Dr. Nagy I. Zoltán szerk.: Fragmenta Mineralogica Et Palaentologica 4. 1973. (Budapest, 1973)

were measurable. The (010) plane in the third group was nearly parallel with the plane of the thin section. The anortite content of the two groups is 85 per cent. Its measurement data are as follows : I. = (010) cleavage and composition plane of the first complex containing the members A, B and C -O n

z = 115 h

x = 24.5 II. = (010) direction of the second complex containing the members D and E n

TT = 330° h

TT = 24° Pig. 5. II "II Mj = - 0.82471 i - 0.38457 £ + 0.41469 k M

TT = + 0.45678 i + 0.79116 j + 0.40673 k 11

o Twin member A: n

a = 233.5 = + 0.80386 i - 0.59482 £ + 0.00000 k n

b - 323.5 h

b = 30 —A = + O.51513 i + 0.69617 I + O.50OOO k —A. *A

ft X *A o o - - O.29741 i - 0.40193 J. + 0.86603 k Twin member B: n

b = 338

( h

b = 21' b„ = + 0.34973 i + 0.86560 J + 0.35837 k n

c = 73.3* h

c = 14*