Geotechnical Drilling Sky Lake What is limestone and what does it mean for geotechnical drilling?

Sky Lake geotechnical drilling clients frequently ask about what kinds of materials they’ll encounter during the drilling project. In Sky Lake and in many other regions of Florida and the southern United States, the bedrock is comprised of limestone, which has its benefits and its drawbacks.

So what is limestone and what does it mean for a project involving geotechnical drilling? Sky Lake drilling techs will explore that topic in today’s article.

Sky Lake geotechnical drilling projects frequently reach down to the bedrock, which is typically comprised of limestone in this part of the country.

Limestone is a sedimentary rock, which means that it forms when sand, silt, shells, minerals and other underground substances are pressed together over time. Limestone commonly forms in warm, shallow ocean waters, where coral, shells and organic debris are compressed together, along with calcium carbonate. Calcium carbonate is typically the primary constituent of limestone. In fact, limestone is, by definition, a stone with at least 50 percent calcium carbonite. It may also contain other stones and minerals, like quartz, siderite, pyrite and feldspar.

Limestone and other sedimentary rocks frequently have shells, coral and even skeletons of animals and plants are captured as fossils. This type of rock tends to be quite soft and it often forms with distinctive, clear layers.

There are many types of limestone, including travertine, tufa, oolitic limestone, lithographic limestone, fossiliferous limestone, coquina (common in Florida coastal areas, where you see limestone with lots of small shell particles) and chalk limestone.

Limestone can also form as the result of evaporation. Water carrying minerals and calcium carbonate flow into a cave or cavern and the water evaporates, leaving the calcium carbonate or minerals behind. When they drip down and form an icicle-like formation, it’s called a stalactite. If the water drips onto the floor of a cavern and the icicle-like formation grows up from the floor, it’s called a stalagmite.

Limestone can be quite crumbly and fractures relatively easily, which can be a problem in terms of stability. Florida’s sandy soil allows water to pass through with ease and ultimately, it seeps down into the limestone bedrock, where it can dissolve when exposed to even mild acids that are found in groundwater. This can result in underground voids that may collapse into a sinkhole. This is one potential use of geotechnical drilling. Sky Lake natives may hire a geotechnical drilling firm to explore the integrity of the limestone bedrock in a particular location, especially if there are signs of instability that can be linked to sinkholes.