Calvin crater
Encyclopedia
Calvin is an impact
crater
located in Calvin Township
, Cass County
in the U.S. state
of Michigan
. It was discovered in 1987 by Randall Milstein of the Michigan Geological Survey while examining data from about 100 test wells drilled in the area.
It is 5 miles (8.5 km) in diameter and the age is estimated to be 450 ± 10 million years (Ordovician
). The crater is not exposed to the surface. It lies about 100 to 400 feet (30–120 m) below today's ground level.
Impact event
An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events have been reported, with some occurrences causing deaths, injuries, property damage or other significant...
crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
located in Calvin Township
Calvin Township, Michigan
Calvin Township is a civil township of Cass County in the U.S. state of Michigan. The population was 2,041 at the 2000 census.-Geography:According to the United States Census Bureau, the township has a total area of , of which, of it is land and of it is water...
, Cass County
Cass County, Michigan
Cass County is a county in the U.S. state of Michigan. As of the 2000 census, the population was 51,104. It is part of the South Bend–Mishawaka, IN-MI, Metropolitan Statistical Area which has a total population of 316,663 and is sometimes considered part of Greater Michiana...
in the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
. It was discovered in 1987 by Randall Milstein of the Michigan Geological Survey while examining data from about 100 test wells drilled in the area.
It is 5 miles (8.5 km) in diameter and the age is estimated to be 450 ± 10 million years (Ordovician
Ordovician
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...
). The crater is not exposed to the surface. It lies about 100 to 400 feet (30–120 m) below today's ground level.