St. Augustine’s Castillo de San Marcos. Coquina: The Secret to Success. Elizabeth “Beth-Anne” McCown Cleveland Court Elementary STEM 5 th Grade. Topics and Sections :. 1. She’s a Grand Ole Town— ( Brief history of St. Augustine and the Castillo)
St. Augustine’s Castillo de San Marcos
Coquina: The Secret to Success
Elizabeth “Beth-Anne” McCown
Cleveland Court Elementary
STEM 5th Grade
(Brief history of St. Augustine and the Castillo)
Option 1: Regular Handout (Your Copy)
Option 2: Pair/Share Word Sort
Option 3: Kagan’s Quiz, Quiz, Trade
St. Augustine is the United States’ oldest city. It survived for many years due to a huge coquina fort, called the Castillo de San Marcos. This fortress protected the city from pirates and British attacks. Later, this fort was used in the Seminole Wars and in the Civil War. Florida’s history would have been very different without this edifice.
Coquina is a shell-like stone that occurs naturally along the east coast of Florida. You can see outcroppings of this stone along its beaches. Sometimes you are even able to climb on coquina stones that stick right up out of the sand!
Coquina is a fairly soft stone. The Spanish workers had to carefully check each stone before they cut it. Only the hardest stone could be used to build the Fort. While it’s wet, even the hardest coquina can be cut with a saw or an axe. The coquina walls you see at the Castillo today are dark and gray, but fresh coquina is yellow. It changes color as it dries.
(See image above.)
Kagan Numbered Heads/Teach-Okay: Why wouldn’t you want to build your fort with only fresh coquina?
A quarry is a place where people go to mine/dig up minerals or stone. The Spanish mined coquina stone from 14 actual quarries. You can visit the Old Spanish Quarry on Anastasia Island. That’s where the Spanish
mined coquina stone for the Castillo de San Marcos. There are still original spots where coquina blocks were cut long ago.
Face Partner/Teach-Okay: If you visit the quarry, what would you likely see there besides the coquina excavations? (Hint: People did all the work there. Do they “leave” clues behind?)
Both the Timucua Natives and the Spanish settlers/soldiers dug through the sand until they reached a layer of solid coquina stone. Chunks of coquina were mined in various sizes. The larger pieces (four feet long and two feet thick) took six men just to budge them. Skilled stoneworkers (masons) shaped the rough coquina blocks. Next, they loaded the coquina blocks onto ox-drawn carts. The Spanish dug several wells along the way to give the oxen places to rest and drink. When the oxen reached the coast, workers loaded the stone onto sturdy rafts, which floated blocks to the mainland.
Once the soft, yellow coquina stone had been unloaded, it had to sit and dry out for a period of up to THREE years.
(Courtesy of Historic Print & Map Co, St. Augustine)
While waiting on the coquina to harden, the settlers/soldiers worked on making mortar
(to use as glue in the Fort’s coquina walls). They made this mortar by burning oyster shells and then adding water. The Spanish dug oyster shells out of old Timucua Indian trash piles (called middens). Many of the native middens around St. Augustine have disappeared
because the Spanish used this shell resource. In a single year, the Spanish could make enough lime mortar to fill the backs of 145 pickup trucks! They also built up a huge pile of drying coquina blocks..
(Courtesy of Historic Print & Map Co, St. Augustine)
Shoulder Partner/Teach-Okay: Why would this practice of using the “middens” hinder an archaeologist’s knowledge of past peoples?
Face Partner/Teach-Okay: Discuss a possible solution to the on-going money/food issues.
It wasn’t until 12 years into the build, the Spanish actually installed the first bathrooms or latrines. They were pretty ingenious…
Twice a day, when the tide came in, all the waste was washed away. These latrines (Florida’s first flush toilets) really improved the worker’s lives – unless they happened to be swimming on the beach….GROSS!
They also built rooms to store food, quarters for soldiers to sleep in, and a prison.
During this time, they also dug the moat – the wide ditch surrounding the Fort. Attacking British soldiers would now have to climb down into that moat to reach the Fort’s walls. They would be easy to shoot while crossing this dry, open ditch.
Once the moat was full of seawater, the Fort’s coquina walls started soaking up all that moisture. Old cracks in the coquina stone got longer and wider! The National Park Service drained the moat and repaired the cracks.
Its roof – also called the gun deck – had plenty of cracks
and leaks as well. Why? Long ago, the Spanish mounted heavy cannons on the Fort’s roof. This weight put a lot of stress on the roof surface, creating cracks. In 1993, the National Park Service decided to look for a solution. First, they researched other solutions that had been tried in the past.
Spanish records showed that the gun deck had already started to leak in 1707. From 1890 to 1993, the gun deck had been layered multiple times with concrete and asphalt. It was still cracking from all the stress of the building’s usage and age. The National Park Service decided they needed to excavate down to where the Castillo’s original materials began. After carefully excavating small areas, archaeologists decided to remove all of the concrete layers and any original materials that were no longer strong enough to support the gun deck.
Before archaeologists could begin repairs, they had to carefully
excavate (dig) down to the original tabby roof made by the Spanish.
Their notes described what each layer was made of (for example: concrete,
coquina sand, or tabby). They also noted the Munsell Color of each
What is a “Munsell Color”? This chart allows scientists to be clear about exactly what color soil they’re observing. These are some of the different colors discovered during the Castillo’s gun deck excavation.
SC.4.E.6.2 Benchmark: Identify the physical properties of common earth-forming minerals, including hardness, color, luster, cleavage, and streak color, and recognize the role of minerals in the formation of rocks.
SC.4.E.6.3 Benchmark: Recognize that humans need resources
found on Earth and that these are either renewable or nonrenewable.
SC.4.E.6.4 Benchmark: Describe the basic differences between
physical weathering and erosion
Weitzel, Kelley. 25 September 2012. http://www.flpublicarchaeology.org. “Castillo De San Marcos”. Florida State Parks. 25 September 2012
Weitzel, Kelley. 26 September 2012. http://www.KelleyWeitzel.com