GSA Today
Volume 29

Cover image

About the cover:
Polished slab of “Texas Pearl,” a countertop rock from the Llano uplift of central Texas. By the standard classification this rock plots near the common corner of the syenogranite/monzogranite/ quartz syenite/quartz monzonite fields. By the method proposed in this issue this is biotite 16,40,25 granite. Slab is 15 × 20 cm. See related article, p. 4–10.

doi: 10.1130/GSATG384A.1

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