Regolith and Landscape Evolution

Regolith—the veneer of weathered rock and sediment that overlies bedrock—forms the interface in which soils develop and landscapes are sculpted. Its genesis begins with the physical disaggregation of rock by processes such as fracturing, frost action and thermal stress, and with the chemical breakdown of minerals under the influence of water, carbonic and organic acids. Biological agents, from lichens and plant roots to burrowing fauna, accelerate both mechanical disruption and chemical alteration. Over time, the accumulation of parent‐material debris and in situ alteration products generates a mantle of unconsolidated material whose thickness, composition and structure depend on climate, lithology, topography and age. Subsequent landscape evolution arises through the coupling of regolith production with mass wasting, fluvial incision, glacial activity and aeolian transport. Tectonic uplift and sea‐level change modulate erosive gradients, while climatic fluctuations influence regolith production rates and transport capacity. The result is a dynamic feedback loop: denudation exposes fresh rock to weathering, while regolith stabilises slopes, regulates runoff and sustains ecosystems. Advances in cosmogenic‐nuclide dating, remote sensing and numerical modelling are now yielding quantitative reconstructions of regolith production and landscape adjustment over timescales from centuries to millions of years, illuminating how surface processes and deep Earth dynamics jointly shape terrain and carbon fluxes.

Research from Nature Portfolio

Recent findings demonstrate that oxidation of ancient rock‐bound organic carbon during regolith weathering can rival or exceed the long‐recognised CO₂ sink from silicate mineral breakdown. By coupling dissolved rhenium measurements with spatial modelling across global catchments, hotspots of organic‐carbon‐derived CO₂ release have been identified in high‐uplift regions such as the Himalayas, Andes and Rockies, overturning the assumption of a net carbon sink during deep weathering. In parallel, global compilations of river chemistry reveal that Alkalinity generation from rock–water reactions responds nonlinearly to warming. Low‐emission warming scenarios may diminish mid‐latitude carbonate alkalinity fluxes, whereas high‐emission pathways could enhance weathering‐derived alkalinity by up to 68 %, with immediate feedbacks on oceanic CO₂ uptake. Lastly, catchment‐scale studies confirm that feldspar dissolution intensity scales monotonically with mean annual temperature between 0 and 30 °C. This strong negative feedback mechanism supports robust climate–weathering coupling, validating chemical‐kinetics predictions and refining models of regolith evolution under variable climates.

Regolith and Landscape Evolution publication trend

The graph below shows the total number of articles in regolith and landscape evolution across all publications each year (not limited to Nature Index journals).

Technical terms

Regolith: The blanket of loose, heterogeneous material covering solid rock, comprising weathered bedrock, soils and transported sediments.

Silicate weathering: Chemical breakdown of silicate minerals by carbonic acid, releasing dissolved cations and bicarbonate and consuming atmospheric CO₂.

Carbonate weathering: Dissolution of carbonate minerals by acidic waters, contributing alkalinity without net CO₂ removal over short timescales.

Organic‐carbon oxidation: Mineralisation of rock‐bound ancient organic matter during weathering, releasing CO₂ to the atmosphere.

Alkalinity generation: The production of base‐forming ions (predominantly bicarbonate) in water through mineral dissolution, buffering acidity and influencing marine carbon uptake.

Cosmogenic‐nuclide dating: Measurement of rare isotopes produced by cosmic rays in surface materials, used to determine exposure ages and regolith production rates.

Chemical‐kinetics feedback: The temperature‐dependent rate control of weathering reactions that stabilises Earth’s climate over geological timescales.

References

1. Rock organic carbon oxidation CO2 release offsets silicate weathering sink. Nature (2023).
2. Alkalinity responses to climate warming destabilise the Earth’s thermostat. Nature Communications (2023).
3. A global temperature control of silicate weathering intensity. Nature Communications (2022).
4. High rates of rock organic carbon oxidation sustained as Andean sediment transits the Amazon foreland-floodplain. Proceedings of the National Academy of Sciences of the United States of America (2023).
5. Temperature dependence of basalt weathering. Earth and Planetary Science Letters (2016).
6. Silicate versus carbonate weathering in Iceland: New insights from Ca isotopes. Earth and Planetary Science Letters (2015).