7.1 The concept and development history of tectonics在线视频

各位同学 大家好
Hello, everyone.

我是西南石油大学孟立丰
I am Meng Lifeng from Southwest Petroleum University.

从这次课开始
Starting from this class,

我们将一起来学《构造地质学》
we will learn the geotectonic part of

课程中的大地构造部分
the course in Structural Geology,

共同领略地球演化的奥秘
and uncover the secrets of the earth's evolution.

对于大地构造学的概念
For the concept of geotectonics,

不同学者都做过相应的定义
many scholars have made definitions,

其本质内涵类似
which, essentially, are similar.

即大地构造学是研究
That is, geotectonics is an integrated discipline studying

大陆 洋盆 山脉 地震带
continents, ocean basins, mountains, seismic belts

及其它地表大尺度构造的
and other large-scale surface structures,

形成 演化过程
their formation and evolution,

及其地球内部驱动力的综合性学科
and geodynamics.

其研究的领域包括了
Its research covers

造山带的起源
the origin of orogenic belts,

大陆的生长
the growth of continents,

洋底的构成
the structure of the ocean floor,

沉积盆地的演化
evolution of sedimentary basins

地震与火山的成因等
and causes of earthquakes and volcanoes, etc..

大地构造学及构造地质学理论
The geotectonics and structural geology theory

自上世纪60年代以来有了飞速发展
has made a rapid development since the 1960s.

大地构造学的板块构造学说
The plate tectonics theory of geotectonics

为研究现今影响着地壳及地幔的
provides a basic theoretical framework

绝大部分大尺度的运动及变形过程
for the study of most large-scale movement and deformation processes

提供了基本理论框架
involving the crust and mantle.

那板块构造学说是如何出现的呢
How did plate tectonics come into being?

那就需要了解一下
Then we need to look at

现代大地构造学发展历史
the history of modern geotectonics,

即从大陆漂移到板块构造学说
starting from continental drift to plate tectonics.

20世纪前期之前
Before the early 20th century,

大地构造学研究者主要研究
geotectonic researchers mainly studied

陆地上的岩石和沉积物
rock and sediment on land,

对洋底所知极少
and knew little about the ocean floor.

并且绝大多数不承认地壳 岩石圈
And the vast majority of geologists refused to accept the crust and lithosphere

有过大规模的水平运动
had had large-scale horizontal movements,

其运动方式主要是垂向为主
and believed that movements were mainly vertical.

认为地质历史中洋陆面貌没有根本的变化
They believed that there had been no fundamental change in the appearance of the ocean and land in geological history.

因此那时候的大地构造学说理论
It was because that the geotectonic theory at that time

以固定论占主导
was dominated by fixed-continent theory,

特别是地槽学说的出现
especially, geosynclinal theory.

统治了大地构造学界上百年
It ruled the geotectonic community for a hundred of years,

被欧美地质学家的普遍接受
generally accepted by European and American geologists.

并在世界各地广为传播和发展
and was widely spread and developed all over the world.

在地槽学说广为传播的过程中
In the course of the spread of geosyncline theory,

也始终遇到一些困扰
some problems still failed to be solved.

例如
For example,

按照现实主义原理(将今论古原则)
according to the principle of realism (the principle of deduction of geology history based on modern geology),

过去的地质环境应有现代的相似物
modern similarities should be found also in the geological history.

但始终没有能找到大家信服的证明
However, no convincing evidence was found.

再者
Furthermore,

无法满意地解释地槽形成
the formation of geosyncline

及其随后变形的原因
and the reasons for its subsequent deformation could not be satisfactorily explained.

因此后人指出地槽造山理论
Therefore, someone criticized the geosyncline orogeny theory

却无法说明山脉是如何形成的
could not explain how mountains were formed.

在地槽学说流行期间
During the period that the geosyncline theory was popular,

大地构造学出现了一些活动论的思想
a few activity theories appeared in geotectonics.

其中以魏格纳于1912年提出的
Among them, the theory of continental drift produced by Wegener in 1912

大陆漂移学说为代表
was outstanding.

在1910年的某一天
One typical day in 1910,

魏格纳目光落到墙上的世界地图时
when Wegener cast his eyes on the world map on the wall,

意外地发现大西洋两岸海岸线惊人的一致
he found the coastline on both sides of the Atlantic surprisingly consistent.

