Puchezh-Katunki crater
Encyclopedia
Puchezh-Katunki is a meteor
METEOR
METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...

 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...

 in the Chkalovsky District
Chkalovsky District, Nizhny Novgorod Oblast
Chkalovsky District, Nizhny Novgorod Oblast is an administrative district , one of the 47 in Nizhny Novgorod Oblast, Russia. Its administrative centre is the town of Chkalovsk....

 of Nizhny Novgorod Oblast
Nizhny Novgorod Oblast
Nizhny Novgorod Oblast is a federal subject of Russia . Its administrative center is the city of Nizhny Novgorod. Population: The oblast is crossed by the Volga River. Apart from Nizhny Novgorod's metropolitan area, the biggest city is Arzamas...

 in Volga Federal District
Volga Federal District
Volga Federal District is one of the eight federal districts of Russia. It forms the southeastern part of European Russia. Its population was 29,900,400 according to the 2010 Census, living on an area of...

, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

. It is 80 km (49.7 mi) in diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...

 and is estimated to be 167 ± 3 million years old, placing it in the Middle Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

. The crater is not exposed to the surface, but appears as variation in the vegetation.

The central dome, ring depression, and ring terrace of the 80 km (49.7 mi) wide impact structure are nearly completely buried under Neogene
Neogene
The Neogene is a geologic period and system in the International Commission on Stratigraphy Geologic Timescale starting 23.03 ± 0.05 million years ago and ending 2.588 million years ago...

 and Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...

 sediments, with the only exposed impactite
Impactite
Impactite is an informal term describing a rock created or modified by the impact of a meteorite. The term encompasses shock-metamorphosed target rocks, melts and mixtures of the two, as well as sedimentary rocks with significant impact-derived components .-Some localities:*Nördlinger Ries...

s found on the banks of the Volga River
Volga River
The Volga is the largest river in Europe in terms of length, discharge, and watershed. It flows through central Russia, and is widely viewed as the national river of Russia. Out of the twenty largest cities of Russia, eleven, including the capital Moscow, are situated in the Volga's drainage...

.
One of the six largest known Phanerozoic
Phanerozoic
The Phanerozoic Eon is the current eon in the geologic timescale, and the one during which abundant animal life has existed. It covers roughly 542 million years and goes back to the time when diverse hard-shelled animals first appeared...

 impact craters, the Puchezh-Katunki crater is the only one not considered as a factor in a biotic extinction event
Extinction event
An extinction event is a sharp decrease in the diversity and abundance of macroscopic life. They occur when the rate of extinction increases with respect to the rate of speciation...

. There is no known significant extinction in the Middle Jurassic, but there are clues suggesting the impact may have occurred coeval with the end-Triassic or Early Jurassic extinction.
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