2022年经济学人 大陆形成新学说(1)

Science & technology

科技版块

Forming continents

形成大陆

Impact creator

撞击的创造者

Earth may have been shaped by forces from outer space

地球可能是由外太空的力量塑造的

The earth is a poor archivist.

地球是一个糟糕的档案保管员。

The rigid¹ tectonic plates of its outer layers are continuously in motion, sliding over one another to swallow almost all records of the past, melting them into the mantle² and then casting them anew.

刚性板块不断运动，相互滑动，吞噬了几乎所有过去的记录，将它们熔化到地幔中，然后重新浇铸。

This makes it difficult to reconstruct the 4.5bn-year-old planet’s formative years.

这使得很难重建这颗有45亿年历史的行星的形成期。

A particular problem is the crucial biographical detail of how the first continents came to be.

一个特别的问题是关于第一个大陆是如何形成的关键传记细节。

Studies of ancient rocks suggest that fragments of solid crust existed as far back as 4bn years ago, when the Earth was mostly covered in water, but their genesis remains³ disputed.

对古代岩石的研究表明，固体地壳的碎片早在40亿年前就已经存在了，当时地球大部分被水覆盖，但它们的起源仍然存在争议。

While plate tectonics are the dominant⁴ mechanism⁵ for generating new continental⁶ crust today, in the distant past Earth’s subsurface temperatures are widely thought to have been too hot to allow plates to form.

虽然板块构造是今天形成新的大陆地壳的主要机制，但在遥远的过去，人们普遍认为地球的地下温度太高，不能形成板块。

A paper published this week in Nature attempts to resolve this conundrum⁷.

本周发表在《自然》杂志上的一篇论文试图解决这个难题。

Tim Johnson of Curtin University, Australia, and his colleagues argue that the planet’s transformation⁸ was not triggered by forces from within, but from outer space—in the form of collisions from meteorites⁹ that disrupted the surface, causing fragments of the crust to melt in the presence of water, cool and resolve themselves into buoyant patches of land that would later act as nuclei¹⁰ for new continents.

澳大利亚科廷大学的蒂姆·约翰逊和他的同事们认为，地球的转变不是由内部的力量引发的，而是来自外部空间的--陨石碰撞破坏了地球表面，导致地壳碎片在水的存在下融化，冷却并分解成漂浮的小块陆地，这些陆地后来成为新大陆的核心。

Dr Johnson’s thesis is not new, but the lack of direct evidence means it has never taken root.

约翰逊博士的论点并不新鲜，但缺乏直接证据，这也意味着这个论点从未站稳脚跟。

The more popular explanation for the first continent formation points the finger at plumes¹¹ of hot matter rising from the Earth’s mantle to the surface, much like bubbles in a lava¹² lamp.

对于第一个大陆形成，更流行的解释是热物质从地幔上升到地表，很像熔岩灯中的气泡。

Then, if sufficiently¹³ hot, their underside would melt to produce buoyant granite¹⁴, leading to the first continental plateaus.

然后，如果温度足够高，它们的底部会融化，产生漂浮的花岗岩，形成第一个大陆高原。

The new study offers evidence that sits uncomfortably with this theory.

这项新研究提供了与这一理论不符的证据。

Dr Johnson and his colleagues looked at the Pilbara craton, an approximately 3.5bn-year-old slab¹⁵ of north-western Australia, roughly the size of Germany, which represents one of the few remaining scraps¹⁶ of the early Earth’s continental crust.

