|
| << vorige | volgende >> |
Tijdschrift beschrijving
Alle jaargangen van het bijbehorende tijdschrift
Alle afleveringen van het bijbehorende jaargang
Alle artikelen van de bijbehorende aflevering
Details van artikel 7 van 8 gevonden artikelen
| Titel: |
Metamorphic evolution and reworking of the Sleaford Complex metapelites in the southern Eyre Peninsula, South Australia |
| Auteur: |
Tong, L. Wilson, C. J. L. Vassallo, J. J. |
| Verschenen in: |
Australian journal of earth sciences |
| Paginering: | Jaargang 51 (2004) nr. 4 pagina's 571-589 |
| Jaar: |
2004-08 |
| Inhoud: |
The partial melting processes of Al-rich and cordierite-absent garnet-orthopyroxene-bearing leucosome assemblages in the reworked Archaean Sleaford Complex in southern Eyre Peninsula, South Australia are examined. The Kimban Orogeny produced a pervasive development of garnet-K-feldspar-dominated leucosome assemblages. The textural relationships suggest that the peak assemblage garnet-orthopyroxene-K-feldspar involved a melt phase and formed through the divariant partial melting reaction garnet + biotite = orthopyroxene + K-feldspar + liquid in the KFMASH system, during a prograde KD1 heating event. A cordierite-bearing metapelite also preserves the peak KD1 assemblage of garnet-cordierite-orthopyroxene-K-feldspar, and the textural relationships suggest that peak assemblages formed through the crossing of the univariant partial melting reaction garnet + biotite = orthopyroxene + cordierite + K-feldspar + liquid in the KFMASH system, during the KD1 prograde heating stage. It is suggested that peak metamorphic P-T conditions reached 850-900°C and 0.9-1.0 GPa, and that the preservation of peak assemblages means that some melt was lost near or during the metamorphic peak. The pervasive interstitial K-feldspar grains nucleated synchronously with decompression, and the second generation of small euhedral garnets are inferred to have formed through decompression-generated partial melting during a KD2 high-strain shear event. The P-T conditions of 700-750°C and 0.5-0.6 GPa were attained during the KD2 high-grade shear event. The inferred clockwise P-T path from KD1 to KD2 is compatible with a collisional tectonic model during the Kimban Orogeny (ca 1730-1700 Ma), whereas syn-KD2 decompression-cooling was a result of rapid tectonic exhumation of the terrain. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 7 van 8 gevonden artikelen
| << vorige | volgende >> |