All Topics  
Tufa

 
Tufa

 
   Email Print
   Bookmark   Link
 

 

Tufa
 
 
  Topics Tufa Topic Home

Tufa is a soft, friable and porous calcite
Calcite

Calcite is a Carbonate minerals and the most stable Polymorphism of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite....
 rock. It is a calcium carbonate
Calcium carbonate

Calcium carbonate is a chemical compound with the chemical formula CalciumCarbonOxygen3. It is a common substance found as Rock in all parts of the world, and is the main component of seashells, snails, and eggshells....
 (CaCO3) deposit that forms by chemical/biological precipitation
Precipitation (chemistry)

Precipitation is the formation of a solid in a solution during a chemical reaction. When the reaction occurs, the solid formed is called the precipitate, and the liquid remaining above the solid is called the supernate....
 from bodies of water with a high dissolved calcium
Calcium

Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft grey alkaline earth metal, and is the fifth most abundant element by mass in the earth's Crust ....
 content. Calcareous
Calcareous

Calcareous refers to a sediment, sedimentary rock, or soil type which is formed from or contains a high proportion of calcium carbonate in the form of calcite or aragonite....
 tufa is not to be confused with tuff
Tuff

Tuff is a type of Rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. Tuff is also sometimes called tufa, particularly when used as construction material....
, a hard volcanic rock
Volcanic rock

Volcanic rock is an igneous rock of Volcano origin.Texture Volcanic rocks are usually fine-grained or aphanitic to glassy in texture....
 that is also sometimes called tufa.

Tufa deposition occurs in seven known ways:
  1. Mechanical precipitation by wave action against the shore. This form of tufa can be useful for identifying the shoreline of extinct lakes (for example in the Lake Lahontan
    Lake Lahontan

    Ancient Lake Lahontan was a large endorheic lake that existed during the ice age, covering much of northwestern Nevada, extending into northeastern California and southern Oregon....
     region).
  2. Precipitation from supersaturated hot spring water entering cooler lake water.
  3. Precipitation in lake bottom sediments which are fed by hot springs from below.
  4. Precipitation from calcium-bearing spring water flowing into an alkaline lake.
  5. Precipitation throughout a lake as the lake water evaporates, leaving the lake supersaturated in calcium.
  6. Through the agency of algae
    Algae

    Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds....
    .






    Discussion
    Ask a question about 'Tufa'
    Start a new discussion about 'Tufa'
    Answer questions from other users
    Full Discussion Forum



    Encyclopedia


    Tufa is a soft, friable and porous calcite
    Calcite

    Calcite is a Carbonate minerals and the most stable Polymorphism of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite....
     rock. It is a calcium carbonate
    Calcium carbonate

    Calcium carbonate is a chemical compound with the chemical formula CalciumCarbonOxygen3. It is a common substance found as Rock in all parts of the world, and is the main component of seashells, snails, and eggshells....
     (CaCO3) deposit that forms by chemical/biological precipitation
    Precipitation (chemistry)

    Precipitation is the formation of a solid in a solution during a chemical reaction. When the reaction occurs, the solid formed is called the precipitate, and the liquid remaining above the solid is called the supernate....
     from bodies of water with a high dissolved calcium
    Calcium

    Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft grey alkaline earth metal, and is the fifth most abundant element by mass in the earth's Crust ....
     content. Calcareous
    Calcareous

    Calcareous refers to a sediment, sedimentary rock, or soil type which is formed from or contains a high proportion of calcium carbonate in the form of calcite or aragonite....
     tufa is not to be confused with tuff
    Tuff

    Tuff is a type of Rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. Tuff is also sometimes called tufa, particularly when used as construction material....
    , a hard volcanic rock
    Volcanic rock

    Volcanic rock is an igneous rock of Volcano origin.Texture Volcanic rocks are usually fine-grained or aphanitic to glassy in texture....
     that is also sometimes called tufa.

