Climate change is obliterating the oldest art of mankind

Limestone cave And rock shelters on Sulawesi in southern Indonesia The oldest traces of human art and storytelling, Has a history of more than 40,000 years. The paintings adorn the walls of at least 300 sites in the Maros-Pangkep karst hills, and are almost certainly to be rediscovered. But archaeologists say that the oldest art of mankind is collapsing before their eyes.

Rustan Lebe, an archaeologist at the Makassar Cultural Heritage Department, said: “We have recorded that in one season (less than five months), the hand-flaking of these ancient art panels quickly disappeared. “

The culprit is salt. When water flows through the limestone cave system, it will carry minerals from the local bedrock, which will eventually enter the limestone. On the surface of limestone, those minerals oxidize into a hardened rock crust. I like almost all the oldest rock art in Maros-Pangkep The oldest drawing in the world An object that depicts an actual object, coated with red or mulberry paint on the hard outer layer. Rocks can resist most weathering and provide a solid canvas for the oldest art of mankind.

But below the surface, trouble is brewing. The flowing water deposits minerals in the voids under the mineralized crust, some of which crystallize as mineral salts. As these crystals form, grow and shrink, they push to the outer layer of mineralized limestone. In the end, people first painted their own world images on rock canvas 40,000 years ago, and then scattered them in hand-sized pieces.

To help understand the severity of the problem and determine that the salt should be blamed, Griffith University archaeologist Jillian Huntley and her colleagues collected data from the walls and ceilings of 11 caves in the area The thin slices, including Leang Timpuseng (Leang Timpuseng), where the oldest hand-made molds are located. They found mineral salts such as salt, salt and calcium sulfate on the back of the slices at three locations. All 11 sites showed high levels of sulfur, a key ingredient in many destructive salts that worries rock protectors.

Exfoliation is not a new process, but Maros-Pangkep archaeologists and site administrators say they have been observing the acceleration of this process over the past few decades. Huntley and her colleagues write that some locals who manage and protect the rock art sites have been passed down from generation to generation, and they report: “In the past few decades, more panel losses have been caused by peeling than at any other time.”

Huntley and her colleagues said it was no coincidence.

The working principle of the process is as follows: From November to March, heavy monsoon rains swept across Indonesia and surrounding areas, and coastal cave systems, flooded paddy fields and brackish aquaculture ponds left water. Water contains a lot of dissolved salt and its minerals-such as table salt or halite minerals, as well as gypsum, sodium sulfate, magnesium sulfate and calcium chloride.

When the water starts to evaporate, the salt that it carries stays behind in the form of crystals, expanding and contracting with changes in temperature and humidity. Some of the aforementioned geological salts can expand to three times their original size when heated, and can exert tremendous pressure on surrounding rocks. The result is similar to a freeze-thaw cycle, causing water ice to crack rocks and concrete.

When the temperature rises and the local weather changes from extremely humid to extremely dry every few months, the entire cycle will be more active and more pronounced. It is the conditions that Indonesia is experiencing as the climate warms and extreme weather events become more frequent. In the past few decades, Severe monsoon flooding A period of severe drought followed.

People struggled, rocks broke, and the deepest connection between humans and themselves gradually disappeared.

Adhi Agus Oktaviana, a rock art expert at the National Archaeological Research Center of Indonesia (ARKENAS), said: “We are racing against time.” “Our team continues to investigate the area and discovers new artworks every year. Almost all of these paintings fall off without exception. In the advanced stage of recession.”