Misplaced Pages

#8991

82-486: The name comes from the distinctive coloration caused by light-colored limestone along with black metamorphic rock on some peaks, giving the mountains a marbled appearance. There are at least five different rock types identified here. The wilderness is in the Klamath Mountains geomorphic province (a large area having similar features such as terrain and geology ). The horseshoe-shaped Salmon Mountains are at

164-455: A Mohs hardness of 2 to 4, dense limestone can have a crushing strength of up to 180 MPa . For comparison, concrete typically has a crushing strength of about 40 MPa. Although limestones show little variability in mineral composition, they show great diversity in texture. However, most limestone consists of sand-sized grains in a carbonate mud matrix. Because limestones are often of biological origin and are usually composed of sediment that

246-463: A bloom of cyanobacteria or microalgae . However, stable isotope ratios in modern carbonate mud appear to be inconsistent with either of these mechanisms, and abrasion of carbonate grains in high-energy environments has been put forward as a third possibility. Formation of limestone has likely been dominated by biological processes throughout the Phanerozoic , the last 540 million years of

328-485: A campground typically consists of open areas where a camper can pitch a tent or park a camper . More specifically, a campsite is a designated area set aside for camping, often requiring a user fee. Campsites typically feature a few (but sometimes no) improvements. Dedicated campsites, known as campgrounds , usually have some amenities. Common amenities include, listed roughly in order from most to least common: Campgrounds may include further amenities: Camping outside

410-434: A carbonate rock outcrop can be estimated in the field by etching the surface with dilute hydrochloric acid. This etches away the calcite and aragonite, leaving behind any silica or dolomite grains. The latter can be identified by their rhombohedral shape. Crystals of calcite, quartz , dolomite or barite may line small cavities ( vugs ) in the rock. Vugs are a form of secondary porosity, formed in existing limestone by

492-616: A central quartz grain or carbonate mineral fragment. These likely form by direct precipitation of calcium carbonate onto the ooid. Pisoliths are similar to ooids, but they are larger than 2 mm in diameter and tend to be more irregular in shape. Limestone composed mostly of ooids is called an oolite or sometimes an oolitic limestone . Ooids form in high-energy environments, such as the Bahama platform, and oolites typically show crossbedding and other features associated with deposition in strong currents. Oncoliths resemble ooids but show

574-424: A certain distance of water sources or developed areas. Camping may also be prohibited in certain ‘special areas’ of national forests containing unusual landforms or vegetation. And if conditions allow campfires, a campfire permit is required for campfires outside of developed campsites. In Britain, it is more commonly known as wild camping , and is mostly illegal. However, Scotland has a relaxed view and wild camping

656-449: A change in environment that increases the solubility of calcite. Dense, massive limestone is sometimes described as "marble". For example, the famous Portoro "marble" of Italy is actually a dense black limestone. True marble is produced by recrystallization of limestone during regional metamorphism that accompanies the mountain building process ( orogeny ). It is distinguished from dense limestone by its coarse crystalline texture and

738-949: A composition reflecting the organisms that produced them and the environment in which they were produced. Low-magnesium calcite skeletal grains are typical of articulate brachiopods , planktonic (free-floating) foraminifera, and coccoliths . High-magnesium calcite skeletal grains are typical of benthic (bottom-dwelling) foraminifera, echinoderms , and coralline algae . Aragonite skeletal grains are typical of molluscs , calcareous green algae , stromatoporoids , corals , and tube worms . The skeletal grains also reflect specific geological periods and environments. For example, coral grains are more common in high-energy environments (characterized by strong currents and turbulence) while bryozoan grains are more common in low-energy environments (characterized by quiet water). Ooids (sometimes called ooliths) are sand-sized grains (less than 2mm in diameter) consisting of one or more layers of calcite or aragonite around

820-412: A considerable fraction of the limestone bed. At depths greater than 1 km (0.62 miles), burial cementation completes the lithification process. Burial cementation does not produce stylolites. When overlying beds are eroded, bringing limestone closer to the surface, the final stage of diagenesis takes place. This produces secondary porosity as some of the cement is dissolved by rainwater infiltrating

