The Oman Ophiolite Virtual Field Trip,
by Paul Browning
This site is a mirror of the original Oman Ophiolite Field Trip Quiz prepared by Paul Browning for the University of Bristol.
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The Oman Ophiolite Virtual Field Trip, by Paul Browning This site is a mirror of the original Oman Ophiolite Field Trip Quiz prepared by Paul Browning for the University of Bristol. | |
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| Slide 1
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| Possible flame-structure developed between olivine-rich and
plagioclase-rich layers in mafic cumulates. Lens cap 6cm.
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| Slide 2
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| Weakly foliated harzburgite tectonite.
Alternating bands of relatively orthopyroxene-rich and orthopyroxene-poor are
seen. The orthopyroxene forms larger grains which weather to a
distrinctive 'bronze' colour. The olivine is finer grained and weathered
orange-red. A later vein of olivine gabbro cuts the harzburgite. Lens cap 6cm.
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| Slide 3
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| The top of the ridge comprises
comprises 100% parallel-sided dolerite dykes. The lighter weathering
slopes at the base of the ridge consists of about 15% dolerite dykes
in gabbro and diorite.
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| Slide 4
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| Orange-brown
weathering harzburgite makes up left of picture. These are overlain
by lighter weathering, NW dipping, layered olivine gabbros. See Slide 10. |
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| Slide 5
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| Transgressive layering structure in olivine gabbros.
A thin anorthositic layer transgressively overlies rhythmically
layered olivine gabbros. The olivine-rich base of the overlying rhythmic layer
can be seen.
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| Slide 6
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| Intensely mylonitised dunites (lighter weathering colour) and
harzburgites.
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| Slide 7
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| Channel-fill structure (25cm deep) in rhythmically-layered
olivine gabbros.
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| Slide 8
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| Detail of 'bolster' form of pillow
lava. Hammer shaft lies parallel to long-axis of tubes. See Slide 18.
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| Slide 9
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| About 60% of the outcrop
comprises parallel-sided (but locally cross-cutting) dolerite dykes hosted by
white weathering trondjemite.
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