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Chemical weathering influences many aspects of the Earth system, including biogeochemical cycling, climate, and ecosystem function. Physical erosion influences chemical weathering rates by setting the supply of fresh minerals to the critical zone. Vegetation also influences chemical weathering rates, both by physical processes that expose mineral surfaces and via production of acids that contribute to mineral dissolution. However, the role of vegetation in setting surface process rates in different landscapes is unclear. Here we use 10Be and geochemical mass balance to quantify soil production, physical erosion, and chemical weathering rates in a landscape where a migrating drainage divide separates catchments with an order-of magnitude contrast in erosion rates and where vegetation spans temperate rainforest, tussock grassland, and unvegetated alpine ecosystems in the western Southern Alps of New Zealand. Soil production, physical erosion, and chemical weathering rates are significantly higher on the rapidly eroding versus the slowly eroding side of the drainage divide. However, chemical weathering intensity does not vary significantly across the divide or as a function of vegetation type. Soil production rates are correlated with ridgetop curvature, and ridgetops are more convex on the rapidly eroding side of the divide, where soil mineral residence times are lowest. Hence our findings suggest fluvially-driven erosion rates control soil production and soil chemical weathering rates by influencing the relationship between hillslope topography and mineral residence times. In the western Southern Alps, soil production and chemical weathering rates are more strongly mediated by physical rock breakdown driven by landscape response to tectonics, than by vegetation.
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This content will become publicly available on May 4, 2026
Hands on Rock Weathering!
In the Earth sciences, weathering encompasses all the physical, chemical, and biological processes that break down rocks in place. Rock weathering takes decades to millions of years and impacts climate and soil formation. In our two-part lesson, students develop an understanding of weathering and how it can influence climate and human society through hands-on experiments. Lesson 1 focuses on how rock weathering impacts climate; students investigate how changing the temperature and acidity of weathering agents affects the rate of rock weathering. Lesson 2 focuses on how weathering impacts human society; students perform experiments simulating weathering of mudstone and granite via shaking rocks in containers; students observe that these rocks weather at different rates and produce different-sized particles because of physical weathering. Students relate their experimental observations to the process of soil formation and then apply this knowledge to societally relevant topics. These lessons bring rock weathering into the classroom with crosscutting concepts and connect the Earth, climate, and human society together in an interactive way.
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- Award ID(s):
- 2141519
- PAR ID:
- 10591834
- Publisher / Repository:
- National Science Teaching Association
- Date Published:
- Journal Name:
- Science Scope
- Volume:
- 48
- Issue:
- 3
- ISSN:
- 0887-2376
- Page Range / eLocation ID:
- 36 to 42
- Subject(s) / Keyword(s):
- Earth Science NGSS Weathering Physical Weathering Chemical Weathering 5E
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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