The Ceraunius Fossae are a set of fractures in the northern

Tharsis Tharsis () is a vast volcanic plateau centered near the equator in the western hemisphere of Mars. The region is home to the largest volcanoes in the Solar System, including the three enormous shield volcanoes Arsia Mons, Pavonis Mons, and Asc ...

region of

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

. They lie directly south of the large

volcano A volcano is a rupture in the Crust (geology), crust of a Planet#Planetary-mass objects, planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Ear ...

Alba Mons Alba Mons (formerly and still occasionally known as Alba Patera, a term that has since been restricted to the volcano's summit caldera; also initially known as the Arcadia ring) is a volcano located in the northern Tharsis region of the planet Ma ...

and consist of numerous parallel faults and tension cracks that deform the ancient highland crust.Carr, M.H. (2006). ''The Surface of Mars;'' Cambridge University Press: Cambridge, UK, p. 87. . In places, younger lava flows cover the fractured terrain, dividing it into several large patches or islands.Raitala, J. (1988). Composite Graben Tectonics of Alba Patera on Mars. ''Earth, Moon, and Planets,'' 42, 277–291. They are found in the

Tharsis quadrangle The Tharsis quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Tharsis quadrangle is also referred to as MC-9 (Mars Chart-9). The name Tharsis refe ...

. The faults are mainly narrow, north-south oriented graben. Graben (the name is both singular and plural) are long, narrow troughs bound by two inward-facing normal faults that enclose a downfaulted block of crust. The graben in the Ceraunius Fossae are commonly several kilometers wide, between 100 and slightly over 1000 m deep, and very closely spaced, giving the terrain a rugged ridge and groove

topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sc ...

.Banerdt, W.B.; Golombek, M.P.; Tanaka, K.L. (1992). Stress and Tectonics on Mars in ''Mars,'' H.H. Kieffer ''et al.,'' Eds.; University of Arizona Press: Tucson, AZ, pp. 248–297. Many of the graben are hundreds of kilometers longTanaka, K.L. (1990). Tectonic history of the Alba Patera–Ceraunius Fossae Region of Mars. ''Lunar. Planet. Sci. Conf.,'' 20, 515–523. http://articles.adsabs.harvard.edu//full/1990LPSC...20..515T/0000515.000.html. and have walls with complex scalloped segments. Some contain pit crater chains (catenae) at their bottoms, suggesting the presence of deep-seated tension cracks into which surface material has drained.

Name Origin

The term Ceraunius is from an albedo feature at lat. 19.78°N, long. 267°E. It was named by Greek Astronomer

E. M. Antoniadi Eugène Michel Antoniadi (Greek: Ευγένιος Αντωνιάδης; 1 March 1870 – 10 February 1944) was a Greek-French astronomer. Biography Antoniadi was born in Istanbul (Constantinople) but spent most of his adult life in France ...

in 1930 for the

Ceraunian Mountains The Ceraunian Mountains ( sq, Malet e Vetëtimës, "Thunderbolt mountains"; el, Κεραύνια Όρη, ''Keravnia ori''; la, Cerauni Montes), also commonly Akroceraunian Mountains ( grc, Ἀκροκεραύνια, sq, Malet Akrokeraune "male ...

on the coast of

Epirus sq, Epiri rup, Epiru , native_name_lang = , settlement_type = Historical region , image_map = Epirus antiquus tabula.jpg , map_alt = , map_caption = Map of ancient Epirus by Heinri ...

Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders ...

Gazetteer of Planetary Nomenclature. http://planetarynames.wr.usgs.gov/Feature/1103. (now southwestern

Albania Albania ( ; sq, Shqipëri or ), or , also or . officially the Republic of Albania ( sq, Republika e Shqipërisë), is a country in Southeastern Europe. It is located on the Adriatic and Ionian Seas within the Mediterranean Sea and shares ...

). Fossa (pl. ''fossae'') is

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

for ditch and is a descriptor term used in planetary geology for a long, narrow depression or trench.Russell, J.F.; Snyder, C.W.; Kieffer, H.H. (1992). Origin and Use of Martian Nomenclature in ''Mars,'' H.H. Kieffer ''et al.,'' Eds.; University of Arizona Press: Tucson, AZ, p. 1311. The

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

(IAU) formally adopted the term Ceraunius Fossae in 1973. The name Ceraunius Fossae is plural and translates into "the Ceraunian trenches". Alba Patera - topography map

Location and size

Most of the Ceraunius Fossae are located in the northern

. A portion extend northward into the southwestern part of the

Arcadia quadrangle The Arcadia quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The quadrangle is located in the north-central portion of Mars’ western hemisphere an ...

where the fossae diverge around the flanks of Alba Mons to form the Alba and Tantalus Fossae systems. The area stretches from lat. 18.9° to 38°N and from long. 247° to 255°E. The entire feature has a north-south length of 1137 km.Gazetteer of Planetary Nomenclature. Specifics of the Gazetteer. http://planetarynames.wr.usgs.gov/Page/Specifics The Ceraunius Fossae lie on a broad topographic ridge up to 1.5 km high,Ivanov, M. A.; Head, J.W. (2006), Alba Patera, Mars: Topography, Structure, and Evolution of a Unique Late Hesperian–Early Amazonian Shield Volcano. ''J. Geophys. Res.,'' 111, E09003, . called the Ceraunius rise.Anderson, R.C. ''et al.'' (2004). Tectonic Histories Between Alba Patera and Syria Planum, Mars. ''Icarus,'' 171, 31–38. The ridge projects from the southern edge of Alba Mons and extends southward for a distance of over 1000 km. The southern half of the Alba Mons volcano is built over the northern extension of this ridge.

