sedimentary geology

Using Milankovitch Cycles to create high-resolution astrochronologies

Lon Abbott November 20, 2020

Image credit: Lon Abbott and Terri Cook

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 the 1970’s. Today, many peopl ...[Read More]

Imaggeo on Mondays: Angular unconformity

André Cortesão November 27, 2017

Angular unconformity. Credit: Daniele Penna (distributed via imaggeo.egu.eu)

It is not unusual to observe abrupt contacts between two, seemingly, contiguous rock layers, such as the one featured in today’s featured image. This type of contact is called an unconformity and marks two very distinct times periods, where the rocks formed under very different conditions. Telheiro Beach is located at the western tip of the Algarve; Portugal’s southernmost mainland region and the ...[Read More]

Imaggeo on Mondays: Sedimentary record of catastrophic floods in the Atacama desert

Manuel Abad and Tatiana Izquierdo May 22, 2017

Sedimentary record of catastrophic floods in the Atacama Desert . Credit: Manu Abad (distributed via imaggeo.egu.eu).

Despite being one of the driest regions on Earth, the Atacama desert is no stranger to catastrophic flood events. Today’s post highlights how the sands, clays and muds left behind once the flood waters recede can hold the key to understanding this natural hazard. During the severe rains that occurred between May 12 and 13, 2017 in the Atacama Region (Northern Chile) the usually dry Copiapó R ...[Read More]

Imaggeo on Mondays: Tones of sand

Laura Roberts-Artal January 2, 2017

Tones of sand Credit: Marc Girons Lopez (distributed via imaggeo.egu.eu

With rocks dating as far back as the Precambrian, mountain building events, violent volcanic eruptions and being covered, on and off, by shallow seas, Death Valley’s geological history is long and complex. Back in the Cenozoic (65 to 30 million years ago), following a turbulent period which saw the eruption of volcanoes (which in time would form the Sierra Nevada of California) and regional uplift ...[Read More]