On October 28, 2021, the global Internet social media giant Facebook announced that it will rename the existing company "Meta", and the company's future development will focus on building a "Metaverse" (Figure 1). The concept of the meta-universe was instantly detonated, and major technology companies have launched technological development plans; various media have fueled the waves and carried out overwhelming publicity; and capital has also rushed to try. In the past 2021, "metaverse" has been a hot word.
Figure 1 Metacosmological concept diagram (Su Zhongzhong, 2022)
The term metaverse first appeared in the 1992 novel Snow crash by American science fiction writer Nile Stephenson, which represents a virtual world in which people in the metaverse can find their avatar. Derived from this meaning, today's metacosm is a virtual world that uses scientific and technological means to connect and create, map and interact with the real world, and is a digital living space with a new social system.
The metacosm, as an economic term, also exists in geoscience. There is no shortage of "Yuan", "Universe", and "Zeus" in the geoscience language. Before introducing the "meta", "universe", and "universe" in geoscience, let's first understand the unit of measurement of all geological records (layered or non-layered rocks) formed at specific time intervals in geological history - chronological stratigraphic units and the geological time units that form these geological records - geological chronological units.
Geological chronological units can be divided into zeus, generation, epoch, epoch, period and sub-period from large to small time scales, and the corresponding chronological stratigraphic units can be divided into universe, boundary, system, system, order, and sub-order (Table 1). The geological history of the earth can be divided into 4 universes: the Pluto, the Archaic, the Proterozoic and the Proterozoic, and the corresponding chronological stratigraphic units are 4 universes: hades, Taikooyu, Proterozoic and Ephemeral. These 4 Universes and 4 Universes are the protagonists of our article today.
Table 1 Formal chronologic and geological chronology (according to the National Stratigraphic Commission, 2000)
Before we officially introduce the protagonist, let's first look at the largest geological age unit in geology, the Eon. The word Eon is an American and Australian English spelling for Aeon. Aeon is derived from the Latin transliteration of the Greek α ν (ho aion), α ν (aiwon), meaning long time, eternal, eternal. After investigation, the author found that the American geologist H. S. Williams proposed the concept of Eon in 1901 as the longest unit of geological age (Figure 2). But the frequency of use of Eon is not very high, the American geologist A. H. Sutton pointed out in his 1940 book that Eon is not a formal geological dating unit, and some scholars have used Era as the longest geological age unit.
Figure 2 American geologist H. Related writings of S. Williams in 1901
Since the 1950s, Eon has become increasingly widely used, officially becoming the largest unit of geological dating. Eon was first introduced to the mainland in 1962 by Mr. Huang Jiqing. Huang Lao transliterated it as "Yon". Later, Mr. Yin Zanxun drew on the concepts of "Four Directions Up and Down Yue Yu, Ancient and Modern Yue Yu" put forward by the ancient mainland book "Corpse Zi" and "Huainan Zi Qi Folk Training" put forward "The Ancient and the Present is called the Universe, and the Four Directions Are Called the Universe", pointing out that the Universe can represent infinite time, and the Universe represents infinite space. The concept of Zeus and Eon is quite similar. Therefore, Elder Yin transliterated Eon as Zeus. Eon's corresponding chronological unit, Enothem (them are suffixes, meaning placed objects and the subject of conversation) is transliterated as 宇 (Figure 3). Since then, Zeus and Universe have officially entered the academic community as the terms of the largest unit of geological age and chronological strata.
▲ Figure 3 Relevant works of Mr. Huang Jiqing in 1962 and related works of Mr. Yin Zanxun in 1966
For the long geological history, the American geologist G. H. Chadwick divided it into two phases, Cryptozoic and Phanerozoic, based on whether there was a significant fossil record. The crypto in Cryptozoic is derived from the Greek word κρυπτ (kryptos), meaning hidden; zoic is derived from the Greek word ζων ν (zoon), meaning animal. The phanero in Phanerozoic is derived from the Greek word φανερ (phaneros), meaning visible or significant. It is worth mentioning that Chadwick's classification scheme does not involve specific geological dating units. With the popularization of the Eon concept, these two phases also had specific geological chronology units, namely Cryptozoic Eon and Phanerozoic Eon. Huang Lao first translated it as Cryptosetic Yi weng and Xiansheng Yi Weng respectively, and later Yin Lao translated it as Cryptozoic and Xiansheng, and the corresponding chronological strata were Cryptosyn and Xianshengyu.
