Chapter 1764 Is This a Tiankeng?

Chapter 1764 Is this a tiankeng?

After hearing what Zhao Zhongyao said, Feifei said,'Okay! Then let's go and see the situation! '

So, Zhao Zhongyao and Feifei flew to the distant valley again. Soon, they flew into the valley.

It's just that when Zhao Zhongyao and Feifei drove the spaceship into the valley again, they saw the volcano that looked very close to them, but in fact, it was very far away from them. They are in the tiankeng and will not be affected by this volcanic eruption. Even if volcanic lava flows out, it will not flow into the sinkhole.

Because Zhao Zhongyao has already observed this valley again. Although this valley extends all the way into this tiankeng. But in the process of leading to this tiankeng, its depth gradually decreases. The closer to the tiankeng, the lower the depth of the valley. When it reached the valley, a gap was formed at the edge of the valley.

Zhao Zhongyao felt that if there was a volcanic eruption in this valley, it would not have much impact on Tiankeng Tiankeng. Because the lava flow flowing out of the volcanic crater will not flow upwards, it will only flow downwards. In other words, these lava flows can only flow to the bottom of the valley, but not to the top of the valley.

Thinking of this, Zhao Zhongyao looked at Feifei and said, 'Feifei, although this volcano wants to erupt. But we don't have to worry about anything, it won't pose any threat to the world in front of us, we just need to go to that sinkhole. '

After hearing what Zhao Zhongyao said, Feifei also nodded and said,'Okay, since this is the case, let's go to that sinkhole to have a look! ’ Feifei sees that this volcano will not affect the tiankeng in the distance, so he is not so afraid of this volcano, and now he still wants to go to the tiankeng to have a look.

‘Okay, then let’s go to the sinkhole! After Zhao Zhongyao finished speaking, he drove the spaceship again and flew towards the sinkhole.

Soon, Zhao Zhongyao drove the spaceship and flew over the tiankeng again. It's just the place where they're going to land in the sinkhole. They also have to discuss it now.

‘Feifei, you said, we should land at the sinkhole now. Zhao Zhongyao looked at his son and asked.

Feifei thought for a while and said, 'I think we should let the spaceship land in the center of the sinkhole first! In this way, we can directly understand what the bottom of the tiankeng looks like. '

Feifei thought, since this is a tiankeng, the middle part of the tiankeng must be the bottom of the tiankeng.

After hearing what his son said, Zhao Zhongyao thought for a while and said, 'Okay, you are right. The middle part of this tiankeng should be the bottom of the tiankeng. Let's just let the spaceship land in the middle of the tiankeng and have a look! '

So, Zhao Zhongyao drove the spaceship again and flew to the bottom of the tiankeng.

Although this tiankeng is very large, it is not very deep, only two to three hundred meters deep. In fact, a more accurate term should be called a basin. However, from a high altitude, it looks more like a tiankeng. Therefore, Zhao Zhongyao and Feifei are still willing to call this huge basin the Tiankeng.

Zhao Zhongyao quickly drove the spaceship to the bottom of the tiankeng. After all, the bottom of this tiankeng is not very deep, and the speed of the spacecraft is very fast. After a while, they flew to the bottom of this tiankeng.

It was only when Zhao Zhongyao flew to the bottom of this tiankeng in his spaceship that he discovered that the bottom of this tiankeng was not a deep pit. It is a 'highland'. Of course, to be more accurate, it should be a big mountain.

And Zhao Zhongyao's spacecraft can just stop at the top of this mountain. And the top of this mountain is a huge rock. The spacecraft can just stop on this huge rock.

After Zhao Zhongyao parked the spacecraft, he looked at Feifei and said, "Feifei, we made a wrong estimate this time." The middle part of this tiankeng is not the lowest place at the bottom of the tiankeng. On the contrary, this middle part should be the highest place at the bottom of the entire tiankeng. '

Zhao Zhongyao can now see the situation outside the spacecraft through the porthole of the spacecraft. Although their spacecraft dropped two or three hundred meters. But the area of ​​this tiankeng is very large. Even if they descended two or three hundred meters to the bottom of the tiankeng, they could still see the surrounding scenery clearly.

