Petrology

Petrology  岩石学

 

Petrology (from Greek: πέτρα, petra, rock; and λόγος, logos, knowledge) is the branch of geology that studies rocks, and the conditions in which rocks form.

岩石学 （希腊文：πέτρα， petra ，岩石和λόγος，标志，知识）是地质学的一个分支，专门研究岩石以及岩石形成的条件。

Lithology was once approximately synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale description of rocks, while petrography is the speciality that deals with microscopic details.

岩性一度是接近岩石学的代名词，但目前的用法是，岩性侧重于宏观手触觉样品或岩石外部的描述，而岩石学则专门研究微观细节。

In the oil industry, lithology, or more specifically mud logging, is the graphic representation of geological formations being drilled through, and drawn on a log called a mud log. As the cuttings are circulated out of the borehole they are sampled, examined (typically under a 10x microscope) and tested chemically when needed.

在石油工业中，岩性或更专门的泥浆测表，是钻进泥层里把数据记录在一个叫泥浆测表的记事簿中，绘成了地质图表。泥土的切片由钻孔取样，在需要时（在10倍显微镜下）检查和作化学测试。

 

Contents  目录

• Methodology  研究方法
• Branches  分支
• See also  另见
• References  参考文献
• External links  外部链接

 

Methodology  研究方法

Petrology utilizes the classical fields of mineralogy, petrography, optical mineralogy, and chemical analyses to describe the composition and texture of rocks. Modern petrologists also include the principles of geochemistry and geophysics through the studies of geochemical trends and cycles and the use of thermodynamic data and experiments to better understand the origins of rocks.

岩石学采用古典研究领域的矿物学，岩石学，光性矿物学和化学分析来描述岩石的成份和质地。现代岩石学家还通过地球化学和物理学的原理去研究地球化学的周期趋势，也使用热力学的数据和实验更了解岩石的起源。

 

Branches  分支

There are three branches of petrology, corresponding to the three types of rocks: igneous, metamorphic, and sedimentary, and another dealing with experimental techniques:

岩石学有三个分支，对应了三种类型的岩石：火成岩，变质岩和沉积岩，另一个则跟实验技术有关：

Igneous petrology focuses on the composition and texture of igneous rocks (rocks such as granite or basalt which have crystallized from molten rock or magma). Igneous rocks include volcanic and plutonic rocks.

火成岩岩石学侧重于研究火成岩的成份和纹理（例如从熔岩或岩浆结晶而成的花岗岩或玄武岩） 。火成岩包括火山岩和深成岩。

Sedimentary petrology focuses on the composition and texture of sedimentary rocks (rocks such as sandstone, shale, or limestone which consist of pieces or particles derived from other rocks or biological or chemical deposits, and are usually bound together in a matrix of finer material).

沉积岩石学侧重于沉积岩的的成份和纹理（例如砂岩，页岩或石灰岩，里面的粒子和碎片来自其他岩石或生物或化学残留物，通常都以更细致的材料编制在一起）。

Metamorphic petrology focuses on the composition and texture of metamorphic rocks (rocks such as slate, marble, gneiss, or schist which started out as sedimentary or igneous rocks but which have undergone chemical, mineralogical or textural changes due to extremes of pressure, temperature or both).

变质岩石学侧重于变质岩的成份和质地（例如板岩，大理石，片麻岩或片岩，开始时只是沉积岩或火成岩，由于极端的压力，温度或岩石两者兼施而经历了化学，矿物学或纹理的变化）

Experimental petrology employs high-pressure, high-temperature apparatus to investigate the geochemistry and phase relations of natural or synthetic materials at elevated pressures and temperatures. Experiments are particularly useful for investigating rocks of the lower crust and upper mantle that rarely survive the journey to the surface in pristine condition. The work of experimental petrologists has laid a foundation on which modern understanding of igneous and metamorphic processes has been built.

