托福听力中关于地质学的讨论常常涵盖地球内部构造、岩石圈活动以及表层现象。虽然对初学者而言这些知识可能略显深奥,但只要掌握了基本原理,就会发现这些内容既易于理解又充满趣味。今天,我们将聚焦于矿石,探讨矿石的种类、形成机制以及它们如何影响地表资源的分布。通过了解这些矿石特性,你可以更清楚地认识到矿石的起源及其与地壳运动之间的联系。现在,让我们一起走进这个充满奥秘的矿石世界吧!

矿石(Ore)

矿石(Ore)是指地球内部经过漫长地质作用沉积和富集后形成的、蕴藏经济价值的矿物质集合体。在地壳运动、岩浆(magma)入侵以及变质作用的综合影响下,这些矿物质逐渐聚集为矿脉或矿床,并在适宜条件下暴露于地表。矿石的形成过程与板块运动及深部构造密切相关,是地球内部物质循环和能量转换的重要环节。矿石的开采和利用不仅推动了人类工业文明的发展,同时也对生态环境产生了深远影响。通过研究矿石,科学家得以揭示地球深层物质分布及其演变历史的奥秘。

图源:千库网

地球上常见的矿石主要分为金属矿石(metal ore)和非金属矿石(non-metal ore)两大类。金属矿石方面,铁矿(iron)、铜矿(copper)和铝矿(aluminum)等都广泛存在于全球各地:铁矿石是制造钢铁的关键原料,铜矿石则被广泛用于电器和电子产品,而铝矿石则为轻质合金的生产提供了重要资源。非金属矿石如石灰石(limestone)、硅石(silica)和磷矿(phosphate)在建筑、化工以及农业领域都有重要应用。

这些矿石的形成过程通常与地壳运动、岩浆活动以及沉积和变质作用密切相关。

在探究地球起源及人类出现前的地质环境时,科学家们主要依赖几种保存了古老信息的矿石。例如,锆石(zircon)因其极高的耐久性和能保存长达数十亿年的放射性同位素信息而备受青睐,其在澳大利亚杰克山脉发现的古老锆石显示,地球最早的固体物质形成时间可能可追溯到44亿年前;

此外,橄榄石(olivine)等超基性矿石也提供了关于地幔(mantle)组成和早期热状态的重要线索;而铬铁矿(chromite)在古地壳中较为普遍,其存在帮助研究人员重建早期地壳运动和构造活动的场景。通过对这些矿石的详细分析,我们能够更清楚地了解地球形成初期的环境条件和内部演化过程。

锆石(Zircon)

锆石(ZrSiO₄)是一种极为耐久且富含地质信息的矿物,经常出现在火成岩(igneous rock )、变质岩(metamorphic rock)以及沉积岩(sedimentary rock)中。由于其具有较高的熔点和极强的抗风化能力,锆石能在地质过程中保存下长达数十亿年的记录,这使得它成为研究地球早期历史的重要工具。

在地质学中,锆石常被用于铀—铅定年法(uranium-lead dating),这是因为锆石能够锁定铀和铅等放射性元素,并在经历漫长地质演化后依然保持其原始的同位素比值。科学家们通过分析这些同位素数据,不仅能够精确测定岩石的形成年代,还能重构地球从初生到现代的演化历程。

此外,锆石内常常包含微小的包裹体(inclusions),这些包裹体可能是其他矿物或流体的痕迹,为研究古环境条件和构造活动提供了珍贵的线索。例如,通过包裹体的组成和结构,研究人员可以推测出当时的温度、压力以及化学环境,从而更全面地了解早期地球内部的动态过程。

在托福听力等地质学讲座中,锆石被频繁提及,作为展示地球起源与矿物演化的经典实例。它不仅向我们揭示了地球内部的物质循环和能量转换过程,也帮助我们理解了板块构造运动、岩浆活动及变质作用等多种地质现象如何共同塑造了今天复杂多样的地球面貌。通过对锆石的深入研究,我们得以窥见地球早期的剧烈环境变化以及漫长而复杂的演化史,这对于理解人类在地球演化历史中的位置具有重要意义。

通过以上的背景知识,我们可以更好的理解下面这篇文章的内容:

Professor: So, a few weeks ago, we talked about zircon. Anyone remember anything about zircon?

