A drumlin, from the Irish word droimnín, first recorded in 1833, and in the classical sense is an elongated hill in the shape of an inverted spoon or half-buried egg formed by glacial ice acting on underlying unconsolidated till or ground moraine.
The Niagara Escarpment is a long escarpment, or cuesta, in the United States and Canada that runs predominantly east/west from New York, through Ontario, Michigan, Wisconsin, and Illinois. The escarpment is most famous as the cliff over which the Niagara River plunges at Niagara Falls, for which it is named.
The Llano uplift is a low geologic dome that is about 90 miles (140 km) in diameter. It consists of an island-like exposure of Precambrian igneous and metamorphic rocks surrounded by outcrops of Paleozoic and Cretaceous sedimentary strata. At their widest, the exposed Precambrian rocks extend about 65 miles (105 km) westward from the valley of the Colorado River and beneath a broad, gentle topographic basin drained by the Llano River. The subdued topographic basin is underlain by Precambrian rocks and bordered by a discontinuous rim of flat-topped hills. These hills are the dissected edge of the Edwards Plateau, which consist of overlying Cretaceous sedimentary strata. Within this basin and along its margin are down-faulted blocks and erosional remnants of Paleozoic strata which form prominent hills.
Flynn Creek crater, is an impact crater situated in Jackson County, approximately 8 km south of Gainesboro, Tennessee, USA. It was formed approximately 360 million years ago as a shallow, saucer-shaped crater, 3.8 km (2.4 mi) in diameter and about 150 m deep. A large central hill, highly deformed rim strata, and a breccia lens 40 m (130 ft) in thickness were produced during formation. Over 2 km2 of flat lying Middle and Upper Paleozoic limestone and dolomite were brecciated and mixed to a depth of 200 m (660 ft), and at least half of the breccia was ejected from the crater. The remaining breccia contains fragments ranging in size from small grains to megabreccia blocks 100 m (330 ft) in length. Undisturbed strata lie 100 m below the original crater floor.
The Oak Ridges Moraine is a geological landform that runs east-west across south central Ontario, Canada. It developed about 12,000 years ago, during the Wisconsin glaciation in North America. A complex ridge of sedimentary material, the moraine is known to have partially developed under water. The Niagara Escarpment played a key role in forming the moraine in that it acted as a dam for glacial meltwater trapped between it and two ice lobes.
A tunnel valley is a large, long, U-shaped valley originally cut under the glacial ice near the margin of continental ice sheets such as that now covering Antarctica and formerly covering portions of all continents during past glacial ages.
The Geology of Pennsylvania consists of six distinct physiographic provinces, three of which are subdivided into different sections. Each province has its own economic advantages and geologic hazards and plays an important role in shaping everyday life in the state. They are: the Atlantic Coastal Plain Province, the Piedmont Province, the New England Province, the Ridge and Valley Province, the Appalachian Plateau Province, and the Central Lowlands Province.
The Weald–Artois anticline is a large anticline, a geological structure running between the regions of the Weald in southern England and Artois in northern France. The fold formed during the Alpine orogeny, from the late Oligocene to middle Miocene as an uplifted form of the Weald basin through inversion of the basin. The folding resulted in uplift of about 180 metres (590 ft), though concurrent erosion may have substantially reduced the actual height of the resulting chalk ridges.
The Siljan Ring is a prehistoric impact crater in Dalarna, central Sweden. It is one of the 15 largest known impact craters on Earth and the largest in Europe, with a diameter of about 52 kilometres (32 mi). The impact that created the Siljan Ring occurred when a meteorite collided with the Earth's surface during the Devonian period, about 376.8 ± 1.7 Ma. This coincides around the first Devonian extinction, the Kellwasser Event or Late Frasnian extinction at 376.1 Ma ± 1.6 Ma. The effects of the impact can clearly be seen in the bedrock in the area. The Cambrian, Ordovician and Silurian sedimentary rocks deformed by the impact are rich in fossils.
Endeavour is an impact crater located in the Meridiani Planum extraterrestrial plain within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars. Endeavour is about 22 kilometers (14 mi) in diameter. Using Mars Reconnaissance Orbiter data, phyllosilicate-bearing outcrops have been detected along its rim. These minerals may have formed under wet conditions in a low-acidic environment during the early history of Mars. There are raised rim segments to the north, east, and southwest. The rim has become worn, rounded and degraded, with infilling of plains material in a manner similar to the Victoria crater.
