Sedimentary rocks are types of rock that are formed by the accumulation or deposition of small particles and subsequent cementation of mineral or organic particles on the floor of oceans or other bodies of water at the Earth's surface. Sedimentation is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus. Before being deposited, the geological detritus was formed by weathering and erosion from the source area, and then transported to the place of deposition by water, wind, ice, mass movement or glaciers, which are called agents of denudation. Biological detritus was formed by bodies and parts of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies. Sedimentation may also occur as dissolved minerals precipitate from water solution.
Chalk is a soft, white, porous, sedimentary carbonate rock, a form of limestone composed of the mineral calcite. Calcite is an ionic salt called calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite shells (coccoliths) shed from micro-organisms called coccolithophores. Flint (a type of chert) is very common as bands parallel to the bedding or as nodules embedded in chalk. It is probably derived from sponge spicules or other siliceous organisms as water is expelled upwards during compaction. Flint is often deposited around larger fossils such as Echinoidea which may be silicified (i.e. replaced molecule by molecule by flint).
There are two common definitions of coastal erosion. It is often defined as the loss or displacement of land along the coastline due to the action of waves, currents, tides, wind-driven water, waterborne ice, or other impacts of storms. In this case, landward retreat of the shoreline, measured to a given spatial datum, is described over a temporal scale of tides, seasons, and other short-term cyclic processes. Alternatively, it is defined as the process of long-term removal of sediment and rocks at the coastline, leading again to loss of land and retreat of the coastline landward. Coastal erosion may be caused by hydraulic action, abrasion, impact and corrosion by wind and water, and other forces, natural or unnatural.
The Red Rock Canyon National Conservation Area in Clark County, Nevada, is an area managed by the Bureau of Land Management as part of its National Landscape Conservation System, and protected as a National Conservation Area. It is about 15 miles (24 km) west of Las Vegas, and is easily seen from the Las Vegas Strip. More than two million people visit the area each year.
A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground.
Mesa is the American English term for tableland, an elevated area of land with a flat top and sides that are usually steep cliffs. It takes its name from its characteristic table-top shape. It may also be called a table hill, table-topped hill or table mountain. It is larger than a butte, which it otherwise resembles closely.
The Kangaroo Point Cliffs are heritage-listed cliffs located at Kangaroo Point just across the Brisbane River from the Brisbane CBD in Queensland, Australia. A popular recreation spot, they are conveniently close to the city and the South Bank Parklands. It can be reached by the Pacific Motorway, South East Busway or a ferry to Thornton Street ferry wharf. The cliffs were formed after stone was quarried from the site and used in the construction of a number of local structures.
Coasteering is a physical activity that encompasses movement along the intertidal zone of a rocky coastline on foot or by swimming, without the aid of boats, surf boards or other craft. It is difficult to define the precise boundaries between, for example, rockpooling and ocean swimming. Coasteering may include all or some of the following:
Dancing Ledge is part of the Jurassic Coast near Langton Matravers in the Isle of Purbeck in Dorset, England. Dancing Ledge is a flat area of rock at the base of a small cliff. A little scrambling is required for access. It is signposted on the South West Coast Path a few kilometres west of Swanage. Dancing Ledge is so called because at certain stages of the tide when the waves wash over the horizontal surface, the surface undulations cause the water to bob about making the ledge appear to dance.
A rockfall or rock-fall refers to quantities of rock falling freely from a cliff face. The term is also used for collapse of rock from roof or walls of mine or quarry workings. A rockfall is a fragment of rock detached by sliding, toppling, or falling, that falls along a vertical or sub-vertical cliff, proceeds down slope by bouncing and flying along ballistic trajectories or by rolling on talus or debris slopes,”. Alternatively, a "rockfall is the natural downward motion of a detached block or series of blocks with a small volume involving free falling, bouncing, rolling, and sliding". The mode of failure differs from that of a rockslide.
A Jumping platform is a naturally occurring or human-made surface for people to jump from. It is usually situated above sufficiently deep water, or above mats, a box-spring mattress, piles of empty cardboard boxes, or other soft landing surfaces, or they may be used together with other means of dampening the impact. Children often improvise platforms, either on a large scale or on a smaller scale.
Fill dirt is earthy material which is used to fill in a depression or hole in the ground or create mounds or otherwise artificially change the grade or elevation of real property.
Hydraulic action is the erosion that occurs when the motion of water against a rock surface produces mechanical weathering. Most generally, it is the ability of moving water to dislodge and transport rock particles. Within this rubric are a number of specific erosional processes, including abrasion, attrition, corrasion, saltation, and scouring (downcutting). Hydraulic action is distinguished from other types of water facilitated erosion, such as static erosion where water leaches salts and floats off organic material from unconsolidated sediments, and from chemical erosion more often called chemical weathering. It is a mechanical process, in which the moving water current flows against the banks and bed of a river, thereby removing rock particles.
Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus, chunks and smaller grains of rock broken off other rocks by physical weathering. Geologists use the term clastic with reference to sedimentary rocks as well as to particles in sediment transport whether in suspension or as bed load, and in sediment deposits.
Salt Point State Park is a state park in Sonoma County, California, United States. The park covers 6,000 acres (2,400 ha) on the coast of Northern California, with 20 miles (32 km) of hiking trails and over 6 miles (9.7 km) of a rough rocky coast line including Salt Point which protrudes into the Pacific Ocean. The park also features the first underwater preserves in California. The constant impact of the waves forms the rocks into many different shapes. These rocks continue underwater providing a wide variety of habitats for marine organisms. The activities at Salt Point include hiking, camping, fishing, scuba diving and many others. The weather is cool with fog and cold winds even during the summer.
Ailladie is an 800 metre long west-facing limestone sea-cliff, varying in height from 8 metres to 35 metres, on the coast of The Burren in County Clare, Ireland. It is one of Ireland's most highly regarded rock-climbing locations. It is also a location for shore-angling competitions, and, with its cliffs and view of the Aran Islands, a popular photography stop for tourists. The cliffs are also referred to locally, and by anglers, as Ballyreen Cliffs and Ballyreen Point, which is an anglicised version of the name of Ailladie's local townland: Irish: Baile Uí Rinn; Ring's homestead.
Creeking is a branch of canoeing and kayaking that involves descending very steep low-volume whitewater. It is usually performed in specialized canoes and kayaks specifically designed to withstand the extreme whitewater environment in which the activity occurs. In addition, the canoes and kayaks give the paddler improved performance and maneuverability needed to avoid river obstacles.
The Quincy Quarries in Quincy, Massachusetts, produced granite for over a century and were the site of the Granite Railway—often credited as being the first railroad in the United States. A 22-acre (8.9 ha) section of the former quarries is owned and operated by the Massachusetts Department of Conservation and Recreation as a public recreation area.
Achilles Point is a rocky point on the headland at the eastern end of the small sandy beach named Ladies Bay, Auckland, New Zealand. The name 'Te Pane o Horoiwi' can also sometimes refer to the whole headland between St Heliers and Tamaki River estuary. Achilles Point is named after a ship called HMNZS Achilles (70) which defeated the German pocket battleship Admiral Graf Spee in 1939. The headland, from the point round to the Tamaki heads, was previously known as Te Pane o Horoiwi, named after Horoiwi who arrived in New Zealand on the Tainui canoe (waka).