约翰逊博士和他的同事们研究了皮尔巴拉地区的古陆核，这是澳大利亚西北部的一个大约有35亿年历史的板块，大致相当于德国的大小，是早期地球大陆地壳为数不多的残余之一。

1 rigid   

adj.严格的，死板的；刚硬的，僵硬的

参考例句：

• She became as rigid as adamant.她变得如顽石般的固执。
• The examination was so rigid that nearly all aspirants were ruled out.考试很严，几乎所有的考生都被淘汰了。

2 mantle   

n.斗篷，覆罩之物，罩子；v.罩住，覆盖，脸红

参考例句：

• The earth had donned her mantle of brightest green.大地披上了苍翠欲滴的绿色斗篷。
• The mountain was covered with a mantle of snow.山上覆盖着一层雪。

3 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

4 dominant   

adj.支配的，统治的；占优势的；显性的；n.主因，要素，主要的人(或物)；显性基因

参考例句：

• The British were formerly dominant in India.英国人从前统治印度。
• She was a dominant figure in the French film industry.她在法国电影界是个举足轻重的人物。

5 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

6 continental   

adj.大陆的，大陆性的，欧洲大陆的

参考例句：

• A continental climate is different from an insular one.大陆性气候不同于岛屿气候。
• The most ancient parts of the continental crust are 4000 million years old.大陆地壳最古老的部分有40亿年历史。

7 conundrum   

n.谜语；难题

参考例句：

• Let me give you some history about a conundrum.让我给你们一些关于谜题的历史。
• Scientists had focused on two explanations to solve this conundrum.科学家已锁定两种解释来解开这个难题。

8 transformation   

n.变化；改造；转变

参考例句：

• Going to college brought about a dramatic transformation in her outlook.上大学使她的观念发生了巨大的变化。
• He was struggling to make the transformation from single man to responsible husband.他正在努力使自己由单身汉变为可靠的丈夫。

9 meteorites   

n.陨星( meteorite的名词复数 )

参考例句：

• Small meteorites have left impact craters all over the planet's surface. 这个行星的表面布满了小块陨石留下的撞击坑。 来自《简明英汉词典》
• One theory about the existence of extraterrestrial life rests on the presence of carbon compounds in meteorites. 地球外存在生命的理论是基于陨星上存在碳化合物质这一事实的。 来自《简明英汉词典》

10 nuclei   

n.核

参考例句：

• To free electrons, something has to make them whirl fast enough to break away from their nuclei. 为了释放电子，必须使电子高速旋转而足以摆脱原子核的束缚。
• Energy is released by the fission of atomic nuclei. 能量是由原子核分裂释放出来的。

11 plumes   

羽毛( plume的名词复数 )； 羽毛饰； 羽毛状物； 升上空中的羽状物

参考例句：

• The dancer wore a headdress of pink ostrich plumes. 那位舞蹈演员戴着粉色鸵鸟毛制作的头饰。
• The plumes on her bonnet barely moved as she nodded. 她点点头，那帽子的羽毛在一个劲儿颤动。

12 lava   

n.熔岩，火山岩

参考例句：

• The lava flowed down the sides of the volcano.熔岩沿火山坡面涌流而下。
• His anger spilled out like lava.他的愤怒像火山爆发似的迸发出来。

13 sufficiently   

adv.足够地，充分地

参考例句：

• It turned out he had not insured the house sufficiently.原来他没有给房屋投足保险。
• The new policy was sufficiently elastic to accommodate both views.新政策充分灵活地适用两种观点。

14 granite   

adj.花岗岩，花岗石

参考例句：

• They squared a block of granite.他们把一块花岗岩加工成四方形。
• The granite overlies the older rocks.花岗岩躺在磨损的岩石上面。

15 slab   

n.平板，厚的切片；v.切成厚板，以平板盖上

参考例句：

• This heavy slab of oak now stood between the bomb and Hitler.这时笨重的橡木厚板就横在炸弹和希特勒之间了。
• The monument consists of two vertical pillars supporting a horizontal slab.这座纪念碑由两根垂直的柱体构成，它们共同支撑着一块平板。

16 scraps   

油渣

参考例句：

• Don't litter up the floor with scraps of paper. 不要在地板上乱扔纸屑。
• A patchwork quilt is a good way of using up scraps of material. 做杂拼花布棉被是利用零碎布料的好办法。