902-590: A designated campsite may be forbidden by law. It is thought to be a nuisance, harmful to the environment, and is often associated with vagrancy . However some countries have specific laws and/or regulations allowing camping on public lands (see Freedom to roam ). In the United States, many national and state parks have dedicated campsites and sometimes also allow impromptu backcountry camping by visitors. U.S. National Forests often have established campsites, but generally allow camping anywhere, except within

SECTION 10

#1732772353009

984-483: A drop of dilute hydrochloric acid is dropped on it. Dolomite is also soft but reacts only feebly with dilute hydrochloric acid, and it usually weathers to a characteristic dull yellow-brown color due to the presence of ferrous iron. This is released and oxidized as the dolomite weathers. Impurities (such as clay , sand, organic remains, iron oxide , and other materials) will cause limestones to exhibit different colors, especially with weathered surfaces. The makeup of

1066-637: A few million years, as this is the most stable form of calcium carbonate. Ancient carbonate formations of the Precambrian and Paleozoic contain abundant dolomite, but limestone dominates the carbonate beds of the Mesozoic and Cenozoic . Modern dolomite is quite rare. There is evidence that, while the modern ocean favors precipitation of aragonite, the oceans of the Paleozoic and middle to late Cenozoic favored precipitation of calcite. This may indicate

1148-455: A few thousand years. As rainwater mixes with groundwater, aragonite and high-magnesium calcite are converted to low-calcium calcite. Cementing of thick carbonate deposits by rainwater may commence even before the retreat of the sea, as rainwater can infiltrate over 100 km (60 miles) into sediments beneath the continental shelf. As carbonate sediments are increasingly deeply buried under younger sediments, chemical and mechanical compaction of

1230-490: A high percentage of the mineral dolomite , CaMg(CO 3 ) 2 . Magnesian limestone is an obsolete and poorly-defined term used variously for dolomite, for limestone containing significant dolomite ( dolomitic limestone ), or for any other limestone containing a significant percentage of magnesium . Most limestone was formed in shallow marine environments, such as continental shelves or platforms , though smaller amounts were formed in many other environments. Much dolomite

1312-435: A limestone sample except in thin section and are less common in ancient limestones, possibly because compaction of carbonate sediments disrupts them. Limeclasts are fragments of existing limestone or partially lithified carbonate sediments. Intraclasts are limeclasts that originate close to where they are deposited in limestone, while extraclasts come from outside the depositional area. Intraclasts include grapestone , which

1394-407: A long-term basis from the land owner and the lease's own mobile home placed on the pitch. Permanent sites owners lease includes the provision by the land owner of water, sewerage and general site and grounds maintenance. Some holiday parks includes a small campsite for those touring the area, where they can pay to pitch tents or site touring caravans and motorhomes. Touring campsites have full access to

1476-471: A lower Mg/Ca ratio in the ocean water of those times. This magnesium depletion may be a consequence of more rapid sea floor spreading , which removes magnesium from ocean water. The modern ocean and the ocean of the Mesozoic have been described as "aragonite seas". Most limestone was formed in shallow marine environments, such as continental shelves or platforms . Such environments form only about 5% of

1558-525: A lower diversity of organisms and a greater fraction of silica and clay minerals characteristic of marls . The Green River Formation is an example of a prominent freshwater sedimentary formation containing numerous limestone beds. Freshwater limestone is typically micritic. Fossils of charophyte (stonewort), a form of freshwater green algae, are characteristic of these environments, where the charophytes produce and trap carbonates. Limestones may also form in evaporite depositional environments . Calcite

1640-523: A mechanism for dolomitization, with one 2004 review paper describing it bluntly as "a myth". Ordinary seawater is capable of converting calcite to dolomite, if the seawater is regularly flushed through the rock, as by the ebb and flow of tides (tidal pumping). Once dolomitization begins, it proceeds rapidly, so that there is very little carbonate rock containing mixed calcite and dolomite. Carbonate rock tends to be either almost all calcite/aragonite or almost all dolomite. About 20% to 25% of sedimentary rock

