Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Breakthroughs in Geological Dating Imminent

22.08.2007
A breakthrough in geological dating can be expected within the next few years, combining existing methods to yield higher accuracy over longer time scales closer to the earth's origin.

This will bring great benefits not just for earth sciences, but also for other fields that rely on accurate dating over geological time. The developments ushering in a new generation of dating methods were discussed at a recent workshop on geochronological timing organised by the European Science Foundation (ESF).

The earth sciences rely on highly accurate timing to unravel past causes and effects, and understand the forces driving many events from ice ages to mass extinctions. Other scientific disciplines, such as evolutionary biology and climate science, in turn depend on accurate timing of geological processes to provide a baseline for their investigations. While significant progress has been made over recent decades, great uncertainties remain that are inhibiting investigations of major past events and formative processes in the earth sciences. In the case of the dinosaur extinction, knowledge of how long the process took would help resolve whether this was caused by a sudden asteroid strike or more gradually following a period of intense volcanic activity for example.

There was intense interest therefore in the ESF workshop, which came six years after the launch of an international project in the same field, called EARTHTIME. The workshop was organised to recognise and boost Europe's leading position in geochronology. It identified the need to improve the three main dating methods currently used, and cross-calibrate between them where possible to yield even greater accuracy, according to Klaudia Kuiper, scientific convenor of the ESF workshop. "The main outcome is that we first aim to work on the improvement of the numerical tools to calibrate the Geological Time Scale," said Kuiper.

Although these methods currently achieve high-sounding accuracies in the order of 0.5 percent to 1 percent, this can equate to an error of several million years over geological time scales. The objective is to reduce the error to better than 0.1 percent, in other words below an error of 100,000 years over a 100 million year time scale.

The three main tools currently used for dating geological events are argon-argon dating, uranium/lead dating, and astronomical methods. Argon-argon dating measures the level of decay from an isotope of potassium to argon, which occurs predictably over time, also taking account of the proportions of the two different isotopes of argon that form during the process.

Uranium/lead dating, one of the oldest and most refined methods, also exploits radioactive decay. However in this case the measurement is based on a correlation between the decay of two isotopes of uranium occurring at different rates, boosting the accuracy as result.

Astronomical timing is quite different, exploiting long term cyclical changes in the earth's orbit and axis. These cause climate changes that can be measured in sediment deposits, providing a dating method that can be correlated with geological events.

The methods each have pros and cons. Astronomical dating is highly accurate, but only over relatively short times on a geological scale, up to at most 250 million years, which is just 5 percent of the earth's age. Radiometric dating can span the earth's whole history back to 4.5 billion years ago, but with less accuracy, and some uncertainties. Currently the astronomical timing is used for events in the last 23 million years, then argon-argon back to 100 million years, and uranium/lead for older events.

Further progress can be made by combining these methods, with astronomical dating already being used to calibrate radiometric timing over the last 10 million years where the former is highly accurate. According to Kuipers, such progress will usher in a new generation of Geological Time Scale (GTS) measurements that will in turn yield fresh insights into critical events during the earth's history. Kuipers believed these could be just as exciting as some of the insights enabled by the previous generation of dating technologies, such as timing of the great ice ages of the Pleistocene between about 2 million and 11,000 years ago. The hope is that the new generation of timing methods will enable older events to be dated accurately.

The workshop Earthtime: The European Contribution - Integration of High-Precision Geochronology and Astronomical Tuning for Calibration of the Cenozoic and Mesozoic Timescales, was held 22-24 April 2007 in Amsterdam, Netherlands, and was convened by Klaudia Kuiper.

Each year, ESF supports approximately 50 Exploratory Workshops across all scientific domains. These small, interactive group sessions are aimed at opening up new directions in research to explore new fields with a potential impact on developments in science.

Thomas Lau | alfa
Further information:
http://www.esf.org
http://www.esf.org/activities/exploratory-workshops.html

More articles from Earth Sciences:

nachricht In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

nachricht Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The fastest light-driven current source

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

Graphene is up to the job

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Nerves control the body’s bacterial community

26.09.2017 | Life Sciences

Four elements make 2-D optical platform

26.09.2017 | Physics and Astronomy

Goodbye, login. Hello, heart scan

26.09.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>