Later, with the discovery of more and more traces of the life activity of the Pre-Phanerozoic, the academic community discovered that the previously thought lifeless Cryptozoic Universe was already pregnant with life on earth. Thus, in the second half of the 20th century, the American geologist P. Cloud divides the geological history into four: the original cryptozoic universe is divided into Pluto, Archaic and Proterozoic from old to new, plus Pleiades; the corresponding chronological stratigraphic units are Hades, Taikoo, Proterospheric and Ethynosaurus. Cloud's scheme was later modified to eventually become the stratigraphic surface of the International Age as we see it today (Figure 4). The following is a brief introduction to the 4 Universes and 4 Universes in Geoscience.
Figure 4 The latest Chinese edition of the International Chronological Stratigraphic Surface
(https://stratigraphy.org/ICSchart/ChronostratChart2021-10Chinese.jpg, the latest international chronological stratigraphic surface has been released in February 2022, but the Chinese version has not yet been released, so the October 2021 version is used, the same below)
Hadean Eon (4.56 billion to 4 billion years ago) is the first earth of geological history, more than 500 million years old, named by Cloud in 1972, derived from the Greek δη, the Greek myth of Hades, which refers to how primitive the earth was when it first formed. All strata of this period belong to Hadean Eonthem.
In the Pluto, the Earth was initially formed by the accumulation of dust and gas, and then underwent a long period of complex evolution, during which the Earth's temperature slowly decreased. About 4.5 billion years ago, a giant impact event that formed the Moon occurred on Earth (Figure 5), which transformed the Earth from a sphere full of molten silicate material into a sphere of divergent circles. From 4.5 billion years ago, the Earth at this time really had a modern Earth's sphere such as the core, mantle, crust, atmosphere and ocean, and began to carry out complex differentiation and evolution.
▲ Figure 5 Restoration of the art of the Earth-Moon system at the end of the Hades
Primordial Earth at the far and Primordial Moon on the near side (according to Wikipedia, https://zh.wikipedia.org/wiki/File:Earearth.png)
Archean Eon (4 billion to 2.5 billion years ago) is the second zeus in geological history, named in 1872 by American geologist and zoologist James Dwight Dana, derived from the Greek word αρχ, meaning beginning, origin. The Archean Is divided into four epochs, from old to new: Eoarchean Era (4 billion to 3.6 billion years ago), Paleoarchean Era (3.6 billion to 3.2 billion years ago), Mesoarchean Era (3.2 billion to 2.8 billion years ago), and Neoarchean Era (2.8 billion to 2.5 billion years ago).
Accordingly, Archean Eonthem is divided into four realms: Eoarchean Erathem, Paleoarchean Erathem, Mesoarchean Erathem, and Neoarchean Erathem (Figure 6).
Figure 6 Taikoo Yu on the stratigraphic surface of the International Age
In the Archean Period, the Earth has formed a thin and active primordial crust after more than a billion years (3.8-2.5 billion years ago), the volcanic-magmatic activity is intense and frequent, and the plate tectonic activity is likely to start during this period (Figure 7); the silicon aluminum crust that makes up the continent begins to form and grow continuously, and the continent is likely to germinate from this period; the geomagnetic field is formed during this period; the hydrosphere and atmosphere are also quite embryonic, giving birth to low-level life, prokaryotes represented by bacteria and low-grade cyanobacteria. But the fossil record left is rather small, hindering our restoration of the earth's biological appearance during this period. In the Archean Age, the Earth has a reducing atmosphere dominated by methane. However, the great oxidation event that occurred at the end of the Archean Age (2.5 billion years ago) sent an oxygen-rich oxidizing atmosphere to the Earth in the subsequent Proterozoic.
