Which of these is diagnostic of shallow seawater (less than 300 feet deep) tropical environment?Group of answer choicesSandstoneLimestonePumiceCoal

Limestone is diagnostic of a shallow seawater (less than 300 feet deep) tropical environment.

Here's why:

1. Limestone is a sedimentary rock that is primarily composed of the mineral calcite (CaCO3). It forms in clear, warm, shallow marine waters, which is an environment where organisms capable of forming calcium carbonate shells and skeletons can easily extract the needed ingredients from ocean water.

2. When these animals die, their shell and skeletal debris accumulate as sediment that might be lithified into limestone. Their waste products can also contribute to the sediment mass. Thus, limestone is a rock of biological origin as opposed to several other sedimentary rocks.

3. Sandstone, on the other hand, is a clastic sedimentary rock composed mainly of sand-sized minerals or rock grains. It forms in a variety of environments, not just shallow seawater.

4. Pumice is a type of extrusive volcanic rock, produced when lava with a very high content of water and gases is discharged from a volcano. It's not specific to shallow seawater environments.

5. Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. It's formed from vegetation, which clearly indicates a terrestrial environment, not a shallow seawater one.

Limestone is diagnostic of a shallow seawater (less than 300 feet deep) tropical environment. This is because limestone is often formed in warm, shallow marine environments through the accumulation of the remains of marine organisms like coral and shells. These organisms thrive in tropical environments. Sandstone, pumice, and coal are not typically associated with this specific environment.