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

, a floater or a float is a piece of

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 Wale ...

that has been

eroded 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 disti ...

, isolated and transported away from its original

outcrop An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth and other terrestrial planets. Features Outcrops do not cover the majority of the Earth's land surface because in most p ...

, and it is found within a soil or

weathering Weathering is the deterioration of rocks, soils and minerals (as well as wood and artificial materials) through contact with water, atmospheric gases, sunlight, and biological organisms. It occurs '' in situ'' (on-site, with little or no move ...

profile. A floater can also be a bigger

rock fragment A rock fragment, in sedimentary geology, is a sand-sized particle or sand grain that is made up of multiple grains that are connected on the grain scale. These can include grains which are sand-sized themselves (a granitic rock fragment), or fin ...

that is detached from the underlying

bedrock In geology, bedrock is solid rock that lies under loose material ( regolith) within the crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface material. An exposed portion of bed ...

Background

Floaters or floats are chiefly loose rocks that have been transported or detached from their original source (largely through physical weathering) and are normally scattered across the

soil profile A soil horizon is a layer parallel to the soil surface whose physical, chemical and biological characteristics differ from the layers above and beneath. Horizons are defined in many cases by obvious physical features, mainly colour and texture. ...

, or even by water transport in a river or creek. Often discovered by

excavation Excavation may refer to: * Archaeological excavation * Excavation (medicine) * ''Excavation'' (The Haxan Cloak album), 2013 * ''Excavation'' (Ben Monder album), 2000 * ''Excavation'' (novel), a 2000 novel by James Rollins * '' Excavation: A Mem ...

, floaters can also be isolated rock

debris Debris (, ) is rubble, wreckage, ruins, litter and discarded waste, garbage/refuse/trash, scattered remains of something destroyed, or, as in geology, large rock fragments left by a melting glacier, etc. Depending on context, ''debris'' can ref ...

of around a

boulder In geology, a boulder (or rarely bowlder) is a rock 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 ...

size rock or a larger one. Smaller ones may be thrusted aside or be shifted a bit by an

earth auger An earth auger, earth drill, or post-hole auger is a drilling tool used for making holes in the ground. It typically consists of a rotating vertical metal rod or pipe with one or more blades attached at the lower end, that cut or scrape the soil. ...

. Large float rocks can be mistaken for the underlying bedrock, which ensues in underestimating the deepness and density of soils,

regolith Regolith () is a blanket of unconsolidated, loose, heterogeneous superficial deposits covering solid rock. It includes dust, broken rocks, and other related materials and is present on Earth, the Moon, Mars, some asteroids, and other terrestria ...

s, and weathering outlines. Loose rock pieces laying around on the surface usually make it difficult for

geologist A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...

s to determine how far they have been shifted away from the bedrock (after being disconnected by weathering processes). A geologist should spend some time determining whether they are dealing with an outcrop, a

subcrop Subcrop is a term in geology. It is a contrast to the term ''outcrop'', if not a perfect antonym. If rocks exposed at the present-day erosion surface are referred to as outcrops, then now-buried rocks that were exposed at ancient erosion surfaces ...

, or a large float, as it is impossible to ascertain that the exposed rock is attached to the bedrock.

Origin

As rocks weather irregularly, water flows into the rock along the fractures, where it prevails in particular physical areas within the rock. Self-reinforcing weathering may follow the tenacity of unweathered or marginally weathered mother rock through a mold of detached, weathered material (i.e.

corestone Spheroidal weathering is a form of chemical weathering that affects jointed bedrock and results in the formation of concentric or spherical layers of highly decayed rock within weathered bedrock that is known as ''saprolite.'' When saprolite ...

s). The more resistant rock is interstratified with the less resistant

lithologies The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples, or with low magnification microscopy. Physical characteristics include colour, texture, grain size, and composition. Lith ...

Sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

and

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

in sedimentary orders are typically stratified, such as in

flysch Flysch () is a sequence of sedimentary rock layers that progress from deep-water and turbidity flow deposits to shallow-water shales and sandstones. It is deposited when a deep basin forms rapidly on the continental side of a mountain building ep ...

settings. Rock decomposition can evade the more unyielding rock as the less impervious material is converted to

saprolite Saprolite is a chemically weathered rock. Saprolites form in the lower zones of soil profiles and represent deep weathering of the bedrock surface. In most outcrops, its color comes from ferric compounds. Deeply weathered profiles are widespread ...

or soil. Downward movement can happen due to gravitational settling, with some sabotaging by soil bioirrigation caused by

burrowing An eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of locomotion. Burrows provide a form of s ...

animals.

Transportation

Tree roots have the ability to pervade the bedrock and raise the formerly unattached fragments, and therefore

tree uprooting Uprooting is a form of treefall in which the root plate of a tree is torn from the soil, disrupting and mixing it and leaving a pit-mound. Purposes Transplanting Small trees can be replanted if their root system is well attached to the trun ...

is one of the most common cause of floaters in woody settings. Rock pieces are upraised as part of the root mass, which settle into uproot holes or on the ground at a higher altitude. The

frost weathering Frost weathering is a collective term for several mechanical weathering processes induced by stresses created by the freezing of water into ice. The term serves as an umbrella term for a variety of processes, such as frost shattering, frost w ...

process can maneuver rock pieces above the ground, in addition to animal and human excavation. Rock debris can also be transported to a site and movie their way downward. Transportation of floaters in the

modern era The modern era or the modern period is considered the current historical period of human history. It was originally applied to the history of Europe and Western history for events that came after the Middle Ages, often from around the year 1500 ...

mainly occurs due to

mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...

, construction, and landscaping activities in general. Rock creep can also move rock pieces that are formed by weathering of surface bedrock outcropping downslope.

