吉林大学地质专业英语 翻译

L E S S O N6I N T R O D U C T I O N T O I G N E O U S E N V I R O N M E N T S 第六课火成环境的介绍

1.Before discussing the methods petrologists use to study and understand igneous rocks, it is useful first to establish some basic definitions.

在开始讨论岩石学家用来研究和理解火成岩的方法之前，首先建立一些基本的概念是有用的。

An igneous rock is defined as any crystalline or glassy rock that formed directly from a magma.

火成岩被定义为直接从岩浆中形成的所有的结晶质或玻璃质岩石。

Magma is a high-temperature molten substance that is chemically complex and contains the molecular building blocks for minerals (the nature and properties of magma are discussed in detail in Chapter 3).

岩浆是一个高温的化学性质很复杂熔融物质包含矿物的分子骨架。（岩浆的性质将在第三章详细讨论）

As it cools and crystallizes, a magma reorganizes itself into igneous minerals that individually have simpler chemistry than the parent magma. In any given igneous rock, these individual minerals (for example, quartz, feldspars, olivine) occur as either small or large crystals, both with variable perfection of crystal form.

当岩浆冷凝和结晶时，岩浆重组自己形成独立的比母岩浆化学性质简单的火成矿物。在任何给定的火成岩里，这些独立的矿物（例如，石英，长石，橄榄石）形成的不是小就是大的晶体，都具有各种完整的晶形。

The minerals found in any igneous rock and the characteristics of these minerals

depend almost entirely on three things: composition of the original magma, the rate at which it cooled; and the depth in the earth at which it solidified.

这些矿物在任何火成岩中都能被发现，这些矿物的特点完全取决于三个因素：原岩的成分，冷凝的速率，固结成岩的地下深度。

The range of products is enormous, from glassy obsidians, which are volcanic rocks that cooled so rapidly that no crystals could form, to pegmatites, which can contain individual crystals a meter or more in size.

火成岩的种类是很多的，从结晶太快而没有矿物形成的玻璃质黑曜岩到含有大颗粒晶体矿物的结晶花岗岩。

What is igneous petrology?

什么是火成岩石学

2.Igneous petrology is the field of geology in which the object of study is any igneous rock or any process involved in formation of igneous rocks.

火成岩石学是一个地质学领域，它的研究对象是火成岩或者包含火成岩信息的任何过程。

The purpose of studying igneous petrology is to gain an appreciation for how the final appearance and characteristics of igneous rocks are controlled by chemical and physical properties of magmas and their surroundings.

学习火成岩石学的目的在于鉴别火成岩的最终形态和特征是怎样受控于岩浆和周围物质的物理化学条件。

Much of the fascination of petrology lies in its "detective story" aspect.

很多岩石学的魅力在于“寻找故事”这些方面。

Through geologic mapping and simple observations of igneous rocks collected with a hammer and viewed through a hand lens, a geologist can amass a wealth of clues to the origin of the rocks.

通过地质填图和由锤子收集到的的火成岩的简单的观察和放大镜看到的，地质学家能够积累大量关于原岩的线索。

By learning how to interpret these clues, we can create a sophisticated recon-struction of geologic history.

通过学习如何解释这些线索，我们可以建造一个关于地质历史的复杂再现（重建）。

Once some of the basic techniques of petrology, such as hand specimen identifi-cation and field examination of igneous rocks, have been mastered, the student moves on to petrography.

一旦基础的岩石学技能例如火成岩的手标本鉴定和野外踏勘被掌握后，学生们就可以转向学习岩相学。

In fact, petrography is commonly a major component of laboratory work in a petrology course.

事实上，岩相学在火成岩的课程里通常是实验课的主要组成部分。

In this subfield of petrology, the techniques of optical mineralogy are used in the microscopic examination of ultrathin, transparent slices of rocks mounted on glass slides.

在这个岩石学的分支学科，光性矿物学的技能被用在盖在玻片上的超薄的薄片的显微鉴定上。

Microscopic observation of rocks opens up a truly fascinating new world of detailed information.