其实在魏格纳之前
In fact, before Wegener,

已有多人注意到这一现象
many people had noticed this phenomenon.

但深入研究大西洋两岸古生物 地质学
But, Wegener was the first geologist who studied in depth

和古气候学等资料的吻合性的
how the both sides of the Atlantic are fitted

in paleontology, geology and paleoclimatology.

魏格纳恢复了晚石炭世时的
Wegener restored the Late Carboniferous

泛大陆
Pangaea,

即联合大陆
the Urkontinent,

周围为泛大洋所包围
surrounded by the Panthalassa.

中生代以来
He found from the Mesozoic,

泛大陆发生分裂
Pangaea started to split

开始形成大西洋和印度洋
and formed the Atlantic and Indian oceans.

分裂后的各个陆块逐渐漂移到现在的位置
After the split, each land mass gradually drifted to its present position.

魏格纳的学说不仅解释了
Wegener's theory not only explained

大西洋两岸海岸线的吻合性
the dove-tailing outlines of the both sides of the Atlantic Ocean,

而且更好地解释了煤田 冰川沉积
but also better explained the distribution of coalfields, glacial deposits,

古动物区系和古植物区系的分布
paleofauna and paleoflora.

魏格纳学说动摇了固定论的基础
Wegener's theory shaked the foundation of fixed theory,

既引起了世界范围的兴趣
aroused worldwide interest.

但也遭到许多人怀疑与反对
But it also met with suspicion and opposition from many people.

魏格纳学说受到攻击的关键
The main criticism on the Wegener's theory

是关于大陆漂移的驱动机制
was about the driving mechanism of continental drift.

魏格纳的主张是与地球自转有关的2种力
Wegener proposed that two forces related to earth's rotation,

即极移力和潮汐牵引力
i.e. polar wander force and tidal force,

两种力的作用使大陆从高纬度
made the continent move from high latitudes

向赤道方向移动并向西漂移
towards the equator and drift westward.

这成为英国著名地球物理学家
This became the focus of attack by a famous British geophysicist

Jeffreys攻击的焦点
Jeffreys.

他通过定量计算表明
He showed through quantitative calculation that

这两种力要比推动大陆漂移所需要的力
these two forces are several orders of magnitude smaller than

小好几个数量级
those needed to push the continents to drift.

不足以推动大陆在硅镁层上运动
They are not big enough to push the mainland to glide over the silicon-magnesium layer.

因此断言大陆漂移是不可能的
Therefore, he asserted that it was impossible to have continental drift.

随着魏格纳不幸于1930年
As Wegener died in 1930

格陵兰考察时遇难
during the tour of exploration in Greenland,

大陆漂移作为一种可行的模式
continental drift which is actually sensible

在北美和大部分欧洲
was gradually forgotten

可以说逐渐销声匿迹
in North America and most of Europe.

直到古地磁学 海洋学等学科的发展
Until paleomagnetism, oceanography and other disciplines were well developed,

才使得大陆漂移学说获得了新生
the theory of continental drift regained popularity.

古地磁学研究认为
Paleomagnetism studies found that

把不同时代的磁极位置标注在地图上
by marking the magnetic pole positions at different times on the map,

各时代的古地磁极连接起来
and connecting paleomagnetic poles of all ages,

就得到古地磁极的迁移轨迹
the migration track of paleomagnetic poles can be obtained.

如果所有的大陆相互位置保持不变
If the positions of all continents remain the same all the time,

那么全球就只有一条极移轨迹
then there should be only one pole wander track in the world.

不同大陆具有不同的极移轨迹
But the fact that different continents have different polar wander tracts,

表明它们相互间发生过相对位移
indicates that they have been displaced relative to each other.

海洋学的发展主要是赫斯1946年
The main progress in oceanography was in 1946 Hess

用声纳对海底做了不间断的观测
continuously observed the seabed using sonar,

记录到一连串的
having recorded a series of

圆形海底山-水下平顶山
circular seabed mountains-underwater table mountains.

它们从平坦的海底上拔地而起
They rose from the flat sea floor

高逾数千米
as high as thousands of meters,

四周壁立而顶部平坦
and are flat on the top but steep on the surrounding.

