Study reveals how stone forests get their spikes

Sept. 8 (UPI) -- Scientists have discovered how rock spires in stone forests get their sharp points.

Stone forests are rock formations featuring towering, pointed pillars of limestone that resemble petrified trees or stalagmites. Found throughout southern China and Madagascar, stone forests are formed, not through addition, but subtraction.

These majestic limestone formations are forged over thousands of years, shaped through dissolution, or the dissolving of limestone. Until now, the dissolution mechanisms that yield stone forests and their sharp points remained a mystery.

Scientists developed a unique mathematical models and ran dozens of computer simulations to determine how rock dissolution and fluid flows interact to shape limestone.

Their analysis, published Tuesday in the journal Proceedings of the National Academy of Sciences, could help researchers develop sharper micro-needles and probes used in medicine.

"This work reveals a mechanism that explains how these sharply pointed rock spires, a source of wonder for centuries, come to be," study co-author Leif Ristroph said in a news release.

"Through a series of simulations and experiments, we show how flowing water carves ultra-sharp spikes in landforms," said Ristroph, an associate professor at New York University's Courant Institute of Mathematical Sciences.

Their simulations revealed the way dissolution patterns influence future fluid flows, which, in turn, reinforce the dissolution pattern, carving sharper and sharper points from the limestone karst.

Scientists tested the predictions of their simulations using sugar-based pinnacles. When the stone forest-like confection was submerged in a tank of water, researchers found they didn't need to create flows, as the dissolution patterns yielded their own flows.

Researchers suspect the same forces they witnessed in the lab occur in China and Madagascar over thousands, even millions, of years.