1722-666: A nominal fee for the privilege of camping there, to cover expenses, and in the case of an independent campground, to make a profit. However, there are some in North America that do not charge a use fee and rely on sources such as donations and tax dollars. Staying the night in a big-box store parking lot is also common (called " boondocking "), and some retailers welcome RVs to their parking lots. Frequently confused with campsites, campgrounds and RV parks, trailer parks are made up of long term or semi-permanent residents occupying mobile homes, park trailers or RVs. The holiday park

SECTION 20

#1732772353009

1804-700: A permit, which may be free, obtainable at visitor centers and ranger stations. Backcountry camping in other areas may not require a permit. Canadians refer to it as crownland camping, or rough camping. Canadian citizens and people who have lived in Canada for at least seven months of the preceding 12-month period can camp for free up to 21 days on any one site in a calendar year. This ensures sites are available to others and helps reduce environmental impacts. The Crownland Atlas (map) provides usage designations and several web pages (map) or blogs provide more details about specific sites. As with camping, campgrounds predated

1886-548: A place used for camping (an overnight stay in an outdoor area). The usage differs between British English and American English. In British English, a campsite is an area, usually divided into a number of camping pitches , where people can camp overnight using tents , campervans or caravans . In the US , the expression used is campground and not campsite . In American English, the term campsite generally means an area where an individual, family, group, or military unit can pitch

1968-448: A plausible source of mud. Another possibility is direct precipitation from the water. A phenomenon known as whitings occurs in shallow waters, in which white streaks containing dispersed micrite appear on the surface of the water. It is uncertain whether this is freshly precipitated aragonite or simply material stirred up from the bottom, but there is some evidence that whitings are caused by biological precipitation of aragonite as part of

2050-449: A radial rather than layered internal structure, indicating that they were formed by algae in a normal marine environment. Peloids are structureless grains of microcrystalline carbonate likely produced by a variety of processes. Many are thought to be fecal pellets produced by marine organisms. Others may be produced by endolithic (boring) algae or other microorganisms or through breakdown of mollusc shells. They are difficult to see in

2132-665: A standard house. A standard lodge uses similar materials as a standard caravan such as wood, gypsum board and plywood where the main difference being the extra width. Lodges and Parkhomes can come in sizes up to 22 feet wide and 45 feet long, making them a popular choice with big families and large groups. Holiday homes can be rented on an ad-hoc basis or purchased – caravans can be purchased from around £30,000 while park homes and lodges can cost between £100,000 and £500,000. Once purchased, holiday homes have various ongoing costs including insurance, site fees, local authority rates, utility charges, winterisation and depreciation. Depending on

2214-451: A tent or park a camper; a campground may contain many campsites. There are two types of campsites ( US ) or pitches ( UK ): one, a designated area with various facilities; or two, an impromptu area (as one might decide to stop while backpacking or hiking , or simply adjacent to a road through the wilderness). The term 'camp' comes from the Latin word campus , meaning "field". Therefore,

2296-463: Is a United Kingdom version of the North American trailer park. Created to allow coastal resorts to enable temporary and high-income accommodation to be easily created, under UK planning laws , no residents are permanent, and the park must be wholly shut to all for at least two months each year. All of the mobile homes are either available for rent from the land owner, or pitches are leased on

2378-409: Is a single unit, built to a maximum of 14 feet wide. Other types of mobile home include Lodges and Park Homes which are more expensive than caravans and offer more luxurious features. Higher end Lodges can be built using some of the same methods as traditional bricks and mortar buildings and include familiar materials like plasterboard and tongue and groove walls for an end result that's very similar to

2460-560: Is also favored on the seaward margin of shelves and platforms, where there is upwelling deep ocean water rich in nutrients that increase organic productivity. Reefs are common here, but when lacking, ooid shoals are found instead. Finer sediments are deposited close to shore. The lack of deep sea limestones is due in part to rapid subduction of oceanic crust, but is more a result of dissolution of calcium carbonate at depth. The solubility of calcium carbonate increases with pressure and even more with higher concentrations of carbon dioxide, which

