Magmatic Layering Granites

The podlesí granite stock czech republic is a fractionated peraluminous f li and p rich and sn w nb ta bearing rare metal granite system.

Magmatic layering granites.

This section depicts magmatic layering within an e w trending magmatic shear zone in the southern part of the corsica batholith. Rhythmic magmatic layering in granites is an intriguing feature that has been reported from plutons with contrasting chemical compositions from a wide range of tectonic settings. Some of the rhyolite dykes contain topaz as. Unidirectional solidification texture ust a type granite magmatic layering aplite pegmatite yttrium garnet train texture.

Loss of interstitial magmatic liquid played at most a minor role in shaping the preserved compositions of the schlieren. Some but not all the images shown have been published in weinberg and searle 1999. Observations in the s type granites s l of the wilson s promontory batholith demonstrate that one type of schlieren in granitic rocks represent accumulations of mainly mafic magmatic minerals with internal layering formed through pulsed magma flow. Its magmatic evolution involved processes typical of intrusions related to porphyry type deposits explosive breccia comb layers rare metal granites stockscheider and rare metal pegmatites extreme f p li enrichment nb ta sn minerals.

Magmatic layering in granites prompted by a recent discussion on the granite research list 1 one that was interesting for a change here are a few photos of magmatic layering in the panafrican peninsula pluton at llanduno on the atlantic side of the peninsula south of cape town. Scale bar 2 5 cm. Layering here is beautifully developed and locally magmatic deformation deforms the original layering in systematic ways. Relationships between enclaves and schlieren layering in granites.

Layered granites are rare and occur in association with volumetrically dominant non layered rocks having similar composition. In the middle unit granitic veins concordant and discordant to the synmigmatitic foliation localized in structurally controlled sites foliation boudin. The most characteristic feature of mingling in high strain in contrast with low strain zones is the development of layering very similar in nature to tectonic solid state sheared gneisses. Some beautiful comb layering unidirectional structures are also well developed.

This is llanduno. The nb 2 o 5 ta 2 o 5 content of cassiterite is 4 8 8 7 wt in granite 2 3 3 in pegmatite and 0 0 0 6 in greisen. Llanduno more photos here. The magmatic origin of accessory cassiterite in the topaz bearing granite average 80 ppm sn is indicated by mode of occurrence and chemical composition of cassiterite.

Introduction rarely occurred magmatic structure unidirectional solidification textures ust are known as a specific type of the magmatic layering. Dark enclave with tip streaming in velay leucogranite le peyral ardèche french massif central.