COSMIC SECRETS
The Enigmas on Earth
Impact Craters on Earth
Impact Craters
Africa
.
Crater List
Algeria
 - Amguid Crater - Database
 - Ouarkziz Crater - Database
 - Talemzane Crater - Database
 - Tin Bider Crater - Database

Botsawana
 - Kgagodi Crater - Database

Chad
 - Aorounga Crater - Database
 - Gweni-Fada Crater - Database

Libya
 - Arkenu 1 & 2 Craters - Database
 - B.P. Structure Crater - Database
 - Oasis Crater - Database

Egypt
 - Kibera Crater

Mauritania
 - Aouelloul Crater - Database
 - El Mrayer Crater - Info
 - Gogui Crater - Info
 - Richat Structure - Info
 - Tenoumer Crater - Database
 - Temimichat Crater - Info

Ghana
 - Bosumtwi Crater - Database

Namibia
 - Roter-Kamm Crater - Database

South Africa
 - Kalkkop Crater - Database
 - Morokweng Crater - Database
 - Tswaing (Pretoria) Crater - Database
 - Vredefort Crater - Database

Jordan
New Crater Report - Jordan Times
 

Visit Also:
Earth Impact Database - The biggest collection of Earth Impact Craters
by the University of New Brunswick, Canada

Visit Also:
Basic Science Studies II: Impact Cratering
by The Remote Sensing Tutorial


Amguid Crater
Algeria
.
Amguid is a meteor crater in Algeria. It is 450 m in diameter and the age is estimated to be less than 100,000 years and is probably Pleistocene. The crater is exposed to the surface.
 

Ouarkziz Crater
Algeria
.
Ouarkziz Crater is a meteor impact crater in Algeria. It is 3.5 kilometers in diameter and the age is estimated to be less than 70 million years (Cretaceous or younger). The crater is exposed to the surface.

Talemzane Crater
Algeria
.
 Credit: NASA/Landsat ETM
Talemzane Crater is a meteor crater in Algeria. It is 1.75 km in diameter and the age is estimated to be less than three million years and is probably Pliocene. The crater is not exposed to the surface.

Tin Bider Crater
Algeria
.
Tin Bider Crater is an impact crater (astrobleme) in Algeria. It is 6 km in diameter and the age is estimated to be less than 70 million years (Cretaceous or younger). The crater is exposed to the surface.

Tenoumer Crater
Mauritania
.
Ground Based Panorama

The Tenoumer crater is about 1,900 m in diameter and is located in the western Sahara desert, Mauritania. The crater is almost perfectly round in shape, and the rim is 110 m high from bottom to top. Tenoumer is located on a peneplain consisting of Precambrian gneisses and granites. A thin layer of sediments that are Pliocene or younger covers the Precambrian rocks. Tenoumer is located on top of the Pliocene sediments. Due to the rare occurrence of fused igneous materials outside the crater, (basalt and rhyodacite) a volcanic origin was favored. The origin of the crater Tenoumer by an impact is currently preferred. Basement rocks have been found in outcrops outside of the crater, located in individual bodies up to 20 m long. These rocks are dark gray, vesicular, and contain altered gneiss and granite clasts. Small fractured glass inclusions are also present. Several deformation features have been found at Tenoumer. The most prominent of these is planar deformation features in quartz grains; the presence of lechatelierite (glass), and deformation of biotite, feldspar, and other minerals. - Source
 

Older Aerial Photograph
More Detailed Information:
The "Impact" Craters of Mauritania
Aouelloul, Tenoumer, Temimichat and El Mrayer
by Norbert Brügge, Germany
 
 Image Courtesy NASA/JPL

Aouelloul Crater
Mauritania
.
 Image Courtesy NASA/JPL
Image Courtesy NASA/JPL

The crater Aouelloul is located in the Adrar region of the western Sahara Desert, Mauritania. The crater is one of the smaller known craters, having a diameter of 390 m. The rim is well defined and rises 15-25 m above the local topography, and 53 m above the crater floor. The crater is located in Ordovician sand stones and quartzite, and is filled with sandy silt and Aeolian sand. Estimates of the thickness of this sedimentary fill are around 23 m...

At Aouelloul, the Os ratios of the glass are extremely similar to those of both chondritic and iron meteorites. This suggests that the Os present in the glass came from a meteorite, as the amount present is much too high to have had a terrestrial origin. An absolute age of 3.1±0.3 million years was obtained by fission track and K-Ar dating of the impact glass... - Source


Temimichat Crater
Mauritania
.
 Image Courtesy NASA/JPL

The crater rim is not completely preserved. Large portions are eroded and dissected, or masked by eolian deposits. The rim is mostly formed by granitoid gneisses. The low lying portions of the rim correspond to the occurrence of gabbroic dikes, which seem to be more easily erodible, with respect to the dominant granitoid bedrock. The crater interior is covered by recent eolian Sediments. Below this surficial cover, sedimentary deposits are likely filling the crater.

