The Red Sea was formed by Arabia
splitting from Africa due to movement of the Red Sea Rift. This split started in the Eocene and
accelerated during the Oligocene. The sea is still widening and it is
considered that the sea will become an ocean in time (as proposed
in the model of John Tuzo Wilson).
Sometimes during the Tertiary period the Bab el Mandeb closed and the Red Sea evaporated
to an empty hot dry salt-floored sink. Effects causing this would
be:
Today surface water temperatures remain relatively constant at
21–25 °C (70–77 °F) and temperature and visibility remain good to
around 200 m (656 ft), but the sea is known for its
strong winds and unpredictable local currents.
In terms of salinity, the Red Sea is greater than the world
average, approximately 4 percent. This is due to several
factors:
- High rate of evaporation and very little precipitation.
- Lack of significant rivers or streams draining into the
sea.
- Limited connection with the Indian Ocean, which has lower water
salinity.
A number of volcanic islands rise from the center of the sea.
Most are dormant, but in 2007 Jabal al-Tair island erupted
violently.
Outcrops allow direct observation and sampling of the bedrock
in
situ for geologic analysis and creating geologic maps. In situ measurements are critical
for proper analysis of geological history and outcrops are
therefore extremely important for understanding the geologic time scale of earth history.
Some of the types of information that can only be obtained from
bedrock outcrops, or through precise drilling and coring
operations, are; structural geology features orientations
(e.g. bedding planes, fold axes, foliation), depositional features orientations
(e.g. paleo-current directions, grading, facies
changes), paleomagnetic orientations. Outcrops are also
critically important for understanding fossil assemblages,
paleo-environment, and evolution as they provide a record of
relative changes within geologic strata.
Accurate description, mapping, and sampling for laboratory
analysis of outcrops made possible all of the geologic sciences and
the development of fundamental geologic laws such as: law of superposition, principle of original
horizontality, principle of lateral
continuity, and principle of faunal
succession. Outcrops can therefore be considered the
fundamental element of geologic science.
Information by
Wikipedia
Especially at the Red Sea Outcrop at the listed coorinates you
can find some quiet typical items for outcrops in this area. Here
you can find a lot of local
fossils quiet typical for this red sea area.
It contains approximately 30 % red coralline algae, 60 % corals
and 10 % of other invertebrates. About half of the corals were of
the genus Porites, a third were of the genus Acropora, and the
genera Platygyra, Favia and Tubularia make up another sixth of the
total coral abundance in the top layer you can see.
Please tell me about them ...
To log this cache you have
to tell me what kind of fossil
items you can see in the outcrop at the coordinates.
Please describe their colour and
their structure. Are there any
mollusks ?
Can you see any stony coral reef
structures in the outrcrop or skeletons ? Please describe your
observation.
Can you see crab exoskeletons
in the outcrop ?
Because of the new guidelines for
Earthcaches photos of you and your GPS are no longer necessary
to
log the cache.
But I would
rather like you to take one
!
Send your answers and your
observations to me using the Mail
function of Geocaching.com
If your answers and observations
are right I´ll tell you
as soon as possible.
So don´t forget go send your
email adress and your nickname !
Logs without my permission
will be deleted !!!
Have fun !!!