Ghar al Hibashi, Harrat Nawasif/Al Buqum, Kingdom of Saudi Arabia
John J. Pint, Mahmoud A. Al-Shanti Abdulrahman J. Al-Juaid, Saeed A. Al-Amoudi, and Paolo Forti
with the collaboration of Rami Akbar, Peter Vincent, Stephan Kempe, Penelope Boston,
Fayek H. Kattan, Ermanno Galli, Antonio Rossi, and Susana Pint
Ghar al Hibashi (sometimes spelled Hebashi) is a lava cave situated near the center of Harrat Nawasif/Al Buqum, a field of vesicular basaltic lava flows located east of Makkah in the Kingdom of Saudi Arabia. The cave lies approximately 6-7 m below the surface and contains 581 m of mainly rectilinear passages. Apart from lava stalactites, stalagmites and columns, Hibashi Cave contains many bones and the desiccated scat of hyenas, wolves, foxes, bats, birds and domestic animals, most of which has been well preserved due to the cave’s temperature of 20-21°C and humidity of 48 percent. A human skull 425 years old and a man-made wall were found in the cave, but no archeological studies have been carried out. It is estimated that the cave may be 1.1 million years old. Two large bat guano deposits in this cave caught fire at some point in the past, heating and partially burning animal bones and rocks lying on the guano surface and possibly affecting “bio-stalactites” thought to be formed of bat urine. These soft, yellowish, accretions, 4 cm or less in length and up to 1 cm in width, are found throughout the cave. A few samples of secondary chemical deposits were collected mainly from the burnt guano areas for mineralogical analysis. Despite the scarcity of these samples, at least 19 different minerals were detected, most of which are related to the biogenic mineralization of bones and guano deposits. Three of them, pyrocoproite, pyrophosphite and arnhemite are extremely rare organic compounds strictly related to the guano combustion, which have been observed until now only in a few caves in Africa. Ghar al Hibashi may now be considered one of the richest known mineralogical shelters of the Arabian Peninsula, for which reason it has been included in the list of the ten minerologically most important lava caves in the world. The original floor of Hibashi Cave is covered with a layer of fine (10 micron particle size) silt or loess, dominated by quartz, feldspar and kaolin, extending to almost every point in the cave. This silt is up to 1.5 m deep and was OSL-dated at 5.8±0.5 ka BP at its lowest level. Because similarly fine material is often blown about on the surface of Mars, researchers planning for the exploration of Martian lava tubes are using photographs and maps of Hibashi Cave to produce robotic motion simulations for testing the capabilities of microrobotic designs to navigate inside the caves of Mars. The potential also exists to study phytoliths, found inside plant material preserved in animal scat abundantly available in Ghar al Hibashi, in order to learn more about past flora of the Arabian Peninsula as well as the process of desertification.
Pint, J.J., Al-Shanti, M.A., Al-Juaid, A.J., Al-Amoudi, S.A., and Forti, P, 2005, Ghar al Hibashi Harrat Nawasif/Al Buqum, Kingdom of Saudi Arabia, with the collaboration of R. Akbar, P. Vincent, S. Kempe, P. Boston, F.H. Kattan, E. Galli, A. Rossi, and S. Pint: Saudi Geological Survey Open-File Report SGS-OF-2004-12, 68 p., 43 figs, 1 table, 2 apps., 1 plate.