卡尔斯巴德洞穴国家公园

     http://www.nps.gov/cave/index.htm

    Carlsbad Caverns National Park is located in the Guadalupe Mountains, a mountain range that runs from west Texas into southeastern New Mexico. Elevations within the park rise from 1,095 meters (3,595 feet) in the lowlands to 1,987 meters (6,520 feet) atop the escarpment. Though there are scattered woodlands in the higher elevations, the park is primarily a variety of grassland and desert shrubland habitats.

    The Chihuahuan Desert is the largest and wettest of the North American deserts. Most of this desert is in Mexico, but the park is one of the few places where it is preserved and protected. The park averages more than 36.6 cm (14.4 in) of annual precipitation and has a semiarid, continental climate with mild winters, warm summers, and summer rains. The mean annual temperature is 19ºC (63ºF).

    The park supports a diverse ecosystem, including habitat for many plants and animals that are at the geographic limits of their ranges. For example, the ponderosa pine reaches its extreme eastern limit here and several species of reptiles are at the edges of their distributions.

The deserts of the Southwest contain some of the highest diversity of mammals, birds, reptiles, and insects in the United States. The park provides important habitat for top predators such as cougars, and is home to what is perhaps the largest colony of cave swallows in the northern hemisphere. The Bat Cave area in Carlsbad Cavern provides important habitat for a large colony of Brazilian (Mexican) free-tailed bats as a place to give birth and raise young, as well as a stopover for migrating bats.

    Rattlesnake Springs, a rare desert wooded riparian area that has been designated an Important Bird Area (IBA) by the National Audubon Society, draws birders from around the world to see some of the 300-plus species that have been noted there. The Carlsbad Cavern Natural Entrance is also an Audubon IBA because of the large colony of cave swallows that resides and breeds there in the summer. Current checklists for park fauna identify 67 species of mammals (including 17 species of bats), 357 species of birds, 55 different reptiles and amphibians, 5 species of fish, and an incomplete list of over 600 insects, with more identified each year. The park’s list of vascular plants includes more than 900 species and subspecies.

    Underlying the rugged desert landscape is one of the most important geologic resources in the United States. The Guadalupe Mountains are the uplifted portion of an ancient reef that thrived along the edge of an inland sea more than 250 million years ago during Permian time. Preserved in the rocks are the bodies of sponges, algae, snails, nautilus, and many other animals that lived in this ancient sea. Scientists from all over the world visit the park each year to study the structure and fauna of the reef.

    The most famous of all the geologic features in the park are the caves. Carlsbad Caverns National Park contains more than 110 limestone caves, the most famous of which is Carlsbad Cavern. Carlsbad Cavern receives more than 300,000 visitors each year and offers a rare glimpse of the underground worlds preserved under the desert above.

    Caves are fragile environments that are affected by human activities and natural processes occurring both underground and on the surface. Many park caves are preserved and managed in a nearly pristine state, so researchers can understand the unique ecosystem within them. These scientists are only beginning to understand the complex, microscopic organisms that inhabit the caves. Studying them has already revealed a food chain that begins with minerals in the rock, and has shown that some of the organisms may help serious human diseases such as cancer.

    卡尔斯巴德洞窟国家公园位于美国佩科斯河西岸，新墨西哥州东南部的吉娃娃森林内，是由目前被发现的8 1 个洞窟组成的喀斯特地形网。它体积庞大，变化多端，还包含了许多精美的矿物质，面积189 平方千米。它是一处神奇的洞窟世界，是迄今人类探查到的最深的洞窟——位于地表以下305 米。溶洞中最大的一处比14个足球场面积的总和还大，整个洞窟群长达近百千米，是世界上最长的山洞群之一。
　　建立这个公园是为了保护卡尔斯巴德洞窟以及其他大量的二叠纪时期的化石。公园那81 个独立的洞窟中，还包括一个全美最深的洞窟，长度为全美第三。1923年10月25日这里最初是作为国家纪念地而建成的，1930 年5 月14日成为国家公园。
　　今天，长4.8千米的小路迂回曲折，通过卡尔斯巴德最有名的溶洞。另外32 千米长的通道和隧洞则少有人光顾。卡尔斯巴德洞窟国家公园内的81个石灰岩洞中以龙舌兰洞窟最特别，构成了一个地下的实验室，在这里可以研究地质变迁的真实过程。沿一系列“之”字形的线路从主走廊下降253米，可到达第一个，也是最深的一个洞窟，名为“绿湖厅”，因其位于洞中央的艳绿色的水潭而得名。该洞窟布满精美的钟乳石，包括一处令人难忘的小瀑布，它与钟乳石相连形成一个圆柱，被贴切地称为“蒙上面纱的雕像”。“皇后厅”设有奇异的帷幕，那里的钟乳石相拥而长，形成一道光线能照透的石幕。“太阳寺”的滴水岩造型由黄色、粉色、蓝色等有着柔和色彩的钟乳石组成。“忸怩的大象”看起来像一头大象的背部到尾部。著名的“老人岩”是一个巨大的钟乳石笋，孤独、雄伟地站立在黑暗的壁龛中。“巨人行”中三个巨大的穹形石笋在站岗放哨，而“王宫”的天花板上则撒下一排令人炫目的钟乳石。《世界自然遗产名录》中收录卡尔斯巴德洞窟是遵循了如下标准：它是一种重要的地质过程的实例，包含了特殊的自然美景。
　　卡尔斯巴德洞窟的另一壮观景象是栖息在卡尔斯巴德洞窟里上百万只的蝙蝠。黄昏时候，上百万只蝙蝠从其白日的栖息地——阴冷黑暗的洞窟中振翼飞出，在黑暗中捕食昆虫，挡住了整个卡尔斯巴德洞口。公园里还有许多小哺乳动物、沙漠爬虫和栖息在矮树丛中的鸟类，如花金鼠、浣熊、轮尾鸟、各种蜥蜴以及兀鹰和鹫。
　　有关洞窟的探究
　　过去，人们认为卡尔斯巴德洞窟这个由石灰岩组成的洞窟，是由碳酸盐岩石经历雨水之后，一点一滴地侵蚀出来的。事实上，按照水溶碳酸盐岩石的方式形成的大多数溶洞都有地下水流，这样才能带走溶于水的石灰石。可是，卡尔斯巴德洞窟不存在地下的水流。后来，地质学家发现，卡尔斯巴德洞窟不是雨水溶开碳酸盐岩石后，再渗到石灰岩上产生侵蚀作用所形成的，而是洞窟里的岩石出现了“冒气泡”现象而形成的。经过考察，洞窟的形成涉及到生物学现象。原来在卡尔斯巴德地区，以小片石油层为食的单细胞微生物才是真正的洞窟雕刻家。生物学家认为，石油中的含碳化合物被微生物吃掉，然后产生了硫化氢。这种致命的硫化氢气体通过岩缝跑出来，直至与水和氧气结合，生成硫酸，这才溶解出若干个体育馆那么大体积的石灰岩洞窟。经证实，在卡尔斯巴德洞窟的勒楚吉拉洞窟，有着大块石膏石，就是硫化氢生成硫酸后，再经过化学反应留下来的副产品。当然，这个洞窟在三四百万年间形成，现在不会有化学副产品的危害了。