2542-482: Is an uncommon mineral in limestone, and siderite or other carbonate minerals are rare. However, the calcite in limestone often contains a few percent of magnesium . Calcite in limestone is divided into low-magnesium and high-magnesium calcite, with the dividing line placed at a composition of 4% magnesium. High-magnesium calcite retains the calcite mineral structure, which is distinct from dolomite. Aragonite does not usually contain significant magnesium. Most limestone

Marble Mountain Wilderness - Misplaced Pages Continue

2624-589: Is both state-listed (1979) and federally listed (1978) as endangered . With 89 lakes and two major Wild and Scenic river systems-Wooley Creek and the North Fork Salmon River , as well as 32 miles (51 km) of the Pacific Crest Trail , there are many recreation opportunities. Elevations range from 400 to 8,299 feet (122 to 2,530 m); the wilderness has highly variable terrain with low-elevation canyons and high ridges such as

2706-402: Is carbonate rock, and most of this is limestone. Limestone is found in sedimentary sequences as old as 2.7 billion years. However, the compositions of carbonate rocks show an uneven distribution in time in the geologic record. About 95% of modern carbonates are composed of high-magnesium calcite and aragonite. The aragonite needles in carbonate mud are converted to low-magnesium calcite within

2788-474: Is clusters of peloids cemented together by organic material or mineral cement. Extraclasts are uncommon, are usually accompanied by other clastic sediments, and indicate deposition in a tectonically active area or as part of a turbidity current . The grains of most limestones are embedded in a matrix of carbonate mud. This is typically the largest fraction of an ancient carbonate rock. Mud consisting of individual crystals less than 5 μm (0.20 mils) in length

2870-416: Is commonly white to gray in color. Limestone that is unusually rich in organic matter can be almost black in color, while traces of iron or manganese can give limestone an off-white to yellow to red color. The density of limestone depends on its porosity, which varies from 0.1% for the densest limestone to 40% for chalk. The density correspondingly ranges from 1.5 to 2.7 g/cm . Although relatively soft, with

2952-420: Is controlled largely by the amount of dissolved carbon dioxide ( CO 2 ) in the water. This is summarized in the reaction: Increases in temperature or decreases in pressure tend to reduce the amount of dissolved CO 2 and precipitate CaCO 3 . Reduction in salinity also reduces the solubility of CaCO 3 , by several orders of magnitude for fresh water versus seawater. Near-surface water of

3034-545: Is converted to low-magnesium calcite. Diagenesis is the likely origin of pisoliths , concentrically layered particles ranging from 1 to 10 mm (0.039 to 0.394 inches) in diameter found in some limestones. Pisoliths superficially resemble ooids but have no nucleus of foreign matter, fit together tightly, and show other signs that they formed after the original deposition of the sediments. Silicification occurs early in diagenesis, at low pH and temperature, and contributes to fossil preservation. Silicification takes place through

3116-503: Is deposited close to where it formed, classification of limestone is usually based on its grain type and mud content. Most grains in limestone are skeletal fragments of marine organisms such as coral or foraminifera . These organisms secrete structures made of aragonite or calcite, and leave these structures behind when they die. Other carbonate grains composing limestones are ooids , peloids , and limeclasts ( intraclasts and extraclasts  [ ca ] ). Skeletal grains have

3198-460: Is described as coquinite . Chalk is a soft, earthy, fine-textured limestone composed of the tests of planktonic microorganisms such as foraminifera, while marl is an earthy mixture of carbonates and silicate sediments. Limestone forms when calcite or aragonite precipitate out of water containing dissolved calcium, which can take place through both biological and nonbiological processes. The solubility of calcium carbonate ( CaCO 3 )

3280-617: Is described as micrite . In fresh carbonate mud, micrite is mostly small aragonite needles, which may precipitate directly from seawater, be secreted by algae, or be produced by abrasion of carbonate grains in a high-energy environment. This is converted to calcite within a few million years of deposition. Further recrystallization of micrite produces microspar , with grains from 5 to 15 μm (0.20 to 0.59 mils) in diameter. Limestone often contains larger crystals of calcite, ranging in size from 0.02 to 0.1 mm (0.79 to 3.94 mils), that are described as sparry calcite or sparite . Sparite