Figure 7 Restoration of the Earth's Face in the Archean Empire (Tim Bertelink, 2017)
The Proterozoic Eon (2.5 billion to 538.8 million years ago) is the third epoch in geological history, led by the American geologist S. A. Thompson. Named in 1888, F. Emmons is derived from the Greek word Πρωτο, meaning primitive. The Proterozoic era (2.5 billion to 1.6 billion years ago), the Mesoproterozoic Era (1.6 billion to 1 billion years ago), and the Neoproterozoic Era (1 billion to 538.8 million years ago) from old to new is divided into three generations.
Accordingly, Proterozoic Eonthem is divided into three realms: Paleoproterozoic Erathem, Mesoproterozoic Erathem, and Neoproterozoic Erathem (Figure 8).
Figure 8 Proterozoic universe on the stratigraphic surface of the International Age
In a nutshell, the Proterozoic is the most important period of the transformation of the earth's tectonic system, atmosphere-marine environment and biological evolution, and it is also a key stage in the transformation of the earth from the hypoxia of the Archean, the "unlivable" atmosphere-marine environment to the oxygen-rich Phanerogene, and the "livable" atmospheric-marine environment. The proterozoic was more active than the Archaic and was the main orogenic period of the Earth, and the size of the continental crust was further expanded. In the Proterozoic, algae and bacteria began to flourish, which was an important stage in the evolution of prokaryotes to eukaryotes, single-celled protozoa to multicellular protozoa. In addition, unlike the fiery Pluto and Archean, the Proterozoic Earth ushered in several great ice ages, of which the Neoproterozoic Ice Age snowball Earth event was the most famous (Figure 9).
Figure 9 Schematic diagram of the Snowball Earth
（https://astronomy.com/news/2019/04/the-story-of-snowball-earth)
The Phanerozoic Eon (538.8 million years to date) is the fourth age of geological history, divided into three epochs, paleozoic Era (538.8 million to 251.9 million years ago), Mesozoic Era (251.9 million to 6600 years ago), and Neozoic Era (66 million years to present), and we now live in the Cenozoic Era. Accordingly, Phanerozoic Eonthem can be divided into three realms: Paleozoic Erathem, Mesozoic Erathem, and Neozoic Erathem (Figure 10). In the Phanerozoic, the earth's geological events and biological evolution are the most colorful (Figure 11), and this public account has a special article to introduce, which will not be introduced here.
Figure 10 The eminent universe on the stratigraphic surface of the International Age
Figure 11 Evolutionary context of earthly organisms (Graham et al., 2008)
References (swipe up and down to view)
Chadwick, G.H. 1930. Subdivision of geologic time. Geological Society of America Bulletin, 41(1): 47-48.
Cloud, P. 1972. A working model of the primitive earth. American Journal of Science, 272(6): 537-548.
Emmons, S. F. 1888. “American Committee Reports”. International Geological Congress. 6: 71.
Joseph, Graham, William, Newman, John, Stacy. 2008, The geologic time spiral—A path to the past (ver. 1.1): U.S. Geological Survey General Information Product 58, poster, 1 sheet. Available online at http://pubs.usgs.gov/gip/2008/58/
Dana, J.D. 1872. Green Mountain geology. On the quartzite. American Journal of Science, 3(16): 250-257.
Tim, Bertelink. 2017. Own work. https://en.wikipedia.org/wiki/Archean#/media/File:Archean.png.
Williams, H.S. 1901. The discrimination of time value in geology. The Journal of Geology, 9(7): 570-585.
DU Xingui. Plate tectonics and the Proterozoic. Seismological Geology Translation Series, (03): 59+33.
HUANG Jiqing, JIANG Chunfa. A preliminary discussion on the development of the Earth's crust from the perspective of multi-spin cyclic tectonic motion. Acta Geologica Sinica, 42(02): 105-152.]
National Stratigraphic Commission. 2001. China Stratigraphic Guide and China Stratigraphic Guide Manual (Revised Edition). Beijing: Geological Publishing House.] 1-59.
SU Zhong, AN Xiaopeng, GAO Hongbing. 2022. Is the metacosm a new technology or a new bubble? Big Data Era, (02): 6-15.
YIN Zanxun. 1966. Division and naming of the largest stages in earth's history. Geological Review, 24(01): 51-52.]
Editor: Xu Ruoxi
Proofreader: Qin Huaqing Jiang Shumin