Årg. 195 Nr. 3 (1972): Meddelelser om Grønland

Introduction. p. 5
Distribution of rock types within the complex. p. 9
Subdivision of rock types. p. 9
Variation within the syenites. p. 10
(a) Coarse brown syenites. p. 10
(b) Heterogeneous quartz syenites. p. 11
(c) Porphyritic syenites. p. 11
The transitional group. p. 12
Mineral layering in the transitional group. p. 13
Variation within the granites. p. 15
Conclusions from field relations. p. 16
Petrography. p.18
General outline of chemical and modal variation. p. 18
Petrography of the syenites. p. 22
(a) Quartz-poor syenites. p. 22
(b) Heterogeneous quartz syenites. p. 25
(c) Porphyritic syenites. p. 29
Petrography of the transition group. p. 30
Petrography of the layered rocks . p. 33
Petrography of the granites. p. 34
(a) Coarse soda granites. p. 34
(b) Microgranites and granophyres. p. 40
Relationships at internal contacts. p. 41
(a) Granite-syenite relationships at the western margin of the northern granite. p. 41
(b) Gradational granite-syenite relationships at the southern margin of the northern granite. p. 43
(c) Contacts of the southern microgranite. p. 44
Feldspar variation. p. 44
(a) Microperthites. p. 44
(b) Late albite. p. 51
(c) Early plagioclase. p. 51
Discussion of petrographic and chemical variation. p. 52

Petrogenesis. p. 59
Peralkalinity. p. 59
Effect of anorthite, acmite and alkali silicate on fractionation represented in the system Ab-Or-Qz, and physical conditions during crystallization. p. 62
Textural relationships between quartz and feldspar and petrogenetic significance of the granophyric intergrowths. p. 64
Origin of the Puklen magmas and summary of intrusive history. p. 68
Acknowledgements. p. 71
References. p. 72