User:Gandydancer/Naica
Formation of the crystals[edit]
Naica lies on an ancient fault and there is an underground magma chamber below the cave. Volcanic activity that began about 26 million years ago created Naica mountain and filled it with the mineral anhydrite.[does not make sense--see anhydrite] FUMAROLES Anhydrite is stable above 136 degrees Fahrenheit (58 degrees Celsius), but below that temperature gypsum is the stable form. When magma underneath the mountain cooled and the temperature dropped and stabilized at around 58 degrees Celsius (136 Farenheit) , the mineral anhydrite, which was abundant in the water-filled cavety,[OR...For hundreds of thousands of years, groundwater saturated with calcium sulfate filtered through the many caves ??] dissolved into gypsum. At this temperature minerals in the water began converting to selenite, molecules of which were laid down to form crystals. (how does selenite fit in?) FORM OF GYPSUM-CLEAR- ALABASTER IS ANOTHER?
Spanish crystallographer Juan Manuel García-Ruiz was one of the first to study the Naica crystals beginning in 2001. By examining bubbles of liquid trapped inside the crystals, García and his colleagues pieced together the story of the crystals' growth. His research suggests the largest of the crystals are about 600,000 years old. Italian scientists extracted pollen that may have been trapped within the bubbles and the grains appear to be 30,000 years old and suggest that this part of Mexico was once covered not by desert but by forest.[1]
how rare is it for crystals to form in water? how did the cave form? [probably old faults/cracks] also remember about the early draining Gandydancer (talk) 02:25, 25 January 2010 (UTC)
- Crystals quite commonly form as precipitates from aqueous solution, depends on the mineral species.
- The host rock is limestone which quite readily dissolves to form caves. The presence of faults and fractures provides the access for the dissolving/mineralizing solutions. SULFURIC ACID SOLN Vsmith (talk) 19:46, 25 January 2010 (UTC)
- Anhydrite is a mineral - anhydrous calcium sulfate —Preceding unsigned comment added by Gandydancer (talk • contribs) 02:48, 25 January 2010 (UTC)
http://news.bbc.co.uk/2/hi/science/nature/8466493.stm Gandydancer (talk) 19:07, 25 January 2010 (UTC)
I know, now, I have forgotton all my chemistry and it was actually fun to try to figure it out again...I have been working on this page for many hours and it is all lost now...seems you moved it before I saved my page...grrr well, thanks for moving it anyway...
So....the mountain is an old volcano and the cave is 1000 ft down in limestone
Geologists conjecture that a chamber of magma, or superheated molten rock, lying two to three miles underneath the mountain forced mineral-rich fluids upward through a fault into openings in the limestone bedrock near the surface. Over a period of time, maybe more than 30 million years, this hydrothermal liquid deposited sulphides rich in silver, lead and zinc on the limestone bedrock. These metals have been mined here since prospectors discovered the deposits in 1794 in a small range of hills south of Chihuahua City. In addition, the hydrothermal fluids dissolved gypsum, the same material used in wallboard and plaster of paris, located in the bedrock. Hot, mineral-rich solutions gave birth to these giant selenite crystals.
In addition to 1 metre diameter columns 15 meters in length, the cavern contains row upon row of shark-teeth-shaped formations up to 1 metre high, which are positioned at odd angles throughout the cave.
Geologists conjecture that a chamber of magma, or superheated molten rock, lying two to three miles underneath the mountain forced mineral-rich fluids upward through a fault into openings in the limestone bedrock near the surface. Over a period of time, maybe more than 30 million years, this hydrothermal liquid deposited sulphides rich in silver, lead and zinc on the limestone bedrock. These metals have been mined here since prospectors discovered the deposits in 1794 in a small range of hills south of Chihuahua City. In addition, the hydrothermal fluids dissolved gypsum, the same material used in wallboard and plaster of paris, located in the bedrock. Hot, mineral-rich solutions gave birth to these giant selenite crystals.
In addition to 1 metre diameter columns 15 meters in length, the cavern contains row upon row of shark-teeth-shaped formations up to 1 metre high, which are positioned at odd angles throughout the cave.
References[edit]
New crystals "sails" http://www.ijs.speleo.it/pdf/65.544.36(1)_Bernabei_et_al.pdf