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Provenance analysis using Raman spectroscopy of carbonaceous material: A case study in the Southern Alps of New Zealand
- Source :
- Journal of Geophysical Research: Earth Surface, Journal of Geophysical Research: Earth Surface, 2015, 120 (10), pp.2056-2079. ⟨10.1002/2015JF003541⟩, Journal of Geophysical Research: Earth Surface, American Geophysical Union/Wiley, 2015, 120 (10), pp.2056-2079. ⟨10.1002/2015JF003541⟩
- Publication Year :
- 2015
- Publisher :
- American Geophysical Union (AGU), 2015.
-
Abstract
- International audience; Detrital provenance analyses in orogenic settings, in which sediments are collected at the outlet of a catchment, have become an important tool to estimate how erosion varies in space and time. Here we present how Raman Spectroscopy on Carbonaceous Material (RSCM) can be used for provenance analysis. RSCM provides an estimate of the peak temperature (RSCM‐T) experienced during metamorphism. We show that we can infer modern erosion patterns in a catchment by combining new measurements on detrital sands with previously acquired bedrock data. We focus on the Whataroa catchment in the Southern Alps of New Zealand and exploit the metamorphic gradient that runs parallel to the main drainage direction. To account for potential sampling biases, we also quantify abrasion properties using flume experiments and measure the total organic carbon content in the bedrock that produced the collected sands. Finally, we integrate these parameters into a mass‐conservative model. Our results first demonstrate that RSCM‐T can be used for detrital studies. Second, we find that spatial variations in tracer concentration and erosion have a first‐order control on the RSCM‐T distributions, even though our flume experiments reveal that weak lithologies produce substantially more fine particles than do more durable lithologies. This result implies that sand specimens are good proxies for mapping spatial variations in erosion when the bedrock concentration of the target mineral is quantified. The modeling suggests that highest present‐day erosion rates (in Whataroa catchment) are not situated at the range front but around 10 km into the mountain belt.
- Subjects :
- geography
Provenance
geography.geographical_feature_category
Lithology
Bedrock
Metamorphic rock
Geochemistry
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences
Metamorphism
15. Life on land
Flume
Geophysics
Denudation
[SDU]Sciences of the Universe [physics]
13. Climate action
Erosion
Cartography
Earth-Surface Processes
Subjects
Details
- ISSN :
- 21699011 and 21699003
- Volume :
- 120
- Database :
- OpenAIRE
- Journal :
- Journal of Geophysical Research: Earth Surface
- Accession number :
- edsair.doi.dedup.....b36ec4d725dea108b87d35d113f8c57f