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How are Cave Soda Straws Formed?

How are Cave Soda Straws Formed?

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Cave Soda Straws And How They Are Formed

For those fascinated with caves, we are sure you have come in contact with the term cave straws. They are a speleothem that is formed in the shape of a hollow mineral cylindrical tube. Hence, the name straw.

Many people also refer to them as tubular stalactites. Soda straws generally grow in areas where water tends to seep through the rocks’ cracks, mainly in the ceiling of the caves. In most cases, soda straws don’t really grow more than a few millimeters per year, with an average one-tenth of a millimeter per year.

How are Cave Soda Straws Formed?

Interestingly, soda straws have the ability to become a stalactite once the hole at the bottom of the “staw” is blocked. Also, if water starts to flow outside of the tube, it has the potential of becoming a stalactite. But did you know that cave soda straws can grow outside of a cave environment? Well, they do! Once the concrete area is exposed to different conditions like weather and water exposure, it will grow and even faster than those grown in a cave. 

According to research, soda straws are known as some of the earliest growth of stalactites. Most are elongated and have the same diameter as the water droplets used to form them. A lot of the drops do hesitate to fall from the tip of the straw, which means it loses some level of carbon dioxide due to the atmospheric conditions that influence it.

As it turns out, some of the calcium carbonates are held back in the solution that runs in liquid form. The calcium carbonate that remains slowly makes its way down the tubular straw down to the tip – yeah, it generally has a pointy end like teeth. 

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How Soda Straws Grow 

Many cave soda straws tend to grow in a deflected manner as the straws sometimes grow in favor of the windward side in which air currents are driven. In addition, whichever direction water flows in the cave, it happens to sometimes grow in that direction as well.

Evaporation is also a powerful factor that contributes to them growing in this manner. While taking a tour of a cave, you may notice one of the most common things about soda straws…they grow in large numbers together. 

With cave soda straws, you may notice some grow up to intriguing lengths – as much as 30 feet long in some cases. The longest single known cave soda straw measures up 9.13 meters long and is found in Wonder Cave, Gunung Mulu, Malaysia.

As for groups of cave soda straws, the longest batch known can be found in an unnamed cave in Mexico, and they measure up to 9.03 meters, with some additional ones close by measuring up to 8 meters. 

When it comes to some of these cave formations, one has to be careful how they traverse the area as they tend to be as soft and delicate as a literal soda straw. If not careful, they can be damaged by helmets or other tools while moving through. Just as much as our habitats need to be preserved, the cave environment is the same.

Think of the camping motto: leave no trace. As it takes thousands of years for cave formations to form, we want to protect that aspect of their nature.

How Cave Soda Straws Are Formed

It is really fascinating how nature works wonders sometimes, and looking at caves, we can see why. Just imagine going through a cave and see something as similar as a feature you use in everyday life. We are sure you would be eager to find out more about it and what purpose they serve.

Cave soda straws are among that group. It is not too difficult to see why they are given that name as they bear similar features as the object itself. But, how exactly are they formed? These tubular objects are created when calcium carbonate or calcium sulfate gets dissolved in water and forms a dripping solution. 

The route the dripping takes leaves deposits over time until the straws are formed. When water seeps through the cracks in the walls, it mixes with the minerals that latch onto the tip of the tube. The mineral that is mixed tends to harden over time, and as the process repeats itself, more and more minerals get lodged at the tip. With this process, the straws become stalactites, and wherever the water drips after depositing, the minerals at the tip of the straws become stalagmites

There are many cave formations, but soda straws are among the most delicate of the speleothems in existence. Much like helictites, cave soda straws can easily be damaged if touched too hard – crushed or broken. Due to this reality, in most of the caves that grant open access to cave enthusiasts and spelunkers, soda straws are not always reachable.

Take, for instance, Kartchner Caverns in southern Arizona. Since its discovery in 1974, they have put extra plans to secure their environs even though they have heavy traffic daily.

Fun Fact: Straws Growing Outside A Cave  

In addition to cave environments, straws can grow below human-made structures, which generally grow faster than those in a cave. Instead of cave soda straws, they are called calthemites as their components are made up of concrete, mortar, lime, and other calcareous materials. These “outdoor straws” are recorded to grow up to 2 mm per day, whereas, in the cave, this measurement is a year’s worth.

huh, overachievers.

Cave soda straws consist of lots of minerals vital to the cave environments and should be protected at all costs. Cave life can be fun and exciting, and there are endless features to learn about. So, the next time you happen to take a cave tour and see these slender formations, you will know exactly what they are and how they are formed. 

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