This earthcache is located at Rum Point on Grand Cayman, a local public beach with white sands and clear, shallow waters. This is a wonderful spot to visit for free access to the beach and enjoy the sun and sand on Grand Cayman. The beach has access to hammocks, shady trees, picnic tables and food venues. There are also public washrooms and change rooms available for visitors.
The location of this cache is fully accessible to the public for free. All of the tiles can be viewed at the entrance to the public area and around the buildings.
Logging Requirements
- Visit the posted coordinates at Rum Point and look at the floor tiles around the public buildings.
- Send your answers within 4 days of your visit.
- Group answers are accepted, however the cacher who sends the answers on behalf of the group needs to identify group members.
Questions
From the cache page write-up
1. From the cache page, the Cayman Islands are remnants of a mountain range that extends from ______________ to _____________.
2. The limestones found in the Cayman Islands are part of what formation?
3. The oldest rocks under the Cayman Islands, granodiorite, are what type of rock? Igneous, Metamorphic or Sedimentary?
From your observations on site
4. Find an example of a fossil. Take a photo and post to your found log.
a) State whether you believe this fossil to be an impression or body fossil!
b) What are the approximate dimensions of the fossil you observed?
Geology of Cayman Islands
The Cayman Islands are remnants of the highest peaks of an underwater mountain range that extends from southeastern Cuba to Belize. The Islands formed when tectonic plates forces rock upwards.
The oldest rocks are believed to be granodiorite, a coarse grained, intrusive igneous rock. These rocks are followed by a cap of basalt and overlain by carbonates deposted during reef building over 30 million years ago. The exposed carbonate accumulation of marine limestones in the Cayman Islands suggest local uplift. These limestones are part of the Ironshore formation in the west, sinsisted of lower reef facies overlain by bedded limestone which reaches 10-12 ft above sea level.
On Grand Cayman, visitors and locals can find fossils in the sedimentary limestone along shorelines as well as in building materials, often in stones used in buiding walls and in tiles used in construction projects. At Rum Point, you can find plenty of local fossils in the tiles used at this public location when visiting the beach and public facilities.
Fossil Impressions
Fossil impressions are imprints or indented marks showing the remains of plants or animals from long ago. These are often plant and animal impressions left in mud, sand and silt when the animal or plant died and was deposited on the ocean floor or along a river bottom. As the plant or animal decayed, a cavity was left showing the impression of the animal or plant.
Fossil impression and mold of a shell fossil
Trace Fossils
Also known as ichnofossils, trace fossils show a geological record of activities and behaviours of past life. trace fossils include
- Track and trails ( footprints)
- Burrows and bores ( worm holes)
- Gastroliths ( stomach stones or gizzard stones
- Coprolites ( fossilized feces)
Trace fossils may consist of impressions made on or in the substrate by an organizim.
For example, burrows, borings (bioerosion), urolites (erosion caused by evacuation of liquid wastes), footprints and feeding marks, and root cavities may all be trace fossils.
The term in its broadest sense also includes the remains of other organic material produced by an organism including coprolites (fossilized droppings) and chemical markers (sedimentological structures produced by biological means. However, most sedimentary structures like those produced by empty shells rolling along the sea floor are not produced through the behaviour of an organism and thus are not considered trace fossils.
Body Fossils
Body fossils are the remains of plants, animals, shells, corals, bones or in some cases bacteria that has fossilized in a large colony called stromatolites.
