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Blowing Rocks Preserve
574 S Beach Rd, Hobe Sound, FL 33455
https://www.nature.org/en-us/get-involved/how-to-help/places-we-protect/blowing-rocks-preserve/
Anastasia Limestone (Coquina)
The Anastasia limestone (or Anastasia Formation) is a Pleistocene-aged deposit, generally estimated to be about 100,000 to 130,000 years old. It formed during the last interglacial period (Marine Isotope Stage 5e) when sea levels were higher, making it one of the youngest lithified marine deposits on the Florida coast.
Devil's Millhopper Geological State Park
Devil's Millhopper Geological State Park
4732 Millhopper Rd, Gainesville, FL 32653
https://www.floridastateparks.org/parks-and-trails/devils-millhopper-geological-state-park
Eocene Ocala Limestone
The Eocene Ocala Limestone is a widespread, fossil-rich geological unit deposited in warm, shallow marine environments approximately 34–38 million years ago during the Late Eocene. As a key component of the Florida platform, it is renowned for abundant, well-preserved marine fossils like echinoids, foraminifera, and bryozoans. The limestone acts as a major aquifer, containing high porosity (\(35\%-37\%\)) and is often found in North Florida
Devil’s Millhopper is unique because it is one of the few places in Florida where more than 100 feet of geologic strata (rock layers) are exposed. Devil's Millhopper is a large, deep, cover-collapse sinkhole.
Kelly Park Rock Springs
Kelly Park Rock Springs
400 E Kelly Park Rd, Apopka, FL 32712
Kelly Park features Miocene-era fossiliferous limestone
The limestone at Kelly Park/Rock Springs is a highly fossiliferous limestone dating back approximately 17 million years. This geological formation is part of a limestone and sand bluff that stands roughly 20 feet high, from which the spring emerges via a partly submerged cavern
The rocks exposed in the walls of Devil’s Millhopper are older the farther you go. A thin layer of soil and quartz sand occurs at the top of the sinkhole, overlying the rocks and sediments of the Hawthorn Group. The outcrop of this geological unit in Devil’s Millhopper is composed of dolostone, phosphatic sands and clay that were deposited during the Miocene Epoch between 5.3 and 23 million years ago.
The Hawthorn Group is underlain by upper Eocene Ocala Limestone, which can be seen in the deepest part of the sink. The Ocala Limestone was deposited in a warm, shallow marine environment more than 34 million years ago. The large cavity that is responsible for the formation of Devil’s Millhopper was dissolved out of the Ocala Limestone.
Fossils are commonly seen in the walls and small creeks that flow into the sink. Shark teeth and fossil remains of marine organisms found at Devil’s Millhopper help geologists understand how these geologic units were formed and how old they are. The clayey sediments of the Hawthorn Group can provide a seal (called an aquiclude) over the highly porous and permeable rocks within the Eocene Ocala Limestone, which comprises the Floridan aquifer system in the region.
Washington Oaks Gardens State Park
6400 N. Oceanshore Blvd. Palm Coast FL 32137
Geology of the Coquina Rocks
https://www.floridastateparks.org/learn/geology-coquina-rocks
The second largest outcropping of Coquina rock is found here, giving visitors a glance back at geologic time. Coquina rock is a type of sedimentary rock (specifically limestone), formed by the deposition and subsequent cementation of mineral or organic particles on the floor of oceans or other bodies of water at the Earth's surface. In other words, the rock is formed by the accumulation of sediments.
The Coquina rocks at Washington Oaks is part of the Anastasia formation, which stretches from St. Augustine to Palm Beach County, and was created during the Pleistocene era (12,000 - 2.5 million years ago). During that era when sea level was lower, shells and sand were exposed to rain. The slightly acidic rainwater dissolved some of the calcium carbonate in the shells, which “glued” together the sand and shells into rock. If you look closely at the rock, you can see millions of the individual shells and sand cemented together.
Hillsborough River State Park
Hillsborough River State Park
15402 N US Hwy 301 Thonotosassa, FL 33592
Oligocene Tampa Member of the Arcadia Formation of the Hawthorn Group
The unique hydrology and geology at Hillsborough River State Park support a lush ecosystem containing endemic plant and animal species enjoyed by thousands of park visitors each year. Some of the most visibly interesting geological features are the rapids on the upper stretch of the river. These rapids are caused by the flow of water over the erosion-resistant, partially silicified sections of the Oligocene Tampa Member of the Arcadia Formation of the Hawthorn Group exposed along the riverbed and the banks of the upper Hillsborough River.
The Tampa Member is a limestone ranging from soft and micritic to hard and crystalline, and it contains an abundant marine invertebrate fossil assemblage and small amounts of sand. More so than other rocks, limestone, which is composed of calcite (CaCO3), is subject to chemical weathering or erosion due to the chemical process of dissolution. However, when limestone has been partially or entirely silicified (a process by which silica replaces other minerals in a rock), it becomes much more resistant to this form of chemical weathering.
Silica is much harder and more erosion-resistant than the calcite in limestone, leaving a more durable layer of silicified rock.
Miami Limestone
Greynold Park
17530 West Dixie Hwy, North Miami Beach, FL 33160
Greynolds Park features exposed, 130,000-year-old oolitic Miami Limestone, characterized by cross-bedded, grain-supported ooids and, in some areas, a bryozoan-rich facies. The park’s geology is defined by historic rock quarrying that created,, in part, the 46-foot-high elevation "Outlook Mound" and deep lakes.
Caspersen Beach in Venice, Florida
Shark Tooth Capital of the World!
(especially south of the jetty), Venice Fishing Pier, and Manasota Key.
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