Climate of the Past

Detrital zircons: how the age of a resistant mineral can help to reconstruct the climate of the past

May 20, 2021

Zircon grains of an igneous rock under the incident light microscope (Image Credit: Martin Lindner).

Name of proxy detrital zircon geochronology Type of record provenance proxy Paleoenvironment any sedimentary environment in a geologically diverse and diagnostic area Period of time investigated any Period of the geological timescale of the Earth, during which sedimentary deposits were formed How does it work? Igneous rocks form through assemblages of minerals crystallising from melt. While ...[Read More]

How humans are influencing climate change and its significance in defining a new geological epoch: the Anthropocene

April 26, 2021

Modern atmospheric CO2 increases, driven mainly by human activities, have led to a marked increase in global mean temperatures and rates of sea-level rise in part through melting of ice-sheets. (© C N Waters).

The Anthropocene Working Group (AWG) is the body tasked to propose a formal definition for the Anthropocene as a geological time unit. Join us at the EGU2021 General Assembly on Wednesday 28th April at 14:15-15:00 CEST for a series of presentations on the Anthropocene in session SSP2.6. The Anthropocene concept Geologists cope with the enormity of 4.5 billion years of Earth history by divid ...[Read More]

Presenting a new European loess map

March 31, 2021

Loess is a silt-sized, aeolian sediment that was produced in large quantities in past geological eras of mid-latitude Europe and Asia, among others (Fig. 1). It is used in Quaternary science to infer about past climatic and environmental conditions. Generally, layers of loess formed during cold and dry periods, while soils formed within/on top the loess during warmer and wetter periods. These soil ...[Read More]

Reconstructing ice sheets and topography of the past

March 24, 2021

Figure 1: Paleotopography of the Arctic at the Last Glacial Maximum, at 20,000 years before present (yr BP). Ice sheets covered much of northern Europe and North America. The lower sea level caused a land bridge to form between Siberia and Alaska. Black lines are the modern coastline.

One of the most profound consequences of past climate changes are the geologically rapid (<100,000 year) changes in global topography. For thousands of years, large ice sheets, similar to what currently exists in Greenland and Antarctica, waxed and waned on North America and Europe. Only 20,000 years ago, if you were sitting in the middle of Canada or Sweden, you would be under thousands ...[Read More]