Page 19 - Atlas of Sedimentary Rocks Under The Microscope

26,27,28 Terrigenous clastic rocks
Rock f r a g ments

(contmued)

tal-.�.:n 1\llh cro�s�.:d polars shows that the fragments arc
made up of very tine-grained quart; (micro-quartz, p. 82).
Small fragments of chert can he dillicult to distinguish
I rom line-gra111cd acid 1 olea me rm:l-. � all hough the Ia Iter
ma) 'ho\\ porphyritic texture�. In the sample illustrated
the matn\ comains subangular to suhrounded quart7
grains and �mall chert fragments set 111 an iron oxide-rich
cement (brown in PPL).

23 wttl 24 Cill'.lllldnmll (irit. Ordtii'U·iull. CloK•ryn. G••y­
tll'tltl ll'ah·'· lllagn{/tcallo/1 x !5. 23 1'1'1 . . 24 X PL.
25 and 26 (ifell lpp Conl{folllcmtc. Ordol'ician. Ayrshire.
\t·otlmul. magni/ll'ation x II. 25 PPI .. 26 X Pl .
•
27 a11d 28. 1/cnf(mfl·hirc Puddlllgltlln<'. l'ertiur_r. Chiltem
1/i/lv. f:'n�/uncl; 11/l/f<ll(/il'lltion x 13. 27 PPL. 28 X PL.
Other rock .fi'agments are shou·11 in 3, 4, 33. 34. 56--61. 66,
67.

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