Reading the landscape: what the ground is telling you

24 questions · by Quizbun

Landforms keep a record of what made them: a U-shaped valley, a line of springs along a cliff, rock layers meeting at an angle. Each question shows a photo of real terrain and asks what happened there, and the explanation draws the cross-section. The route runs from glaciated mountains through rivers, limestone and desert to the coast, and ends at the Scottish outcrop where James Hutton saw deep time.

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Questions

Not answered. This valley has a broad, flat floor and steep walls that curve up to meet it. What carved it into this shape?
Not answered. This waterfall pours off the lip of a side valley that ends high above the main valley floor. Why does the side valley stop so abruptly?
Not answered. From the summit of Helvellyn you look down on a round lake in a steep-walled bowl, beside a knife-edged ridge. What can you read from this view?
Not answered. This bare rock hump has one long, smooth, gently rising side and one short, steep side broken into blocks. Glaciers made it. Which way was the ice moving?
Not answered. Low, smooth hills like this one come in swarms, all stretched the same way. Each has a steep, blunt end and a long, tapering tail. What shaped them, and which way does the blunt end face?
Not answered. A road runs for kilometres along the crest of this narrow, winding ridge, with lakes on both sides. Its core is layers of sand and gravel. What built it?
Not answered. This hummocky ridge near New Zealand's Tasman Glacier is strewn with boulders of every size, from pebbles to blocks as big as sheep. What can you conclude about it?
Not answered. This lone granite boulder sits in a Connecticut wood. What would best show that ice carried it here, rather than it rolling downhill or weathering out on the spot?
Not answered. Below these cliffs, loose rock has built up into long, straight-sided slopes of scree. Where on a scree slope do you usually find the biggest blocks?
Not answered. At Weeping Rock in Zion, water drips from one level across an overhanging cliff, and ferns grow in a band along it. What can you conclude from where the water comes out?
Not answered. Malham Cove is an 80-metre curved limestone cliff with a dry lip. A stream flows out of a cave at its foot, and on the moor above, about a mile away, another stream disappears into the ground. What does this tell you about limestone country?
Not answered. This crater opened in an Alabama wood in 1972, apparently all at once. There is limestone underneath and a thick layer of clay on top. Why can a hole like this appear so suddenly?
Not answered. Look at any loop of this river: one bank is a gentle bar of gravel and sand, and the other is a steep, eroding edge. Which statements about a river bend are true?
Not answered. From the air, this river is surrounded by crescent-shaped lakes whose curves match the river's own loops. How did they get cut off?
Not answered. This shaded-relief map shows a river valley in Japan (green is low, orange is high). The valley sides rise in a staircase of flat steps. Which step is the oldest?
Not answered. Seen from above, where each canyon opens onto Death Valley's flat floor, a cone of gravel spreads out. Why does the sediment pile up right at the canyon mouth?
Not answered. This fresh step in the ground appeared in a single morning in 1983, running for kilometres along the foot of Idaho's Lost River Range. What made it?
Not answered. Inside this sandstone, thin layers are stacked in sets, and within each set they tilt the same way before being cut off by the set above. What made these tilted layers?
Not answered. Monument Valley's buttes stand alone on a flat desert, each with a flat top and vertical sides. Why does erosion leave them this shape?
Not answered. In this canyon wall, pale pink bands slice straight across the dark, streaky rock. Which formed first?
Not answered. The Giant's Causeway is a pavement of tightly fitting stone columns, mostly six-sided. What made them?
Not answered. Off this chalk headland, a big block has a tunnel through its base, and a lone pillar stands further out. What was the lone pillar before it stood alone?
Not answered. At Siccar Point in Scotland, grey rock layers stand almost vertical, and flatter red sandstone lies across their eroded tops. Why do the two sets meet at an angle?
Not answered. You're walking an unfamiliar landscape. Which of these finds, taken alone, tell you that glaciers once covered it?