The results show that the whole rocks and single minerals have widely variableδ 18O values (－ 2.4‰～ 2.0‰ for whole rock, 0.0‰～ 5.8‰ for quartz,－ 3.8‰～ 0.1‰ for alkaline feldspar, and－ 8.5‰～－ 1.0‰ for magnetite), and depleted in 18O.
From the heating experiments it is concluded that Fe~(3+), Al~(3+) and Fe~(3+), Si~(4+) exchange among the distinct T sites in the lattice of alkali feldspar is distinctly more sluggish than Al~(3+) and Si~(4+).
At a burial depth of 2 400-2 600 m, δ13C and δ18O in the carbonate (Ⅱ) formed in the sulfate reduction zone are in the range -7‰ to - 10‰ and -8‰ to - 10%%%%, respectively, where the dissolution of feldspar constitutes the 1st secondary pore zone.
The feldspars in mineralized and alkali_feldspar granites are characterized by the lower w (LREE)/ w (HREE) ratios and by the smaller europium positive anomalies ( δ (Eu)<6 for alkali_feldspars, and δ (Eu)<4 for plagioclases).
and the δ~ 18 O is also stable in value from 4.90×10~ -3 to 8.49×10~ -3 . It shows that the potassium feldspars in the studied area were from the same magma source but occurred in different stages and processes.
for RAs(and their evaporites) from reactions with feldspars,kaolinite,and montmorillonite,value Si/Al is less than original,showing higher rate and extent of acid etching of tetrahedron ~(5-) in feldspars crystal and octahedron [Al_4(OH)_6]~(6+) in clay crystal are larger than that of tetrahedron ~(4-) in crystals of these minerals;
Through systematic study of compositions of hornblendes, plagioclases, alkali feldspars, apatites and biotites from granitoids in Eastern Tianshan Mountains,Xinjiang China,it is determined that the granitoids crystallized at the depth of 11—17 km;
5. After adjusting content of raw materials and optimizing the fabrication process, feldspathic ceramics have been produced. Its fracture toughness reaches 1.19 Mpa-m1/2, which is equal to the one of Vita Mark II (1.21 Mpa-m1/2).
5．经过原料的筛选和工艺优化，研制出的可加工长石瓷的断裂韧性(1.19 Mpa·m~(1/2))非常接近国外同类可加工长石瓷产品Vita Mark Ⅱ(1.21 Mpa·m~(1/2))。
The experiment testifies that fracture toughness value of feldspathic porcelain prepared by SPS has researched about 1.60 MPa·m~(1/2) when the panicle size is 5～6μm and crystalline phase content is 10%～15%.
The composition of the ore ranges- from 95 to 97 percent kaolinite,1 to 2 percent illite and accessory amounts of limonite,rutile,quartz,felspar,carbonaceous rock,with trace amounts of pyrite and leucoxene.
SiC powder as the backbone together with the ceramic binder comsposed of felspar mixed with clay and pore-forming carbon were chosen, several firing temperatures were experimented, and some porosities and strengthes of the porous SiC ceramics were analysed.
To produce the calcium silicate board by using felspar powder instead ofquarth powder can lower the product cost, turns the waste material into a benefit and is beneficial to theenvirorunental protection.
The rocks are classified into greywackes or feldspar sandstones, grains of which are the mixtures of mafic rocks, felsic rocks, and quartz+calcite.
In conjunction with high abundances of Ba and Sr, as well as low abundances of Y and HREE, these patterns suggest a feldspar-poor, garnet±amohibole-rich fractionation mineral assemblage.
Empirical relationships describing the composition dependences of the chemical durability of glasses in the diopside-albite, diopside-anorthite, diopside-orthoclase, diopside-quartz, and diopside-feldspar systems are derived.
Two glasses of the same chemical composition manufactured while using two different sources of aluminosilicates: (1) sodium feldspar and (2) volcanic tuffs have been compared .
The influence of bacterial activity on glauconite formation is supported by the study of dissolution zones on quartz and feldspar grains, which revealed biomorphic structures akin to fossilized bacteria.