Magmatic Layering Granites

Scale bar 2 5 cm.

Magmatic layering granites.

Introduction rarely occurred magmatic structure unidirectional solidification textures ust are known as a specific type of the magmatic layering. 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. 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. Layering can be defined by tml gnt or feldspar.

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. 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. Llanduno more photos here. This section depicts magmatic layering within an e w trending magmatic shear zone in the southern part of the corsica batholith.

Layered granites are rare and occur in association with volumetrically dominant non layered rocks having similar composition. Layering here is beautifully developed and locally magmatic deformation deforms the original layering in systematic ways. Some beautiful comb layering unidirectional structures are also well developed. Dark enclave with tip streaming in velay leucogranite le peyral ardèche french massif central.

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. Some but not all the images shown have been published in weinberg and searle 1999. 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. In the middle unit granitic veins concordant and discordant to the synmigmatitic foliation localized in structurally controlled sites foliation boudin.

Loss of interstitial magmatic liquid played at most a minor role in shaping the preserved compositions of the schlieren. 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. Unidirectional solidification texture ust a type granite magmatic layering aplite pegmatite yttrium garnet train texture. This non genetic term describes the.

Instabilities within the magmatic layer. Relationships between enclaves and schlieren layering in granites.