Mole Hill (Virginia) facts for kids
Mole Hill is a round hill in Rockingham County, near Harrisonburg, Virginia. It's made of a dark volcanic rock called basalt. This hill is actually what's left of an old volcano that was active about 47 million years ago! That makes it one of the youngest volcanoes ever found on the east coast of North America.
What is Mole Hill?
Mole Hill looks like a lonely, round hill covered in trees. It stands out in a mostly flat valley surrounded by farms. The top of Mole Hill is about 1,893 feet (577 meters) above sea level.
This hill is a special type of landform called a monadnock. A monadnock is a hill or mountain that stands alone in a flat area. It happens when the land around it wears away over time, but the harder rock of the hill stays put.
The rock at the top of Mole Hill is a type of basalt. This basalt is dark greenish-gray to black. It has small crystals of minerals like olivine and pyroxene mixed in. This volcanic rock pushed its way up through older rocks, which are called Ordovician carbonate rocks.
How Old is Mole Hill?
Scientists first thought the basalt rock at Mole Hill was very old, from the Paleozoic Era. But in 1969, scientists named Fullagar and Bottino used special tests called radiometric dating. These tests measure how old rocks are by looking at tiny amounts of radioactive elements inside them.
They found that the rocks were much younger than expected. Mole Hill's basalt is about 47 million years old. This means it formed during the Eocene epoch. The Eocene epoch was a time when Earth was much warmer than today.
Other places, like Trimble Knob in Highland County and some rocks near Ugly Mountain in Pendleton County, West Virginia, are similar to Mole Hill. Scientists think they formed around the same time.
Images for kids
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View facing east from Mole Hill Road
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View facing northwest from Swope Road
See also
In Spanish: Mole Hill para niños
