The Ghor Depression, or the Jordan Rift Valley, has been of great scientific interest from numerous scientists since the 19th century and even earlier. The enigmatic geology, the variety of unique environments with their specific, partly endemic faunas and flora, as well as the ancient prehistoric and archaeological sites, all contribute to the worldwide interest even today. Scientific expeditions from Great Britain and other European countries have been visiting and studying the region since the late 18th century, usually resulting in the publication of impressive volumes.
Geological origin
The place where the Ghor depression is located is just a gift to geologists. They can study most rocks without much hassle due to relatively easy access to outcrops along the rift. The earliest expeditions were organized to the Southern Levant in the 19th century, although Lynch (1849), Larteth (1869), Hull (1886) and many others made preliminary explorations in this area.
Parts of rocks from the Precambrian onwards are exposed along the flanks of the Jordan Rift Valley. They show major stages in the geological history of the Near East, both before rifting and during complex rifting processes. Precambrian basement rocks are exposed mainly on the eastern slopes of the fault, along the southern end of the Dead Sea and almost continuously to the Red Sea. Rocks - both igneous and metamorphic - make up the northernmost tip of the Arab-Nubian massif, surrounded by large molasses that accompanied mountain building.
Geographic features of the Rift Valley
On the map, the Ghor Depression is a narrow elongated depression that separates Israel and Palestine in the west, the Kingdom of Jordan and Syria in the east for almost 400 kilometers. It is also home to the lowest point on Earth, the Dead Sea. It is located at an altitude of more than 400 meters below sea level and serves as the base level of drainage for the entire Jordan Valley. The depression is bounded by faults on both sides, but is not continuous along its entire length. Internal faults often occur, forming a complex and intricate system of rift valleys.
Mediterranean environment in the northern Jordan Valley, transitioning to bare, extremely arid desert in the south. Morphology results in relatively high temperatures, and boundary faults are responsible for multiple sources. The combination of heat and water has created unique subtropical microenvironments along the basin that serverefuge for animals and plants of various origins. It was in the Ghor Basin that the earliest hominin sites outside of Africa were discovered. The combination of favorable conditions, ease of movement in the valley - all this made the valley the most suitable option for the settlement of early hominids. This process began at least two million years ago, maybe even earlier.
Searching for minerals
Picard, in his essay "A History of Mineral Exploration in Israel" (1954), points to the fact that in prehistoric times, people had all the raw materials they needed in the Jordan Valley, as they were almost entirely limited to flint and clay. However, the situation changed when metals began to be valued, among them copper was discovered and used. Iron was mined in Wadi Zarqa (Nahal Yabbok), a tributary of the Jordan River, where ancient mines have been found. The ores are of metasomatic origin and consist mainly of limonite and hematite. The gold was supposed to have been imported, but recently a small early Islamic mine was discovered near Eilat.
After the termination of the British Mandate, several prospective mining areas were listed. Dead Sea for potassium, bromine and magnesium; Mount Sedom for oil, bitumen and s alt; Nabi Musa and Yarmuk area for bituminous limestones; Nabi Musa for phosphates and Menahemya for plaster. To them should be added Lake Hulu with peat and natural gas.
Valley Hydrology
Today the valley is an inland drainage basin with an area of about40,000 km2, the end point of which is the Dead Sea. The main waterway is the Jordan River, which flows from Mount Hermon through the lakes to the Dead Sea. In the Ghor basin, along the river, there are three reservoirs of a completely different nature: Lake Hula at an altitude of +70 m, Kinneret at -210 m, and the surface of the Dead Sea is about 400 m below sea level.
The water balance of the valley has undergone significant changes over long geological time and was mainly controlled by climate during the Pleistocene and early Holocene. During the last century, the anthropogenic impact has become noticeable. First, the drainage and creation of a canal in the Hula region, later the diversion of water from the Sea of Galilee and the Yarmukh River for consumption and irrigation in both Israel and Jordan. The result was a decrease in runoff in the lower Jordan River, as well as an increase in salinity. The latter effect is largely associated with the diversion of a number of coastal s alt sources from Lake Kinneret. Due to the flow of water and fluctuations in the depth of precipitation, the flow of the Jordan River has noticeably decreased.
