The Rhine is one of the major European rivers. The river begins in the Swiss canton of Graubünden in the southeastern [[Swiss Alps]. It forms part of the Swiss-Liechtenstein, Swiss-Austrian, Swiss-German borders. After that the Rhine defines much of the Franco-German border, after which it flows in a mostly northerly direction through the German Rhineland. Finally in Germany the Rhine turns into a predominantly westerly direction and flows into the Netherlands where it eventually empties into the North Sea.
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand and silt can be carried in suspension in river water and on reaching the sea bed deposited by sedimentation; if buried, they may eventually become sandstone and siltstone through lithification.
A braided river, or braided channel, consists of a network of river channels separated by small, often temporary, islands called braid bars or, in English usage, aits or eyots.
An alluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to semiarid climates, but are also found in more humid environments subject to intense rainfall and in areas of modern glaciation. They range in area from less than 1 square kilometer (0.4 sq mi) to almost 20,000 square kilometers (7,700 sq mi).
In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluvioglacial is used.
The geology of the Grand Canyon area includes one of the most complete and studied sequences of rock on Earth. The nearly 40 major sedimentary rock layers exposed in the Grand Canyon and in the Grand Canyon National Park area range in age from about 200 million to nearly 2 billion years old. Most were deposited in warm, shallow seas and near ancient, long-gone sea shores in western North America. Both marine and terrestrial sediments are represented, including lithified sand dunes from an extinct desert. There are at least 14 known unconformities in the geologic record found in the Grand Canyon.
A meander is one of a series of regular sinuous curves in the channel of a river or other watercourse. It is produced as a watercourse erodes the sediments of an outer, concave bank and deposits sediments on an inner, convex bank which is typically a point bar. The result of this coupled erosion and sedimentation is the formation of a sinuous course as the channel migrates back and forth across the axis of a floodplain.
The Val di Stava Dam collapse occurred on 19 July 1985, when two tailings dams above the village of Stava, near Tesero, Italy, failed. It resulted in one of Italy's worst disasters, killing 268 people, destroying 63 buildings and demolishing eight bridges.
The Two Medicine Formation is a geological formation, or rock body, in northwestern Montana and southern Alberta that was deposited between 83.5 ± 0.7 Ma and 70.6 ± 3.4 Ma, during Campanian time. It crops out to the east of the Rocky Mountain Overthrust Belt, and the western portion of this formation is folded and faulted while the eastern part, which thins out into the Sweetgrass Arch, is mostly undeformed plains. Below the formation are the nearshore deposits of the Virgelle Sandstone, and above it is the marine Bearpaw Shale. Throughout the Campanian, the Two Medicine Formation was deposited between the western shoreline of the Late Cretaceous Interior Seaway and the eastward advancing margin of the Cordilleran Overthrust Belt. The Two Medicine Formation is mostly sandstone, deposited by rivers and deltas.
In geology, ripple marks are sedimentary structures and indicate agitation by water or wind.
Monte San Giorgio is a mountain and UNESCO World Heritage Site on the border between Switzerland and Italy. It is part of the Lugano Prealps, overlooking Lake Lugano in the Swiss Canton of Ticino.
An antidune is a bedform found in fluvial and other channeled environments. Antidunes occur in supercritical flow, meaning that the Froude number is greater than 1.0 or the flow velocity exceeds the wave velocity; this is also known as upper flow regime. In antidunes, sediment is deposited on the upstream (stoss) side and eroded from the downstream (lee) side, opposite lower flow regime bedforms. As a result, antidunes migrate in an upstream direction, counter to the current flow. Antidunes are called in-phase bedforms, meaning that the water surface elevation mimics the bed elevation; this is due to the supercritical flow regime. Antidune bedforms evolve rapidly, growing in amplitude as they migrate upstream. The resultant wave at the water's surface also increases in amplitude. When that wave becomes unstable, breaks and washes downstream, much of the antidune bedform may be destroyed.
Inverted relief, inverted topography, or topographic inversion refers to landscape features that have reversed their elevation relative to other features. It most often occurs when low areas of a landscape become filled with lava or sediment that hardens into material that is more resistant to erosion than the material that surrounds it. Differential erosion then removes the less resistant surrounding material, leaving behind the younger resistant material, which may then appear as a ridge where previously there was a valley. Terms such as "inverted valley" or "inverted channel" are used to describe such features. Inverted relief has been observed on the surfaces of other planets as well as on Earth. For example, well-documented inverted topographies have been discovered on Mars.
The Triassic Lockatong Formation is a mapped bedrock unit in Pennsylvania, New Jersey, and New York. It is named after the Lockatong Creek in Hunterdon County, New Jersey.
Lower House Stream Section is a Site of Special Scientific Interest in the Rhymney Valley, in Caerphilly County Borough, south Wales.
Montour Run is a tributary of Fishing Creek in Columbia County, Pennsylvania. It is the last named tributary to join the creek and is 3.1 miles (5.0 km) long. The stream's watershed has an area of approximately 4.7 square miles and is located in Montour Township, Columbia County and Cooper Township, Montour County. The annual load of sediment in the watershed is 4,248,000 pounds (1,927,000 kg), most of which comes from agricultural lands. Minnows live in the stream.
The Pahasapa Formation is a geological unit of primarily limestone and dolomite that is exposed in the Black Hills of South Dakota and northwestern Wyoming, and underlies parts of Nebraska. Also referred to as the Pahasapa Limestone, this unit is analogous to the Madison Limestone and the Burlington Limestone, other Mississippian-aged limestones and dolomites in the midwestern United States. Two of the ten longest caves in the world are found in the Pahasapa.
Abrahams Creek is a tributary of the Susquehanna River in Luzerne County, Pennsylvania, in the United States. It is approximately 10.7 miles (17.2 km) long and flows through Franklin Township, Dallas Township, Kingston Township, West Wyoming, Wyoming, and Forty Fort. The watershed of the creek has an area of 17.4 square miles (45 km2) and occupies portions of nine municipalities in northeastern Luzerne County. The watershed is divided into the upper Abraham Creek watershed and the lower Abraham Creek watershed, which are joined by a canyon known as The Hollow. The upper part of the watershed is mostly rural, but the lower part is heavily urbanized. The creek's channel has been heavily modified in many places. Its drainage basin is designated as a Coldwater Fishery and a Migratory Fishery.
Miller Run is a tributary of Limestone Run in Union County, Pennsylvania, in the United States. It is approximately 1.2 miles (1.9 km) long and flows through East Buffalo Township and Lewisburg. The watershed of the stream has an area of 0.87 square miles (2.3 km2). The stream has no officially named tributaries. It is very small and is not a perennial stream, but is impacted by stormwater flows and also has high concentrations of sediment. The stream's chemical hydrology has been significantly affected by human use. Major rock formations in its watershed include the Bloomsburg Formation, the Keyser-Tonoloway Formation, and the Wills Creek Formation.
'Busa del Pomar' is an ancient silver mine located in the north of Italy, just north east Trento.
