M01. Amphibolite - Lough Nagilly, Donegal - Virtual Microscope
Click the microscope button to view a thin section for this sample. M01. Amphibolite - Lough Nagilly, Donegal. An amphibolite raft in the Thor Granite (Caledonian). The sample was collected from a huge xenolith, or raft, enclosed within the Thor pluton, which is one of the component plutons of the Donegal Granite batholith.
Amphiboles - ALEX STREKEISEN
The most common amphibole, hornblende, has very variable composition owing to significant substitution of Na + and K + in A site and Fe 3+ and Al 3+ in M 1-2-3 sites. Hornblende is the result of two main substitutions starting from tremolite: Si 4+ + (Mg 2+ ,Fe 2+ ) ↔ 2Al 3+ , and Si 4+ + ↔ A-site ↔ Al 3+ + (Na + ,K + ).
Tremolite thin section - Double chain Inosilicates - MicROCKScopic
Basal sections are diamond shaped and show the typical amphibole cleavage. Longitudinal sections (parallel to the c axis) are roughly rectangular and show only one cleavage trace. Cleavage: Good in two directions {110} – in two directions are at nearly obtuse angles (124° with 56°), and in one direction for longitudinal section.
ALEX STREKEISEN-Amphibolite-
Amphibolite is a gneissose or granofelsic metamorphic rock mainly consisting of green, brown or black amphibole and plagioclase (including albite), which combined form ≥75% of the rock and both of which are present as major constituents; the amphibole constitutes ≥50% of the total mafic constituents and is present in an amount of ≥30%.
Thin Section: Plane light: Moderate to high positive relief. Colorless to pale green to deep green in thin sectoin with varying degrees of pleochroism. Stronger pleochroism correlates to higher iron contents. Crossed Polars: Biaxial (-) 2V 75-88°. Maximum interference colors are upper first order. Basal sections will show symmetrical extinction,
Amphibolite Schist under PPL and XPL - ResearchGate
These major rocks and minerals are studied as thin section under microscope, ICP analysis and ASD FieldSpec 3 Spectro-radiometer to construct a model to map such resources successfully. This...
Amphibole in garnet-amphibolite unit shown in thin section …
Amphibole in garnet-amphibolite unit shown in thin section (magnified by 10 times) (a) PPL; (b) XPL. The Gelmandeh Massive is located in the Central part of Iranian Microcontinent....
Leeds 12 - Garnet Amphibolite - Virtual Microscope
This collection of virtual thin sections is the result of a collaboration between earth scientists at Leeds University and The Open University. The collection consists of 20 slides from the Leeds teaching collection, including igneous, metamorphic and sedimentary rocks.
2021年5月3日 · a parallelogram cross-section when seen in thin section, Figure 1, above, is a good example. Chemistry and Structure The general chemical formula for amphiboles is as follows: X 2-3 Y 5 Z 8 0 22 (OH) 2 Where: X is Ca, Na, K, Mg Y 2+is Mg, Fe , Fe3+, Al, Ti, Mn, Cr, Li, Zn and where Z is Si, Al
Sodic Amphibole - University of North Dakota
Most of this thin section consists of blades of the blue amphibole glaucophane. In XP light, its interference colors are somewhat anomalous because the color of the mineral has added to the normal upper first-order interference colors. The light …