3362-462: Is distinguished from micrite by a grain size of over 20 μm (0.79 mils) and because sparite stands out under a hand lens or in thin section as white or transparent crystals. Sparite is distinguished from carbonate grains by its lack of internal structure and its characteristic crystal shapes. Geologists are careful to distinguish between sparite deposited as cement and sparite formed by recrystallization of micrite or carbonate grains. Sparite cement

Marble Mountain Wilderness - Misplaced Pages Continue

3444-411: Is legal in most of Scotland. In many parts of Canada, "roughing it" or "dormir a la belle etoile" (French) is considered to be wilderness camping on government owned, public land known as crown land and commonly called "the bush". There are no amenities of any kind and typically no development except for possibly logging roads or ATV trails, and few rules beyond the requirement in some provinces to move

3526-560: Is one of the first minerals to precipitate in marine evaporites. Most limestone is formed by the activities of living organisms near reefs, but the organisms responsible for reef formation have changed over geologic time. For example, stromatolites are mound-shaped structures in ancient limestones, interpreted as colonies of cyanobacteria that accumulated carbonate sediments, but stromatolites are rare in younger limestones. Organisms precipitate limestone both directly as part of their skeletons, and indirectly by removing carbon dioxide from

3608-473: Is otherwise chemically fairly pure, with clastic sediments (mainly fine-grained quartz and clay minerals ) making up less than 5% to 10% of the composition. Organic matter typically makes up around 0.2% of a limestone and rarely exceeds 1%. Limestone often contains variable amounts of silica in the form of chert or siliceous skeletal fragments (such as sponge spicules, diatoms , or radiolarians ). Fossils are also common in limestone. Limestone

3690-472: Is produced by decaying organic matter settling into the deep ocean that is not removed by photosynthesis in the dark depths. As a result, there is a fairly sharp transition from water saturated with calcium carbonate to water unsaturated with calcium carbonate, the lysocline , which occurs at the calcite compensation depth of 4,000 to 7,000 m (13,000 to 23,000 feet). Below this depth, foraminifera tests and other skeletal particles rapidly dissolve, and

3772-518: Is secondary dolomite, formed by chemical alteration of limestone. Limestone is exposed over large regions of the Earth's surface, and because limestone is slightly soluble in rainwater, these exposures often are eroded to become karst landscapes. Most cave systems are found in limestone bedrock. Limestone has numerous uses: as a chemical feedstock for the production of lime used for cement (an essential component of concrete ), as aggregate for

3854-413: The 22-mile (35 km)-long English Peak ridge. Popular activities include fishing, backpacking and cross-country skiing . There are also numerous caves within this wilderness, accessible to prepared spelunkers . They all feature stalactites and other flowstone formations, and are accessible mostly by vertical drops. Due to the hidden nature of most of the cave mouths, caving is not regulated, though

3936-525: The Deep Lake area. All of the subalpine fir groves in northwest California are more than 50 miles (80 km) from the next closest subalpine fir stand, which is in southern Oregon on Mount Ashland . In addition, the headwaters of the Salmon River in the wilderness also hold a relict stand of Pacific silver fir , which is the southernmost stand in the range of the species. Common wildlife include

4018-496: The Earth's history. Limestone may have been deposited by microorganisms in the Precambrian , prior to 540 million years ago, but inorganic processes were probably more important and likely took place in an ocean more highly oversaturated in calcium carbonate than the modern ocean. Diagenesis is the process in which sediments are compacted and turned into solid rock . During diagenesis of carbonate sediments, significant chemical and textural changes take place. For example, aragonite

4100-581: The Forest Service and National Speleological Society request only experienced cavers attempt to access these dangerous caves. Signs at the trail heads that access the Marble Rim warn of white nose syndrome . One of the deepest caves in the continental US is located in the wilderness, Bigfoot Cave. There are several national forest campgrounds outside the boundary and one camp inside the wilderness near Wooley Creek, named after Anthony Milne, who

