graben

Graben is a loan word from German, meaning 'ditch' or 'trench'. The first known usage of the word in the geologic context was by Eduard Suess in 1883.{{oed|graben}} The plural form is either graben[https://glossary.oilfield.slb.com/en/terms/g/graben Schlumberger Oilfield Glossary] or grabens.{{cite encyclopedia

| title = horst and graben

| encyclopedia = Encyclopædia Britannica

| url = https://www.britannica.com/EBchecked/topic/272443/horst-and-graben

| access-date = 2012-11-15}}

A graben is a valley with a distinct escarpment on each side caused by the displacement of a block of land downward. Graben often occur side by side with horsts. Horst and graben structures indicate tensional forces and crustal stretching.

Graben are produced by sets of normal faults that have parallel fault traces, where the displacement of the hanging wall is downward, while that of the footwall is upward. The faults typically dip toward the center of the graben from both sides. Horsts are parallel blocks that remain between graben; the bounding faults of a horst typically dip away from the center line of the horst. Single or multiple graben can produce a rift valley.

{{Main|Half-graben}}

File:Newark Basin Cross Section.jpg, an early Mesozoic half-graben]]

In many rifts, the graben are asymmetric, with a major fault along only one of the boundaries, and these are known as half-graben. The polarity (throw direction) of the main bounding faults typically alternates along the length of the rift. The asymmetry of a half-graben strongly affects syntectonic deposition. Comparatively little sediment enters the half-graben across the main bounding fault because of footwall uplift on the drainage systems. The exception is at any major offset in the bounding fault, where a relay ramp may provide an important sediment input point. Most of the sediment will enter the half-graben down the unfaulted hanging wall side (e.g., Lake Baikal).{{cite journal|last1=Hans Nelson|first1=C.|last2=Karabanov|first2=Evgeny B.|last3=Colman|first3=Steven M.|last4=Escutia|first4=Carlota|title=Tectonic and sediment supply control of deep rift lake turbidite systems: Lake Baikal, Russia|journal=Geology|date=1999|volume=27|issue=2|pages=163–166|doi=10.1130/0091-7613(1999)027<0163:TASSCO>2.3.CO;2|bibcode=1999Geo....27..163N}}

Image:Rima Ariadaeus-1.jpg on the Moon is thought to be a graben. The lack of erosion on the Moon makes its structure with two parallel faults and the sunken block in between particularly obvious.]]

• East African Rift Valley
• Lucapa Graben, Lunda Norte Province, Angola

• Lambert Graben, Antarctica

• Narmada River Valley, central India
• lower Godavari River Valley, southern India
• Baikal Rift Zone, Siberia, Russia
• Moma Graben, Sakha Republic, Russia
• Büyük Menderes Graben, Turkey
• Fossa Magna, Honshu, Japan
• Ariake Sea as part of the Unzen graben, Kyushu, Japan
• Beppu–Shimabara graben, Kyushu, Japan

• Rhine valley, border area of west Germany and northeast France
• Oslo graben around Oslo, Norway
• Central Lowlands, Scotland
• Worcester Basin, England
• Central Graben, North Sea
• Viking Graben, North Sea
• Vättern, Sweden
• Lowtherville Graben, Ventnor, Isle of Wight, England{{Cite thesis |title=The Progressive Development and Post-failure Behaviour of Deep-seated Landslide Complexes |url=http://etheses.dur.ac.uk/3186/ |publisher=Durham University |date=2011 |degree=Doctoral |first=JONATHAN |last=CAREY}}{{Cite journal |last=Carey |first=Jonathan |date=November 2014 |title=Patterns of movement in the Ventnor landslide complex, Isle of Wight, southern England |url=https://www.researchgate.net/publication/284942330 |journal=Landslides|volume=12 |issue=6 |page=1107 |doi=10.1007/s10346-014-0538-1 |bibcode=2015Lands..12.1107C }}

• Ottawa-Bonnechere Graben, Ontario and Quebec, Canada
• Saguenay Graben, Quebec, Canada

• Guatemala City valley, Guatemala

• Basin and Range Province of southwestern North America is an example of multiple horst/graben structures, including Death Valley, with Salt Lake Valley being the easternmost and Owens Valley being the westernmost.
• Lake George Basin, New York, U.S.
• Lake Tahoe Basin, California and Nevada, U.S.
• Republic Graben, Republic, Washington, U.S.
• Rio Grande Rift Valley in Colorado/New Mexico/Texas of the United States
• Rough Creek Graben, Kentucky, U.S.
• Santa Clara Valley, California, U.S.
• Western Snake River Plain, Idaho, U.S.
• Southwest San Bernardino Valley (Arizona), U.S.

• Eastern North America Rift Basins, Canada and the U.S.
• Midcontinent Rift System, Canada and the U.S.
• Salton Trough, Mexico and the U.S.

• Firth of Thames of Hauraki Gulf and Hauraki Plains of Hauraki Rift (Hauraki half grabens), North Island, New Zealand{{Cite journal|doi = 10.1080/00288306.1979.10422550|title = Geophysical study of the Hauraki Depression, North Island, New Zealand|year = 1979|last1 = Hochstein|first1 = M.P.|last2 = Nixon|first2 = I.M.|journal = New Zealand Journal of Geology and Geophysics|volume = 22| issue=1 |pages = 1–19|doi-access = free| bibcode=1979NZJGG..22....1H }}
• Tikitere Graben within the Taupō Rift, North Island, New Zealand.{{cite journal|first1= V. |last1=Manville |first2= K. A. |last2=Hodgson |first3=I. A. |last3=Nairn |year=2007 |title=A review of break-out floods from volcanogenic lakes in New Zealand |journal= New Zealand Journal of Geology and Geophysics|volume=50 |issue=2 |pages=131–150 |doi=10.1080/00288300709509826 |s2cid=129792354 |doi-access=free |bibcode=2007NZJGG..50..131M }}
• Gulf St Vincent, South Australia, Australia{{cite journal | url=http://www.publish.csiro.au/AJ/AJ60011 | title=The Oil and Gas Prospects of the St. Vincents Gulf Graben | last=Sprigg | first=R.C. | journal=The APPEA Journal | year=1961 | volume=1 | issue=1 | pages=71–88 | doi=10.1071/AJ60011}}
• Tamar Valley, Tasmania, AustraliaStacey, A. R., and Berry, R. F., (2004). "[http://www.mrt.tas.gov.au/mrtdoc/tasxplor/download/05_5109/StructuralHistoryOfTasmana.pdf The Structural history of Tasmania: a review for petroleum explorers]", PESA Eastern Australasian Basins Symposium II

• Guanabara Graben, Rio de Janeiro, Brazil

• European Cenozoic Rift System
• {{annotated link|Fossa (geology)}}

{{Reflist}}

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• {{cite book | author1=McKnight, Tom L | author2=Hess, Darrel | year=2000 | chapter=The Internal Processes: Graben | title=Physical Geography: A Landscape Appreciation | pages=[https://archive.org/details/physicalgeographmckn/page/417 417] | location=Upper Saddle River, NJ | publisher=Prentice Hall | isbn=0-13-020263-0 | chapter-url-access=registration | chapter-url=https://archive.org/details/physicalgeographmckn/page/417 }}

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{{Structural geology}}

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Category:Structural geology

Category:Tectonic landforms