Geomorphological applications of cosmogenic isotope analysis

Abstract

Cosmogenic isotope analysis involves the measurement of cosmogenic nuclides that have accumulated in the upper few metres of the Earth's surface as a result of interactions between cosmic rays and target elements. The concentrations of these cosmogenic nuclides can provide quantitative estimates of the timing and rate of geomorphic processes. In dating applications the concentration of cosmogenic nuclides is interpreted as reflecting the time elapsed since a surface exposure event. However, over most of the Earth's surface for most of the time the landsurface experiences incremental denudation and in these circumstances cosmogenic nuclide concentrations are related to the rate of denudation. Applications of event dating using cosmogenic isotopes include constructional landforms such as volcanic and depositional features, fault displacement, meteorite impacts, rapid mass movement, bedrock surfaces rapidly eroded by fluvial or wave action or exposed by glacial retreat, and the burial of sediment or ice. Strategies for quantifying rates of incremental change include estimates of denudation rates from site-specific samples and from fluvial sediment samples reflecting catchment-wide rates, and measurements of cosmogenic nuclide concentrations in soils and regolith to quantify rates of rock weathering. The past decade has seen a rapid growth in applications of cosmogenic isotope analysis to a wide range of geomorphological problems, and the technique is now playing a major role in dating and quantifying rates of landscape change over timescales of several thousands to several millions of years.

Climate forcing of volcano lateral collapse: evidence from Mount Etna, Sicily

“…Cosmogenic exposure dating, based upon in situ-generated nuclides, is an established tool used for providing quantitative estimates of the timing and rate of a range of geomorphological and geological processes including uplift, resurfacing, burial, faulting, fluvial erosion, marine action, glacial retreat and rapid mass movement (see Cockburn & Summerfield 2004 and references therein for a comprehensive review of geomorphological applications). On volcanoes, the method is increasingly widely used to date lava flows and cinder cones, to build and constrain eruptive chronologies and to shed light on processes and mechanisms such as rift-zone reorganization (e.g.…”

First attempt to combine terrestrial cosmogenic nuclide (10Be) and Schmidt hammer relative-age dating: Strauchon Glacier, Southern Alps, New Zealand

“…[52][53][54][55][56][57]. Until now, regional studies applying terrestrial cosmogenic nuclide dating (TCND) in New Zealand have focused on the glacier chronology of the late-Glacial and the MIS 2/1 transition, respectively, e.g.…”

DATAÇÃO DE SOTERRAMENTO UTILIZANDO OS ISÓTOPOS COSMOGÊNICOS 10Be E 26Al: SÍNTESE METODOLÓGICA E BREVE REVISÃO DE SUAS APLICAÇÕES EM GEOCIÊNCIAS

“…As bases conceituais que constituem o método de datação e algumas de suas aplicações em geociências são aqui descritas com os objetivos de sua difusão, quer para a mera compreensão de suas potencialidades e limitações, quer para motivar novas pesquisas. Embora a utilização de isótopos cosmogênicos para composição de idades de soterramento fique em número de trabalhos publicados atrás de suas aplicações consanguíneas para obtenção de idades de exposição e taxas de erosão , seu uso não se restringe a estudos geológicos e geomorfológicos (Cockburn & Summerfield, 2004;Granger, 2006) e importantes contribuições já podem ser elencadas no âmbito de estudos paleoclimáticos (Balco et al, 2005;Fujioka et al, 2009) e arqueológicos (Partridge et al, 2003;Carbonell et al, 2008;Pappu et al, 2011).…”