Gobi Desert

The Gobi is made of old rock and layers of mud and sand that turned to stone.

Long ago, there were more lakes. Over thousands of years, many lakes shrank. Rivers here are usually dry, but water hides underground.

The Gobi's plains are made of chalk and other rocks that formed from layers of sediment, mostly within the last 66 million years, Britannica says, while some low, rocky hills are older. Scientists have found fossils of dinosaurs and of ancient mammals in the Gobi's rocks.

The Gobi gets very little rain or snow: less than 50 millimeters a year in the driest west and more than 200 in the northeast. Most of its water is underground. Mountain streams soon disappear into the dry soil, and many rivers flow only in summer. Over the last 11,700 years, the Gobi's lakes have shrunk, leaving old shorelines high above today's water.

Britannica describes the Gobi's plains as chalk and other sedimentary rocks chiefly of Cenozoic age, up to about 66 million years old, with some older low isolated hills, small masses of shifting sand, and soils that are grayish brown and brown, carbonaceous, gypseous and gravelly, often with sandy salt marshes and takyr. Elsewhere in the desert, Late Cretaceous rocks (about 100 to 66 million years old) hold exceptionally preserved dinosaur assemblages.

The climate is acutely continental: severe winters, dry cold springs, warm summers, average January lows reaching −40 °C and July highs of 45 °C, and large daily ranges. Precipitation ranges from under 50 mm in the west to over 200 mm in the northeast, where a monsoon-like summer maximum occurs; northerly and northwesterly winds dominate in autumn, winter and spring. Drainage is largely underground. During the Holocene the Gobi's lakes shrank, leaving terraces well above present shores; Orog, Bööntsagaan and Ulaan lakes are, in Britannica's words, but shadows of their former selves. Since 1995, joint Mongolian-American and Mongolian-European expeditions have studied the Gobi's tectonic history and landscape evolution.

Long ago, dinosaurs lived where the Gobi is now.

Scientists found their bones at a place called the Flaming Cliffs. They found dinosaur eggs too! These were the first dinosaur eggs that scientists studied.

In 1922 an expedition led by Roy Chapman Andrews of the American Museum of Natural History found pieces of dinosaur eggshell in southern Mongolia, at a place they called the Flaming Cliffs. The next year they came back and found whole dinosaur eggs, some still arranged in nests. The Embryo Project at Arizona State University explains that these were the first dinosaur eggs to be scientifically recognized.

At first, the team thought the eggs belonged to Protoceratops, a dinosaur whose fossils were common at the site. But in the 1990s, scientists found an egg of the same kind with a baby dinosaur inside, and it was more like Oviraptor, a bird-like dinosaur. Britannica says expeditions in the 1990s found many more exceptionally preserved dinosaur fossils in the Gobi.

The Central Asiatic Expeditions of the American Museum of Natural History, led by Roy Chapman Andrews, ran from 1922 to 1930. According to Arizona State University's Embryo Project, the 1922 team collected dinosaur eggshell at the Flaming Cliffs in southern Mongolia, and in 1923 returned to excavate more fragments and whole eggs, including clutches: the first scientifically recognized dinosaur eggs and the first evidence that some dinosaurs laid eggs in clutches. Because no embryos were found, the eggs were attributed to the abundant Protoceratops andrewsi, named for Andrews, an assignment Osborn published in 1924.

In the 1990s an AMNH team led by Mark Norell recovered identical eggs from the Djadochta Formation, one containing an embryo resembling the bird-like Oviraptor philoceratops (published in Science in 1994), and the attribution was revised. Britannica notes that US and European expeditions in the 1990s researched exceptionally preserved Late Cretaceous dinosaur assemblages in the Gobi, and that excavations at Tsagaan Agui (White Cave) produced human artifacts up to 35,000 years old.

The Gobi can be very hot or very cold.

Bring lots of water, a hat and warm clothes. Travel with a grown-up and a guide who knows the way. Leave fossils and rocks where you find them.

The Gobi is a place of extremes. Britannica says average lows in January can reach minus 40 °C, while July highs can climb to 45 °C, and temperatures can change a lot between day and night. Many rivers flow only in summer, and there are almost no wells or springs in the driest parts.

So plan carefully: travel with an experienced guide and a reliable vehicle, carry plenty of drinking water, and pack for both sun and cold. Stay on known tracks, because the desert is huge and empty. Fossils are part of the Gobi's scientific treasure, so look at them, photograph them, and leave them where they are for scientists to study.

Britannica describes an acutely continental climate, with average January lows of −40 °C, July highs of 45 °C and large daily ranges; in the Trans-Altai Gobi precipitation is under 100 mm a year and there are virtually no wells or springs, though water exists underground. Distances are great: the road from Ulaanbaatar to Dalandzadgad alone covers about 500 km, and population density is below one person per km².

Travel therefore calls for experienced local guides, dependable vehicles, ample water, and clothing for heat, sun and severe cold. The Gobi's fossil beds are a scientific resource studied by Mongolian and international teams since the 1920s; visitors should leave fossils in place. Britannica's account of desertification, groundwater contamination and overgrazing is a reminder to tread lightly, use water carefully and carry out all waste.