Limestone cave Owned by the rock shelter in southern Sulawesi, Indonesia The oldest traces of human art and storytelling, Has a history of more than 40,000 years. At least 300 locations on the Maros-Pangkep Karst Mountains are decorated with paintings on the walls, and there are almost certainly more locations waiting 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 recorded the rapid loss of hand-sized peeling pieces of these ancient art panels in one season (less than five months).”
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, these minerals oxidize into a hardened rocky crust.Almost all the oldest rock paintings in Maros-Pangkep-such as The oldest painting in the world Depicts a real object-painted red or mulberry paint on a hard outer layer. This kind of rock resists most weathering and provides a durable canvas for the oldest art of mankind.
But below the surface, trouble is brewing. The flowing water deposits minerals in the void space below the mineralized crust, some of which crystallize into mineral salts. As these crystals form, grow and shrink, they push the outer layer of mineralized limestone. In the end, the rock canvas on which people first painted their world image 40,000 years ago shattered into hand-sized flakes.
To help understand the severity of the problem and confirm that salt is the culprit, Griffith University archaeologist Jillian Huntley and her colleagues collected flakes from the walls and ceilings of 11 caves in the area, including the oldest handmade templates The location of Leang Timpuseng. They found mineral salts such as rock salt and calcium sulfate on the back of the slices at three locations. All 11 sites showed high levels of sulfur, which is a key component of many destructive salt that worries the protectors of petroglyphs.
Exfoliation is not a new process, but archaeologists and site administrators at Maros-Pangkep say they have seen this process accelerate in the past few decades. Huntley and her colleagues wrote that some locals who manage and protect rock art sites have done this for generations. They report that “in recent decades, the loss of panels caused by flaking has been greater than at any time in people’s memory. many”.
Huntley and her colleagues said it was no coincidence.
This process works like this: From November to March, monsoon rains swept across Indonesia and surrounding areas, leaving water in cave systems, flooded rice fields, and saltwater aquaculture ponds along the coast. Water contains a large amount of dissolved salt and its mineral components-such as table or rock salt, as well as gypsum, sodium sulfate, magnesium sulfate and calcium chloride.
When the water starts to evaporate, the salt it carries stays behind in the form of crystals, expanding and contracting with changes in temperature and humidity. Some geological salts, such as those mentioned above, can expand to three times their original size when heated, and they can exert tremendous pressure on surrounding rocks. The result is similar to a freeze-thaw cycle that causes 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 whole cycle will be more active and noticeable. As the climate warms and extreme weather events become more frequent, this is exactly what Indonesia is experiencing. In the past few decades, more and more, Severe monsoon flooding A period of severe drought followed.
People struggled, rocks broke, and the deepest connection between humans and themselves gradually disappeared.
“We are racing against time,” said Adhi Agus Oktaviana, a rock art expert at the National Archaeological Research Center of Indonesia (ARKENAS). “Our team continues to investigate the area and discovers new artworks every year. Almost without exception, these paintings are peeling off and are in the late stages of decay.”