Folk’s Classification

Allochem (“Grains”) occur either “floating” In microcrystalline matrix (“micrite”), or packed

Together and cemented with calcite (“spar”).

Analogies: Sandstones Limestones Quartz.........................Grains Clay ............................Micrite Cement .......................Cement Prefix of Rock Name denotes kind of grain: bio ..........fossil intra ........intraclasts (soft sediment “Pebbles) pel...........pellets (faecal in origin) oö............oölites Suffix denotes interstitial material (i.e., micrite or spar)

biomicrite biosparite

oömicrite oösparite

intramicrite intrasparite

pelmicrite pelsparite