Petrogenesis of kornerupine at the classic locality of Waldheim, German Democratic Republic

Conference · Tue Jan 01 00:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6596617

Grew, E S

The Waldheim kornerupine rock (Sauer, 1886), a 3 x 15m lens in the Saxony granulites, consists of an Na-oligoclase (Pl) matrix containing rutile (Rt), biotite (Bt), corundum (Crn), sapphire (Spr), kyanite (Ky), sillimanite (Sil), andalusite (And), kornerupine (Krn), tourmaline (Tur), dumortierite (Dum), and zoned garnet (Grt). Newly collected samples and chemical analyses, together with literature data (mostly Kalkowsky, 1907; Scheumann, 1960; Schreyer, Abraham, and Behr, 1975) are used to propose a petrogenetic model for the kornerupine rock. A suggested precursor is an Na-rich sediment into which boron had been introduced by exhalative processes or by an evaporite brine. Boron contents are Tur (11.7), Krn (3.40), Spr (0.81), Sil (0.32), Pl (0.02), Bt (0.004), and Ky(0). Ion microprobe fluorine contents (weight %) are Krn (0.73), Bt (2.7), and Tur (0.77) and lithium (as oxide), Krn (0.12), Bt (0.10), and Tur (trace). Equilibrium Fe-Mg fractionation, with increasing Fe (all ferrous) is: Tur < Bt < Krn < Spr < Grt. Krn appears in addition to Tur during the middle stage, because F, B, and water activities are buffered by the mineral assemblage and an anatectic melt. The absence of Krn is most granulite-facies pelitic gneisses, rocks that may have originally contained Tur, could be due to the absence of such buffering, resulting in loss of boron as Tur breaks down.

• Research Organization: Univ. of Maine, Orono (USA)
• OSTI ID: 6596617
• Report Number(s): CONF-8510489-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
GERMAN DEMOCRATIC REPUBLIC
GNEISSES
CHEMICAL COMPOSITION
MINERALOGY
PETROGENESIS
BIOTITE
CORUNDUM
GARNETS
GEOCHEMISTRY
ION MICROPROBE ANALYSIS
METAMORPHISM
RUTILE
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMISTRY
EASTERN EUROPE
EUROPE
MATERIALS
METAMORPHIC ROCKS
MICA
MICROANALYSIS
MINERALS
NONDESTRUCTIVE ANALYSIS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
RADIOACTIVE MATERIALS
RADIOACTIVE MINERALS
ROCKS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
580300* - Mineralogy
Petrology
&amp; Rock Mechanics- (-1989)
580400 - Geochemistry- (-1989)