 Image Courtesy NASA/JPL

New Evidences of an Impact Origin for Temimichat Crater, Mauritania - LPI Pdf


El Mrayer Crater
Mauritania
.
 Image Courtesy LPI
The crater has a diameter of about 2 km and it is located on Cambro-Ordovician substrate. The geometry appears rather complex: a subcircular inner ring is bound by an apparently concentric deformed region. Nearby (2 km toward N) a possible secondary small crater is visible.
Source: LPI 1309 PDF

Gogui Crater
Mauritania
.
 Image Courtesy LPI
Gogui Crater: Latitude 15° 50' N; Longitude 11° 40' W







The crater is about 500-600 m wide and shows a relatively pristine morphology. The bedrock consists of Paleozoic metamorphic rocks. It has a distinct circular rim and a rather flat bottom. The age of formation of the crater could be very recent, looking
at its pristine aspect.

Source: LPI 1309 PDF


Richat Structure Crater
Mauritania
.
 Credit:  Landsat 7, USGS,  NASA
Click Image for full size

Bosumtwi Crater
Ghana, West Africa
.
 Image Courtesy NASA/JPL

This crater is situated in crystalline bed rocks of the West African Shield and is filled almost entirely by Lake Bosumtwi. Chemical, isotopic, and age studies demonstrate that the crater is the most probable source for the Ivory Coast tektites, which are found on land in the Ivory Coast region of central Africa and as micro tektites in nearby ocean sediments. In this photo the crater lake is partly obscured by clouds. (Courtesy NASA/LPI) 
 

NASA Space Shuttle image STS 51 I-39-031
Meteorite Crater Drilling Provides Extensive Samples - and a Mystery

Drillings made in the Bosumtwi crater in Ghana, one of the youngest meteorite craters in the world, led to yet another mysterious finding - the rock formation caused by the heat of the meteoric impact is only half as thick as expected. - Source and Rest of Story
 

Satellite photos of the Bosumtwi crater in Ghana, West Africa
Credit: Christian Köberl

BP Structure Crater
Libya
.
 Courtesy of Jeff Plescia, John Hopkins University
The BP Structure, also known as Gebel Dalma, is an impact crater in Libya. It is so called because it was found by a geological survey team belonging to BP, formerly British Petroleum.

It is 2 km in diameter and the age is estimated to be less than 120 million years (Lower Cretaceous or later). The crater is exposed to the surface.


Arkenu 1 & 2 Craters
Libya
.
 Courtesy NASA/Landsat 7
Double Impact Crater Site Found In Libya Using JERS-1 Data

The newly discovered structures are located 100 km west of Djebel Arkenu and 250 km south of Kufra oasis in Libya, at coordinates N22 deg 04', E23 deg 45'. It is a flat and hyperarid area, presenting a Cretaceous sandstone formation covered by active aeolian deposits and Quaternary soils, located tens of kilometers away from any track, in a hazardous zone due to the proximity of Second World War minefields.

The optical Landsat-7 image shows a sandy region with large sand dunes trending SW-NE, while the corresponding L-band radar image extracted from the JERS-1 radar mosaic reveals two circular structures partially hidden by Quaternary deposits.

The radar scene then clearly reveals a double circular structure composed of a southwestern crater 10.3 km in diameter and a northeastern crater of diameter 6.8 km. The NE crater is composed of concentric inner and outer rings separated by a depression filled with sediments, also observed in the optical scene.

Its morphology is very similar to the Aorounga crater in Chad, corresponding to a typical complex crater. The SW crater also presents a circular shape with possibly three concentric annular ridges. The host rock of the double circular structure is a cross bedded coarse grained to conglomeratic sandstone of Lower Cretaceous age containing plant fossils and thin shale inter beds, leading to an estimated impact age of less than 140 Ma.

SOURCE AND REST OF STORY


Oasis Crater
Libya
.
Oasis is a meteor crater in Libya. It is 18 km in diameter and the age is estimated to be less than 120 million years (Lower Cretaceous). The crater is exposed to the surface.
 

Kibera Crater
Egypt
.
Image courtesy of Boston University Center for Remote Sensing
Landsat image (color composite) of the newfound Kebira Crater in the Western Desert of Egypt at the border with Libya. The outer rim of the crater is about 19 miles (31 km) in diameter.
Huge Crater Found in Egypt
By Robert Roy Britt, Senior Science Writer
Posted: 03 March 2006

Scientists have discovered a huge crater in the Saharan desert, the largest one ever found there.