Because this sinkhole is not on the back of Mercury, but on the front of Mercury. The face of Mercury is always daytime. There is always plenty of sunshine. Even at the bottom of this tiankeng, you can clearly see the surrounding scenery.

It's just that when Zhao Zhongyao and Feifei were in the sky above the tiankeng just now, when they looked at the scenery below, they felt that they couldn't see clearly. This is because the light above the tiankeng is very strong. This strong light affects your view of other places.

Originally, things could be seen clearly under the tiankeng. Just because the spacecraft was above the tiankeng before, it was not so easy for people to see the situation inside the tiankeng clearly. But now, Zhao Zhongyao and Feifei have come to the bottom of the Tiankeng. They can now see clearly the scenery at the bottom of the tiankeng.

Now Zhao Zhongyao and Feifei also have Qu Yuqian and Tiantian. The family curiously began to look outside through the porthole of the spaceship. When they saw this, their eyes widened in surprise.

Because the entire situation outside was completely beyond everyone's expectations. Just now they thought that there might not be anything magical at the bottom of the tiankeng. Probably some rocks or something.

But when they got to the bottom of the tiankeng, they saw that the whole bottom of the tiankeng was covered with emerald green, and the whole was a big undulating grass

Original. Because the bottom of the entire tiankeng grows lush green grass.

‘Dad, there is a prairie below this! ’ Feifei said very excitedly.

Of course Zhao Zhongyao also saw all this, and he was also very surprised, and he didn't understand how there was such a magical place at the bottom of the tiankeng.

‘That’s right, this is an underground prairie. 'Zhao Zhongyao also looked surprised.

At first glance, the outside world turned out to be a prairie. Then Feifei would be happy. He immediately looked at Zhao Zhongyao and said, Dad, what are you waiting for. Since there is a prairie outside, shall we hurry to the prairie to have a look? '

After hearing Feifei's words, Zhao Zhongyao thought for a while and said, 'Feifei, don't worry. Let's observe the situation outside first. This is Mercury. We don't know much about this planet. It is amazing that such a prairie suddenly appeared here. We still have to tread carefully. '

After hearing what his father said, Feifei also said, 'Okay, then let's see what's going on outside first. ’ Feifei also felt that what Dad said was right, they had just arrived at the bottom of the tiankeng, and they couldn’t act rashly, they had to observe for a while before talking.

'Okay, then let's observe the situation outside first. See if there is anything dangerous outside. Zhao Zhongyao said so.

It's just that Feifei watched it for a day, and felt that there was nothing special about it. Just some grass. There is nothing but grass. Not even a single tree can be seen.

After watching it for a while, Feifei felt that it was meaningless. So, he looked at Zhao Zhongyao again and said, Dad, there seems to be no movement outside! It seems that there are no animals on this prairie. We can go to the prairie outside to play as much as we want. ’ Feifei wants to go out and play now!

But Zhao Zhongyao heard what Feifei said, and said again, Feifei, don t worry. We are now in a sinkhole. We want to go outside to play. It is still necessary to learn more about Tiankeng. '

After hearing what Zhao Zhongyao said, Feifei said,'Okay then! Dad will tell us some knowledge about Tiankeng first! '

Tiantian is also very happy to see the prairie outside. I also want to go outside to play. It's just that she also wants to learn about the tiankeng. So, he also looked at Zhao Zhongyao and said, 'Dad, then you should hurry up and tell us something about Tiankeng! I would also like to learn more about this. '

‘Okay, since that’s the case, let me tell you some knowledge about sinkholes first! After Zhao Zhongyao finished speaking, he thought about it. Then, I told my son some knowledge about Tiankeng.

Tiankeng refers to a karst negative landform with steep walls and hundreds of meters in depth and diameter developed in the carbonate karst area. It has a huge volume and is connected to an underground river at the bottom. This karst landform was later named "tiankeng" by scholars.

