“Trona Pinnacles”的意思、由来-开放百科全书

The Trona Pinnacles are an unusual geological feature in the California Desert National Conservation Area. The unusual landscape consists of more than 500 tufa spires (porous rock formed as a deposit when springs interact with other bodies of water), some as high as {{convert|140|ft|m|0}}, rising from the bed of the Searles Lake (dry) basin. The pinnacles vary in size and shape from short and squat to tall and thin, and are composed primarily of calcium carbonate (tufa). They now sit isolated and slowly crumbling away near the south end of the valley, surrounded by many square miles of flat, dried mud and with stark mountain ranges at either side.

Geography

The Trona Pinnacles, at an elevation of {{convert|1800|ft|m|-1}} above sea level, are located approximately {{convert|10.0|mi|km|1}} south of Trona, California. Access to the site is from a BLM dirt road (RM143) that leaves State Highway 178, about {{convert|7.7|mi|km|0}} east of the intersection of State Highway 178 and the Trona-Red Mountain Road. The {{convert|5.0|mi|km|0|sing=on}} long dirt road from State Highway 178 to the Pinnacles is usually accessible to 2-wheel drive vehicles, however, the road may be closed during the winter months after a heavy rain.

The Pinnacles are located within {{convert|3800|acre|km2|0}} of federal land managed by the Bureau of Land Management. The Trona Pinnacles are inside a BLM Area of Critical Environmental Concern (ACEC) designated to protect and preserve unique resources.

Geology

During the Pleistocene, massive runoff spilled from the Sierra Nevada into a chain of inland seas. The system of interconnected lakes stretched from Mono Lake to Death Valley and included Searles Lake.

Deep beneath Searles Lake, calcium-rich groundwater and alkaline lake water combined to grow tufa formations. Similar (modern) formations can be found today at Mono Lake to the north.

Known as tufa pinnacles, these strange shapes formed underwater 10,000 to 100,000 years ago. The pinnacles did not all form at the same time. They are divided by age and elevation into three groups. The groups are dubbed the northern, middle, and southern groups because they formed during three ice ages.

The northern group is the youngest at 11,000 to 25,000 years old. These are the best examples of what are known as tufa towers. The northern group also include shapes called tombstones, ridges and cones. The small middle group claims only 100 spires, but boasts the tallest "tower", rising {{convert|140|ft|m|0}}. The southern group, includes 200 tufa formations aged 32,000 to 100,000 years old.

People have historically given names to the strange forms. These ancient spires were once dubbed "Cathedral City". Geologically, the pinnacles are classified into four general shapes. Towers are taller than they are wide and rise {{convert|30-40|ft|m|0}}. Tombstones are stubby and squat and rise {{convert|20-30|ft|m|0}}. Most tombstones are in the northern-most tufa formations. Ridges are massive toothy tufa ruins. Trona has three ridges, one in the northern tufa cluster and two in the middle group. One ridge is {{convert|800|ft|m|-1}} long and {{convert|500|ft|m|-1}} wide and {{convert|140|ft|m|0}} tall. Cones are less than {{convert|10|ft|m|0}} tall. Dumpy{{clarify|reason=what does this word mean in this context? Is there a synonym that's not slang that can be used?|date=December 2018}} and mounded, cone shapes lie scattered throughout the Trona Pinnacles.

Films

The Pinnacles are recognizable in more than a dozen hit movies. Over thirty film projects a year are shot among the tufa pinnacles, including backdrops for car commercials and sci-fi movies and television series such as Battlestar Galactica, The Final Frontier, Disney's Dinosaur, The Gate II, Lost in Space, and Planet of the Apes.^[1]

References

1. ^David Kelly, Stark Beauty, Solitude, Squalor and Sulfur – Trona Has It All, The Los Angeles Times, October 4, 2006, Accessed December 28, 2006.

External links