The crater is about 19 miles (31 kilometers) wide, more than twice as big as the next largest Saharan crater known. It utterly dwarfs Meteor Crater in Arizona, which is about three fourths of a mile (1.2 kilometers) in diameter.

In fact, the newfound crater, in Egypt, was likely carved by a space rock that was itself roughly 0.75 miles wide in an event that would have been quite a shock, destroying everything for hundreds of miles. For comparison, the Chicxulub crater left by a dinosaur killing asteroid 65 million years ago is estimated to be 100 to 150 miles (160 to 240 kilometers) wide.

SOURCE: Space.com and rest of article.


Aorounga Crater
Chad, Africa
.

The impact of an asteroid or comet several hundred million years ago left scars in the landscape that are still visible in this space borne radar image of an area in the Sahara Desert of northern Chad. The concentric ring structure is the Aorounga impact crater, with a diameter of about 17 kilometers (10.5 miles). The original crater was buried by sediments, which were then partially eroded to reveal the current ring like appearance. The dark streaks are deposits of windblown sand that migrate along valleys cut by thousands of years of wind erosion. The dark band in the upper right of the image is a portion of a proposed second crater. Scientists are using radar images to investigate the possibility that Aorounga is one of a string of impact craters formed by multiple impacts. Radar imaging is a valuable tool for the study of desert regions because the radar waves can penetrate thin layers of dry sand to reveal details of geologic structure that are invisible to other sensors. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on April 18 and 19, 1994, onboard the space shuttle Endeavor. The area shown is 22 kilometers by 28 kilometers (14 miles by 17 miles) and is centered at 19.1 degrees north latitude, 19.3 degrees east longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarization as follows: red is L-band, horizontally transmitted and received; green is C-band, horizontally transmitted and received; and blue is C-band, horizontally transmitted, vertically received. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth program.

This image is in the public domain and is copyright free. - SOURCE: Solar Views
 

Image Courtesy Google Earth

Gweni Fada Crater
Chad, Africa
.
 Image Courtesy Google Earth
 Image Courtesy NASA/Landsat
Gweni-Fada is a meteor crater in Chad, Africa. It is 14 km in diameter and the age is estimated to be less than 345 million years (Carboniferous). The crater is exposed to the surface.

Kgagodi Basin Impact Structure
Botswana
.
 Image Provided by Dr. Carlos Roberto de Souza Filho
Kgagodi basin, located at 27°34.4E/22°28.6S in eastern Botswana, is a confirmed impact
structure (Brandt et al., 2002). The surface expression of this 3.4 km wide structure is
completely eroded, and the crater was only discovered as a result of gravity studies in
preparation of hydrological drilling. 

See Also
A Proposal for Drilling of the Kgagodi Basin Impact Structure, Botswana - PDF File


Roter Kamm
Namibia, South West Africa
.

Located in the Namibia Desert, the raised crater rim is clearly visible against darker background vegetation. Target rocks include primarily Precambrian crystalline rocks and modest amounts of younger sedimentary rocks. Outcrops of impact melt breccias are found exclusively on the crater rim. The crater floor is covered by broad, shifting sand dunes. This image shows an oblique view of the crater, from about 150 meters (492 feet) above ground looking southeast. (Courtesy of W. U. Reimold and LPI) 
 

Roter Kamm, SAR-C/X-SAR Image

This space radar image shows the Roter Kamm impact crater. The crater rim is seen as a radar bright, circular feature. The bright white, irregular feature in the lower left corner is a small hill of exposed rock outcrop. Roter Kamm is a moderate sized impact crater, 2.5 kilometers (1.55 miles) in diameter, and is 130 meters (427 feet) deep. However, its original floor is covered by sand deposits at least 100 meters (328 feet) thick. In a conventional aerial photograph, the brightly colored surfaces immediately surrounding the crater cannot be seen because they are covered by sand. The faint blue surfaces adjacent to the rim might indicate the presence of a layer of rocks ejected from the crater during the impact. The darkest areas are thick, windblown sand deposits which form dunes and sand sheets. The sand surface is smooth relative to the surrounding granite and limestone rock outcrops and appears dark in radar image. The green tones are related primarily to larger vegetation growing on sand soil, and the reddish tones are associated with thinly mantled limestone outcrops. (Courtesy NASA/JPL) 

Credit:  Landsat 7, USGS,  NASA
Click Image for full size

Vredefort Dome
Free State, South Africa
STS-51 I-33-56AA
.

