首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
In Death Valley, California, one of the hottest, most arid places in North America, there is much salt, and salt can damage rock
In Death Valley, California, one of the hottest, most arid places in North America, there is much salt, and salt can damage rock
admin
2012-08-25
27
问题
In Death Valley, California, one of the hottest, most arid places in North America, there is much salt, and salt can damage rocks impressively. Inhabitants of areas elsewhere, where streets and highways are salted to control ice, are familiar with the resulting rust and deterioration on cars. That attests to the chemically corrosive nature of salt, but it is not the way salt destroys rocks. Salt breaks rocks apart principally by a process called crystal prying and wedging. This happens not by soaking the rocks in salt water, but by moistening their bottoms with salt water. Such conditions exist in many areas along the eastern edge of central Death Valley. There, salty water rises from the groundwater table by capillary action through tiny spaces in sediment until it reaches the surface.
Most stones have capillary passages that suck salt water from the wet ground. Death Valley provides an ultra-dry atmosphere and high daily temperatures, which promote evaporation and the formation of salt crystals along the cracks or other openings within stones. These crystals grow as long as salt water is available. Like tree roots breaking up a sidewalk, the growing crystals exert pressure on the rock and eventually pry the rock apart along planes of weakness, such as banding in metamorphic rocks, bedding in sedimentary rocks, or preexisting or incipient fractions, and along boundaries between individual mineral crystals or grains. Besides crystal growth, the expansion of halite crystals(the same as everyday table salt) by heating and of sulfates and similar salts by hydration can contribute additional stresses. A rock durable enough to have withstood natural conditions for a very long time in other areas could probably be shattered into small pieces by salt weathering within a few generations.
The dominant salt in Death Valley is halite, or sodium chloride, but other salts, mostly carbonates and sulfates, also cause prying and wedging, as does ordinary ice. Weathering by a variety of salts, though often subtle, is a worldwide phenomenon. Not restricted to arid regions, intense salt weathering occurs mostly in salt-rich places like the seashore, near the large saline lakes in the Dry Valleys of Antarctica, and in desert sections of Australia, New Zealand, and central Asia.
Which of the following can be inferred from the passage about rocks that are found in areas where ice is common?
选项
A、They are protected from weathering.
B、They do not allow capillary action of water.
C、They show similar kinds of damage as rocks in Death Valley.
D、They contain more carbonates than sulfates.
答案
C
解析
转载请注明原文地址:https://kaotiyun.com/show/3uyO777K
0
托福(TOEFL)
相关试题推荐
Lookatthefollowingopinionsordeedsandthelistofpeoplebelow.Matcheachopinionordeedwiththecorrectperson,A-
Answerthequestionsbelow.ChooseNOMORETHANTWOWORDSAND/ORANUMBERfromthepassageforeachanswer.Writeyouranswersi
Thievesoftentargetstudents’homesbecausestudents______.Ifpersonalitemsarelost,destroyedordamaged,theinsurancec
WhichmetalweretheCeltsusingatthebeginningofthefirstmillenniumB.C.?
WhichmetalweretheCeltsusingatthebeginningofthefirstmillenniumB.C.?
WritetheappropriatelettersA-CagainstQuestions17-20.WhatarethelocationsofthefollowingplacesinRadford?(A)par
Completethenotesbelow.WriteONEWORDONLYforeachanswer.NotesonCustomer’sInformationExampleAnswerInforma
Completetheformbelow.WriteNOMORETHANTHREEWORDSAND/ORANUMBERforeachanswer.ProductIncidentReportExampleAnswer
Choosethecorrectanswer,A,BorC.Africancrocodilesusuallyliveinareaswith
basicneeds本题有关卫生城市的标准。meet与其后的allitsinhabitants连接,可推测意思为满足人们的需求。录音原文用定语从句的形式(itsinhabitants’basicneedsthat’s…)替换了题目中Aof
随机试题
背阔肌
阑尾位置常有变异是由于()
我国现阶段在实施GCP方面还存在的问题不包括
防治癌病的重要手段是
有关呼吸困难的叙述,正确的是
灰土地基采用的土料应过筛,最大粒径不应大于()mm。
金融监管国际化的进程如下:1975年2月,在瑞士巴塞尔成立了银行管理和监督实施委员会,简称巴塞尔银行监管委员会。1988年7月,巴塞尔银行监管委员会公布了《关于统一国际银行资本测量和资本标准的报告》,简称“巴塞尔资本协议”。1997年9月,巴塞尔银行
钠中度缺乏的表现有()。
在一个小型出版社有三本入门级的教科书F、G、H以及三本高级的教科书X、Y、Z,将被编辑和出版商分别评阅一次,他们将从第一周到第六周的连续六周内对这些书进行评阅。每一个评阅者每周恰好评阅一本教科书,没有教科书会被J和R同一周内评阅,下面是评阅必须遵守的其他条
Thecommoncoldistheworld’smostwidespreadillness,whichisplagues(疫病)thatfleshreceives.Themostwidespreadfallac
最新回复
(
0
)