Jakarta (Indonesia Window) - Geological researchers from the College of Marine Sciences at King Abdulaziz University (KAU) and the Department of Fossils at the Saudi Geological Survey have carried out studies to determine the geological ages of mountain cliffs made of tender limestone in the northern part of Saudi Arabia.

The study concludes that the mountains are estimated to be around 37 million years old, according to the Saudi Gazette report quoted by Indonesia Window here on Tuesday.

Marine calcareous coccolith fossils were used in a first-of-its-kind study conducted by Dr. Muhammad Hamdi Al-Jahdali, a member of the faculty at the Marine Geology Department at the KAU College of Marine Sciences.

Coccoliths are individual plates of calcium carbonate formed by coccolithophores which are arranged around them in a coccosphere.

Coccoliths fossil are small stalactites of single-celled algal cells.

After dying and disintegrating, they scatter the stalactite residue, which ranges in size from 3-30 micrometers (1 millimeter = 1,000 micrometers).

Al-Jahdali is the first Saudi to have participated in global exploration missions twice in a row on board the research ship Joides Resolution in the Pacific and the Caribbean while studying for his master’s and doctoral degrees at State University Florida.

The State University has published his research on the Kingdom’s northern mountains by way of micro-collette marine fossils.

Al-Jahdali revealed that these mountains are semi-deep sediments that are 37 million years old, and these organisms appeared in the geological record about 200 million years ago.

They are important tools in determining the geological ages of limestone sedimentary rocks in geological studies, given their concentration and density in marine geological systems of ages.

Large parts of northern Saudi Arabia and neighboring countries were covered with semi-deep marine environments in the late Eocene period, that is, about 37 million years ago, when the micro-coccoliths were floating on the surface of the water, before their death and falling on the seabed in the form of limestone showers in the seas, which formed the limestone rocks, in addition to the coccolith fossils.

Large marine fossils such as sea urchins are also present in the study area.

Al-Jahdali's research on the mountains of northern Saudi Arabia is published in the August 2020 issue of the Journal of Applied Ecology and Environmental Research.

Reporting by Indonesia Window