验性岩石学采用高压，高温设备去研究在较高压力和温度下的天然或人工合成的材料和地质化学与阶段变化的关系。实验特别是用来研究下地壳和上地幔的岩石，因为它们很少在原始状态之下浮上地面。实验岩石学的工作奠定了火成岩和变质过程的基础提供现代的新理解。

 

See Also  另见

• Important publications in petrology  岩石学的重要出版物
• Ore  金矿

 

External Link  外部链接

• Atlas of Igneous and metamorphic rocks, minerals, and textures – Geology Department, University of North Carolina

 火成岩和变质岩，矿物和纹理地图集 – 北卡罗莱纳大学地质学系

• Metamorphic Petrology Database (MetPetDB) – Department of Earth and Environmental Sciences, Rensselaer Polytechnic Institute

[http://metpetdb.rpi.edu变质岩石学数据库（MetPetDB）] -伦斯勒理工学院，地球与环境科学系

• Petrological Database of the Ocean Floor (PetDB) – Center for International Earth Science Information Network (CIESIN), Columbia University

 洋底岩石数据库（PetDB） -哥伦比亚大学，国际地球科学信息网中心（CIESIN）

 

Categories  分类

• Petrology  岩石学

• Petroleum geology  石油地质学

• Oilfield terminology  油田术语

 

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Source > Wikipedia at en.wikipedia.org/wiki/Petrology

Translated by > BlogHost

Word Count > approx. 580 words in English

Baleen

Baleen   鲸须

 

Baleen or whalebone is a filter-feeder system inside the mouths of baleen whales. The baleen system works when a whale opens its mouth underwater and then water pours into the whale’s mouth. The whale then pushes the water out, and animals such as krill are filtered by the baleen and remain as food source for the whale. Baleen is similar to bristles and is made of keratin, the same substance found in human fingernails and hair. Some whales, such as the bowhead whale, have longer baleen than others. Others whales, such as the gray whale, only use one side of their baleen. These baleen bristles are arranged in plates across the upper jaw of the whale.

鲸须或鲸骨是须鲸嘴里的过滤喂食器。鲸须的系统运作原理是在鲸鱼在水里打开它的嘴巴让水灌入时才开始运作。鲸鱼把水排出去时，动物如磷虾类就被鲸须过滤留在体内成为食物来源。鲸须是角质材质的，类似刷毛，这类物质在人类的的指甲和头发上也有。一些鲸鱼如露脊鲸有比较长的鲸须。其他鲸如灰鲸只使用须的一边而已。这些须的刷毛就长在鲸鱼上颚的鲸须板上。

Depending on the species, a baleen plate can be 0.5 to 3.5 metres (1.6 to 11 ft) long, and weigh up to 90 kilograms (200 lb). Its hairy fringes are called baleen hair or whalebone-hair. They are also called baleen bristles, which in sei whales are highly calcified, calcification functioning to increase their stiffness. Baleen plates are broader at the gumline (base). The plates have been compared to sieves or Venetian blinds.

根据品种，鲸须板可以长达0.5到3.5米(1.6到11英尺)，重达90公斤(200磅)。毛茸茸的边缘部份被称为须发或鲸发。他们也被称为鲸须刷毛，在鲸体内则高度钙化，钙化是为了提高其韧度。鲸须板在牙龈线(底盘)的部份比较宽大。这些鲸须板就像筛网或百叶帘。

 

Contents  目录

• Etymology  词源
• Evolution  进化
• Filter feeding  滤食性能
• Human uses  人类用途
• As a habitat  栖息地
• References  参考资料
• Further reading  其他读物

 

Etymology  词源

The word “baleen” derives from Early Modern English word meaning “whale”. This in turn derives from the Latin balaena, related to the Greek phalaina – both of these also mean “whale”.

“鲸须”一词源自于早期的现代英语单词，意思是“ 鲸鱼 ”,也是出自拉丁文的balaena，跟希腊文的phalaina有关，两者的意思都是”鲸鱼”.

