Ukinrek Maars, Alaska; the result of a 10-day eruption in 1977. Maar is about 300 m in diameter.

A Maar (from Latin mare: the sea; also called "tuff cone") is a broad, low relief crater that is caused by a phreatic eruption or explosion caused by groundwater contact with hot lava or magma. The maar typically fills with water to form a relatively shallow crater lake that may be active or dormant depending on how long ago it was formed. Ukinrek Maars, Alaska; the result of a 10-day eruption in 1977. ... Ukinrek Maars, Alaska; the result of a 10-day eruption in 1977. ... Latin is an ancient Indo-European language originally spoken in the region around Rome called Latium. ... Welded tuff at Golden Gate in Yellowstone National Park Tuff (from the Italian tufo and pronounced tuf) is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. ... Phreatic eruption at the summit of Mount St. ... Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of geologic formations. ... Look up lava, Aa, pahoehoe in Wiktionary, the free dictionary. ... Magma is molten rock located beneath the surface of the Earth (or any other rocky planet), and which often collects in a magma chamber. ...

Maars are shallow, flat-floored craters that scientists interpret have formed above diatremes as a result of a violent expansion of magmatic gas or steam; deep erosion of a maar presumably would expose a diatreme. Maars range in size from 200 to 6,500 feet across and from 30 to 650 feet deep, and most are commonly filled with water to form natural lakes. Most maars have low rims composed of a mixture of loose fragments of volcanic rocks and rocks torn from the walls of the diatreme. A Diatreme is a volcanic pipe or feature formed by a gas or volatile rich explosive magma. ...

Maars occur in the western United States, in the Eifel region of Germany, and in other geologically young volcanic regions of the world. An excellent example of a maar is Zuni Salt Lake in New Mexico, a shallow saline lake that occupies a flat-floored crater about 6,500 feet across and 400 feet deep. Its low rim is composed of loose pieces of basaltic lava and wallrocks (sandstone, shale, limestone) of the underlying diatreme, as well as random chunks of ancient crystalline rocks blasted upward from great depths. If you have been redirected here after viewing any statistical information, note that as defined by the Census Bureau, the western United States includes 13 states: Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, New Mexico, Nevada, Oregon, Utah, Washington, and Wyoming. ... The Eifel is a hilly region in Germany. ... Zuni Salt Lake (also Zuñi Salt Lake and Fence Lake), located about 60 miles south of the Zuni Pueblo, is a rare, high desert lake, and a classic maar. ... Official language(s) None Capital Santa Fe Largest city Albuquerque Area  Ranked 5th  - Total 121,665 sq. ... A Diatreme is a volcanic pipe or feature formed by a gas or volatile rich explosive magma. ...

Reference

• United States Geological Survey