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45-542: The resort is located on U.S. Route 302 in the White Mountains of New Hampshire . The terrain occupies 464 acres (1.88 km) adjacent to the White Mountain National Forest . 92% of the trails have snowmaking. There are 98 trails currently, and the resort receives an average of over 200 inches (5,100 mm) of snow per year. The resort includes 8 lifts, four of which are high speed quads. They run at

90-400: A chilled margin is often found on the intrusion side of the contact, while a contact aureole is found on the country rock side. The chilled margin is much finer grained than most of the intrusion, and may be different in composition, reflecting the initial composition of the intrusion before fractional crystallization, assimilation of country rock, or further magmatic injections modified

135-402: A layered intrusion . The ultimate source of magma is partial melting of rock in the upper mantle and lower crust . This produces magma that is less dense than its source rock. For example, a granitic magma, which is high in silica, has a density of 2.4 Mg/m , much less than the 2.8 Mg/m of high-grade metamorphic rock. This gives the magma tremendous buoyancy, so that ascent of the magma

180-518: A mountain range covering about a quarter of the state of New Hampshire and a small portion of western Maine in the United States . They are a subrange of the northern Appalachian Mountains and the most rugged mountains in New England . Several of the higher peaks contain an Alpine tundra . The range is heavily visited due to its proximity to Boston , New York City , and Montreal . Most of

225-528: A "school", since they did not all paint in the same style as, for example, those artists of the Hudson River School . Nathaniel Hawthorne chose the White Mountains as the setting for his short story " The Great Carbuncle ". Other White Mountain tales by Hawthorne include " The Ambitious Guest ", "Sketches from Memory" and "The Great Stone Face". The White Mountain region also figures prominently in

270-655: A capacity of 14,000 people per hour. Bretton Woods has eight chairlifts and two magic carpets. Eateries around the ski area include the Top O' Quad Restaurant, Maple Leaf BBQ, West Mountain BBQ, the Food Court, The Switchback Grill, and the Sugar Shack. In the 2013/2014 SKI Magazine Reader's Poll, Bretton Woods was named #1 in the East for snow, grooming, service, and weather. Also, Bretton Woods

315-502: A contact aureole, and often contain xenolithic fragments of country rock suggesting brittle fracturing. Such intrusions are interpreted as occurring at shallow depth, and are commonly associated with volcanic rocks and collapse structures. An intrusion does not crystallize all minerals at once; rather, there is a sequence of crystallization that is reflected in the Bowen reaction series . Crystals formed early in cooling are generally denser than

360-518: A crystallized magma chamber . A pluton that has intruded and obscured the contact between a terrane and adjacent rock is called a stitching pluton . Intrusions are broadly divided into discordant intrusions , which cut across the existing structure of the country rock, and concordant intrusions that intrude parallel to existing bedding or fabric . These are further classified according to such criteria as size, evident mode of origin, or whether they are tabular in shape. An intrusive suite

405-467: A natural feature dubbed "The Basin", consisting of a granite bowl, 20 feet (6 m) in diameter, fed by a waterfall, worn smooth by the Pemigewasset River . The areas around The Basin are popular spots for swimming in the cold water. The range is crossed north–south by U.S. Route 3 and Interstate 93 through Franconia Notch and New Hampshire Route 16 through Pinkham Notch , and east–west by

450-428: A retail price of one dollar. Other early maps of the region were drawn by H. Conant and by Harvard astronomer George Phillips Bond , who published the first topographical map of the region in 1853. The White Mountains drew hundreds of painters during the 19th century. This group of artists is sometimes referred to as belonging to the "White Mountain school" of art. Others dispute the notion that these painters were

495-450: A volcanic neck, suggesting that necks tend to form at intersections of dikes where passage of magma is least obstructed. Diatremes and breccia pipes are pipe-like bodies of breccia that are formed by particular kinds of explosive eruptions . As they have reached the surface they are really extrusions, but the non erupted material is an intrusion and indeed due to erosion may be difficult to distinguish from an intrusion that never reached

