GEOL 2540 Lecture Notes - Lecture 2: Albite, Miscibility, Anorthite

• School: University of Manitoba
• Department: Geological Sciences
• Course: GEOL 2540
• Professor: Chakhmouradian Anton

Document Summary

O rig in cla ssific a tio n. O rig in, cla ssific a tio n, Atomic ( point ) defects in crystal structures (1) vacancies (atoms missing from ( t f i i the regular sequence of atoms) (2) substituting atoms (3) Interstitial atoms (impurity atoms accommodated in sites atoms accommodated in sites not normally occupied) (1) mechanism of substitution. Pyrite ( fes ) and cos ( cattierite) form a series of compositions. Pyrite ( fes2) and cos2 ( cattierite) form a series of compositions. 2ti4+ + fe2+ 2nb5+ + [ vac] Si4+ + [ vac] al3+ + na1+ (2) number of atoms involved in substitution. Fe2+ co2+ in ilmenite ( fe,mg) tio3 in pyrite ( fe,co) s2. Na+ + si4+ ca2+ + al3+ in plagioclases ( na,ca) ( si,al) alsi2o8. Ca2+ + mg2+ na+ + al3+ in pyroxenes ( ca,na) ( mg,al) si2o6 (3) extent of substitution.