Caribou Island is an uninhabited island in the eastern end of Lake Superior, 40 kilometres (25 mi) south of Michipicoten Island. It lies entirely within the territorial waters of Canada although only about five kilometres from the international border between Canada and the United States. It is approximately 5.6 kilometres (3.5 mi) long and 2.4 kilometres (1.5 mi) wide, and 1,600 acres (647 ha) in area. The interior is low scrub and bog with small lakes, Little Italy, Hambone, and Deer Lake among many unnamed ones. Several of the lakes are maintained by beavers and all are several feet above Lake Superior.
Overdeepening is a characteristic of basins and valleys eroded by glaciers. An overdeepened valley profile is often eroded to depths which are hundreds of metres below the deepest continuous line along a valley or watercourse. This phenomenon is observed under modern day glaciers, in salt-water fjords and fresh-water lakes remaining after glaciers melt, as well as in tunnel valleys which are partially or totally filled with sediment. When the channel produced by a glacier is filled with debris, the subsurface geomorphic structure is found to be erosionally cut into bedrock and subsequently filled by sediments. These overdeepened cuts into bedrock structures can reach a depth of several hundred metres below the valley floor.
The Shadow Lake formation is a geological unit that crops out in Southern Ontario, Canada and northern Pennsylvania, United States. The shaly sections act as a caprock to petroleum reservoirs.
The Corossol structure, which is also known as the Corossol crater, is a circular, 4.3-by-3.9-kilometer in diameter, underwater bedrock feature that is exposed on the gulf floor of the northwestern Gulf of Saint Lawrence 20-kilometer (12 mi) offshore of the city of Sept-Îles, Quebec in eastern Canada. It is hypothesized to be a possible pre-Pleistocene, extraterrestrial impact structure. It lies underwater at a depth of 40–208-meter (131–682 ft). This underwater feature was found during the study of high-resolution bathymetric and sub-bottom profiler data collected south of the city of Sept-Iles in the northwestern Gulf of Saint Lawrence.
Bloody Creek crater, which is also known as the Bloody Creek structure, is a 420-by-350-meter in diameter elliptical feature that is located in southwestern Nova Scotia, Canada. It is argued to be either a possible extraterrestrial impact crater or an impact structure. It lies between Bridgetown and West Dalhousie, Annapolis County, Nova Scotia, where the Bloody Creek structure straddles what was once a stretch of Bloody Creek. It also is informally known as the Astrid crater.
The Wallaby Plateau, which is also known as the Cuvier Plateau, is a large bathymetric high about 450 kilometres (280 mi) west of Carnarvon, Western Australia. The Wallaby Plateau covers approximately 100,000 km2 (39,000 sq mi) and is in water depths of 2,200 meters (7,200 ft) to greater than 5,000 meters (16,000 ft). In the west, the Wallaby Plateau is separated from the Zenith Plateau by a 100–150-kilometre (62–93 mi) wide, north to northeast-trending bathymetric trough. Wallaby Plateau is the name used by the Australian geologists and government for this undersea plateau. This name was first used in a Hartog AGSO bathymetric map and formally recognized in a peer-reviewed paper by Symonds and Cameron in 1977. In contrast, the internationally recognized name for it is Cuvier Plateau. Cuvier is a historical name that is presumably derived from the adjacent Cape Cuvier. Cape Cuvier was named for Georges Cuvier, zoologist and statesman, by a French expedition led by Baudin in 1800 – 1803. The Wallaby Plateau lies inside the Australian Exclusive Economic Zone.
Castle Lake is a barrier lake formed by the May 18, 1980 eruption of Mount St. Helens, when an avalanche dammed the South Fork of Castle Creek. The lake covers just slightly more than 1 square kilometer (0.39 sq mi). In 1981 a spillway was constructed to alleviate concerns about sudden erosion. The lake is difficult to access, but trails have been built to it and recreational fishing is allowed.
The geology of Estonia is the study of rocks, minerals, water, landforms and geologic history in Estonia. The crust is part of the East European Craton and formed beginning in the Paleoproterozoic nearly two billion years ago. Shallow marine environments predominated in Estonia, producing extensive natural resources from organic matter such as oil shale and phosphorite. The Mesozoic and much of the Cenozoic are not well-preserved in the rock record, although the glaciations during the Pleistocene buried deep valleys in sediment, rechanneled streams and left a landscape of extensive lakes and peat bogs.
The geology of Thailand includes deep crystalline metamorphic basement rocks, overlain by extensive sandstone, limestone, turbidites and some volcanic rocks. The region experienced complicated tectonics during the Paleozoic, long-running shallow water conditions and then renewed uplift and erosion in the past several million years ago.