4182-648: The Holiday parks facilities, including clothes washing and showering. Most holiday parks include a central entertainments block, which can include a shop, restaurants, and a multi-purpose theatre used for both stage and activity-based entertainment. Holiday parks vary in size and type, as do the kinds of accommodation available within them. Caravans are a popular choice with holiday makers, and modern varieties come complete with features like double glazing and central heating, cookers, fridges, showers, hot/cold water supplies, electricity and gas mains input. A standard caravan

SECTION 50

#1732772353009

4264-494: The U.S., backcountry or dispersed camping is common in large undeveloped protected areas. These areas can only be reached on foot, bicycle, canoe or on horseback . The camping areas are usually established campsites or "zones", which have a predetermined maximum number of persons that are allowed to stay in the section per night. Strict regulations are imposed regarding food storage and resource protection. Usually in organized parks or wilderness areas, backcountry campsites require

4346-510: The United States were nothing more than large, dedicated clearings, free of trees, within which to concentrate groups of tourists.” A plant pathologist named Emilio Meinecke, was commissioned to study the effect of motor tourism in the Redwoods in 1929. Meinicke's recommendations explained that instead of allowing campers to park haphazardly within a park, the camper's impact on the environment could be minimized through campground roads forming

4428-430: The accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life. About 20% to 25% of sedimentary rock is carbonate rock, and most of this is limestone. The remaining carbonate rock is mostly dolomite , a closely related rock, which contains

4510-551: The automobile. When President Theodore Roosevelt addressed Congress in 1901, he called for the creation of free campgrounds on Federal lands. Already four national parks—Yellowstone, Sequoia, Yosemite, and Mount Rainier—were established and by the time Congress formally established the National Park Service in 1916, America had a dozen national parks. While a handful of campgrounds, both public and private, could be found at tourist destinations, as late as 1936 it

4592-434: The base of roads, as white pigment or filler in products such as toothpaste or paint, as a soil conditioner , and as a popular decorative addition to rock gardens . Limestone formations contain about 30% of the world's petroleum reservoirs . Limestone is composed mostly of the minerals calcite and aragonite , which are different crystal forms of calcium carbonate ( CaCO 3 ). Dolomite , CaMg(CO 3 ) 2 ,

4674-657: The beds. This may include the formation of vugs , which are crystal-lined cavities within the limestone. Diagenesis may include conversion of limestone to dolomite by magnesium-rich fluids. There is considerable evidence of replacement of limestone by dolomite, including sharp replacement boundaries that cut across bedding. The process of dolomitization remains an area of active research, but possible mechanisms include exposure to concentrated brines in hot environments ( evaporative reflux ) or exposure to diluted seawater in delta or estuary environments ( Dorag dolomitization ). However, Dorag dolomitization has fallen into disfavor as

4756-547: The black-tailed deer and black bear . Less commonly seen species are badger and wolverine . Bird species include the great gray owl and northern goshawk , and also the peregrine falcon and bald eagle , both of which have been removed (August 2007 and August 1999, respectively) from the federal threatened/endangered species list. Fish species include summer steelhead and a spring run of king salmon in Wooley Creek, as well as resident rainbow trout in other streams in

4838-529: The bottom with the concave face downwards. This traps a void space that can later be filled by sparite. Geologists use geopetal structures to determine which direction was up at the time of deposition, which is not always obvious with highly deformed limestone formations. The cyanobacterium Hyella balani can bore through limestone; as can the green alga Eugamantia sacculata and the fungus Ostracolaba implexa . Campground Campsite , campground , and camping pitch are all related terms regarding

4920-547: The core of the wilderness with Marble Mountain being a north-trending spur ridge of the Salmons. The highest point in the Marbles is Boulder Peak at 8,299 feet (2,530 m). This area of high divides, deep canyons and perennial mountain streams provides habitat for a wide variety of plant and animal life. With more than 7,000 feet (2,100 m) of vertical relief, soils from several rock types, and abundant rain and snowfall,

5002-466: The depositional fabric of carbonate rocks. Dunham divides the rocks into four main groups based on relative proportions of coarser clastic particles, based on criteria such as whether the grains were originally in mutual contact, and therefore self-supporting, or whether the rock is characterized by the presence of frame builders and algal mats. Unlike the Folk scheme, Dunham deals with the original porosity of