This crater consists of a near circular bay, about 5 kilometers (3 miles) wide and 220 meters (720 feet) deep, in the otherwise shallow Reindeer Lake. Such deep circular lakes are unusual in this region, which is dominated by the shallow gouging of glacial erosion. The circular shoreline, at a diameter of 11 kilometers (6.8 miles), is partially surrounded by a ridge with heights to 100 meters (328 feet) above the lake surface. The diameter of this ridge, ~13 kilometers (8 miles), is likely the outer rim of the impact structure. The structure was formed in Precambrian metamorphic crystalline rocks with a conspicuous northwest trending fabric. Although not obvious from the surface, Deep Bay is a complex impact structure with a low, totally submerged central uplift. Samples obtained in the 1960's from drilling into the central structure revealed shocked and fractured metamorphic rocks flanked by deposits of allocthonous, mixed breccias. (Courtesy NASA/LPI) 


Tswaing or Pretoria Salt Pan Crater
South Africa
.
 Courtesy of the Canadian Geological Survey
Forty kilometers north of Pretoria lies a ring of hills a kilometer in diameter and 100 meters high. These hills are the walls of an impact crater left by an asteroid which hit there some 200, 000 years ago. The Tswaing crater is similar in size to the well known Barringer meteor crater in Arizona. The crater walls at Tswaing were originally about twice as high as they are today.

The crater is called Tswaing in seTswana, the local language of the area, or Soutpan in Afrikaans. Both names mean Salt Pan and this derives from the lake of salty water that fills the center. - SOURCE

The photograph above is taken during the dry season, while the one below is taken during the rainy season. Both show you what it looks like today.

This picture was taken from the rim looking down into the crater. The pan at the bottom has been mined for salt for hundreds of years.
 
Landsat satellite image of the crater and immediate surroundings.
Tswaing is located 45 minutes from Johannesburg
Photo courtesy of Martin Tuchscherer, University of the Witwatersrand tuchscm@science.pg.wits.ac.za

Kalkkop Crater
South Africa
.
Image Courtesy NASA/ Landsat Thematic Mapper

Kalkkop is an impact crater and can be found on a private farm 48.3 km south west of the town of Graaff-Reinet in the Eastern Cape Province of South Africa. Co-ordinates (32°43'S, 24°34'E). The name is derived from two Afrikaans words, namely "kalk" meaning limestone and "kop" meaning head.

The meteor impact occurred just under 1.8 million years ago (in Pleistocene) on what is now the flat Karoo landscape. It left a crater 640 m in diameter and a few hundred meters deep. Over time, draining water left a limestone deposit 88.4 m deep. This lies over a breccia layer a further 210 m deep. Only a weathered circular ridge is still visible at the surface. 


Morokweng Crater
South Africa
.
Image Courtesy NASA/ Landsat

An impact crater, about 160 km (100 miles) in diameter, that lies buried under the sands of the Kalahari Desert sands near Morokweng, in the northwest part of South Africa (latitude 26° 28' S, longitude 23° 32' E). The Morokweng crater has an estimated age of 145.0 ± 0.8 million years, placing it at the boundary of the Jurassic and Cretaceous periods. It was created by an asteroid measuring about 5-10 km (3-6 miles) in diameter.

In 2006, scientists recovered meteorite fragments from the crater at a depth of 770 meters (2,500 ft). These fragments may not have been attached to the asteroid but may have trailed behind it as it entered Earth's atmosphere. They are among the oldest meteorite specimens ever found on this planet.


Huge Meteorite Crater Discovered in Eastern Jordan

A huge crater caused by a gigantic meteorite has been discovered recently in the eastern part of Jordan, the largest meteorite crater in the region, the Jordan Times reported on Tuesday.

The impact site in Jabal Waqf es Swwan, some 200 km east of the Karak governorate in eastern Jordan, was discovered by geology professors of University of Jordan Elias Salameh and Hani Khoury, along with German professor Werner Schneider.

A meteorite struck the area around 7,500-10,000 years ago with an impact diameter of about 100 meters, the report said.

"The damage force of such an impact might equal 5,000 times that of the Hiroshima atomic bomb," Salameh said, adding that it would have destroyed everything within a radius of hundreds of kilometers.

The crater consists of two concentric circles. The diameter of the outer ring measures around 5.5 km, with the inner ring measuring 2.7 km.

The impact size and velocity, according to Salameh, would have raised the atmospheric temperature within a radius of 10 kilometers to more than 1,000 degrees centigrade, spewing millions of tons of rocks, vapor, dust and smoke into the atmosphere.

The discovery is thought to be the largest such meteorite crater in the region, a statement issued by the University of Jordan said.

Salameh said that the site is expected to explain many geologic and historic features and events such as calcinated rocks, molten rock, highly jointed and cracked rocks

SOURCE

More:
Scientists discover region's largest meteor crater

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