The karst tiankengs caused by collapse are the main type discovered so far, and they have an absolute advantage in number, such as Xiaozhai tiankeng, Dashiwei tiankeng group, Xiaoyanwan tiankeng, Longgang tiankeng, etc.

The collapsed tiankeng is formed by the continuous collapse of the rock formation and reaching the surface due to the strong dissolution and erosion of the underground river. Its development is from underground to surface, and has gone through several main stages of underground river tunnel, underground collapse hall, and surface tiankeng. The formation of collapse-type tiankeng should meet the following necessary conditions: continuous deposition, huge thickness of carbonate rock formations, and wide continuous exposure and distribution; horizontal to gentle occurrence of rock formations, especially wide and flat anticlines The axis is the most favorable; the relatively low drainage base level and the thickness of the aquifer's vadose zone are more than 50-200m; the climate conditions are warm, humid and rainy from tropical to subtropical; there are substances and energy input and output functions in the aquifer. power system.

Erosion type tiankeng is a kind of sinkhole or blind valley tiankeng formed under special geological, landform and hydrological conditions. Only two cases have been found so far. Its development conditions should meet: the upper and lower parts should have a superimposed structure of thick non-karstized and karstized rock strata, and they should be widely exposed in the upstream and downstream respectively.

The rock formations are generally horizontal to gentle; there is an aquifer aeration zone with a thickness of 100-200 meters in the lower karstized rock formation; the tropical to subtropical climate conditions are warm, humid and rainy; the crust has a history of continuous uplift for more than hundreds of thousands of years. Tiankeng is the largest individual form formed by karstization. It was formed through internal and external dynamic geological processes in the long geological history, and it is scarce and non-renewable.

It has great scientific value in karst and related scientific research. The formation of tiankengs is closely related to karst hydrogeological processes and the evolution of aquifers. The study of the formation mechanism of tiankengs and their distribution and evolution may lead to a great leap in people's understanding of the nature and evolution of aquifers.

The research on tiankeng will contribute to the deepening and development of the understanding of the basic mechanism of karst action, especially the mechanism of dissolution, erosion and collapse and their interrelationships. Tiankeng is a natural wonder and is unique to karst. It has a series of special tourism appreciation value and sensory attributes such as rarity, precipitousness, peculiarity, grandeur, magnificence and unique ecological environment.

Zhao Zhongyao looked at Feifei and Tiantian, and told him what he knew about Tiankeng. Feifei and Tiantian were very curious after hearing what their father said. I don't understand how the huge tiankeng in front of me was formed.

Tian Tian looked at his father and asked naively, 'Dad, is this huge tiankeng also a collapse pit in karst terrain? '

After hearing Tian Tian's words, Zhao Zhongyao wanted to talk. But Feifei just looked at his sister, pretending to be smart

Said bluntly, 'Sister, what you asked is not nonsense. Since this huge deep pit is also a tiankeng, the cause of this tiankeng must be the same as the cause of tiankengs on our earth. '

After hearing Feifei's words, Zhao Zhongnian smiled and said, 'That's not necessarily the case. This is Mercury. This is not Earth. The deep pits on Mercury are not necessarily the same as the sinkholes on Earth. '

After hearing what Dad said, Feifei said inexplicably, 'Dad, what are you talking about. Just now you clearly said that this deep pit is a tiankeng. How do you say it now, the reason for the formation of this tiankeng is not the same as the tiankeng on our earth. '

After hearing what his son said, Zhao Zhongyao smiled again and said,'This is Mercury, not Earth. The deep pit formed here may be different from the sinkhole on our earth. The reason why I call him Tiankeng is because it looks like a Tiankeng. But in reality, it can't be a sinkhole. '

'Dad, then I don't understand. Since this deep pit is not a tiankeng, why do you call it a tiankeng? ’ Feifei can’t understand Dad’s words now.

Zhao Zhongyao had no choice but to look at Feifei again and said,' That's it, the reason why I call this huge deep pit a tiankeng. Just because it looks more like a tiankeng. But in fact it is unlikely to be a sinkhole. '