SECTION 60

#1732772353009

5084-469: The deposits are highly porous, so that they have a spongelike texture, they are typically described as tufa . Secondary calcite deposited by supersaturated meteoric waters ( groundwater ) in caves is also sometimes described as travertine. This produces speleothems , such as stalagmites and stalactites . Coquina is a poorly consolidated limestone composed of abraded pieces of coral , shells , or other fossil debris. When better consolidated, it

5166-541: The diversity of ecosystems is unequaled anywhere else in the country. The wilderness contains a number of isolated stands of locally rare conifers. For example, the subalpine fir grows along the granite moraines at the head of watersheds above 6,000 feet (1,800 m) in open areas surrounding lakes and meadows, in the Sky High Lakes Basin, in Shelly Meadow along the Pacific Crest Trail and in

5248-406: The earth's oceans are oversaturated with CaCO 3 by a factor of more than six. The failure of CaCO 3 to rapidly precipitate out of these waters is likely due to interference by dissolved magnesium ions with nucleation of calcite crystals, the necessary first step in precipitation. Precipitation of aragonite may be suppressed by the presence of naturally occurring organic phosphates in

5330-611: The economic benefits of a campground in their community. The Denver Civic Association wrote that a campground was just as essential to a town as a railway station. The trailer industry's efforts were effective. The number of campgrounds in the Trailer Travel Magazine's directory of campgrounds doubled to 1,650 by the end of 1936 and promised to double again by the end of 1937. The campgrounds themselves also changed. Martin Hogue wrote, “The first public campgrounds in

5412-399: The first refers to the grains and the second to the cement. For example, a limestone consisting mainly of ooids, with a crystalline matrix, would be termed an oosparite. It is helpful to have a petrographic microscope when using the Folk scheme, because it is easier to determine the components present in each sample. Robert J. Dunham published his system for limestone in 1962. It focuses on

5494-572: The formation of distinctive minerals from the silica and clay present in the original limestone. Two major classification schemes, the Folk and Dunham, are used for identifying the types of carbonate rocks collectively known as limestone. Robert L. Folk developed a classification system that places primary emphasis on the detailed composition of grains and interstitial material in carbonate rocks . Based on composition, there are three main components: allochems (grains), matrix (mostly micrite), and cement (sparite). The Folk system uses two-part names;

5576-429: The geologic record are called bioherms . Many are rich in fossils, but most lack any connected organic framework like that seen in modern reefs. The fossil remains are present as separate fragments embedded in ample mud matrix. Much of the sedimentation shows indications of occurring in the intertidal or supratidal zones, suggesting sediments rapidly fill available accommodation space in the shelf or platform. Deposition

5658-536: The holiday home and the park these costs can range from £1,000 to £40,000 per year. Certificated and Certified Locations are smaller privately owned caravan sites which have to be approved by the UK based Camping and Caravanning Club, The Caravan Club, and other organisations). These campsites are normally reserved exclusively for Club members. These smaller campsites are allowed to operate under The Public Health Act 1936 and The Caravan and Control of Development Act 1960. In

5740-410: The ocean basins, but limestone is rarely preserved in continental slope and deep sea environments. The best environments for deposition are warm waters, which have both a high organic productivity and increased saturation of calcium carbonate due to lower concentrations of dissolved carbon dioxide. Modern limestone deposits are almost always in areas with very little silica-rich sedimentation, reflected in

5822-426: The reaction: Fossils are often preserved in exquisite detail as chert. Cementing takes place rapidly in carbonate sediments, typically within less than a million years of deposition. Some cementing occurs while the sediments are still under water, forming hardgrounds . Cementing accelerates after the retreat of the sea from the depositional environment, as rainwater infiltrates the sediment beds, often within just

5904-482: The relative purity of most limestones. Reef organisms are destroyed by muddy, brackish river water, and carbonate grains are ground down by much harder silicate grains. Unlike clastic sedimentary rock, limestone is produced almost entirely from sediments originating at or near the place of deposition. Limestone formations tend to show abrupt changes in thickness. Large moundlike features in a limestone formation are interpreted as ancient reefs , which when they appear in

