GeoLog

Stratigraphy, Sedimentology and Palaeontology

Imaggeo On Monday: The tree that gave birth to a forest

Imaggeo On Monday: The tree that gave birth to a forest

This 10 centimetre giant is a pioneer of marine conquest. All summer, glassworts (Salicornia europaea) will be rhythmically swept by the tide, gradually trapping seaborne sediment on the shores of Aberlady Bay in Scotland. The resulting elevation of the mudflat marks the start of a race of growth against waves, currents and sea level rise, …[Read More]

Winners of the EGU Best Blog Posts of 2020 Competition

Winners of the EGU Best Blog Posts of 2020 Competition

2020 was a brilliant year for our blogging network here at EGU. Across the EGU’s official blog, GeoLog, as well as the network and division blogs there were so many interesting, educational and just downright entertaining posts this year it was hard to get the blog editors to choose their favourites! Nevertheless at the beginning of January, to …[Read More]

Imaggeo On Monday: Great Sand Dunes Sunset

Imaggeo On Monday: Great Sand Dunes Sunset

On a late afternoon in Colorado’s Great Sand Dunes, the sun came out from behind the clouds for a brief moment before it went behind the horizon, illuminating the stoss side of an eroding dune. Sand originated from lacustrine deposits in the San Luis Valley; the Sangre de Cristo mountains, which can be seen in …[Read More]

Using Milankovitch Cycles to create high-resolution astrochronologies

Using Milankovitch Cycles to create high-resolution astrochronologies

This year marks the 100th anniversary of Milutin Milankovitch’s first paper about Earth’s climate. Milankovitch argued that the amount of solar radiation Earth receives, and hence its climate, varies cyclically as its orbit changes due to gravitational tugs from the other planets. His climate theory fell into disrepute during the 1950’s but was rehabilitated in …[Read More]

Imaggeo On Monday: Erosion and suspension

Imaggeo On Monday: Erosion and suspension

This image shows bottomset beds from the Kerinitis Gilbert-type delta. The Pleistocene delta uplifts along the active southern margin of the Corinth rift in Greece. A bottomset bed is one where layers of sedimentary material lying along the bottom of a body of water near the point of entry of a stream are subsequently covered …[Read More]

Imaggeo On Monday: Micro and Nano composition

Imaggeo On Monday: Micro and Nano composition

This image shows benthic foraminifera species of Favulina hexagona (Williamson, 1848) together with nanofossils enclosed inside the shell hexagons. This modern foraminifera species was found in the sediment core retrieved from the western slope of the Rio Grande Rise (western South Atlantic).   Description by Liubov Kuleshova, after the description on imaggeo.egu.eu.   Imaggeo is the …[Read More]

Imaggeo On Monday: Patterns in the landform

Imaggeo On Monday: Patterns in the landform

The badlands at the Zabriskie Point (Death Valley, California, USA) rest upon a mudstone foundation. In the prehistoric lakes of Death Valley, fine grained sediments were deposited to form soft rocks. The clay minerals in the mudstone are shaped like tiny plates, which helps create the layers. The combination of the almost impermeable mudstone and …[Read More]

Imaggeo on Mondays: Red triassic sandstone

Imaggeo on Mondays: Red triassic sandstone

As child growing up on the south coast of Devon in the UK, I never really realised that our beaches were unusual. A glorious, glowing orange-red colour, the cliffs that you can see in this photograph by Sarah Weick produced similarly red sand beaches and warm ochre soils. The bright colour is the result of …[Read More]

Imaggeo On Mondays: Psychedelic Foraminifera

Imaggeo On Mondays: Psychedelic Foraminifera

This is a transmitted light microscope image of a thin section – a 50-micron thick sliver of rock. This sample was collected from Jebel Hafit, a mountain which straddles the United Arab Emirates and Oman border. Jebel Hafit is approximately 900 m high and is made up of Eocene to Miocene age carbonate rocks which …[Read More]