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540-482: Is 1,100 kilometers (680 mi) long and 50 kilometers (31 mi) wide. They are usually formed from magma rich in silica , and never from gabbro or other rock rich in mafic minerals, but some batholiths are composed almost entirely of anorthosite . A sill is a tabular concordant intrusion, typically taking the form of a sheet parallel to sedimentary beds. They are otherwise similar to dikes. Most are of mafic composition, relatively low in silica, which gives them

585-501: Is a group of intrusions related in time and space. Dikes are tabular discordant intrusions, taking the form of sheets that cut across existing rock beds. They tend to resist erosion, so that they stand out as natural walls on the landscape. They vary in thickness from millimeter-thick films to over 300 meters (980 ft) and an individual sheet can have an area of 12,000 square kilometers (4,600 sq mi). They also vary widely in composition. Dikes form by hydraulic fracturing of

630-399: Is called the room problem , and it remains a subject of active investigation for many kinds of intrusions. The term pluton is poorly defined, but has been used to describe an intrusion emplaced at great depth; as a synonym for all igneous intrusions; as a dustbin category for intrusions whose size or character are not well determined; or as a name for a very large intrusion or for

675-438: Is coarse-grained ( phaneritic ). Intrusive igneous rocks are classified separately from extrusive igneous rocks, generally on the basis of their mineral content. The relative amounts of quartz , alkali feldspar , plagioclase , and feldspathoid is particularly important in classifying intrusive igneous rocks. Intrusions must displace existing country rock to make room for themselves. The question of how this takes place

720-404: Is inevitable once enough magma has accumulated. However, the question of precisely how large quantities of magma are able to shove aside country rock to make room for themselves (the room problem ) is still a matter of research. The composition of the magma and country rock and the stresses affecting the country rock strongly influence the kinds of intrusions that take place. For example, where

765-492: The Appalachian Mountain Club . The Appalachian Trail crosses the area from southwest to northeast. It is not clear where the name "White Mountains" came from. There is no record of what Native Americans called the range, although pre-Colonial names for many individual peaks are known. The name and similar ones such as "White Hills" or "Wine Hills" are found in literature from Colonial times. According to tradition,

810-627: The Franconia Range , Sandwich Range , Carter-Moriah Range and Kinsman Range in New Hampshire, and the Mahoosuc Range straddling the border between it and Maine. In all, there are 48 peaks within New Hampshire as well as one ( Old Speck Mountain ) in Maine over 4,000 feet (1,200 m), known as the four-thousand footers . The Whites are known for a system of alpine huts for hikers operated by

855-488: The Kancamagus Highway (part of New Hampshire Route 112 ) through Kancamagus Pass and U.S. Route 302 through Crawford Notch . Many of these highways are designated as scenic routes . Several amusement parks lie in or near the White Mountains, including Story Land , Santa's Village , Whale's Tale Water Park and Clark's Trading Post . The White Mountains region is also home to numerous hiking attractions through

900-821: The Palisades Sill of New York and New Jersey ; the Henry Mountains of Utah ; the Bushveld Igneous Complex of South Africa ; Shiprock in New Mexico ; the Ardnamurchan intrusion in Scotland; and the Sierra Nevada Batholith of California . Because the solid country rock into which magma intrudes is an excellent insulator , cooling of the magma is extremely slow, and intrusive igneous rock

945-545: The White Mountains today were created 124 to 100 million years ago as the North American Plate moved westward over the New England hotspot . Widespread evidence of glaciation may be seen in the U-shaped form of various notches, or mountain passes . Glacial cirques form the heads of Tuckerman Ravine on Mt. Washington and King Ravine on Mt. Adams . Glacial striations are visible at numerous locations, including on

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990-640: The area is public land, including the White Mountain National Forest and a number of state parks . Its most famous mountain is 6,288-foot (1,917 m) Mount Washington , which is the highest peak in the Northeastern U.S. and for 76 years held the record for fastest surface wind gust in the world (231 miles per hour (372 km/h) in 1934). Mount Washington is part of a line of summits, the Presidential Range , that are named after U.S. presidents and other prominent Americans. The White Mountains also include

1035-477: The classification is meaningful for bodies which do not change much in area with depth and that have other features suggesting a distinctive origin and mode of emplacement. Batholiths are discordant intrusions with an exposed area greater than 100 square kilometers (39 sq mi). Some are of truly enormous size, and their lower contacts are very rarely exposed. For example, the Coastal Batholith of Peru

