The earliest explorers of Saudi Arabia's desert caves were bedouins, whose daily lives represented a never-ending struggle for survival in one of the harshest environments on earth. For them, the caves promised a possible respite from heat, cold, and howling sandstorms. Many times, a brackish pool hidden at the bottom of a deep pit was their only source of water.
For the most part, the photographs in this site represent cave exploration in Saudi Arabia during the last twenty years. This activity was triggered by a study of old maps showing a great number of natural water wells clustered around a small settlement named Ma'aqala, located just east of the Dahna desert atop a great bed of limestone and dolomite known as the Umm-Er-Radhuma formation.
Cavers requested permission to explore these cavities from the Emir of Ma'aqala who assigned a knowledgeable old-timer to guide the visitors to thc caves. He led them to a hard-pan area filled with holes, within walking distance of the red sand dunes of the Dahna. These cavities they explored methodically, frequently finding all the horizontal passages blocked by sand, with no sign of the limestone formations they had hoped to see.
The situation seemed less than encouraging until the day they came upon a small hole no wider than a dinner plate. Warm, humid air was blowing from this hole so strongly that it seemed worth the effort to enlarge it with a chisel.
Caves are airfilled underground voids developed by the former action of water on rock that over a long period of time was dissolved, opening up holes and tunnels in the ground. The holes and tunnels in cave systems are normally interconnected, depending on how the water seeped through the rock along joints and cracks, working its way down to the water table below the surface of the ground.
The process of forming caves in soluble rock is very slow. As rain falls through the air, it absorbs a small amount of carbon dioxide and picks up additional carbon dioxide from the soil. The result is a weak solution of carbonic acid that seeps downward, dissolving the limestone bedrock and opening up cavities and inter-connected channels. If streams flow on the surface - and in the recent geologic past, Saudi Arabia was much wetter and probably had permanent drainage - additional weakly acid water would enter the limestone where streams sink down holes and cavities. The underground water will move along the bedding and down the joints, forming long tunnels by combined solution and normal erosion. Sometimes the water moves very slowly and dissolves the rock instead of wearing it away, creating an intricate labyrinth of passageways. In other places, joints become enlarged, resulting in vertical shafts and chimneys.
A large part of the fascination that people feel for caves is because of the wonderful varied types of deposits that form inside caves after the water table drops and they begin to dry out. This is because the water that drips into, or flows through the now air-filled cave, is still full of dissolved minerals that precipitate as the carbon dioxide escapes from the water. The results are cave deposits, or speleothems, as they are technically called, There are two main types: stalactites, which are formed by water dripping from the ceiling and hang from the cave roof and stalagmites, which grow up from the floor where the drops fall.
Some caves have beautiful coatings of minerals where thin sheets of water flow down the cave walls or along inclines. Others have small pebble-like deposits or cave pearls that grow in small pools.
The Importance of Caves
Caves are important, not only because they are beautiful and awe-inspiring, but because they provide a detailed record of past climate, surface processes, fauna, and flora.
Careful chemical analysis of the cave deposits reveals information about the abundances of different isotopes of carbon, sulphur, and other trace elements that were present in the atmosphere when the deposits formed and gives an age of the deposits. The two types of information - chemical and chronologic - provide a record of climate change.
Examination of bones, pollen, and spores that may be trapped in dust and silt in the caves gives information about the types of animals and plants that existed in the recent past in areas that are now desert.
Surveying the caves and mapping the types and distributions of cave deposits provides information about the rise and fall of the water table, which, in turn, is a key to understanding the changing rates of discharge and recharge of the water volume and increases and decreases of rainfall.
• Ain Hit: Diving in the Desert
• Dahls and Survival in the Desert
• Dharb Al Najem
• Gecko Gave
• Mossy Cave
• Surprise Cave
• The Discovery of Dahl Sultan
• The KFUPM – Austrian Expedition Project
• The Whistling Teapot
• Treasures of Dahl B-7/ Murubbeh
• UPM Cave
DAHLS AND SURVIVAL IN THE DESERT
Dharb al Najem
The KFUPM – Austrian Expedition Project
The Whistling Teapot
UPM Cave was one of the major discoveries made by speleologists from King Fahd University of Petroleum and Minerals and the Austrian Academy of Sciences. It has passages on three different levels and is impressive not only because of a huge hall (45 by 80 meters and 17 meters high) which once housed an underground lake, but also thanks to rhe delicate beauty of small formations such as tiny pools of cave pearls and an ever-growing rimstone dam. So far, speleothems of this sort have been found nowhere else in the Kingdom.
In addition to the book Desert Caves of Saudi Arabia, the SGS has also issued a number of open-file and data-file reports on Saudi caves and lava tubes, which are available from the SGS. For information on obtaining SGS publications contact SGS at firstname.lastname@example.org .