lect#5 carbonate rocks

oolites

high energy; tidal shoals

carbonates rock components

skeletal grains, pores, cement, non-skeletal grains

lime mud

silt & clay-sized carbonate sediment (<62 μm)(fine grianed)

why is lime mud important geologically?

constitutes 50% of carbonate strata by volume

modern carbonates muds

high porosity(50-80%)

small crystals will be Aragonite & HMCalcite w/ 62-10 μm size, primarily skeletal bits

or 5-10 μm size, primarily Aragonite needles

whiting

Inorganic precipitation of calcium carbonate from sea water

chalk

compromised of calcareous nannoplankton, coccoliths

Skeletal Breakdown

Browsers/scrapers eat substrate, make pellets that decay, resulting from the boring endolithic organisms

primary

made thur the original depositions between/ within grains

fabric selective

means it looks at the grain, the shape, etc of the rock

interparticles

intraparticle

empty space within the grains

moldic

mold of a grain

fenestral

will be within the sediments, layering

growth framework

empty spaces within the growth of colonies

vugs-

the empty space is larger than the grains

vadose

marine waters/possibly hypersaline

meniscal

bridge of cement through the pores that connect 2 grains