1080-423: The composition of the rest of the intrusion. Isotherms (surfaces of constant temperature) propagate away from the margin according to a square root law, so that if the outermost meter of the magma takes ten years to cool to a given temperature, the next inward meter will take 40 years, the next will take 90 years, and so on. This is an idealization, and such processes as magma convection (where cooled magma next to

1125-461: The contact between intrusion and country rock give clues to the conditions under which the intrusion took place. Catazonal intrusions have a thick aureole that grades into the intrusive body with no sharp margin, indicating considerable chemical reaction between intrusion and country rock, and often have broad migmatite zones. Foliations in the intrusion and the surrounding country rock are roughly parallel, with indications of extreme deformation in

1170-416: The contact is given by the relationship T / T 0 = 1 2 + 1 2 erf ⁡ ( x 2 k t ) {\displaystyle T/T_{0}={\frac {1}{2}}+{\frac {1}{2}}\operatorname {erf} ({\frac {x}{2{\sqrt {kt}}}})} where T 0 {\displaystyle T_{0}} is the initial temperature of

1215-468: The contact sinks to the bottom of the magma chamber and hotter magma takes its place) can alter the cooling process, reducing the thickness of chilled margins while hastening cooling of the intrusion as a whole. However, it is clear that thin dikes will cool much faster than larger intrusions, which explains why small intrusions near the surface (where the country rock is initially cold) are often nearly as fine-grained as volcanic rock. Structural features of

1260-451: The country rock by magma under pressure, and are more common in regions of crustal tension. Ring dikes and cone sheets are dikes with particular forms that are associated with the formation of calderas . Volcanic necks are feeder pipes for volcanoes that have been exposed by erosion . Surface exposures are typically cylindrical, but the intrusion often becomes elliptical or even cloverleaf -shaped at depth. Dikes often radiate from

1305-510: The country rock. Such intrusions are interpreted as taking placed at great depth. Mesozonal intrusions have a much lower degree of metamorphism in their contact aureoles, and the contact between country rock and intrusion is clearly discernible. Migmatites are rare and deformation of country rock is moderate. Such intrusions are interpreted as occurring at medium depth. Epizonal intrusions are discordant with country rock and have sharp contacts with chilled margins, with only limited metamorphism in

1350-501: The crust is undergoing extension, magma can easily rise into tensional fractures in the upper crust to form dikes. Where the crust is under compression, magma at shallow depth will tend to form laccoliths instead, with the magma penetrating the least competent beds, such as shale beds. Ring dikes and cone sheets form only at shallow depth, where a plug of overlying country rock can be raised or lowered. The immense volumes of magma involved in batholiths can force their way upwards only when

1395-705: The exposed rocks at the summit of Pine Mountain in Gorham . The Red Hill Syenite , a rock unit of the White Mountains, found in central New Hampshire, is of interest to researchers due to the fact that it contains feldspathoids as well as quartz-bearing rocks. The White Mountain National Forest , formed in 1911 after passage of the Weeks Act , includes most of the mountain range and now covers 800,000 acres (3,200 km ) in New Hampshire and western Maine. The Mount Washington Auto Road and Mount Washington Cog Railway ascend

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1440-401: The field, there is geochemical evidence. Zircon zoning provides important evidence for determining if a single magmatic event or a series of injections were the methods of emplacement. Large felsic intrusions likely form from melting of lower crust that has been heated by an intrusion of mafic magma from the upper mantle. The different densities of felsic and mafic magma limit mixing, so that

1485-478: The first two tourist maps of the mountains was that produced by Franklin Leavitt, a self-taught artist born near Lancaster, New Hampshire in 1824. Leavitt's hand-drawn map, today in the collection of Harvard University , is largely folk art , but does convey some of the region's features. Leavitt drew several versions of his map, beginning in 1852. The fourth version, printed in 1871, was printed at Boston and carried

1530-407: The hot material, k is the thermal diffusivity (typically close to 10 m s for most geologic materials), x is the distance from the contact, and t is the time since intrusion. This formula suggests that the magma close to the contact will be rapidly chilled while the country rock close to the contact is rapidly heated, while material further from the contact will be much slower to cool or heat. Thus

