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| The deserts
of Oman vary from the rolling sand seas of the Wahiba, with
classic photogenic dunes of rich gold, to the flat stony Jiddat
al Harasis in central Oman and the Rub al-Khali or 'Empty
Quarter' further south, where individual mountains of sand
rise from a flat desert and stretch endlessly across the border
into Saudi Arabia. However, far from being empty, the desert
is host to a surprising amount of wildlife. Caracal lynx,
sand foxes and wild sand cats, with hair-covered feet that
help provide grip in soft sand, are some of the larger predators.
Rheem gazelle, Arabia's largest gazelle, also seem to prefer
sandy regions. On rocky outcrops, such as the Huqf escarpment
to the east of the Jiddat al Harasis plains, live Nubian ibex.
They are also found in more mountainous areas in Oman. The
males, in particular, are an impressive sight, sporting magnificent
horns with which they spar for females. The desert provides
habitat too for skinks, lizards and geckos and their more
deadly cousins, such as the saw-scales or carpet viper and
the horned adder. A host of small rodents survive the desert
heat despite the high metabolic rates of small mammals. A
number of species of gerbils, jirds, jerboas, mice, shrews
and rats have all adapted to life under harsh conditions.
Flocks of Coronetted, Chestnut-bellied, Spotted and Lichtenstein's
Sandgrouse can be regularly seen at precise times, soaking
their modified breast feathers in precious watering holes
and transporting the stored water to ground nests some distance
away. There are very few people, even those who have visited
desert environments many times, who are not continually surprised
and enthralled by the activity and profusion of wildlife. |
| SEMAIL
OPHIOLITE |
It is the
largest and best-exposed fragment of oceanic lithosphere found
on land in the world. The ophiolites are named after named
Wadi Semail that crosses the Oman mountains and the ophiolite
rocks in E-W direction. Not surprisingly these rocks have
been the focus of many studies since their first detailed
description by Geologists of the Shell Group (Glennie et al.,
1974). They provide a unique opportunity to study the anatomy
of the oceanic crust. From the coast in the east crossing
into the mountains westward one passes along basalts with
pillow lavas and even the occasional ‘black smokers’;
the sulphide vents found at mid-oceanic ridges. The horizontal
traverse westwards takes you deeper into the oceanic crust
even passing the Moho – the compositional boundary between
the crust and mantle and on into the upper mantle.
Originally the name ophiolite
was almost synonymous to serpentinite and included a variety
of rocks associated with serpentinites. In the early 20th
century the name was adopted as a term used for an association
of rocks that commonly occurred together, rather than a specific
type of rocks. There was a lot of debate on what that rock
association meant. Only in the second half of the 20th century
the diverse opinions converged on the interpretation as an
oceanic crust (lithosphere) succession. |
| CAVES
OF OMAN |
AL-HOOTA
CAVE
The Al-Hoota cave is one of the most accessible caves in
Oman. It is situated at the southern side of Jabal Akdhar
near Al-Hamra. The Al-Hoota cave system like many other
caves in Oman was formed by the dissolution of limestone
by acidic water. The cave system occurs in the Cretaceous
Natih Formation. Currently, and under the auspicious of
the Directorate of General Tourism, work is being carried
out to transform Al-Hoota cave to a popular attraction.
In the near future it will be possible for locals and tourists
to enjoy the spectacular scenery of Al-Hoota cave. Furthermore,
the lakes harbor populations of unique blindfish, endemic
beetles and other rare and interesting species. Certainly,
the cave would attract local, regional and international
tourists.”
