fig01.htm

Figure 1. Magmatic differentiation trends proposed for the Skaergaard intrusion. "Natural" trends are based on mass-balance calculations [Hunter and Sparks, 1987; Wager and Brown, 1967], dike rock compositions [Brooks and Nielsen, 1978, 1990], and results of melting experiments [McBirney and Nakamura, 1973; McBirney and Naslund, 1990]. Zones and subzones are shown next to the relevant symbol: HZ, Hidden zone (after 35% assumed crystallization); LZ, lower zone (76%); MZ, middle zone (88.2%); UZ, upper zone (UZa, 95.7%; UZb, 98.2%; UZc, 99.3%). Calculated crystallization trends represent phase equilibria modeling with COMAGMAT-3.5 at P = 1 atm and QFM [Ariskin, 1999]: TM is the initial "trapped" melt obtained at 1165oC as a result of geochemical thermometry of MBS rocks (Table 1); EG 4507 and KT -39 are the chilled gabbros [Hoover, 1989; Wager and Brown, 1967].


This document was generated by TeXWeb (Win32, v.1.3) on February 3, 2003.