Suffosion

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Suffosion is one of the two geological processes by which subsidence sinkholes or dolines are formed, the other being due to collapse of an underlying cave or void, [1] with most sinkholes formed by the suffosion process. [2] Suffosion sinkholes are normally associated with karst topography although they may form in other types of rock including chalk, gypsum and basalt. In the karst of the UK's Yorkshire Dales, numerous surface depressions known locally as "shakeholes" are the result of glacial till washing into fissures in the underlying limestone.[ citation needed ]

Contents

Formation of a suffosion sinkhole SuffosionSinkholeFormation.jpg
Formation of a suffosion sinkhole

Process

Suffosion occurs when loose soil, loess, or other non-cohesive material lies on top of a limestone substratum containing fissures and joints. Rain and surface water gradually wash this material through these fissures and into caves beneath. [2] Over time, this creates a depression on the landscape of varying depth.

Suffosion versus suffusion

Suffosion is a destructive process that creates instability leading to collapse of the soil structure, characterized by both mass loss and volumetric contraction. In suffosion, coarser particles lose their point-to-point contact. This is in contrast to suffusion, which is non-destructive and is characterized by mass loss without change in volume. In suffusion, coarser particles remain in point-to-point contact and fine particles are removed through the voids between them. [3] [4]

Examples

The following sites are examples of sinkholes formed by suffosion:

Related Research Articles

<span class="mw-page-title-main">Karst</span> Topography from dissolved soluble rocks

Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes. However, in regions where the dissolved bedrock is covered or confined by one or more superimposed non-soluble rock strata, distinctive karst features may occur only at subsurface levels and can be totally missing above ground.

<span class="mw-page-title-main">Aquifer</span> Underground layer of water-bearing permeable rock

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<span class="mw-page-title-main">Subsidence</span> Downward vertical movement of the Earths surface

Subsidence is a general term for downward vertical movement of the Earth's surface, which can be caused by both natural processes and human activities. Subsidence involves little or no horizontal movement, which distinguishes it from slope movement.

<span class="mw-page-title-main">Sinkhole</span> Geologically-formed topological depression

A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are locally also known as vrtače and shakeholes, and to openings where surface water enters into underground passages known as ponor, swallow hole or swallet. A cenote is a type of sinkhole that exposes groundwater underneath. A sink or stream sink are more general terms for sites that drain surface water, possibly by infiltration into sediment or crumbled rock.

Landforms are categorized by characteristic physical attributes such as their creating process, shape, elevation, slope, orientation, rock exposure, and soil type.

<span class="mw-page-title-main">Cenote</span> Natural pit or sinkhole that exposes groundwater underneath

A cenote is a natural pit, or sinkhole, resulting from the collapse of limestone bedrock that exposes groundwater. The regional term is specifically associated with the Yucatán Peninsula of Mexico, where cenotes were commonly used for water supplies by the ancient Maya, and occasionally for sacrificial offerings. The term derives from a word used by the lowland Yucatec Maya—tsʼonot—to refer to any location with accessible groundwater.

<span class="mw-page-title-main">Depression (geology)</span> Landform sunken or depressed below the surrounding area

In geology, a depression is a landform sunken or depressed below the surrounding area. Depressions form by various mechanisms.

<span class="mw-page-title-main">Blue hole</span> Marine cavern or sinkhole, open to the surface, in carbonate bedrock

A blue hole is a large marine cavern or sinkhole, which is open to the surface and has developed in a bank or island composed of a carbonate bedrock. Their existence was discovered in the late 20th century by fishermen and recreational divers. Blue holes typically contain tidally influenced water of fresh, marine, or mixed chemistry. They extend below sea level for most of their depth and may provide access to submerged cave passages. Well-known examples are the Dragon Hole and, in the Caribbean, the Great Blue Hole and Dean's Blue Hole.

Internal erosion is the formation of voids within a soil caused by the removal of material by seepage. It is the second most common cause of failure in levees and one of the leading causes of failures in earth dams, responsible for about half of embankment dam failures.

<span class="mw-page-title-main">Sea cave</span> Cave formed by the wave action of the sea and located along present or former coastlines

A sea cave, also known as a littoral cave, is a type of cave formed primarily by the wave action of the sea. The primary process involved is erosion. Sea caves are found throughout the world, actively forming along present coastlines and as relict sea caves on former coastlines. Some of the largest wave-cut caves in the world are found on the coast of Norway, but are now 100 feet or more above present sea level. These would still be classified as littoral caves. By contrast, in places like Thailand's Phang Nga Bay, solutionally formed caves in limestone have been flooded by the rising sea and are now subject to littoral erosion, representing a new phase of their enlargement.

