VOA慢速英语2016--甘尼逊黑峡谷国家公园的荒野环境

Wild Surroundings at Black Canyon¹ of the Gunnison 甘尼逊黑峡谷国家公园的荒野环境

Our national parks journey this week takes us to the western state of Colorado. There, you will find a 77-kilometer-long canyon. Its exposed rocks are among the oldest you will find on Earth.

The canyon is so narrow and so deep that sunlight shines only briefly² at the bottom at midday. That frequent darkness is what has given this canyon its name.

Welcome to Black Canyon of the Gunnison National Park!

Black Canyon seems impossibly steep and narrow. The fast moving Gunnison River formed the canyon over millions of years. As the river flows through the canyon, it drops an average of 18 meters per kilometer. The Gunnison River loses more elevation³ in its 77 kilometer canyon stretch than the Mississippi River does in 2,400 kilometers from Minnesota to the Gulf⁴ of Mexico.

This loss in elevation causes the river to gain speed and force. Over time, that force has carved and cut the hard rock, and created the wild and jagged rock formations found at Black Canyon. That process is known as erosion.

At its widest, Black Canyon is 14 kilometers. At its deepest point, it is 829 kilometers from the canyon edge to the floor.

Black Canyon attracted little attention from early Western explorers. In fact, no early Spanish explorers to the southwestern United States reported seeing Black Canyon. The first written record about the canyon came in 1873.

The Ute Indians certainly knew of Black Canyon. But only its rim⁵, never the gorge⁶, shows evidence of past human occupation. Even today, the depth and steepness of Black Canyon make it extremely difficult for humans to access.

Birds, however, have no problem surviving in the canyon environment. Black Canyon is home to many kinds of birds. They live at the canyon rim, along its walls, and by the river. Mountain bluebirds and great horned owls⁷ live in the rim area. The owls eat seeds and berries from the pinyon, juniper and oak trees found there.

Canyon wrens⁸ sing loudly within Black Canyon. Visitors are more likely to hear the birds than seen them. They build their nests on flat surfaces of the canyon walls. So do peregrine falcons⁹. They prey¹⁰ on other birds. They dive at speeds up to 300 kilometers per hour to catch them.

American dippers build their nests in the gorge, next to the Gunnison River. A gorge is a narrow valley between hills or mountains. These dippers feed on insects and small fish.

Some people come to Black Canyon of the Gunnison National Park for world-class birdwatching.

But, it is the canyon itself that appeals to most visitors. Walking along the rim, seeing the canyon’s towering cliffs, and hearing the powerful flow of the Gunnison River far below is an overwhelming experience.

At Black Canyon, visitors can view some of the planet’s oldest exposed rocks. They are Precambrian rocks. Precambrian accounts for the Earth’s history from its very beginning up until about 540 million years ago.

Precambrian rocks are described as “basement rocks” because they are usually buried deep under the surface. The only become exposed when younger rocks have been cut away by erosion or other forces. At Black Canyon, the Gunnison has eroded¹¹ the canyon walls so greatly that Precambrian rocks have become visible.

Often, the canyon’s rock walls look like works of art. Different kinds of rocks fold together and form colorful patterns. The patterns change as the sun hits different parts of the walls.

One area of the canyon is known as Painted Wall. It is the highest cliff in Colorado. Long pink bands of rock cover this section of the canyon, as if a person took a paintbrush to the wall.

This pattern formed as hot liquid from below the Earth’s surface forced its way into rock cracks. As it slowly cooled, large crystals formed. The bands get their pink color from a crystallized mineral called potassium feldspar.

Protecting the canyon

Local people knew how just special Black Canyon was. They began urging Congress to protect the canyon in the 1930s. It became a national monument in 1933. And in 1999 it became a national park.

The park protects more than 22 kilometers of the canyon. Most visitors spend their time exploring the canyon rim by foot or by car. Several kilometers of trails lead to many overlook points. A road also leads to several breathtaking views.

The U.S. Congress named the lands below the canyon rim a Wilderness¹² Preservation¹³ System. This is meant to “protect forever the land’s natural conditions.”

Some adventurous¹⁴ travelers choose to explore this wilderness by hiking down to the inner canyon. There are no marked trails to guide them. Hikers must first get a wilderness use permit. These permits are free, but only a limited number are available each day.

Many of the paths are difficult to follow. Some are also dangerous. The Warner Point trail, for example, drops more than 820 meters. Walking down takes more than two hours. Walking back up can take up to four hours.

The park service warns that poison ivy¹⁵ grows wildly in the inner canyon. There is also the risk of falling rocks.

But, to reach a place where no humans ever tried to live is the reward. In the words of a 1901 explorer to Black Canyon’s river area, “Our surroundings were of the wildest possible description. The roar of the water...was constantly in our ears...Occasionally a rock would fall from one side or the other, with a roar and crash, exploding like a ton of dynamite¹⁶ when it struck bottom, making us think our last day had come.”