You don't have to be a serious "caver" or spelunker
to appreciate the geology of Al-Hoota cave. However, great
care must be taken to protect and preserve these great underground
wonders. Caves are non-renewable natural resources, which
benefit and enrich our lives in many ways, a few of which
are: Scientific Knowledge, Water Supply and Education/Recreation
MAJLIS
AL-JINN
The entrance: Three vertical sinkhole entrances
lead to the main chamber of the cave. They all require a
free descent of 118 m to 158 m. The opening occurred due
to the weathering of the intersected north south and east
west fractures. The circular sinkhole known as Khoshilat
Maqandeli is about 20 by 14 m while a smaller second entrance
is about 120 m to the west. The latter known as Khoshilat
Minqod or 'Cheryl's Drop', named after the woman who first
entered the cave using this hole. The third, Vhoshilat beyn
Al Hiyool or Asterisk Drop, is the largest and is about
50 m south of Khoshilat Minqod and about 150 m southeast
of the circular first drop (see Davison 1985). Only experienced
speleologists with proper climbing equipment may attempt
to enter this cave. The area is so remote that in case of
emergency, help will take some time to arrive (please see
the safety guide at the end of the book).
The main chamber:
This is the second largest known cave chamber in
the world (4 m5). It is larger than the size of the greatest
Egyptian pyramid and can accommodate more than 5 Al Bustan
Palace Hotels. We did not enter the cave and therefore the
features inside the main chamber mentioned here are taken
from Donald Davison's 1985 report (PAWR 85-20). He described
the main chamber as semi-domed; 300 long by 200 wide with
the roof reaching approximately 120m. Its floor is about
60,000 m2 in area. It includes steep fallen debris cones,
particularly below Khoshilat Beyn Al Hiyool and Khoshilat
Maqandeli. Much finer debris cones dominate the western,
southern and eastern sides of the chamber. Some of these
debris cones grade into gentle slopes and outwash fans.
The northern part of the cave floor is an alluvial plain
covered with mudstone. In places Davison reports that the
lower slopes of the debris on the cones are covered with
up to 10 cm of fine dry dust, most probably blown in through
the cave entrance. Pollen and seeds were also found. |
| OMAN
OLD ROCKS (THE PRECAMBRIAN HUQF SUPERGROUP) |
The Huqf
area is a special one for geologists because there are rocks
to look at from almost all of Oman’s geological history.
This is possible because of the Huqf’s location near
the eastern edge of the Arabian Plate which has kept it
up-lifted through long periods of geological time.
The oldest rocks in the area are dated using mineral isotopes
at about 730 million years. These are basement rocks, a
type of granite, which formed deep within the earth’s
crust from molten rock. Granite is a type of igneous rock.
As the years went by, the basement rocks became covered
in layers and layers of rocks, each layer being younger
than the one before. These rocks that are made up of lots
of fragments of weathered rock or shell fragments, are sedimentary
rocks. Often they have fossils or features which give clues
about how they formed.
The Huqf area has not always been a desert. At one time,
about 300 million years ago, the rocks show evidence that
ice sheets covered the area. At other times, it was under
a shallow tropical sea. The layers left behind by these
seas often contain fossils, but the fossils vary a great
deal over time. The oldest fossils are mound structures
made by mats of algae, which are called stromatolites. Younger
fossils include wonderful tropical shells, such as the rudists
bivalve. At yet another time, the area was fairly arid,
but with big rivers flowing through. Fossil soils and trees
occur in these layers. Each type of climate left behind
its own particular pattern of layers of rocks which geologists
interpret by looking at what goes on today in places with
a similar environment. In the 1950s, geologists began to
study and map the region. They used their understanding
of the fossils and rock layers present in the Huqf to help
them drill for oil at Fahud, Ghaba and Haima. They found
that the rock layers which produce oil from deep below the
ground, are the same as those that can be seen at the surface
in the Huqf area. So when oil company geologists want to
understand the characteristics of the layers of rocks that
make up an oil or gas reservoir, they often visit the rocks
in the Huqf. Other geologists and students from Sultan Qaboos
University and other universities around the world also
visit this area with its fascinating geology.
Much of the Huqf area off lies within the Arabian Oryx Sanctuary.
If you want to leave the blacktop roads to look at the spectacular
scenery, geology and wildlife, then you need to obtain permission
from the Ministry of Municipalities, Environment and Water
Resources. The Ministry is working to conserve the rich
natural heritage of the area. |
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Geological
Tours & Excursion in Oman