impacts with the Earth can produce effects of a more subtle and insidious kind than just catastrophic extinction.

Researchers at the Institute of Geological and Nuclear Sciences in Lower Hutt, New Zealand, said the shattering impact of meteors on rocks can produce increased groundwater-rock surface interaction, affecting the quality of groundwater that percolates through the fractured, melted rocks of the impact structure.

The scientists said a good example was found at the Canadian town of Gypsumville, Manitoba, located near the Lake St. Martin meteor impact crater. Domestic wells in the town have elevated salinity, sulfate and fluoride concentrations. The fluoride, which exceeds health limits, is of concern as excess intake causes mottling of teeth at moderate levels, to softening of bones and neurological damage at higher levels.

The groundwater with elevated fluoride is shown to occur exclusively within the impact structure, and the study is thought to be the first to document enhanced groundwater fluoride concentrations associated with impact structures.

The research is detailed in the journal Geology.