1575-521: The like. The Mount Washington Hotel located in Bretton Woods was the site of the Bretton Woods Conference following World War II , and today remains one of the few early twentieth century grand hotels still in use. An estimated six million visitors visit the region yearly. Some of the earliest maps of the White Mountains were produced as tourist maps and not topographical maps. One of

1620-541: The low viscosity necessary to penetrate between sedimentary beds. A laccolith is a concordant intrusion with a flat base and domed roof. Laccoliths typically form at shallow depth, less than 3 kilometers (1.9 mi), and in regions of crustal compression. Lopoliths are concordant intrusions with a saucer shape, somewhat resembling an inverted laccolith, but they can be much larger and form by different processes. Their immense size promotes very slow cooling, and this produces an unusually complete mineral segregation called

1665-510: The magma is highly silicic and buoyant, and are likely do so as diapirs in the ductile deep crust and through a variety of other mechanisms in the brittle upper crust. Igneous intrusions may form from a single magmatic event or several incremental events. Recent evidence suggests that incremental formation is more common for large intrusions. For example, the Palisades Sill was never a single body of magma 300 meters (980 ft) thick, but

1710-515: The mountains were first sighted from shipboard off the coast near the Piscataqua estuary . The highest peaks would often be snow-capped, appearing white. An alternate theory is that the mica -laden granite of the summits looked white to observers. The White Mountains are a physiographic section of the larger New England province , which in turn is part of the larger Appalachian Highlands physiographic division. The magma intrusions forming

1755-551: The range's highest peak, which hosts a visitor center and weather observatory . Heavily visited Arethusa Falls , the second tallest waterfall in New Hampshire, lies on a southwest flank of Crawford Notch. The Old Man of the Mountain , a rock formation on Cannon Mountain that resembled the craggy profile of a man's face, was a White Mountain landmark until it fell in May 2003. It remains the state symbol of New Hampshire. The range also includes

1800-405: The silicic magma floats on the mafic magma. Such limited mixing as takes place results in the small inclusions of mafic rock commonly found in granites and granodiorites. An intrusion of magma loses heat to the surrounding country rock through heat conduction. Near the contact of hot material with cold material, if the hot material is initially uniform in temperature, the temperature profile across

1845-401: The surface when magma/lava. The root material of a diatreme is identical to intrusive material nearby, if it exists, that never reached the then surface when formed. A stock is a non-tabular discordant intrusion whose exposure covers less than 100 square kilometers (39 sq mi). Although this seems arbitrary, particularly since the exposure may be only the tip of a larger intrusive body,

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1890-716: The various river gorges, ravines, and caves in the area. The Flume Gorge , Lost River Reservation and Polar Caves Park all provide moderate hikes that one can complete in a few hours. Skiing is a popular attraction in the area. Cannon Mountain Ski Area , Loon Mountain Ski Resort , Attitash Mountain Resort , Wildcat Mountain Ski Area , Bretton Woods Mountain Resort , and Waterville Valley Resort are all popular winter ski resorts, and many of them provide year-round outdoor activities such as bridle paths , hiking trails, alpine slides , and

1935-525: The writings of Louisa May Alcott , including the novel Eight Cousins and its sequel, Rose in Bloom . Intrusion In geology , an igneous intrusion (or intrusive body or simply intrusion ) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth . Intrusions have a wide variety of forms and compositions, illustrated by examples like

1980-423: Was chosen as the #12 ski resort in the world and the #6 ski resort in the U.S. and Canada by the readers of Condé Nast Traveler. Bretton Woods was named #1 in New Hampshire for lifts, lodging, and dining, and overall ski resort. Bretton Woods was also named Top 5 in the East for family programs and scenery and Top 10 in the East for on mountain food. White Mountains (New Hampshire) The White Mountains are

2025-401: Was formed from multiple injections of magma. An intrusive body is described as multiple when it forms from repeated injections of magma of similar composition, and as composite when formed of repeated injections of magma of unlike composition. A composite dike can include rocks as different as granophyre and diabase . While there is often little visual evidence of multiple injections in

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