Greywacke or graywacke is a variety of sandstone generally characterized by its hardness, dark color, and poorly sorted angular grains of quartz, feldspar, and small rock fragments or sand-size lithic fragments set in a compact, clay-fine matrix. It is a texturally immature sedimentary rock generally found in Paleozoic strata. The larger grains can be sand- to gravel-sized, and matrix materials generally constitute more than 15% of the rock by volume.
The Penninic nappes or the Penninicum, commonly abbreviated as Penninic, are one of three nappe stacks and geological zones in which the Alps can be divided. In the western Alps the Penninic nappes are more obviously present than in the eastern Alps, where they crop out as a narrow band. The name Penninic is derived from the Pennine Alps, an area in which rocks from the Penninic nappes are abundant.
The Austroalpine nappes are a geological nappe stack in the European Alps. The Alps contain three such stacks, of which the Austroalpine nappes are structurally on top of the other two. The name Austroalpine means Southern Alpine, because these nappes crop out mainly in the Eastern Alps.
In geology, basement and crystalline basement are crystalline rocks lying above the mantle and beneath all other rocks and sediments. They are sometimes exposed at the surface, but often they are buried under miles of rock and sediment. The basement rocks lie below a sedimentary platform or cover, or more generally any rock below sedimentary rocks or sedimentary basins that are metamorphic or igneous in origin. In the same way, the sediments or sedimentary rocks on top of the basement can be called a "cover" or "sedimentary cover".
The Moehau Range is the northernmost range on the Coromandel Peninsula, extending from the settlement of Colville, New Zealand northwards to the tip of the peninsula. Mount Moehau is the highest point of the range, at 892m above sea level.
The Haast Schist, which contains both the Alpine and Otago Schist, is a metamorphic unit in the South Island of New Zealand. It extends from Central Otago, along the eastern side of the Alpine Fault to Cook Strait. There are also isolated outcrops of the Haast Schist within the central North Island. The schists were named after Haast Pass on the West Coast. The Haast Schist can be divided geographically from north to south into the Kaimanawa, Terawhiti, Marlborough, Alpine, Otago and Chatham schist.
The geology of New Zealand is noted for its volcanic activity, earthquakes and geothermal areas because of its position on the boundary of the Australian Plate and Pacific Plates. New Zealand is part of Zealandia, a microcontinent nearly half the size of Australia that broke away from the Gondwanan supercontinent about 83 million years ago. New Zealand's early separation from other landmasses and subsequent evolution have created a unique fossil record and modern ecology.
The Big River has also been known by several other names, Windsor River and Māori names Hakapoua, Okopowa, Patu-po, or Patupō, though that last name, meaning kill by night, might refer to a place near Long Point and Waitutu. It is a river of southern Fiordland, New Zealand, and is one of three rivers of that name in the South Island. It is the main source of Lake Hakapoua and a lower stretch is the lake's 2-kilometre (1.2 mi) outflow to the sea. The river rises on the 1,123 m (3,684 ft) high Arnett Peak, in the Cameron Mountains, runs about 23 km (14 mi) to the lake. At about the mid point of the river it runs through a narrow gorge. Elsewhere it is generally very shallow. The river is in the Fiordland National Park.
The Waikato and King Country regions of New Zealand are built upon a basement of greywacke rocks, which form many of the hills. Much of the land to the west of the Waikato River and in the King Country to the south has been covered by limestone and sandstone, forming bluffs and a karst landscape. The volcanic cones of Karioi and Pirongia dominate the landscape near Raglan and Kawhia Harbours. To the east, the land has been covered with ignimbrite deposits from the Taupō Volcanic Zone. Large amounts of pumice from the Taupō Volcanic Zone have been deposited in the Waikato Basin and Hauraki Plains.
The Wellington Region of New Zealand has a foundation of Torlesse Greywacke rocks, that make up the Tararua and Rimutaka Ranges, that go from Wellington in the south to the Manawatū Gorge, where they are renamed as the Ruahine Ranges, and continue further north-northeast, towards East Cape. To the west of the Tararua Ranges are the Manawatū coastal plains. To the east of the Ruahine Ranges is the Wairarapa-Masterton Basin, then the Eastern Uplands that border the eastern coast of the North Island from Cape Palliser to Napier.
The Raukumara Region of New Zealand corresponds to the East Cape of the North Island, and associated mountain ranges.
Canterbury in New Zealand is the portion of the South Island to the east of the Southern Alps / Kā Tiritiri o te Moana, from the Waiau Uwha River in the north, to the Waitaki River in the south.
New Zealand's Northland Region is built upon a basement consisting mainly of greywacke rocks, which are exposed on the eastern side of the peninsula. In-place Eocene coal measures crop out at Kamo, near Whangarei, and Oligocene limestone crops out at Hikurangi, near Whangarei.
The Tasman Region, and the small adjoining Nelson Region, form one of the more geologically interesting regions of New Zealand. It contains the oldest rocks of anywhere on New Zealand's main islands. It contains all the main terranes that make up New Zealand's basement. These basement rocks include Ultramafic rocks, such as Serpentine and Dunite, and valuable minerals, such as Gold. The Nelson Region is bordered to the south by the Alpine Fault, the main fault forming the boundary between the Pacific Plate and the Indo-Australian Plate, that generated the Southern Alps.
Lake Whangape is shallow, supertrophic, lateral and the second largest lake in the lower Waikato River basin in New Zealand. One source said the name translated to 'a large sheet of water', another that it was a chief's name.
The Mangatangi River, or Mangatangi Stream, originates on the eastern slopes of the Hunua Ranges in New Zealand and flows roughly southwards until it is joined by the Ruaotehuia Stream just north of State Highway 2 between Mangatāwhiri and Maramarua, where it becomes the Maramarua River. Mangatangi can be translated as manga tangi to stream of weeping, or as rippling stream, or babbling brook.
The geology of Alaska includes Precambrian igneous and metamorphic rocks formed in offshore terranes and added to the western margin of North America from the Paleozoic through modern times. The region was submerged for much of the Paleozoic and Mesozoic and formed extensive oil and gas reserves due to tectonic activity in the Arctic Ocean. Alaska was largely ice free during the Pleistocene, allowing humans to migrate into the Americas.
The Tākaka Terrane is a Paleozoic terrane that outcrops in the South Island of New Zealand. It is most extensively exposed within the Kahurangi National Park in the Tasman District. The terrane is mostly made up of marble and volcanic rocks but is highly variable in composition. It ranges in age from mid-Cambrian to Devonian time, including New Zealand's oldest rocks, which are found in the Cobb Valley in north-west Nelson. The Cobb Valley is also the location of "Trilobite Rock" a glacial dropstone made from the moulted exoskeletons of trilobites. Asbestos was mined in the Cobb Valley from the Tākaka Terrene between the late 1880s and 1917. The Tākaka Terrane is highly deformed and has been intruded by many batholiths.
This is a list of the units into which the rock succession of New Zealand is formally divided. As new geological relationships have been discovered new names have been proposed and others are made obsolete. Not all these changes have been universally adopted. This table is based on the 2014 New Zealand Stratigraphic Lexicon (Litho2014). However, obsolete names that are still in use and names postdating the lexicon are included if it aids in understanding.
The geology of the West Coast of New Zealand's South Island is divided in two by the Alpine Fault, which runs through the Region in a North-East direction. To the West of the fault Paleozoic basement rocks are interluded by plutones and both are unconformably covered in a sedimentary sequence. To the East of the Alpine Fault are the Mesozoic Alpine Schist and Greywacke of the Southern Alps. There are numerous active faults throughout the region.
