geology Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Ea ...

, a boulder (or rarely bowlder) is a

rock Rock most often refers to: * Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids * Rock music, a genre of popular music Rock or Rocks may also refer to: Places United Kingdom * Rock, Caerphilly, a location in Wales ...

fragment with size greater than in diameter. Smaller pieces are called cobbles and pebbles. While a boulder may be small enough to move or roll manually, others are extremely massive. In common usage, a boulder is too large for a person to move. Smaller boulders are usually just called

s or stones. The word ''boulder'' derives from ''boulder stone'', from the

Middle English Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English ...

''bulderston'' or

Swedish Swedish or ' may refer to: Anything from or related to Sweden, a country in Northern Europe. Or, specifically: * Swedish language, a North Germanic language spoken primarily in Sweden and Finland ** Swedish alphabet, the official alphabet used by ...

''bullersten''.boulder. (n.d.)
Online Etymology Dictionary. Retrieved December 9, 2011, from Dictionary.com website. In places covered by

ice sheet In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at La ...

s during

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...

s, such as

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and Swe ...

, northern North America, and

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive region, geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a ...

glacial erratic A glacial erratic is glacially deposited rock differing from the type of rock native to the area in which it rests. Erratics, which take their name from the Latin word ' ("to wander"), are carried by glacial ice, often over distances of hundre ...

s are common. Erratics are boulders picked up by ice sheets during their advance, and deposited when they melt. These boulders are called "erratic" because they typically are of a different rock type than the bedrock on which they are deposited. One such boulder is used as the

pedestal A pedestal (from French ''piédestal'', Italian ''piedistallo'' 'foot of a stall') or plinth is a support at the bottom of a statue, vase, column, or certain altars. Smaller pedestals, especially if round in shape, may be called socles. In ...

the Bronze Horseman The ''Bronze Horseman'' (russian: link=no, Медный всадник, literally "copper horseman") is an equestrian statue of Peter the Great in the Senate Square in Saint Petersburg, Russia. It was opened to the public on 7 (18) August ...

Saint Petersburg Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), i ...

, Russia. Some noted rock formations involve giant boulders exposed by

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is dis ...

, such as the Devil's Marbles in Australia's

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an Australian territory in the central and central northern regions of Australia. The Northern Territory shares its borders with Western Aust ...

, the

Horeke basalts The Horeke basalts is a disused formation that contained Miocene-Pliocene basalt lava flows that covered a large area in central Northland Region of New Zealand, and in places forms a high plateau around Okaihau. Wairere Boulders is a nature ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

, where an entire

valley A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams ove ...

contains only boulders, and

The Baths The Baths is a beach area on the island of Virgin Gorda among the British Virgin Islands in the Caribbean. Geography The Baths is situated about south off the maintown Spanish Town at the southern tip of the island between Spring Bay and Devil ...

on the island of

Virgin Gorda Virgin Gorda () is the third-largest island (after Tortola and Anegada) and second-most populous of the British Virgin Islands (BVI). Geography Located at about 18 degrees, 48 minutes North, and 64 degrees, 30 minutes West, it covers an area ...

in the

British Virgin Islands ) , anthem = "God Save the King" , song_type = Territorial song , song = " Oh, Beautiful Virgin Islands" , image_map = File:British Virgin Islands on the globe (Americas centered).svg , map_caption = , mapsize = 290px , image_map2 = Bri ...

. Boulder-sized

clast Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus,Essentials of Geology, 3rd Ed, Stephen Marshak, p. G-3 chunks, and smaller grains of rock broken off other rocks ...

s are found in some

sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

s, such as coarse conglomerate and

boulder clay Boulder clay is an unsorted agglomeration of clastic sediment that is unstratified and structureless and contains gravel of various sizes, shapes, and compositions distributed at random in a fine-grained matrix. The fine-grained matrix consists o ...

. The climbing of large boulders is called

bouldering Bouldering is a form of free climbing that is performed on small rock formations or artificial rock walls without the use of ropes or harnesses. While bouldering can be done without any equipment, most climbers use climbing shoes to help se ...

References

External links

{{Authority control Rocks Rock formations Garden features Natural materials

See also

References

External links