赫斯对其形成过程做了长时间的思索
Hess thought for a long time about its formation process,

直到他提出海底扩张假说
until he put forward the hypothesis of seafloor spreading.

以地幔对流机制来解释海底地形时
and interpreted submarine topography by mantle convection mechanism,

才给出了一个满意的解释
a satisfactory explanation was obtained.

他在1962年发表“洋盆的历史”
He published "the History of Ocean Basins" in 1962,

对1930年代以来
in which he summarized

海洋地质与地球物理的成果
achievements in marine geology and geophysics,

以及有关大陆漂移研究
new progresses in research on continental drift obtained

的新进展进行了总结
since 1930s.

以地幔对流机制来解释
In addition, he used the mantle convection mechanism

海底地形地质特征及其演化
to explain the topographic and geological characteristics of seabed and its evolution.

其强调地幔物质从洋中脊
He stressed the mantle material rose from the mid-ocean ridge

裂谷处上升形成新海底
and formed a new seabed,

在对流体的下降翼又返回深部
and then returned to the deep ocean along the downward convecting limb of a mantle cell.

海底扩张假说的建立
The seafloor spreading hypothesis

由Vine-Matthews-Morley
has been confirmed by Vine-Matthews-Morley

等基于海底岩石磁化方向正反交替
based on the alternating magnetization directions of seabed rocks,

并由洋中脊轴部向外推移
and their migration from that mid-ocean ridge axis to the outside

并平行于洋脊顶峰延伸
and extension parallel

得到证实
to that crest of the ridge.

表明一场地球革命已经酝酿成熟
It predicted that a revolution on geotectonics had already been underway.

随后在威尔逊 麦肯齐及帕克
Later, thanks to the contributions of Wilson, Mackenzie, Parker,

摩根 勒皮雄 艾萨克斯等人的贡献下
Morgan, Le Pichon, Isaacs and others,

1968年底
at the end of 1968,

整个北美和英国的地球物理界
the entire geophysical community and marine geological community in North America and Britain

和海洋地质界都转向了新地球观
all turned to a new view of the earth.

尽管当时这一新观点
Despite at that time it was unclear how to apply

对陆地地质学的应用还不清楚
this new view to continental geology,

但地质学家迅速看出海底扩张
geologists quickly saw the significance of sea floor expanding

和板块构造对大陆地质的意义
and plate tectonics in continental geology.

并且板块构造作用
Plate tectonics

不仅可用于现代构造活动研究
can be used not only for the study of modern tectonic activities,

而且适用于古代大陆地质
but also for ancient continental geology.

因此
Therefore,

大陆保存的历史纪录也被综合了进来
the historical records kept by continents have also uses.

例如
For example,

认为蛇绿岩是洋壳和地幔的碎块
ophiolite was found to be the fragments of oceanic crust and mantle,

有些形成于扩张中心
and some formed in the spreading center;

板块的汇聚和陆块的碰撞产生造山构造
the convergence of plates and the collision of land masses can produce orogenic structures;

浅水沉积与深水沉积的构造并置
structures are juxtaposed for shallow and deep water deposition,

以及在火山弧和造山带
and in volcanic arcs and orogenic belts

产生岩浆岩和变质岩
magmatic and metamorphic rocks can be produced.

通过研究很快发现
Through research, it was soon discovered that

大陆漂移不是地球历史短暂的一幕
continental drift is not a brief episode in the history of the earth,

而是连续的过程
but a continuous process.

魏格纳的联合大陆
The Urkontinent of Wegener

是由早先分散的陆块群拼合起来的
was pieced together by previously scattered land masses.

魏格纳的假说只是一个长剧的最后一幕
Wegener's hypothesis is only the last act of a long play.

把地质学研究分割成不同领域的障壁
The barriers that divide geological research into different fields

终于被打开了
were broken,

板块构造理论成为地质学各领域新的规范
and the plate tectonics theory has become a new norm in various fields of geology.

板块构造理论在其影响与完美程度上
The theory of plate tectonics in its influence and perfection

可同原子理论 进化论
is comparable to the atomic theory, evolutionary theory,

量子力学 相对论相媲美
quantum mechanics, and relativity theory.

今天这节课就上到这里
That's all for today's lesson.

谢谢
Thank you.