Catchment-wide weathering and erosion rates of mafic, ultramafic, and granitic rock from cosmogenic meteoric 10Be/9Be ratios

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F18%3A00000271" target="_blank" >RIV/00025798:_____/18:00000271 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0016703717307147?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0016703717307147?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.gca.2017.11.005" target="_blank" >10.1016/j.gca.2017.11.005</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Catchment-wide weathering and erosion rates of mafic, ultramafic, and granitic rock from cosmogenic meteoric 10Be/9Be ratios

Popis výsledku v původním jazyce

We present catchment-wide rates of weathering, erosion,and denudation measured with cosmogenic nuclides. We use the ratio of the meteoric cosmogenic nuclide 10Be, deposited from the atmosphere onto the weathering zone, to stable 9Be, a trace metal released by silicate weathering.We tested this approach in stream sediment and water from three upland forested catchments in the Czech Republic. The catchments are underlain by felsic (granite), mafic (amphibolite) and ultramafic (serpentinite) rocks. Due to acid deposition, the waters in the granite catchment exhibit acidic pH, whereas waters in the mafic catchments exhibit neutral to alkaline pH values due to their acid buffering capability. The atmospheric depositional 10Be flux is estimated to be balancedwith the streams’ dissolved and particulate meteoric 10Be export flux to within a factor of two. Derived Earth surface metrics comprise (1) Denudation rates calculated from the 10Be/9Be ratio of the ‘‘reactive” Be range between 110 and 185 t km 2 y 1 (40 and 70 mm ky 1). These rates are similar to denudation rateswe obtained from in situ-cosmogenic 10Be in quartz minerals present in the bedrock or in quartz veins in the felsic and the maficcatchment. (2) The degree of weathering, calculated from the fraction of 9Be released from primary minerals as a new proxy, isabout 40–50percent in the mafic catchments, and 10percent in the granitic catchment. Lastly, (3) erosion rates were calculated from 10Be concentrationsin river sediment and corrected for sorting and dissolved loss. These amount to 50percent of denudation rates from 10Be/9Bein the mafic and ultramafic catchments, the remainder being mass loss in the dissolved form by weathering. In contrast, erosioncomprises most of the mass loss in the granitic catchment. This method allows quantifying rates of erosion and weathering in mafic rock over the time scale of weathering that are, unlike in situ cosmogenic 10Be, independent from the presence of quartz.

Název v anglickém jazyce

Catchment-wide weathering and erosion rates of mafic, ultramafic, and granitic rock from cosmogenic meteoric 10Be/9Be ratios

Popis výsledku anglicky

We present catchment-wide rates of weathering, erosion,and denudation measured with cosmogenic nuclides. We use the ratio of the meteoric cosmogenic nuclide 10Be, deposited from the atmosphere onto the weathering zone, to stable 9Be, a trace metal released by silicate weathering.We tested this approach in stream sediment and water from three upland forested catchments in the Czech Republic. The catchments are underlain by felsic (granite), mafic (amphibolite) and ultramafic (serpentinite) rocks. Due to acid deposition, the waters in the granite catchment exhibit acidic pH, whereas waters in the mafic catchments exhibit neutral to alkaline pH values due to their acid buffering capability. The atmospheric depositional 10Be flux is estimated to be balancedwith the streams’ dissolved and particulate meteoric 10Be export flux to within a factor of two. Derived Earth surface metrics comprise (1) Denudation rates calculated from the 10Be/9Be ratio of the ‘‘reactive” Be range between 110 and 185 t km 2 y 1 (40 and 70 mm ky 1). These rates are similar to denudation rateswe obtained from in situ-cosmogenic 10Be in quartz minerals present in the bedrock or in quartz veins in the felsic and the maficcatchment. (2) The degree of weathering, calculated from the fraction of 9Be released from primary minerals as a new proxy, isabout 40–50percent in the mafic catchments, and 10percent in the granitic catchment. Lastly, (3) erosion rates were calculated from 10Be concentrationsin river sediment and corrected for sorting and dissolved loss. These amount to 50percent of denudation rates from 10Be/9Bein the mafic and ultramafic catchments, the remainder being mass loss in the dissolved form by weathering. In contrast, erosioncomprises most of the mass loss in the granitic catchment. This method allows quantifying rates of erosion and weathering in mafic rock over the time scale of weathering that are, unlike in situ cosmogenic 10Be, independent from the presence of quartz.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10511 - Environmental sciences (social aspects to be 5.7)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Geochimica et Cosmochimica Acta

ISSN

0016-7037

e-ISSN

—

Svazek periodika

222

Číslo periodika v rámci svazku

February

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

24

Strana od-do

618-641

Kód UT WoS článku

000424972200035

EID výsledku v databázi Scopus

2-s2.0-85036579637