28 Contacts can be combinations of… InjectionDeformationMelting/in situ reactionsThings to consider on Wednesday!
29 Dome & keel structures in the Barberton granitoid-greenstone terrain Domes:3.4 & 3.2 Ga gneissic TTG`sConcentric foliation patterns concordant with foliation in the surrounding supracrustalsKeels:tightly folded synformal supracrustals with TPC`s.5 kmAfter Anhaeusser et al. (1981)Anhaeusser (2001).
66 Batholiths Plutons associations Definition not too clear Old litterature: « primordial » granitic level, somewhere down.Modern conceptions: associations of individual plutons, each with its shape and structuresProbably rather flat as well!
67 “Vertical” intrusions Figure Schematic block diagram of some intrusive bodies.
68 An “old” view of a batholith Figure Schematic cross section of the Coastal batholith of Peru. The shallow flat-topped and steep-sided “bell-jar”-shaped plutons are stoped into place. Successive pulses may be nested at a single locality. The heavy line is the present erosion surface. From Myers (1975) Geol. Soc. Amer. Bull., 86,
69 Modern conceptions: flat batholiths Figure Diagrammatic cross section of the Boulder Batholith, Montana, prior to exposure. After Hamilton and Myers (1967), The nature of batholiths. USGS Prof. Paper, 554-C, c1-c30.