RELATIONS BETWEEN GRANITES AND PEGMATITES
At the pegmatitic stage, some elements that exist in the ppm range at the source become sufficiently concentrated to precipitate minerals of their own, e.g., as spodumene (Li), beryl (Be), pollucite, (Cs), cassiterite (Sn), and tantalite (Ta). Using melting relations and element partitioning, then, we can predict the concentration of a particular trace element at the beginning of granite magmatism and at the end pegmatitic stage (e.g., London et al., 1999). This allows us to model and answer an important and recurring question in the relations between granites and pegmatites how much crystal fractionation must take place from anatexis to produce a pegmatite capable of precipitating spodumene, beryl, etc. (Fig. 2)? Most of our work has been on the elements of Groups IA (alkalis: Li, Na, K, Rb, and Cs) and IIA (alkaline earths: Be, Ca, Sr, and Ba the behavior of Mg during crystal fractionation is sufficiently well understood).We have also studied the behavior of added components to the granite system that may influence partitioning behavior. These include the important fluxes and ligands of boron (B), fluorine (F), and phosphorus (P). Like many of the economically important specialty metals, these ligands behave incompatibly in felsic crystal-melt systems and hence both are concentrated together in granite and pegmatite ore deposits. The association is so strong, e.g., between Sn and B, that many economic geologists presume that the specialty metal and exotic ligand form a stable complex in melt, and that this complex itself is responsible for incompatibility and concentration toward the ends stages of magmatism.
Figure 2. Fractionation of an incompatible trace element (purple sphere), from anatexis to saturation in melt. (A) The trace element signature of melt is controlled by partitioning between residual minerals and melt. (B) The trace element signature of melt is modified by fractional crystallization from the melt. (C) increasing concentration of the trace element finally achieves saturation of melt and precipitation of a mineral in which the trace element is an essential constituent, e.g,. Be in beryl.
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Granite lends itself to a variety of locations in traditional and modern houses for hallways,stairways, living areas, bathrooms and particularly, work surfaces such as kitchen tops and vanity tops.
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Installing marble tiles is similar to working with ceramic tiles. However, the subsurface should be as rigid as possible to reduce the risk of cracking from vibration or flexing.
Kitchen Countertop
When you choose your countertop, select a color and texture that compliments your cabinetry, floor or paint selection. Don't be afraid to combine two or more countertop materials in one kitchen.
Vanity tops
Granite lends itself to a variety of locations in traditional and modern houses for hallways,stairways, living areas, bathrooms and particularly, work surfaces such as kitchen tops and vanity tops.
Marble Tile
Installing marble tiles is similar to working with ceramic tiles. However, the subsurface should be as rigid as possible to reduce the risk of cracking from vibration or flexing.