The area of this pond seems to be not large, and there is indeed a lot of water stored in it, seven or eight people poured out the water with buckets one after another, and before noon, they barely put the water out completely, but, the result is unsatisfactory, the water content in these sand and dust is very large, no matter how clean the bottom is, and then wait for ten minutes, a moment and a moment, you can always accumulate a lot of water remaining in the sand, and if you get it a few more times, you will have exhausted everyone.

Yue Guanchao put down the bucket, stood by the sand pit and complained, "No, we dug a water curtain hole, this is like a bottomless pit, why can't it be cleaned? Where does all this water come from? Why are there more and more left?"

Song Siyuan also felt that the current situation was a bit tricky, took a closer look at the water that was constantly seeping out of the sand pit, and said, "The sand is like this, some of the sand is dry because all the water they have left has seeped into the underground river."

After a pause, she seemed to understand the reason for the formation of the pond, and went on to explain: "The pond we see is able to store water, which can of course be explained by the rock formations under the sand layer blocking the gaps in the underground channel, and after the violent storms here, the excess rainwater should have been drained through the underground river, because some rock formations blocked the gaps in the underground river, and all the water was left in the sand layer, and when the water content in the sand layer continued to increase and could not be discharged, it could only be evacuated to other sand......

The sand itself is loose and sticks together after being soaked with water, which also makes part of the volume of the sand continue to compress, and when compressed to a certain extent, the sand that is soaked by water can no longer withstand the pressure, and continues to collapse under the pressure of gravity, forming this inverted bucket-shaped sand pit.

At this time, due to the low terrain of the bunker, a lot of water seeping into the sand will flow into the pond that has collapsed into an inverted bucket sand pit with the high and low terrain, until the pond is completely filled, and the balance will be reached, and the water will no longer seep into the pond.

Speaking of this, Song Siyuan's eyes lit up: "I think it is also for this reason that a mixed dry and wet bunker pond has been formed on the west bank, and when you get here, I think you also understand."

The sand near the bunkers can be kept dry, on the one hand, because they are connected to the underground river, which can drain excess water into the underground river, and on the other hand, because they have sand pits nearby, the excess water will fall into the pond under the height difference, and the surrounding sand will also become dry due to seepage into the puddle, and then evaporated by high heat, except for the pond, the rest of the surface sand layer will of course completely dry again.

From this point of view, the pond they see is only the result, as long as the water level in the pond is lowered, then the water at the top will still fall into the pond, just like the dirt pit by the river, you just dig the pit down, and after a while, it will automatically seep water.

This is because the pit is so close to the river that the soil is full of water, and the sand pit in front of you is in this state.

She finally said, "If we just need to carry water, we won't be able to clean it at any time, so let's dig a pit and see what is going on as long as we can dig down the rock formations."

Helpless, Yue Guanchao and they could only jump into the pond, pick up the sapper pickaxe and keep digging the moist sand.

The watery sand is much heavier than ordinary sand, and in the process of digging sand, every time you dig a shovel, you can feel the water seeping out of the sand, but for a while, the water has come above the knee, and you need to keep using a bucket to bring out the infiltrated water, so that the water can return to the ankle in order to continue digging.

They kept digging up the sand five or six meters underground, and then they started digging out the gravel from the wet sand.

Click, Yue Guanchao picked up the shovel and shoveled into the sand, the touch was no longer wet and sagging, as if it had touched some hard object, the shovel collided with a foreign object, and there was a gurgling sound.

Noticing that there was something hard under the shovel, he picked up his arm and continued to dig through the dirt on it, and finally began to dig out a lot of fine stones, and when these small stones were also dug up, the large stones under them began to be clearly visible.

At this point, it can be regarded as digging the rock layer under the sand, which is also in line with Song Siyuan's inference - the geological disaster has piled up a lot of stones, and in the thousands of years of wind and sand erosion, all of them have been buried under the sand layer.

The era of their appearance is at the end of the Tang Dynasty, and it has only been one or two thousand years since now.

Of course, there is not much weathering, it is only buried in the shallow layers of the desert, if it is those rock layers that have been eroded by wind and sand for thousands of years, digging thousands of meters and hundreds of meters, you may not be able to find a shadow.

No matter what these rock formations are, they have at least achieved results after going through a thousand difficulties.

Yue Guanchao and they dug out most of the large stones and put them into buckets, walked up the sand bank along the slope of the pond, and when they poured out the stones, Song Siyuan also took out the stones they found from Hongbai Mountain, poured a bucket of water on the stones, and a large amount of sediment wrapped in the outer layer was washed away, and the original appearance of the stones was clearly seen by everyone.