Words in This Story

steep – adj. almost straight up and down : rising or falling very sharply

elevation – n. the height of a place

jagged – adj. having a sharp, uneven¹⁷ edge or surface

erosion – n. the process by which something is worn away

rim – n. the outer edge of a usually round object

access – n. a way of getting near, at, or to something or someone

cliff – n. a high, steep surface of rock, earth, or ice

overwhelming – adj. very great in effect

basement – n. the part of a building that is entirely¹⁸ or partly below the ground

adventurous – adj. not afraid to do new and dangerous or exciting things

1 canyon   

n.峡谷，溪谷

参考例句：

• The Grand Canyon in the USA is 1900 metres deep.美国的大峡谷1900米深。
• The canyon is famous for producing echoes.这个峡谷以回声而闻名。

2 briefly   

adv.简单地，简短地

参考例句：

• I want to touch briefly on another aspect of the problem.我想简单地谈一下这个问题的另一方面。
• He was kidnapped and briefly detained by a terrorist group.他被一个恐怖组织绑架并短暂拘禁。

3 elevation   

n.高度；海拔；高地；上升；提高

参考例句：

• The house is at an elevation of 2,000 metres.那幢房子位于海拔两千米的高处。
• His elevation to the position of General Manager was announced yesterday.昨天宣布他晋升总经理职位。

4 gulf   

n.海湾；深渊，鸿沟；分歧，隔阂

参考例句：

• The gulf between the two leaders cannot be bridged.两位领导人之间的鸿沟难以跨越。
• There is a gulf between the two cities.这两座城市间有个海湾。

5 rim   

n.(圆物的)边，轮缘；边界

参考例句：

• The water was even with the rim of the basin.盆里的水与盆边平齐了。
• She looked at him over the rim of her glass.她的目光越过玻璃杯的边沿看着他。

6 gorge   

n.咽喉，胃，暴食，山峡；v.塞饱，狼吞虎咽地吃

参考例句：

• East of the gorge leveled out.峡谷东面地势变得平坦起来。
• It made my gorge rise to hear the news.这消息令我作呕。

7 owls   

n.猫头鹰( owl的名词复数 )

参考例句：

• 'Clumsy fellows,'said I; 'they must still be drunk as owls.' “这些笨蛋，”我说，“他们大概还醉得像死猪一样。” 来自英汉文学 - 金银岛
• The great majority of barn owls are reared in captivity. 大多数仓鸮都是笼养的。 来自辞典例句

8 wrens   

n.鹪鹩( wren的名词复数 )

参考例句：

• Other songbirds, such as wrens, have hundreds of songs. 有的鸣鸟，例如鹪鹩，会唱几百只歌。 来自辞典例句

9 falcons   

n.猎鹰( falcon的名词复数 )

参考例句：

• Peregrine falcons usually pluck the feathers and strip the flesh off their bird prey. 游隼捕到鸟类猎物时，通常是先拔掉它们的羽毛，再把肉撕下来。 来自《简明英汉词典》
• Though he doubted the wisdom of using falcons, Dr. de la Fuente undertook the project. 虽然德·拉·富恩特博士怀疑使用游隼是否明智，但他还是执行了这项计划。 来自辞典例句

10 prey   

n.被掠食者，牺牲者，掠食；v.捕食，掠夺，折磨

参考例句：

• Stronger animals prey on weaker ones.弱肉强食。
• The lion was hunting for its prey.狮子在寻找猎物。

11 eroded   

adj. 被侵蚀的，有蚀痕的 动词erode的过去式和过去分词形式

参考例句：

• The cliff face has been steadily eroded by the sea. 峭壁表面逐渐被海水侵蚀。
• The stream eroded a channel in the solid rock. 小溪在硬石中侵蚀成一条水道。

12 wilderness   

n.杳无人烟的一片陆地、水等，荒漠

参考例句：

• She drove the herd of cattle through the wilderness.她赶着牛群穿过荒野。
• Education in the wilderness is not a matter of monetary means.荒凉地区的教育不是钱财问题。

13 preservation   

n.保护，维护，保存，保留，保持

参考例句：

• The police are responsible for the preservation of law and order.警察负责维持法律与秩序。
• The picture is in an excellent state of preservation.这幅画保存得极为完好。

14 adventurous   

adj.爱冒险的；惊心动魄的，惊险的，刺激的　

参考例句：

• I was filled with envy at their adventurous lifestyle.我很羨慕他们敢于冒险的生活方式。
• He was predestined to lead an adventurous life.他注定要过冒险的生活。

15 ivy   

n.常青藤，常春藤

参考例句：

• Her wedding bouquet consisted of roses and ivy.她的婚礼花篮包括玫瑰和长春藤。
• The wall is covered all over with ivy.墙上爬满了常春藤。

16 dynamite   

n./vt.(用)炸药(爆破)

参考例句：

• The workmen detonated the dynamite.工人们把炸药引爆了。
• The philosopher was still political dynamite.那位哲学家仍旧是政治上的爆炸性人物。

17 uneven   

adj.不平坦的，不规则的，不均匀的

参考例句：

• The sidewalk is very uneven—be careful where you walk.这人行道凹凸不平—走路时请小心。
• The country was noted for its uneven distribution of land resources.这个国家以土地资源分布不均匀出名。

18 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。