Human use

prehistory Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use ...

, as far back as the

paleolithic The Paleolithic or Palaeolithic ( years ago) ( ), also called the Old Stone Age (), is a period in human prehistory that is distinguished by the original development of stone tools, and which represents almost the entire period of human prehist ...

era, floaters would have been easily obtained and used by humans and early

hominids The Hominidae (), whose members are known as the great apes or hominids (), are a taxonomic family of primates that includes eight extant species in four genera: '' Pongo'' (the Bornean, Sumatran and Tapanuli orangutan); '' Gorilla'' (the ...

stone tool Stone tools have been used throughout human history but are most closely associated with prehistoric cultures and in particular those of the Stone Age. Stone tools may be made of either ground stone or knapped stone, the latter fashioned by a ...

s, due to their widespread nature through the soil profile.

Early humans ''Homo'' () is a genus of great ape (family Hominidae) that emerged from the genus ''Australopithecus'' and encompasses only a single extant species, ''Homo sapiens'' (modern humans), along with a number of extinct species (collectively called ...

used them to create a variety of equipment made of either

ground stone In archaeology, ground stone is a category of stone tool formed by the grinding of a coarse-grained tool stone, either purposely or incidentally. Ground stone tools are usually made of basalt, rhyolite, granite, or other cryptocrystalline and ...

or knapped stone, as the

Stone Age The Stone Age was a broad prehistory, prehistoric period during which Rock (geology), stone was widely used to make stone tools with an edge, a point, or a percussion surface. The period lasted for roughly 3.4 million years and ended b ...

was a period of widespread stone tool usage. Throughout

human history Human history or world history is the record of humankind from prehistory to the present. Early modern human, Modern humans evolved in Africa around 300,000 years ago and initially lived as hunter-gatherers. They Early expansions of hominin ...

, people have transported stone for

construction Construction are processes involved in delivering buildings, infrastructure, industrial facilities, and associated activities through to the end of their life. It typically starts with planning, financing, and design that continues until the a ...

and for making

hearth A hearth () is the place in a home where a fire is or was traditionally kept for home heating and for cooking, usually constituted by a horizontal hearthstone and often enclosed to varying degrees by any combination of reredos (a low, partial ...

s and fire bowls, at times with help of

domesticated animal This page gives a list of domesticated animals, also including a list of domestication of animals, animals which are or may be currently undergoing the process of domestication and animals that have an extensive relationship with humans beyond simp ...

s. In

Ancient Egypt Ancient Egypt () was a cradle of civilization concentrated along the lower reaches of the Nile River in Northeast Africa. It emerged from prehistoric Egypt around 3150BC (according to conventional Egyptian chronology), when Upper and Lower E ...

, easily worked, soft

sedimentary rock Sedimentary rocks are types of rock (geology), rock formed by the cementation (geology), cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or de ...

s were quarried for construction as early as 4000 BCE. In modern real estate, floaters may be expensive to remove, though this depends on their size. However, a building constructed on them could compromise the structure with time.

Gallery

FossilBeach6 DMarshall2017.jpg, Floaters on beach in

Sedbury Sedbury is a village in the Forest of Dean district of west Gloucestershire, England. It is located on the eastern bank of the River Wye, facing the town of Chepstow in Monmouthshire. The village is in the parish of Tidenham. It had a populatio ...

Gloucestershire Gloucestershire ( , ; abbreviated Glos.) is a Ceremonial counties of England, ceremonial county in South West England. It is bordered by Herefordshire to the north-west, Worcestershire to the north, Warwickshire to the north-east, Oxfordshire ...

Phosphate-rich sedimentary rock (Phosphoria Formation, Permian; Deer Creek Valley area; Preuss Range, Idaho, USA) 6.jpg, Preuss Range,

Idaho Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...

, USA Sulfidic dike intruding basaltic lapillistone (Middle Tholeiitic Unit, Kidd-Munro Assemblage, Neoarchean, 2.711-2.719 Ga; just east of the Potter Mine, east of Timmins, Ontario, Canada) (40899745123).jpg, East of

Timmins Timmins ( ) is a city in northeastern Ontario, Canada, located on the Mattagami River. The city is the fourth-largest city in the Northeastern Ontario region with a population of 41,145 at the 2021 Canadian census and an estimated population of ...

, Ontario, Canada Tsherige Member.jpg, A large

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock co ...

floater south of White Rock, New Mexico Typic Haprendoll (loamy over fragmental, mixed, active, isothermic) (5468736277).jpg,

Limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

floaters in

Sri Lanka Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka, also known historically as Ceylon, is an island country in South Asia. It lies in the Indian Ocean, southwest of the Bay of Bengal, separated from the Indian subcontinent, ...

Moss, rocks, and bare soil, by Great Sacandaga Lake (2008).jpg, Floaters by the

Great Sacandaga Lake The Great Sacandaga Lake (formerly the Sacandaga Reservoir) is a large lake in the Adirondack Park in northern New York in the United States. The lake has a surface area of about at capacity, and the length is about . The word ''Sacandaga'' me ...

New York New York most commonly refers to: * New York (state), a state in the northeastern United States * New York City, the most populous city in the United States, located in the state of New York New York may also refer to: Places United Kingdom * ...

Stromatoporoid fragments (Ashlock Formation, Upper Ordovician; Paint Lick Elementary School outcrop, Garrard County, Kentucky, USA) 23.jpg,

Upper Ordovician The Late Ordovician is the third and final epoch of the Ordovician period, lasting million years and spanning from around 458.2 to 443.1 million years ago. The rocks associated with this epoch are referred to as the Upper Ordovician Series. At ...

floaters in Garrard County, Kentucky

References