Science question ???

Material deposited by groundwater in cracks in rocks forms





veins


dikes


batholiths


stalactites|||Veins.


I got this copy from Wikipedia. My very first Wiki copy on Y!A. (the key word is cracks (fissures))





"In geology, a vein is a finite volume within a rock, having a distinct shape, filled with crystals of one or more minerals, which were precipitated from an (aqueous) fluid. Veins are formed by fluids carrying mineral constituents into a rock mass as a consequence of some form of hydraulic flow within the rock. Usually this is the result of hydrothermal circulation.





Veins are classically thought of as being the result of growth of crystals on the walls of planar fractures in rocks, with the crystal growth occurring normal to the walls of the cavity, and the crystal protruding into open space.





This certainly is the method for the formation of some veins. However, it is rare in geology for significant open space to remain open in large volumes of rock, especially several kilometers below the surface. Thus, there are two main mechanisms considered likely for the formation of veins: open-space filling and crack-seal growth."





Cite location:


http://en.wikipedia.org/wiki/Vein_%28geo鈥?/a>


Here's another geologic cite reference:


http://www.uky.edu/KGS/rocksmn/vein.htm|||Hahahaha|||Stalactites.|||stalactites





wiki: "Stalactites are formed by the deposition of calcium carbonate and other minerals, which is precipitated from mineralized water solutions. Limestone is calcium carbonate rock which is dissolved by water that contains carbon dioxide, forming a calcium bicarbonate solution."