Geology

The Ceraunius Fossae are

tectonic Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents ...

features indicating stresses in the planet's lithosphere. The fractures form when the stresses exceed the

yield strength In materials science and engineering, the yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning of plastic behavior. Below the yield point, a material will deform elastically and ...

of rock, resulting in deformation of surface materials. Typically, this deformation is manifested as slip on faults that are recognizable in images from orbit. Most of the tectonic features in the western hemisphere of Mars are explained by crustal deformation from the Tharsis bulge (a huge volcanic mass up to 7 km high that covers nearly a quarter of the planet’s surface). Among the processes proposed to explain the tectonic features associated with Tharsis are domal uplifting,

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...

tic intrusion, and volcanic loading (deformation due to the large, sagging weight of the volcanic mass).Head, J.W. (2007). The Geology of Mars: New Insights and Outstanding Questions in ''The Geology of Mars: Evidence from Earth-Based Analogs,'' M. Chapman, Ed.; Cambridge University Press: Cambridge: UK, p. 23. . The Ceraunius Fossae fractures are

extensional In any of several fields of study that treat the use of signs — for example, in linguistics Linguistics is the science, scientific study of human language. It is called a scientific study because it entails a comprehensive, systematic, obj ...

features produced when the crust is stretched apart. The fractures are oriented north-south, radial to an early center of volcano-tectonic activity in Syria Planum, a region in southern Tharsis. A large number of extensional structures, including graben and

rift In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-grabe ...

s, radiate outward from the center of Tharsis.

Mechanical Mechanical may refer to: Machine * Machine (mechanical), a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement * Mechanical calculator, a device used to perform the basic operations of ...

studies indicate that a regional pattern of radiating graben and rifts is consistent with stresses caused by loading of the lithosphere by the enormous weight of the Tharsis bulge. The immense

Valles Marineris Valles Marineris (; Latin for '' Mariner Valleys'', named after the ''Mariner 9'' Mars orbiter of 1971–72 which discovered it) is a system of canyons that runs along the Martian surface east of the Tharsis region. At more than long, wide and ...

is probably the best known example of a rift system that lies radial to Tharsis. Several generations of grabens with slightly different orientations are present in Ceraunius Fossae, indicating that

stress field A stress field is the distribution of internal forces in a body that balance a given set of external forces. Stress fields are widely used in fluid dynamics and materials science. Consider that one can picture the stress fields as the stress cre ...

s have changed somewhat over time. Southern part of Ceraunius Fossae based on day THEMIS

In addition to producing normal faults and graben, extensional stresses can produce dilatant fractures or tension cracks that can open up subsurface voids. When surface material slides into the void, a pit crater may form. Pit craters are distinguishable from impact craters in lacking raised rims and surrounding

ejecta blanket An ejecta blanket is a generally symmetrical apron of ejecta that surrounds an impact crater; it is layered thickly at the crater's rim and thin to discontinuous at the blanket's outer edge. The impact cratering is one of the basic surface format ...

s. On Mars, individual pit craters can coalesce to form

crater chain A crater chain is a line of craters along the surface of an astronomical body. The descriptor term for crater chains is catena , plural catenae (Latin for "chain"), as specified by the International Astronomical Union's rules on planetary nome ...

s (catenae) or troughs with scalloped edges.Ferrill, D.A.; Wyrick, D.Y.; Morris, A.P; Sims, D.W.; Franklin, N.M. (2004). Dilational Fault Slip and Pit Chain Formation on Mars. ''GSA Today,'' 14(10), 4-12. Evidence also exists that some of the graben and crater chains in the Ceraunius Fossae may have been formed by the intrusion of

, which forms large underground

dikes Dyke (UK) or dike (US) may refer to: General uses * Dyke (slang), a slang word meaning "lesbian" * Dike (geology), a subvertical sheet-like intrusion of magma or sediment * Dike (mythology), ''Dikē'', the Greek goddess of moral justice * Dikes ...

. The migration of the magma exploits or opens up fractures in the subsurface, causing a crack or pit crater chain to form at the surface.Wilson, L.; Head, J.W. (2002). Tharsis-Radial Graben Systems as the Surface Manifestation of Plume-Related Dike Intrusion Complexes: Models and Implications. ''J. Geophys. Res.,'' 107(E8), 5057, . Knowledge of the locations and formation mechanisms of pit craters and fossae is important for the future colonization of Mars because subsurface fractures may act as conduits or reservoirs for water and ice.

Photo gallery

Image:Tharsis Quadrangle map-la.svg, Map of Tharsis quadrangle with major features indicated. The Ceraunius Fossae are in the upper right. Image:Ceraunius Valley PIA07864.jpg, Graben in the Ceraunius Fossae, as seen by

Mars Global Surveyor ''Mars Global Surveyor'' (MGS) was an American robotic space probe developed by NASA's Jet Propulsion Laboratory and launched November 1996. MGS was a global mapping mission that examined the entire planet, from the ionosphere down through t ...

MOC. Note dark slope streaks. Image:Ceraunius Fossae.JPG, The Ceraunius Fossae, as seen by

HiRISE High Resolution Imaging Science Experiment is a camera on board the '' Mars Reconnaissance Orbiter'' which has been orbiting and studying Mars since 2006. The 65 kg (143 lb), US$40 million instrument was built under the direction ...

. Image:Ceraunius Pits.jpg, Pit crater chain in Ceraunius Catena, as seen by

References

{{Portal bar, Solar System Valleys and canyons on Mars Tharsis quadrangle

Name Origin

Location and size

Geology

Photo gallery

See also

References