There are many amazing geological structures in nature, from the Giant Causeway in Ireland to the Castleton Tower in Utah, and the various processes through which such structures have been formed have long been of interest to scientists. A team of applied mathematicians from New York University has turned its attention to the so-called “stone forest” prevalent in China and parts of Madagascar. According to the NYU team, these point rock formations, such as the famous Stone Forest in Yunnan Province, China, are the result of dissolving into liquids in the presence of gravity, which produces a natural excitatory flow, according to the NYU team. They described their findings in a recent study published in the Proceedings of the National Science Department.

Co-author Leif Ristoff told Ars that his team at NYU’s Applied Math Lab was interested in studying rock forests (technically a type of karst topography) in a somewhat indirect way. They were using simulations and experiments to find out the interesting shapes that had developed in the landscape due to several “shape” processes, especially erosion and dissolution.

“When we put the candy in the water tank and later came back to look for the needle-like spire, we discovered the spikes created by the first melting.” “Grade student, first author Mac Huang even accidentally cut himself while admiring the shape. This is one of our problems. And we were very excited when we realized the connection between the rock china and the rock forest, which had been quite mysterious in their development. We hope our experiments tell a simple ‘source story’ behind these landforms.

To test their simulations in the lab, the team mixed donor table sugar, corn syrup, and molded water to form a single column of block and hard (hard-cracked) candy – adjacent to soluble rocks that typically produce cursor topography. The mold for the block included perforated blocks to make the arrays of vertical metal rods closer to the “seed”. They placed these candy blocks and pillars in a plasiglass tank filled with water at room temperature – it was so deep that the dissolved sugars settled at the bottom and moved away from examining the object. One minute apart they captured the dissolution process by taking digital photographs.

You can watch a time-lapse video of the experiment below, so that the candy-sized melted blocks in an array of sharp spikes resembling a nail bed. The block starts with an internal hole and is completely submerged under water, where it dissolves and becomes a “candy forest” before breaking.

It even occurs in stagnant water. “We have seen that the melting process itself generates the flow responsible for the spike-shaped engraving,” Ristroff said. “Basically, in our experiments the mineral – or, lollipop candy served as Molly Rock, dissolves and the surrounding liquid becomes heavy and then flows down due to gravity. So our process does not require any specific flow conditions or other external conditions. The recipe only involves dissolving between liquid and gravity. “

Restroof Etc. Suggest that a similar process is working on the formation of rock forests, only on a long-term scale. Soluble rocks such as limestone, dolomite, and gypsum are submerged in water, where minerals are slowly dissolved in the surrounding water. The heavy water then pulls down to the bottom of the gravity and the flow slowly builds up to kart topography. As the water recedes, pillar and rock forests emerge.

On the surface, these rock forests look like “Penitentes”: icebergs are formed in very dry air that is found high in the Andean glaciers. Some physicists have suggested that penitents are formed when sunlight directly evaporates snow into water without passing through the water (ecstasy). Tiny crests and wells form and sunlight is trapped between them, creating additional heat which decorates the deeper grooves and these curved surfaces act as lenses, further accelerating the high quality process. The alternative proposal adds an additional mechanism to account for the oddly periodic specific intervals of the Penitents: the combination of vapor diffusion and heat transfer that produces a steep temperature gradient and therefore a higher sublimation rate.

Physicists have been able to recreate artificial versions of penitents in the lab. But Penitentus and the rock forests are actually quite different in terms of the processes involved in their formation, said Ristof, “I think the mills are quite well known.” “Of course, the‘ sculpture ’process is very different in terms of the main driving effect.

Granted, NYU researchers have achieved their results in ideological situations – intentionally, according to the authors, it is better to clearly identify and characterize the sharpening process, the underlying process and the mathematical structure. As a result, “this study reveals the minimum elements required for needle and nail polish motifs,” the authors wrote. In the future, they hope the lab will further examine the formation process in different environmental conditions, such as how this precipitation and surface climate, or how burial under loose sediment can affect peak formation.

DOI: PNAS, 2020. 10.1073 / pnas.2001524117 (About DOI).