Page 21 - Atlas of Sedimentary Rocks Under The Microscope

Terrigenous clastic rocks
C l a y m i n e r a l s

Clay minerals form a significant fraction of sandstones
and arc the major constituents of argillaceous rocks. They
may be detrital or authigenic. However. since they cannot
be readily identified using an ordinary light microscope,
but arc studied by usc of the electron microscope and by
X-ray diffraction. they are not considered in detail here.
Clay minerals can be seen in plates 22-24, 45, 46,
62�7.

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