问题 问答题 简答题

背斜圈闭按成因可分为哪几种类型?说明各类型特征。

答案

参考答案:

①褶皱作用形成的背斜油气藏:主要在侧压力挤压作用下而形成。背斜轴向一般与区域构造线平行;两翼倾角较大,不对称,靠近褶皱山一侧较另一侧缓;闭合高度较大,且伴生有断层。

②与基底活动有关的背斜圈闭和油气藏:直接覆于基底之上的地层弯曲较显著,有时还可遇到受基底断裂控制的继承性断裂,向上地层弯曲渐趋平缓,而后逐渐消失;两翼地层倾角缓,闭合度小,闭合面积大。

③与同生断层有关的逆牵引背斜圈闭及油气藏:这种背斜圈闭都位于同生断层的下降盘,多为小型宽缓不对称的短轴背斜,靠近断层一翼陡,远离断层一翼缓,轴线与断层线近于平行,常沿断层成串分布。背斜的形态、宽度等均受同生断层的控制

④与塑性流动物质有关的背斜圈闭及油气藏:由于地下塑性地层受不均衡压力作用,向着压力降低的上方流动,使上覆地层变曲形成的背斜圈闭。闭合高度低,面积大,常被断层所切割。

⑤与剥蚀作用及压实作用有关的差异压实背斜及油气藏:这种背斜通常称为披盖背斜,它反映了下伏古地形突起的分布范围和形状,闭合度比古地形突起的高度小,并向上递减直至消失;在成因上很难与基底隆起有关的背斜区分开。

阅读理解

Life on Mars could become a reality and it could happen in your lifetime.

A welcoming planet

Scientists say Earth’s neighbor Mars, a bright red planet about half Earth’s size, is the most likely to support human life. Mars even has frozen water on its surface.

Since the late 1990s, NASA has been exploring Mars using remote-controlled vehicles(装置). Most recently Curiosity, a car-size vehicle, traveled through space on an unpiloted spacecraft(航天器) and landed on Mars in August 2012. Directed by NASA scientists , the vehicles move on the surface, taking pictures , collecting and analyzing soil, and looking for signs of life.

But what about human explorers? Plans are already in the works to send astronauts to Mars as soon as the mid-2030s.

_____________________________________

But before you start packing your bags, let’s consider the challenges. For starters, Mars is far away. Just getting there could take up to 10 months.

Scientists already know that time away from Earth’s gravity harms the human body. Bones and muscles get weaker. The body produces less blood. What damage would months and months of living in space do?

And then there is the matter of water, oxygen, food and fuel. Scientists will have to find solutions to these problems, or the first humans on Mars won’t survive very long in their new home.

Tiny Dangers

There’s another tinier risk. It’s so tiny that you can’t even see it: germs.

Some scientists believe that our germs could pollute the whole planet of Mars. Potentially killing Martian life before we have the chance to discover it. Worse, there is a small but terrifying chance that any microscopic life already there might be harmful to us .

Worse still, if any of those Martian germs(火星细菌) were brought back to Earth, the result could be disastrous. Animals, plants, and people could be wiped out.

Worth the $$$?

A more practical concern is the cost. The price could approach $ 1 trillion(万亿). How can we justify spending that much when so many problems—poverty, disease—could use the cash here on Earth?

小题1:Which of the following is TRUE according to the “A welcoming planet” part?

A.Mars is a little bigger than Earth.

B.There are flowing rivers on Mars.

C.People haven’t been to Mars so far.

D.Scientists have discovered signs of life on Mars.小题2:Which of the following can best fill in the blank in the passage?

A.Living in space.

B.Limited resources.

C.Extreme conditions.

D.Interesting challenges.小题3:By “Tiny dangers” the author means ________________.

A.there is no serious danger

B.people won’t be in any danger

C.it’s difficult for people to realize the danger

D.the danger may be caused by very small things小题4:Which may cause the biggest danger?

A.Martian germs may be different from those on Earth.

B.Martian germs may be brought back to Earth.

C.People may carry germs to Mars.

D.There may be germs on Mars.小题5:Which section of a newspaper is the passage most probably taken from?

A.People

B.History

C.Science

D.Business