"Cultural layer", in the academic terminology of archaeology, specifically refers to the accumulation of soil layers formed by human activities in the site.

In archaeological fieldwork, the cultural layer is one of the most important conditions for judging a site.

The difficulty that Deng Xin is encountering now is.

More than two meters underground, she has found some remnants of the Sanxingdui civilization period, including pottery shards, stone tools, etc.

However, she couldn't tell what period Sanxingdui left behind.

You must know that although several sacrificial pits unearthed in Sanxingdui are all of the same era, that is, the Late Shang period.

However, this does not mean that the Sanxingdui people only existed in the late Shang period.

I've said it before.

At present, archaeologists have divided the existence of Sanxingdui civilization into four periods.

That is, Sanxingdui Phase I, Sanxingdui Phase II, Sanxingdui Phase III, and Sanxingdui Phase IV.

The age of the entire site group starts from the late Neolithic period to the end of the Shang and early Zhou periods, and lasts for nearly 2,000 years.

And the sacrificial pits 1 to 8 are only the products of the fourth Neolithic period at the top.

There are three more issues stacked below.

And even if it is the fourth issue, it will be subdivided.

For example, in geochronology, the "Song Dynasty cultural layer" is regarded as a layer.

But in this layer, it spans the Northern and Southern Song Dynasty, and for so many years in between, it has also gone through different stages.

Moreover, the division of cultural layers is not necessarily sequential.

It's not like some laymen imagine, just divide it according to modern, modern, Qing Dynasty, Ming Dynasty, and Song Dynasty.

It's impossible!

Because the soil layer in many places does not have traces of human activity in every era.

Some places may have been a village in the Qing Dynasty, but in the Ming Dynasty it was a wilderness, and in the Song Dynasty it was a metropolis.

In this way, in geology, the cultural layer of the Qing Dynasty may be slightly more obvious, and then the lower layer is directly the soil layer of the Song Dynasty, and there is no Ming Dynasty soil layer in the middle.

Because there is no trace of human activity in the middle, that is, there is no artificial "dumping" on the ground, there will be no cultural layer left.

"Scratch it and see."

After asking Deng Xin about his problem, Xie Dafei held a shovel in his hand and jumped off the probe directly.

Chen Han hurriedly followed him down.

To be honest, he is not very familiar with the stratification of cultural layers.

In the past, when I was interning with a teacher, the teacher was doing this kind of thing, and the students were studying on the sidelines.

After that, he followed Kong Jianwen all over the country, and they were all directly dug tombs, not archaeology of the nature of the site.

At the very least, it will be used for archaeology before the Shang and Zhou dynasties to be investigated and judged by the cultural layer.

Before the Shang and Zhou dynasties, whether it was a site or a tomb, basically you only need to enter the tomb to find the cultural relics of the relevant era.

Therefore, in the cultural investigation, Chen Han is actually not very good at it.

He and Deng Xin, just like the two students, stood behind Xie Dafei honestly, watching him divide the cultural layer.

"Needless to say, the top layer must be the cultivated layer of topsoil."

"The second layer is modern."

Xie Dafei took the shovel and skillfully walked on the pit wall and began to draw lines.

In fact, the most obvious difference between different age layers is the difference in earth color.

The higher the soil layer, the more yellow the color is.

The further down the soil layer, the darker the color will be.

Of course, this is not absolute, and the color of the soil layer will be different in some places, after all, there are red clay and black soil.

However, there is absolutely nothing wrong with distinguishing the cultural layer by relying on different colors, and it is the most basic method for distinguishing the cultural layer.

However, it would be nice if the cultural layer really had such a good score.

In fact, when it comes to the third layer, the situation starts to get complicated.

"This third layer is currently set at the level of the Song Dynasty." Xie Dafei groaned: "On this side of Moon Bay, from the Song Dynasty to modern times, there are no traces of human activities. ”

"Even in modern times, this area has always been used as a cultivated field."

What does that mean?

It was from the Song Dynasty to the end of the Qing Dynasty that Moon Bay was a deserted wilderness.

Some people will think, this is not right!

The country of abundance in Sichuan, after the Song Dynasty, has been an important granary of the Central Plains Dynasty of China, human activities are very intensive, why is there a blank here?

Hey, that's true.

Ancient people are different from modern people, in fact, even in the Ming and Qing dynasties, when the population was very explosive, except for the Central Plains and the Jiangnan region, the population density in other places was still very low.

Sichuan is indeed the land of abundance, but not every place has always been inhabited by human activities.

In fact, until the Republic of China, most of the Sichuan people also gathered around Chengdu and Chongqing.

As for the other cities and counties, they only lived around the city.

Although it is said that Guanghan has had a city for a long time, it was an important city in Shu Han when it was Shu Han.

However, the Sanxingdui Moon Bay site is an area far away from Guanghan City, and it may have been a mountain forest in the past.

At least from the Song Dynasty to the Ming and Qing dynasties, it has not been developed.

On the contrary, there is a cultural layer of human activities left over from the Song Dynasty.

This shows that Moon Bay was a place where there were traces of intensive human activities in the Song Dynasty, or villages, or cities.

But after the Song Dynasty, it was abandoned.

Maybe it has something to do with the chaotic war at the end of the Yuan Dynasty.

"And the fourth layer under the Song Dynasty went directly to the Shang and Zhou dynasties."

"However, the age of this fourth layer may be relatively late, and it will not be earlier than the Twelve Bridges culture period at the earliest."

Xie Dafei took the hand shovel to draw the line while teaching Deng Xin.

The so-called Twelve Bridges Culture period is another peak in the history of the development of ancient Shu civilization in Sichuan after the Sanxingdui culture.

Because it was found in the Twelve Bridges Road of Shudu Avenue in Chengdu, it was named the Twelve Bridges Culture.

The Twelve Bridges Culture is a settlement site centered on the Twelve Bridges Road, which is the architectural site from the Shang Dynasty to the Western Zhou Dynasty (1700-771 BC), covering an area of more than 50,000 square meters along the Pijiang River and its tributaries.

At the site of the Twelve Bridges, the characters on the unearthed pottery spinning wheels are different from the so-called "Bashu script" and close to the oracle bone writing system of Yinxu.

Bashu characters refer to some images and symbols engraved on Bashu bronzes in the Warring States Period.

The text of the Twelve Bridges culture is different from the Bashu culture, which shows that there is no connection between the two.

That is to say, after the destruction of the Twelve Bridges culture later, it was not inherited by the Shu State during the Spring and Autumn Period and the Warring States Period.

According to the current research, the Twelve Bridges culture should have appeared after the Sanxingdui civilization.

And the geographical location has also moved from Guanghan in Sanxingdui to Chengdu.

According to the current continuous research, most scholars in China tend to believe that the Twelve Bridges culture is a continuation of the Sanxingdui civilization.

The transformation of Sanxingdui culture to Twelve Bridges culture has a transition period, and there are many ruins.

In the past, the relics of this stage were generally classified into the Twelve Bridges Culture, and in recent years, it has been proposed to classify or partially classify them into the Sanxingdui Culture.

On the side of Moon Bay, it was found that there was a cultural layer distribution during the "Twelve Bridges Culture" period, which once again showed that there should be a connection between the Sanxingdui civilization and the Twelve Bridges culture!

"And under this Shang and Zhou cultural layer, it is the staging of Sanxingdui!"