《The Determination of the Feldspars in thin Section》求取 ⇩

Ⅰ. CHEMICAL COMPOSTTION OF THE FFLDSPARS1

ALKALI FELDSPARS2

PLAGIOCLASE FELDSPARS4

Ⅱ. CRYSTAL MORPHOLOGY OF THE FELDSPARS 5

ALKALI FELDSPARS5

PLAGIOCLASE FELDSPARS7

Ⅲ. OPTICAL PROPERTIES OF THE FELDSPARS9

ATM ALT FELDSPARS10

PLAGIOCLASE FELDSPARS11

Ⅳ. DETERMINATION OF THE ALKALI FELDSPARS16

POTASH-FELDSPARS16

ORTHOCLASE16

MICROCLINE17

POTASH-SODA-FELDSPARS18

PERTHITE (ANTIPERTHITE)18

ANORTHOCLASE18

Ⅴ. DETERMINATION OF THE PLAGIOCLASE FELDSPARS19

A. DETERMINATIONS WITH THE PETROGRAPHIC MICRO-SCOPE19

1. THE METHOD OF RELATIVE REFRINGENCE20

2. DETERMINATION BY THE EXTINCTION ANGLES ON CERTAIN FACES AND IN CERTAIN ZONES23

(a) EXTINCTION ANGLES IN CLEAVAGE FL AKES PARALLEL TO P (001) AND M (010)23

(b) EXTINCTION ANGLES IN SECTIONS FROM THE SYMMETRICAL ZONE24

(c) EXTINCTION ANGLES IN SECTIONS NORMAL TO THE a-AXIS27

(d) EXTINCTION ANGLES IN SECTIONS WITH COMBINED ALBITE-CARLSEAD TWINNING29

(e) EXTINCTION ANGLES IN SECTIONS NORMAL TO A BISECTRIX (SECTIONS NORMAL TO X OR Z)31

B. DETERMINATIONS WITH THE FEDOROW UNIVERSAL STAGE38

PRELIMINARY ADJUSTMENTS 39

THE ZONAL METHOD41

1. FUNDAMENTALS OF THE ZONAL METHOD41

2. SUITABLE SECTIONS42

3. DETERMINATION OF THE COMPOSITION (TWINNING) PLANE42

4. DETERMINATION OF COMPOSITION AND TWIN- NING IN THE ZONE┵(010)44

(a) THE DIRECTION OF THE a-AXIS [100]44

(b) THE DIRECTION OF THE PERICLINE TWINNING LAMELLAE (PL)46

(c) THE DIRECTION OF MAXIMUM EXTINC-TION47

(d) COMBINED ALBITE-CARLSBAD TWIN- NING 47

(e) PRACTICAL EXAMPLES49

(f) LIMITATIONS IN THE CASE OF THE ZONE┴(010)55

(g) CONTROL OF THE DETERMINATIONS IN THE ZONE┴(010) (010)55

5. DETERMINATION OF COMPOSITION AND TWINNING IN THE ZONE┴(001)58

(a) THE DIRECTION OF THE a-AXIS [100]59

(b) THE DIRECTION OF MAXIMUM EXTINCTION 59

(e) LIMITATION IN THE CASE OF THE ZONE┴(001)61

6. DETERMINATIONS IN THE ZONE NORMAL TO THE PERICLINE COMPOSITION PLANE61

BIBLIOGRAPHY62