The stones in these ponds are mostly gray and black or earthy yellow, and there are traces of wind and sand erosion on the surface, and there are many things similar to metal dots in the section, as if the stones are mixed with a lot of metal powder, crystal particles, and miscellaneous colored stones, which shimmer slightly under the sun.

At the same time, Song Siyuan also paid attention to the stones they took out from the Red and White Mountain.

The material of these stones is the same as that of the stones under the bunker, whether it is the color, texture, hardness or veins of the stones, they are similar to the stones under the sand ponds, and the sections also have granular metallic dark lines and variegation, so it is more certain that they belong to the same type of rock formation.

Realizing this, Song Siyuan's guess in her heart had come true, and she said in an excited tone: "The rock formations we see in Hongbai Shenshan should be similar to sandstone, sedimentary rock, travertine, hydrogenic rock, and dolomite, among which something similar to glass powder and variegated stone is probably the hidden jade veins on Hongbai Mountain, and metal particle powder is the metal ore that exists in the mountain."

"In addition, there should be a lot of agate stone, opal, bloodstone, dolomite jade and other raw stones in the rock formation."

"You mean, there is also jade from Kunlun Mountain on the Red and White Mountain?"

Quini grew up in the Hotan Oasis, and knew where the Kunlun jade veins were distributed, mostly along the Karakoram Mountains and the Kashgar River, or along the Altyn Mountains.

It is curious because Hongbai Mountain is located in the desert, which is too far away from Kunlun Mountain, and it should not be regarded as a side mountain of Kunlun Mountain, which can be said to be completely unbounded. I was surprised because Hongbai Mountain is in the desert, the soil on the mountain is basically eroded, and most of the mountains are the original nature of the rock formations.

Song Siyuan nodded, she knew where everyone's curiosity was, and explained, "When I first heard the introduction of the Red and White Divine Mountain, I was also curious about why this mountain has appeared in the desert for thousands of years, why it has not been eroded by the wind and sand? Even if all the dirt on the mountain has completely disappeared, it can still stand firm in the desert, and the millennia of wind and sand does not seem to work for him."

"Or, it means that this mountain really has divine power and can resist the erosion of wind and sand. Either it means that the material of the mountain rock is very hard and not easy to be eroded by water and soil."

She paused for a moment, and her tone returned to seriousness: "Judging from the stone materials we found, I think it should belong to the latter, which has something to do with the geological formation of the Red and White Mountains......

Back in ancient times, the geological pull of the Indian Ocean plate and the Eurasian plate caused the Himalayan orogeny, which caused the southwestern part of the Tarim Basin to uplift and fracture, and under the pressure of geological activities, the current Hongbai Shenshan was formed.

This mountain should be hidden under the basin, if it is not for geological movement, it will not appear on the ground, the plate of the entire peak and Kunlun Mountain belong to the same plate, in fact, it is the same kind of geological rock formation, but they are in the desert, and the surrounding is full of sand, completely different surface geology, covering the real rock formation, which makes them feel that Hongbai Mountain and Kunlun Mountain are not related.

Then, again, the gravel in the pond they found was made of the same material as the gravel in the Hongbai Mountain Cave, which proved Song Siyuan's guess!

A thousand years ago, at the end of the Tang Dynasty, there was indeed a geological disaster near Hongbai Mountain, and the result of this geological disaster was that a section of Hongbai Mountain near the Hotan River broke and collapsed, and the ground shook and the rock layer continued to fall into the desert on the west bank of the Hotan River, forming a rocky beach on the sandy soil.

It is also this part of the rubble that blocks the passage of the underground river

It was covered by the sand of thousands of years, thus forming the flat sand dunes on the west bank, and only in the case of excessive rain, the phenomenon of pond accumulation will appear, and the gravel they just dug up is the broken stone produced when the red and white mountains were broken.

If this is the case, it would explain why the eastern foothills of the Red and White Mountains are so steep, as if the mountain had encountered some impenetrable barrier and came to an abrupt end near a tributary of the Hotan River.

This is because the rock formations here were fractured thousands of years ago, and if you look at the situation of the entire west bank, it can be inferred that the fracture of the mountain has almost reached the level of an earthquake disaster, so that the broken stones produced by the mountain shattering completely cover the sand of the west bank for nearly ten miles.

"Even if it proves that the gravel in the bunker is made of the same material as the Red and White Mountain, where are we going to find the Sand Sea King?"

Yue Guanchao was puzzled, narrowed his eyes and asked.

Song Siyuan's eyes flashed with light, and he pointed his fingers down and said, "Far away in the sky, close in front of you, the Sand Sea King City is buried under the rock formation."