5986-460: The rock. The Dunham scheme is more useful for hand samples because it is based on texture, not the grains in the sample. A revised classification was proposed by Wright (1992). It adds some diagenetic patterns to the classification scheme. Travertine is a term applied to calcium carbonate deposits formed in freshwater environments, particularly waterfalls , cascades and hot springs . Such deposits are typically massive, dense, and banded. When

6068-479: The sediments increases. Chemical compaction takes place by pressure solution of the sediments. This process dissolves minerals from points of contact between grains and redeposits it in pore space, reducing the porosity of the limestone from an initial high value of 40% to 80% to less than 10%. Pressure solution produces distinctive stylolites , irregular surfaces within the limestone at which silica-rich sediments accumulate. These may reflect dissolution and loss of

6150-662: The sediments of the ocean floor abruptly transition from carbonate ooze rich in foraminifera and coccolith remains ( Globigerina ooze) to silicic mud lacking carbonates. In rare cases, turbidites or other silica-rich sediments bury and preserve benthic (deep ocean) carbonate deposits. Ancient benthic limestones are microcrystalline and are identified by their tectonic setting. Fossils typically are foraminifera and coccoliths. No pre-Jurassic benthic limestones are known, probably because carbonate-shelled plankton had not yet evolved. Limestones also form in freshwater environments. These limestones are not unlike marine limestone, but have

6232-406: The site at least 100 metres every 21 days. In North America many campgrounds have facilities for Recreational Vehicles and are also known as RV parks. Similar facilities in the UK are known as Caravan Parks . The Kampgrounds of America (KOA) is a large chain of commercial campgrounds located throughout the United States and Canada. Both commercial and governmental campgrounds typically charge

6314-533: The water by photosynthesis and thereby decreasing the solubility of calcium carbonate. Limestone shows the same range of sedimentary structures found in other sedimentary rocks. However, finer structures, such as lamination , are often destroyed by the burrowing activities of organisms ( bioturbation ). Fine lamination is characteristic of limestone formed in playa lakes , which lack the burrowing organisms. Limestones also show distinctive features such as geopetal structures , which form when curved shells settle to

6396-553: The water. Although ooids likely form through purely inorganic processes, the bulk of CaCO 3 precipitation in the oceans is the result of biological activity. Much of this takes place on carbonate platforms . The origin of carbonate mud, and the processes by which it is converted to micrite, continue to be a subject of research. Modern carbonate mud is composed mostly of aragonite needles around 5 μm (0.20 mils) in length. Needles of this shape and composition are produced by calcareous algae such as Penicillus , making this

6478-519: The wilderness. There are several rare wildflowers that are adapted to serpentine soils of the Marble Mountain Wilderness and surrounding area. These include crested cinquefoil or crested potentilla ( Potentilla cristae ), Siskiyou fireweed ( Epilobium siskiyouense ), and McDonald's rock cress ( Arabis blepharophylla var. macdonaldiana ), a perennial found in conifer forests of California and Oregon. MacDonald's rockcress

6560-527: Was a miner in the area around 1885. Limestone Limestone ( calcium carbonate CaCO 3 ) is a type of carbonate sedimentary rock which is the main source of the material lime . It is composed mostly of the minerals calcite and aragonite , which are different crystal forms of CaCO 3 . Limestone forms when these minerals precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as

6642-416: Was likely deposited in pore space between grains, suggesting a high-energy depositional environment that removed carbonate mud. Recrystallized sparite is not diagnostic of depositional environment. Limestone outcrops are recognized in the field by their softness (calcite and aragonite both have a Mohs hardness of less than 4, well below common silicate minerals) and because limestone bubbles vigorously when

6724-498: Was still difficult to find places to stop along the route to these parks. Instead, it was common for motorists to pull off the road and set up camp on private property. This practice not only reinforced the negative, nomadic image of RV travelers, it was a detriment to expanding the trailer market. The Trailer Coach Manufacturers Association began to lobby states to establish sanitation standards and worked with civic and business leaders to establish additional campgrounds, emphasizing

#8991