<span class="mw-page-title-main">Altopiano delle Murge</span>

The Altopiano delle Murge is a karst topographic plateau of rectangular shape in southern Italy. Most of it lies within Apulia and corresponds with the sub-region known as Murgia or Le Murge. The plateau lies mainly in the Metropolitan City of Bari and the province of Barletta-Andria-Trani, but extends into the provinces of Brindisi and Taranto to the south, and into Matera in Basilicata to the west. The name is believed to originate from the Latin murex, meaning "sharp stone".

<span class="mw-page-title-main">Eramosa Karst</span>

The Eramosa Karst is a provincially significant Earth Science Area of Natural and Scientific Interest in Ontario, Canada, located in Stoney Creek, a constituent community of the City of Hamilton, and immediately south of the Niagara Escarpment.

<span class="mw-page-title-main">Ponor</span>

A ponor is a natural opening where surface water enters into underground passages; they may be found in karst landscapes where the geology and the geomorphology is typically dominated by porous limestone rock. Ponors can drain stream or lake water continuously or can at times work as springs, similar to estavelles. Morphologically, ponors come in forms of large pits and caves, large fissures and caverns, networks of smaller cracks, and sedimentary, alluvial drains.

Škocjan Caves Regional Park is located in the Škocjan Karst, a vast flat landscape that lies at an elevation between 420 and 450 m in the southeast part of the Karst area. Following its independence, the Slovenia committed itself to protecting the Škocjan Caves area; for this reason, it established Škocjan Caves Regional Park and its managing authority, the Škocjan Caves Park Public Service Agency.

<span class="mw-page-title-main">Uvala (landform)</span> Toponym for a closed karst depression

Uvala is originally a local toponym used by people in some regions in Slovenia, Croatia, Bosnia and Herzegovina, Montenegro and Serbia. In geosciences it denotes a closed karst depression, a terrain form usually of elongated or compound structure and of larger size than that of sinkholes. It is a morphological form frequently found in the "Outer Dinarides" anywhere between Slovenia and Greece. But large closed karst depressions are found on all continents in different landscapes and therefore uvala has become a globally established term, used also to distinguish such depressions from poljes. Definitions of uvalas are often poorly empirically supported. "The coalescence of dolines" is a most frequently found and still dominant explanation. Yet because of the ongoing dissatisfaction with this definition the term 'uvala' has often been belittled – occasionally it was even proposed that the term be given up altogether.

Little Blue Lake is a water-filled doline in the Australian state of South Australia located in the state's south-east in the locality of Mount Schank about 20 kilometres (12 mi) south of the municipal seat of Mount Gambier. It is notable locally as a swimming hole and nationally as a cave diving site. It is managed by the District Council of Grant and has been developed as a recreational and tourism venue.

<span class="mw-page-title-main">Cedar Sink</span>

Cedar Sink is a vertical-walled large depression, or sinkhole, in the ground, that is located in Edmonson County, Kentucky and contained within and managed by Mammoth Cave National Park. The sinkhole measures 300 feet (91.4 m) from the top sandstone plateau to the bottom of the sink and was caused by collapse of the surface soil. The landscape is karst topography, which means the region is influenced by the dissolution of soluble rocks. Sinkholes, caves, and dolines typically characterize these underground drainage systems. Cedar Sink has a bottom area of about 7 acres (2.8 ha) and has more fertile soil compared to the ridgetops.

<span class="mw-page-title-main">Pulicchio di Gravina</span>

Pulicchio di Gravina is the second-largest doline in the Murge plateau after Pulo di Altamura. It falls into the territory of Gravina in Puglia, being located about 10 kilometers (6.2 mi) north of the latter, close to the border with Altamura's territory. It shares the local toponym pulo with other large dolines of the region, i.e. Pulo di Altamura, Pulo di Molfetta and Pulicchio di Toritto.

<span class="mw-page-title-main">Fissure</span> Long, narrow crack opening on a planetary surface

A fissure is a long, narrow crack opening along the surface of Earth. The term is derived from the Latin word fissura, which means 'cleft' or 'crack'. Fissures emerge in Earth's crust, on ice sheets and glaciers, and on volcanoes.

References

  1. Waltham, T.; Bell, T.; Culshaw, M. (2005). Sinkholes and Subsidence. Berlin: Springer. ISBN   978-3540207252.
  2. 1 2 "Dolines and sinkholes". British Geological Survey . Retrieved February 21, 2011.
  3. Fannin, R. J.; Slangen, P. (2014). "On the Distinct Phenomena of Suffusion and Suffosion". Géotechnique Letters. 4 (4): 289–294. doi:10.1680/geolett.14.00051.
  4. Guyer, J. Paul (2022). An Introduction to Seepage Failure Modes in Embankment Dams for Professional Engineers. Author. p. 17. ISBN   979-8830928250.