The Impact Field Studies Group (IFSG) is a scientific organization emphasizing geologic field research of suspected and confirmed sites of impact craters

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...

 and impact structures

Impact structure

The term impact structure is closely related to the terms impact crater or meteorite impact crater, and is used in cases where erosion or burial have destroyed or masked the original topographic feature with which we normally associate the term crater...

. The group is composed of researchers, professionals and students involved in study of impact sites. IFSG's web site is hosted by the Department of Earth and Planetary Sciences at University of Tennessee, Knoxville

University of Tennessee

The University of Tennessee is a public land-grant university headquartered at Knoxville, Tennessee, United States...

.

Impact Database

IFSG member David Rajmon maintains for the organization a list which was originally called the Suspected Earth Impact Sites (SEIS) list from 2004 to 2009. It was then renamed to simply the Impact Database. The list classifies impact sites as confirmed, most probable, probable, possible, improbable, rejected and proposed (unevaluated). The list retains rejected entries because they tend to be submitted repeatedly.

The IFSG Impact Database accepts submissions of proposed new impact sites. However, they require submitters do some significant homework as listed below first.

• The submitter should download the Impact Database or KML (Google Earth) version of it to verify that the site has not already been included, and possibly rejected.
• If the submitter is not familiar with the science behind recognition of impact craters, they must read Traces of Catastrophe
  Traces of Catastrophe
  The book Traces of Catastrophe: A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures, or more commonly shortened to Traces of Catastrophe, was written by Bevan M. French of the Smithsonian Institution. It is a comprehensive technical reference on the science of impact...
  
  .
• They should look at maps to consider other alternatives to impact craters, whether man-made (such as mining pits and ponds) or natural (such as sinkholes and volcanic vents).
• The page lists some suggestions how to avoid fixating on the possibility of an impact and consider more open investigation of what the feature is.

Field trips

IFSG arranges field trips to impact-related sites. Past events have included

• Marquez crater
  Marquez crater
  Marquez is a meteorite crater located in Leon County, Texas near the small town of Marquez about northeast of Austin, Texas, United States.It is 12.7 km in diameter and the age is estimated to be 58 ± 2 million years . The crater is not exposed at the surface.- References :...
  
  , Texas, USA, 2004
• Serpent Mound crater
  Serpent Mound crater
  Serpent Mound crater, also known as the Serpent Mound Disturbance, is an eroded meteorite impact crater in Ohio, United States. It lies largely in Adams County, with the northern part mostly in Highland County, except for a small northeast part in Pike County.It is classified as a complex crater...
  
  , Ohio, USA, 2004
• K–T boundary
  K–T boundary
  The K–T boundary is a geological signature, usually a thin band, dated to 65.5 ± 0.3 Ma ago. K is the traditional abbreviation for the Cretaceous period, and T is the abbreviation for the Tertiary period...
  
  , Texas, USA, 2005
• Middlesboro crater
  Middlesboro crater
  The Middlesboro crater is a meteorite crater in Kentucky, United States. It is named after the city of Middlesborough , which today occupies much of the crater....
  
  , Ohio, USA and Flynn Creek crater
  Flynn Creek crater
  Flynn Creek crater, is an impact crater situated in Jackson County, approximately 8 km south of Gainesboro, Tennessee, USA. It was formed approximately 360 million years ago as a shallow, saucer-shaped crater, 3.8 km in diameter and about 150 m deep. A large central hill, highly deformed rim...
  
  , Tennessee, USA, 2005
• Sierra Madera crater
  Sierra Madera crater
  Sierra Madera crater is a meteorite crater in southwestern Pecos County, Texas, United States. The central peak of the rebound structure of the impact crater rises 793 feet above the surrounding land. The peak is visible from U.S. Highway 385 between Fort Stockton, Texas and Marathon, Texas...
  
  , Texas, USA, 2006
• Kentland crater
  Kentland crater
  The Kentland crater, also known as the Kentland structure or the Kentland disturbed area, is an impact crater located near the town of Kentland in Newton County, Indiana, United States....
  
  , Indiana, USA, 2007
• Wells Creek crater
  Wells Creek crater
  Wells Creek is an impact crater in Tennessee, United States.It is 7.46 miles in diameter and the age is estimated to be 200 ± 100 Ma , placing it in the Jurassic or a neighboring period. The crater is exposed to the surface. The center of the crater contains some of the finest shatter cones in the...
  
  , Tennessee, USA, 2008
• Nevada Test Site
  Nevada Test Site
  The Nevada National Security Site , previously the Nevada Test Site , is a United States Department of Energy reservation located in southeastern Nye County, Nevada, about northwest of the city of Las Vegas...
  
  , Nevada, USA, 2009 (nuclear explosion craters at NTS were how shock metamorphism
  Shock metamorphism
  Shock metamorphism or impact metamorphism describes the effects of shock-wave related deformation and heating during impact events. The formation of similar features during explosive volcanism is generally discounted due to the lack of metamorphic effects unequivocally associated with explosions...
  
   was studied by Eugene Shoemaker
  Eugene Merle Shoemaker
  Eugene Merle Shoemaker , American geologist, was one of the founders of the fields of planetary science....
  
  and then applied to create the science of impact geology)

External links

• Impact Field Studies Group
• Impact Database maintained for IFSG by member David Rajmon