The rocks in front of you are Ordovician in age (about 475 million
years old) and belong to layers known by geologists as the Pittman
Formation.
These rocks were formed at the bottom of a deep sea (up to 100m
deep) and sand and mud was moved into the area by huge underwater
landslides called turbidity flows. The muds eventually turned into
shale and the sands turned into sandstones.
Since then these rocks have been metamorphosed and folded. The
shales became very fractured because they contained platey
minerals. The sandstones became much harder.
The steep wall of this quarry is made up of the harder
sandstone. The more sloping area is made up of the shale. However,
most of the shale was removed and ground up into clay to make
bricks.
Walk up the hill towards S 35 17.898 E 149 06.844. At this point
you will find some great examples of the hard sandstone on the
ground. This sandstone has many small white veins of the mineral
quartz running through it.
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following question ..What is the widest of these veins of quartz
that you can find at the last stop? Include in your log the number
of people who were with your group when you visited.
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