Tel Aviv University researchers have found that the ancient copper industry in Timna was “not managed in a sustainable manner,” with overexploitation of local vegetation eventually leading to the disappearance of both the plants and the industry. Does the modern man have the same bad habits as those living at the time of the Bible?
Examining fuel remains from furnaces in the biblical-era copper mines of Timna Valley, the researchers concluded that the immense copper industry had overexploited woody plants used to prepare charcoal. Without them, the industry itself was eventually forced to shut down.
The study was published under the title “Fuel exploitation and environmental degradation at the Iron Age copper industry of the Timna Valley, southern Israel” in the prestigious journal Scientific Reports from Nature publishers.
Unfortunately, to this day, the local environment has not recovered from the severe damage, bemoaned doctoral student Mark Cavanagh, who conducted the research with Prof. Erez Ben-Yosef and Dr. Dafna Langgut, head of the Tel Aviv University (TAU) Laboratory of Archaeobotany and Ancient Environments. All three are from TAU’s Department of Archaeology and Ancient Near Eastern Cultures, while Langgut is also affiliated with the Steinhardt Museum of Natural History.
The samples of charcoal fuel they examined under a microscope showed that the charcoal fuels that were used changed over time. The earlier samples contained mostly local white broom and acacia thorn trees, but the quality of the firewood had deteriorated over time, with later samples consisting of low-quality wood fuel and timber imported from afar.
What was the copper industry in biblical times?
The copper industry was run by the local Edomites, who specialized in the profession, and copper from Timna was exported to distant lands, including Egypt, Lebanon and even Greece, Ben-Yosef said. “This study shows, however, that the industry was not sustainable, a fact that may fit in well with occupation by a foreign power, perhaps ruled from Jerusalem,” he said.
The researchers added: “Our findings indicate that copper production was not renewed in this region until about 1,000 years later, by the Nabateans, and the local environment has not recovered fully to this day.”
“Many findings in the Timna Valley indicate that a vast copper industry flourished here for a period of about 250 years, between the 11th and ninth centuries BCE, with thousands of mining sites and about 10 processing sites that used furnaces to extricate copper from the ore,” said Ben-Yosef. “This impressive operation is known to the public as ‘King Solomon’s Mines,’ and today we know that copper production actually peaked here at about the time of King David and King Solomon.”
The Bible never mentions the mines in this capacity, but it does tell us that David conquered the area of Timna, known at the time as Edom, said Ben-Yosef. “He placed garrisons [military posts] throughout the land so that the Edomites became his subjects. His son Solomon used huge quantities of copper for building the Temple in Jerusalem. We can only assume that David took an interest in this remote desert region because of its copper, an important and valuable metal at the time, used for making bronze, among other purposes.”
Timna’s copper industry was highly advanced for its time, and the metalsmiths who processed the copper were skilled and well-respected individuals, the team wrote. “The copper was extracted from the ore via smelting in earthenware furnaces at a temperature of 1,200 degrees Celsius. The entire process took about eight hours, after which the furnace was smashed and the copper retrieved from its base. The wood charcoal required to attain the high temperature was manufactured beforehand at special sites by slow combustion of trees and bushes cut down for this purpose.”
The copper industry at Timna was first discovered about 200 years ago, and, ever since, every researcher who has visited the area has asked the same question: What fuel was used to heat the smelting furnaces – and, since vegetation is very sparse in this desert area, where did the firewood come from?
What was used as fuel?
The charcoal samples, well-preserved thanks to the dry desert climate, were taken from mounds of industrial waste at two large production sites in the Timna Valley and brought to the lab. “We examined more than 1,000 charcoal samples under an electronic microscope,” said Langgut. “The anatomic structure of the original wood is preserved in the charcoal, and, under the microscope, the species can be identified. The samples were dated according to the layer of the waste mound in which they had been found, and some were also sent out for carbon-14 dating.”
“We found significant changes in the composition of the charcoal as time went on. Charcoal from the bottom layer of the mounds, dated to the 11th century BCE, mostly contained two plants known to be excellent burning materials – 40% acacia thorn trees, and 40% local white broom, including broom roots,” Cavanagh noted. “The ‘burning coals of the broom tree’ are even mentioned in the Bible as excellent firewood (Psalm 120, 4). About a century later, around the middle of the 10th century BCE, we saw a change in the makeup of the charcoal. The industry had begun to use fuel of a lower quality, such as various desert bushes and palm trees. In this latter stage, other trees were imported from far away, such as junipers from the Edomite plateau in present-day Jordan, covering distances of up to 100 km from Timna, and terebinth, also transported from dozens of kilometers away.”
The researchers claim that the gradual change in the contents of the charcoal resulted from overexploitation that had destroyed the natural resources – in this case, the acacia and white broom.
“Based on the amount of industrial waste found at the processing sites, we can calculate the number of woody plants required for producing copper. For example, the production site called the ‘Slaves’ Hill,’ which was only one of several sites operating simultaneously, burned as many as 400 acacias and 1,800 brooms every year. As these resources dwindled, the industry looked for other solutions, as evidenced by the changing composition of the charcoal,” said Cavanagh. “However, transporting woody plants from afar did not prove cost-effective for the long run, and, eventually, during the ninth century BCE, all production sites were shut down.”
“Our study indicates that, 3,000 years ago, humans caused severe environmental damage in the Timna Valley, which affects the area to this day. The damage was caused through overexploitation, especially of the acacia and white broom, which, as key species in the ecosystem of the Southern Arava, had supported many other species, stored water, and stabilized the soil. Their disappearance generated a domino effect of environmental damage, irreparably harming the entire area. Three thousand years later, the local environment still hasn’t recovered from the crisis. Some species, like the white broom, once prevalent in the Timna Valley, are now very rare, and others have disappeared forever,” concluded Langgut.