Reports of the earth shaking and hearing booms in the night are preliminary evidence that an earthquake may have struck in Wellsville Borough in Northern York County Saturday night, according to a local geologist.

Jeri Jones, of Jones Geological Services, said he received reports from several people that they felt shaking and heard booming noises around 9:20 p.m. Saturday.

Jones said many of the reports came from the Wellsville area, but they extended north to Lower Allen Township in Cumberland County and south to East Berlin in Adams County.

Jones said the presence of a rock caused diabase could be the cause of the tremors, especially if it is settling after heavy rainfall, like the 10 inches of rain that fell in the area in mid-October.

Jones said diabase is also present in the Dillsburg area, where local residents reported multiple instances of tremors from 2008 until 2010.

"It seems like a common denominator," Jones said.

Jones said it will take a few more days to collect residents' reports to determine an epicenter. Jones said the tremors were too small for the nearest seismic station in Millersville to detect them.

No significant damage was reported.