    Tufa deposition occurs in seven known ways:
    1. Mechanical precipitation by wave action against the shore. This form of tufa can be useful for identifying the shoreline of extinct lakes (for example in the Lake Lahontan
      Lake Lahontan

      Ancient Lake Lahontan was a large endorheic lake that existed during the ice age, covering much of northwestern Nevada, extending into northeastern California and southern Oregon....
       region).
    2. Precipitation from supersaturated hot spring water entering cooler lake water.
    3. Precipitation in lake bottom sediments which are fed by hot springs from below.
    4. Precipitation from calcium-bearing spring water flowing into an alkaline lake.
    5. Precipitation throughout a lake as the lake water evaporates, leaving the lake supersaturated in calcium.
    6. Through the agency of algae
      Algae

      Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds....
      . Microbial influence is often vital to tufa precipitation and may be involved in the other methods listed.
    7. Precipitation from cold water springs (for example in the foothills of the Rocky Mountains
      Rocky Mountains

      The Rocky Mountains, often called the Rockies, are a mountain range in western North America. The Rocky Mountains stretch more than 4,800 kilometre from the northernmost part of British Columbia, in Canada, to New Mexico, in the United States....
       near Hinton, Alberta
      Hinton, Alberta

      Hinton is a town in west-central Alberta, Canada.It is located in Yellowhead County, Alberta, northeast of Jasper, Alberta and about west of Alberta's capital city, Edmonton, Alberta, at the intersection of Alberta Highway 16 and Alberta Highway 40, in the Athabasca River valley....
      ).


    Tufa is common in many parts of the world. There are some prominent towers of tufa at Mono Lake
    Mono Lake

    Mono Lake is an alkaline and hypersaline lake in California, United States that is a critical nesting habitat for several bird speciesand is an unusually productive ecosystem....
     and Trona Pinnacles
    Trona Pinnacles

    The Trona Pinnacles is one of the most unusual geological features in the California Desert National Conservation Area. The unusual landscape consists of more than 500 tufa spires , some as high as , rising from the bed of the Searles Lake basin....
     in California
    California

    California is a U.S. state on the West Coast of the United States of the United States, along the Pacific Ocean. It is bordered by Oregon to the north, Nevada to the east, Arizona to the southeast, and to the south the Mexico state of Baja California....
    , USA, formed by the fourth method mentioned above whilst submerged and subsequently exposed by falling water levels. Tufa is also common in Armenia
    Armenia

    Armenia , officially the Republic of Armenia , is a landlocked mountainous country in South Caucasus between the Black Sea and the Caspian Sea....
     and Great Britain
    Great Britain

    Great Britain is an island lying to the northwest of Continental Europe. It is the List of islands by area, and the largest in Europe. With a population of 58.9 million people it is List of islands by population....
    .

    Practical use

    Tufa is today occasionally shaped into a planter
    Planter

    Planter may refer to:*A box or flowerpot for plants also known as a jardiniere*A person who, or object that, planting*A colonialism.*Planter - device towed behind tractor for sowing crops...
    . Its porous consistency makes tufa ideal for alpine gardens. A concrete mixture called hypertufa
    Hypertufa

    Hypertufa is an Anthropic rock made from various Aggregate bonded together using Portland cement.Hypertufa is intended as a manufactured substitute for natural tufa, which is a slowly precipitated limestone rock; being very porous, it is favorable for plant growth....
     is used for similar purposes.

    See also

    • Calc-sinter
      Calc-sinter

      Calc-sinter is a solid calcium carbonate deposit. When calcium bicarbonate is dissolved in water, any major change in the environmental conditions causes the water to release part of its carbon dioxide as gas, much like carbonated beverages....
    • Travertine
      Travertine

      Travertine is a sedimentary rock. It is a natural chemical precipitation of carbonate minerals; typically aragonite, but often recrystallized to, or primarily, calcite....
    • North Dock Tufa
      North Dock Tufa

      The North Dock Tufa is a small dome-shaped petrified well, with stalactites and stalagmites, tucked away behind the Marine Activities Centre at Sunderland marina....


    External links