--- title: Weathering and erosion — a lesson of Mova's school · trees and pragmatics description: «Weathering and erosion», a lesson of the geography course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Rocks look as if they last for ever, but they are slowly being broken and carried away. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Geography](https://md.mova.elamur.ai/free/en/corpora/school/geography/) / Weathering and erosion # Weathering and erosion Lesson 52 of the geography course of Mova's primary school: 17 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/geography/52-weathering-and-erosion/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/0/) — Rocks look as if they last for ever, but they are slowly being broken and carried away. - [1](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/1/) — Breaking rock where it stands is called weathering; carrying the bits away is called erosion. - [2](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/2/) — Leave a full glass bottle of water in the freezer and it can crack, because water grows by about 9% when it freezes. - [3](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/3/) — The same thing happens in the cracks of rocks on a frosty mountain, night after night. - [4](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/4/) — Rain is slightly acidic and slowly dissolves limestone, and roots and lichens break rock too. - [5](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/5/) — Then rivers, wind, ice and gravity carry the pieces off, and drop them when they slow down. - [6](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/6/) — Given millions of years, this wins against anything: the old mountains of Scotland were once as high as the Alps. - [7](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/7/) — Weathering is the breaking down of rock where it is, by weather, chemicals and living things. - [8](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/8/) — Water in cracks freezes and expands by about 9%, pushing the rock apart bit by bit. - [9](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/9/) — Rainwater is slightly acidic and slowly dissolves rocks such as limestone. - [10](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/10/) — Plant roots grow into cracks and split rocks, and lichens slowly eat into their surface. - [11](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/11/) — Erosion is the carrying away of weathered bits of rock by water, wind, ice or gravity. - [13](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/13/) — Running water is the most powerful agent of erosion on Earth. - [14](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/14/) — In deserts wind blasts sand against rocks and carves strange shapes. - [15](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/15/) — When water or wind slows down, it drops what it carries, a process called deposition. - [16](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/16/) — Even great mountains are slowly worn down, and old mountains like those of Scotland were once as high as the Alps. - [17](https://md.mova.elamur.ai/free/en/corpora/school/geography/52-weathering-and-erosion/17/) — Clearing forests and ploughing can make soil erode many times faster than natural rates. - ← previous: [Gemstones and precious metals](https://md.mova.elamur.ai/free/en/corpora/school/geography/51-gemstones-and-precious-metals/) - next →: [Rivers shaping the land](https://md.mova.elamur.ai/free/en/corpora/school/geography/53-rivers-shaping-the-land/) - ↑ back to [Geography](https://md.mova.elamur.ai/free/en/corpora/school/geography/)