Florida's Beaches and Its Types of Sands
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Parking Coordinates:
N 27 06.053
W 082 27.602
Please park as close to the Beach Side Food Mart as possible. Walk to to beach via the wide trail next to and sort of behind the Beach Side Food Mart, then it will be a leisurely stroll to the observation area.
A beach is a geological landform along the shoreline of an ocean, sea, lake or river. It usually consists of loose particles which are often composed of rock, such as sand, gravel, shingle, pebbles or cobblestones. These particles comprising the beach are occasionally biological in origin such as mollusk shells or coralline algae.
Beaches form as waves deposit sand and other sediments and wind pushes these sediments inland, creating a beach and accompanying dunes. The size and shape of a beach can wax and wane dramatically throughout its lifetime, as beaches are influenced by tides, weather, winds and man-made objects on and around the beach. Therefore, it is possible to track seasonal and yearly changes on many beaches, and these changes are sometimes used to keep track of larger weather trends in the area.
Potentially, a beach can form anywhere the ocean comes into contact with the shore. Beaches form over millennia, starting with wave-cut terraces caused by the ocean's action on the shore, along with geological changes created by shifting tectonic plates. Over time, a flattened area emerges where the waves hit the shore, and a beach starts to form. When beaches form, the larger they get, the better their foothold; while small beaches may vanish entirely in some years, big beaches will genereally remain intact.
Beaches are what are known as deposition landmasses, meaning that they are formed by deposits of sediment and other materials. These sediments take the form of sand, stones and other materials which wash out from inland regions into the ocean; sediments are also created through erosion of the ocean bottom, and the deposition of dead marine animals and plants. Some of these sediments settle to the ocean bottom, but many more are picked up and carried in currents which eventually come close enough to the shore for waves to pull the suspended sediments back onto the land.
As waves push sand and sediment up the beach, they inevitably leave some sediments behind, especially when the tide recedes. Coastal winds then push the sediments up beyond the reach of the waveas, creating the start of the beach. Ancient beaches are often surrounded by dunes created from sediments, reflecting a dramatic shift in topography created when these beaches form.
In addition to being pulled up by the wind, sediments can also move through a process known as salation, where they actually bounce up on the beach out of the reach of the waves. The process of deposition and salation can be accererated by storms and other severe weather, causing a beach to grow or shrink depending on which direction the sediment is moved in. Storms often lead to the deposition of large amounts of sediment which may slowly erode away in the months following the storm. In other cases entirely new beaches form in response to dramatic weather.
The Florida peninsula is a porous plateau of karst limestone sitting atop bedrock known as the Florida Platform. The emergent portion of the platform was created during the Eocene to Oligocene as the Gulf Trough filled with silts, clays and sands. Flora and fauna began appearing during the Miocene. No land animals were present in Florida prior to the Miocene.
Extended systems of underwater caves, sinkholes and springs are found throughout the state and supply most of the water used by residents. The limestone is topped with sandy soils deposited as ancient beaches over millioins of years as global sea levels rose and fell. During the last glacial period, lower sea levels and a drier climate revealed a much wider peninsula.
Much of the sand on Florida beaches is made up of quartz crystals produced by the weathering of continential land masses like the Appalachain Mountains. The quartz is washed down America's great rivers into the Atlantic Ocean and the Gulf of Mexico. It is carried onto the beaches by water currents and waves.
On many beaches, tiny fragments of shell are mixed in with the quartz crystals, making a colorful mix that may appear light brown or light gray. The shell and sand are smooth and polished from years of abrasion.
Ormond Beach and Daytona Beach have sand that, here and there in patches, looks quite orange. It isn't the sand that is orange, but the coquina shell fragments that have absorbed the rusty color of the iron oxide.
Beach sand along the Southeast Florida coast and the Keys is often composed of coral and mollusk shell fragments than quartz crystals.
The Keys are the exposed portions of ancient coral reef. The Florida Keys have taken their present form as the result of drastic changes in sea level associated with recent glaciations or ice ages. Beginning some 130,000 years ago the Sangamonian Stage rasied sea levels to approximately 25 feet above the current level. All of southern Florida was covered by a shallow sea. Several parallel lines of reef formed along the edge of the submerged Florida Plateau. This reef formed the Key Largo limestone that is exposed on the surface. The types of coral that formed Key Largo limstone can be identified on the exposed surface of these Keys.
There are some beaches in VENICE that have black sand; not pure black, but nearly so in some spots. Black and dark brown fossil fragments are mixed in with the white quartz sand, creating a dark gray to almost black beach. Venice beaches have a large variety of fossilized sharks teeth.
Here on VENICE BEACH, scientists beleve when south Florida was still under water many years ago, the waves in the VENICE area were calmer than in other areas. The calm waters keep the teeth from the decomposed shark carcasses at the ocean floor in place instead of sweeping them out further to be scattered. After the water receded from Florida, as the sea and storms eroded the coastline near Venice Beach, the buried teeth were exposed more and more, washing them up onshore and making Venice Beach the recognized shark tooth hotspot that it is today. Sharks teeth are exposed more by every storm.
Coastal erosion is the wearing away of land and the removal of beach or dune sediments by wave action, tidal currents or drainage. Waves, generated by storms, wind or fast moving motor craft cause coastal erosion.
Venice beaches suffer from the effects of erosion, so from time to time, fresh sand is brought in from offshore to augment the beaches in a procedure call "re-nourishment".
Beach re-nourishment describes a process by which sediment (usually sand) lost through longshore drift or erosion is replaced from sources outside of the eroding beach.
In the 1990's, Venice Beach began a beach re-nourishment program, and the beaches were fortified with a million cubic yards of sand dredged from offshore, which to some extent covered the original fossil rich sand. Re-nourishment can cover up the sharks teeth of Venice Beach and make them more difficult to find until erosion again exposes them.
Please E-Mail me the answers to the following questions:
1. Is this beach formed by "deposition" or "salation"?
2. Are there any signs of erosion here? What are they?
3. Why are these vines on the beach?
4. On that wide trail to the beach-what aquatic creatures are depicted on the sign?
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