Male student: Well, it's a mineral. Uh, I know it has unusual properties, but.

Professor: Great and no, that's a good start. Zircon is a particularly sturdy mineral. It forms crystals. And the thing about zircon is when it forms crystals, these crystals encapsulate or grow around other materials, so the zircon crystals retain evidence of the conditions that were present when they formed, and even the other materials that were present at the time.

根据上面的内容,我们看下面这道题:

According to the professor, what is true about the mineral zircon? [Click in the correct boxes.]

It is very durable.

It can form around other substances.

Most of it was destroyed during Earth’s first 500 million years.

It requires extremely high temperatures to form.

这是一个考察细节信息的题,是比较少见的判断题,难度较大;

题干中提到了mineral zircon,那就是在介绍zircon的部分去找答案;

我们可以听到教授提出的问题“So, a few weeks ago, we talked about zircon. Anyone   remember anything about zircon?”,通过问答我们也可以预测接下来要听到关于zircon的特性等内容了。

对应原文“Zircon is a particularly sturdy mineral. It forms crystals. And the thing about zircon is when it forms crystals, these crystals encapsulate or grow around other materials, so the zircon crystals retain evidence of the conditions that were present when they formed, and even the other materials that were present at the time.”

两个点对应It is very durable.和 It can form around other substances.是正确的,剩下两个内容与原文提出的相反,所以是错误的。

当然我们根据背景知识也学习了同样的知识点,如果对于锆石我们有过提前了解,那么理解这道题将会非常简单。

答案:TTFF

我们在看下面这部分段落的内容:

Now, researchers in the 1980s discovered some zircon crystals in Australia. At that time, though, we lacked the technology to make any definite claims about the materials found in the zircon. There seemed to be some evidence of material from way way back before scientists thought Earth had cooled enough for it to exist. But researchers didn't have any conclusive evidence at the time.

Male student: So they still thought Earth started cooling when it was 500 million years old.

Professor: The Discovery of those zircon crystals was pretty exciting. But really, most scientists had to stick with the theory that had the clearest evidence. Like I said, technology just wasn't at the point yet where it could really challenge the accepted view.

根据上面的内容,我们看下面这道题:

4. The professor mentions research done in Australia in the 1980s. What is the professor’s opinion of the result of that research?
A. It was disappointing, because a new technology provided unreliable data.
B. It was unexpected because it disproved the most accepted theory.
C. It was misleading because it reinforced an incorrect theory.
D. It was useful because it led researchers to question a theory.

这是一道态度题,从professor’s opinion可以判断;

根据题干可知,态度是对于research done in Australia in the 1980s的,那我们就要在教授提到这个research的前后找答案;

从“Now, researchers in the 1980s discovered some zircon crystals in Australia.”我们知道老师开始要说具体的事例了,通过这句“There seemed to be some evidence of material from way way back before scientists thought Earth had cooled enough for it to exist.”以及“. But really, most scientists had to stick with the theory that had the clearest evidence.”

我们可以知道虽然1980的研究并没有得到明确的结果,但是确实让之前的观点有所质疑,并且文章后面也提到了“So, the question was, were these zircon crystals an indication that earth started cooling earlier than we thought?”都是在说明这一点。

从背景知识中我们了解到了澳大利亚发现的矿脉中发现的古老矿石,对于地球最早的固体物质形成时间可能可追溯到44亿年前。

答案:D

本文作者

TD托福听力老师

托福听力备考资料免费领取

到这里,与矿石相关的背景知识就给大家讲完了,希望能帮助到大家,那么这几篇出题点是在哪里呢?如何在听的时候精准定位到答案呢?发送暗号【矿石】,题目和题目解析会放在赠送材料中等待大家去领取哦。