 

Evolution  进化

The oldest true fossils of baleen are only 15 million years old, but baleen rarely fossilizes, and scientists believe it originated considerably earlier than that. This is indicated by baleen-related skull modifications being found in fossils from considerably earlier, including a buttress of bone in the upper jaw beneath the eyes, and loose lower jaw bones at the chin. Baleen is believed to have evolved around thirty million years ago, possibly from a hard, gummy upper jaw, like the one a Dall’s porpoise has. In fact, it resembles baleen closely at the microscopic level.

鲸须最古老的化石只有1千5百万年，但鲸须很少变成化石，因此科学家相信它的起源更早。这一点可以从更早以前发现的有鲸须的鲸鱼头骨化石看出来，尤其是眼睛下方上颚骨里的一排骨头，以及下巴松动的下颚骨。科学家相信鲸须在大约三千万年前进化而成，有可能是从硬的上颚骨牙龈那里长出来，像达尔江豚也有的。 事实上，在微观层面上它更像鲸须。

Many early baleen whales also had teeth, but these were probably used only peripherally, or perhaps not at all (again like Dall’s porpoise, which catches squid and fish by gripping them against its hard upper jaw).

许多早期的须鲸也有牙齿，但这些都可能只是偶尔用到，或者完全不用（又像达尔江豚那样，只用来抓住鱿鱼和鱼压在硬上颚）。

 

Filter Feeding  滤食性能

A whale’s baleen plates play the most important role in its filter-feeding process. In order to feed, a baleen whale opens its mouth widely and scoops in dense shoals of prey (such as krill, copepods, small fish and sometimes birds that happen to be near the shoals), together with large volumes of water. It then partly shuts its mouth and presses its tongue against its upper jaw, forcing the water to pass out sideways through the baleen, thus sieving out the prey which it then swallows.

鲸鱼的鲸须板在这个滤食性过程中发挥最重要的作用。为了喂食，须鲸必须大开嘴巴，在佈满食物的浅滩里连同大量海水搜刮食物（如磷虾，桡足类，小鱼，有时是碰巧靠近浅滩的鸟）。然后，它关闭部份嘴巴用舌头压住上颚，迫使海水通过的须的两侧排出，以便滤出食物再吞下去。

 

Human Uses  人类用途

People formerly used baleen for making numerous items where flexibility and strength were required, including collar stiffeners, buggy whips and parasol ribs, and as corset stays. It was commonly used to crease paper; its flexibility kept it from damaging the paper. It was also occasionally used in cable-backed bows. Synthetic materials are now usually used for similar purposes, especially plastic and fibre glass. Baleen was frequently used in the 18th and early 19th centuries as the handle for silver punch or toddy ladles. It was chosen for this use because of its insulating qualities. Baleen plates are also used by indigenous people to create fine crafts.

以前人们使用鲸须的弹性和强度来制造许多东西，如衣领加强筋，越野车，遮阳伞的肋骨，和紧身胸衣。也常用来折纸痕，其灵活性不会损坏纸张。偶尔也用当支撑电缆的弓。现在的合成材料也用在类似用途，尤其是塑料和玻璃纤维。鲸须在18世纪和19世纪初普遍用来制作银色打孔器或椰汁杓，因为它的绝缘性质而被选用。鲸须板也被土著用来制造工艺用品。

 

As a Habitat  栖息地

Baleen serves as a habitat for some species from the gastropod families Pyropeltidae, Cocculinidae, Osteopeltidae and Neolepetopsidae.

鲸须也成为某些物种的栖息地，譬如腹足类家族的Pyropeltidae，Cocculinidae，Osteopeltidae以及Neolepetopsidae。

 

See Also  另见

• John Henry Devereux South Carolina architect who used whale jaw bones to adorn the largest mansion on Sullivan’s Island.

南卡罗来纳州的建筑师John Henry Devereux约翰亨利德弗罗用鲸鱼颚骨来装饰Sullivan苏里曼岛上最大的豪宅。

• Cetaceans   鲸类动物

• Whale Products  鲸鱼产品

 

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Source > Wikipedia at en.wikipedia.org/wiki/Baleen

Translated by > BlogHost

Word Count > approx. 630 words in English