TS
Tectonics and Structural Geology

Tectonics and Structural Geology

TS Must-Read – Cowie and Scholz (1992) – Physical explanation for the displacement-length relationship of faults using a post-yield fracture mechanics model

February 9, 2022
TS Must-Read – Cowie and Scholz (1992) – Physical explanation for the displacement-length relationship of faults using a post-yield fracture mechanics model

The Must-Read paper by Cowie and Scholz (1992) uses theory from fracture mechanics to explain fault growth and fault displacement profiles. The article initially points out the weaknesses in previous work, specifically highlighting how the abrupt termination of displacement profiles at fault tips would imply an infinite stress in the surrounding material. The paper then introduces a physical model ...[Read More]

TS Must-Read – Fossen and Tikoff (1993): The deformation matrix for simultaneous simple shearing, pure shearing and volume change, and its application to transpression-transtension tectonics

January 31, 2022
TS Must-Read – Fossen and Tikoff (1993): The deformation matrix for simultaneous simple shearing, pure shearing and volume change, and its application to transpression-transtension tectonics

With their milestone article in Journal of Structural Geology (Fossen and Tikoff, 1993)⁠ and its companion article in Tectonophysics (Tikoff and Fossen, 1993)⁠, the authors marked a step forward for the quantification of strain in the deep crust. These articles popularized a new approach, the deformation matrix. An easy solution to quantify strain in finite geological systems is to find continuous ...[Read More]

TS Must-read – Buck (1991): Modes of continental lithospheric extension

January 24, 2022
TS Must-read – Buck (1991): Modes of continental lithospheric extension

Buck (1991) aims at solving the  intense ‘70s and ‘80s tectonic debate concerning the way extension is accommodated in continental regions (see our previous blog posts here and here). His article explores the physical conditions that can lead to the three end-member modes of lithospheric extension in continents: core complex mode, wide rift mode and narrow rift mode. The three extensional modes th ...[Read More]

The power and pitfalls of compliments

January 19, 2022
The power and pitfalls of compliments
Credit: cottonbro. Distributed via Pexels.

Part of a good workplace vibe is good contact between colleagues, as well as good contact between you and your supervisor – or between you and your supervisee. A potentially complex ingredient is the power of compliments. Compliments, per definition, are meant well. However, they can backfire enormously, when they are not received in the spirit in which they are meant. Additionally, part of being ...[Read More]

Geomythology. Hawaii islands and the journey of Pele

January 12, 2022
Geomythology. Hawaii islands and the journey of Pele
A painting of the Goddess Pele, PELEHONUAMEA (Photo credit: Herb Kane)

Hotspot Theory How would you explain a series of volcanoes in the middle of the ocean such as the Hawaii, the Midway or the Canary islands? J.T. Wilson, in 1963, suggested they are formed by relatively small, long-lasting, and exceptionally hot regions of magma located beneath the Earth crust, so-called “hotspots” (Wilson, 1963). Firstly, he applied this idea to the Hawaiian Islands, but the conce ...[Read More]

TS Must-Read – Molnar & England (1990): Late Cenozoic uplift of mountain ranges and global climate change: chicken or egg?

January 7, 2022
TS Must-Read – Molnar & England (1990): Late Cenozoic uplift of mountain ranges and global climate change: chicken or egg?

The idea that the Pleistocene glaciation was caused by a late Cenozoic rise of mountain ranges had been developed since the mid 19th century. Although this original idea did not hold, new arguments for a relation between a late Cenozoic uplift of mountains and global cooling were presented from the 1970s onward. These arguments focused on how increased surface elevations would affect the albedo, t ...[Read More]

Extensional tectonics at oceanic transform faults: a new perspective on plate tectonics

November 24, 2021
Extensional tectonics at oceanic transform faults: a new perspective on plate tectonics
Viscosity structure of the oceanic transform fault revealed by geodynamic simulations. Credit: Grevemeyer et al., 2021.

Yu Ren is a PhD candidate at GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany. He uses three primary tools to study marine tectonics: geomorphology, seismology, and numerical modelling. His PhD project is on the structural and tectonic characterization of oceanic transform faults.   Oceanic transform faults (OTFs), usually considered as first-order tectonic segmentation of mid-ocean r ...[Read More]

Geomythology. Japan’s Earthquakes – The work of Namazu?

October 22, 2021
Geomythology. Japan’s Earthquakes – The work of Namazu?
Namazu the giant catfish (image credit: pinktentacle.com).

Welcome to this first post on the EGU TS blog’s newest series on Geomythology. Plate tectonic theory has existed for just over half a century but the Earth beneath us has always been active. In this series we explore historical and mythological explanations to tectonic phenomena we now understand, such as earthquakes, volcanoes, mountains, and others.   Japanese Earthquakes Japan is one of th ...[Read More]

Features from the Field: Sheath Folds

and October 4, 2021
Features from the Field: Sheath Folds
Spectacular sheath folds in Cap de Creus (Spain), produced by deformation in a Variscan shear zone. Photo by Dr. Melanie Finch.

Shear zones are areas of intense deformation that localize the movement of one block of the crust with respect to another. In previous posts, we have seen that shear zones contain some very deformed rocks called mylonites, lineations that tell us the direction of movement, and useful kinematic indicators, such as S-C fabrics, that allow geologists to understand which way the rocks moved. However, ...[Read More]

GeoMod 2021 in Utrecht: connecting on-site and online

and September 27, 2021
GeoMod 2021 in Utrecht: connecting on-site and online
Group picture of the on-site participants of GeoMod 2021 in front of the venue Landgoed Zonheuvel. Credit: the GeoMod organisers.

After a year and a half in which all of us have had to become accustomed to meeting our colleagues and collaborators only in digital space, it was finally time for an in-person conference again. From 19-23 of September 2021, the ninth edition of GeoMod took place in a conference center outside sunny Utrecht (the Netherlands). The organizing committee, led by Ernst Willingshofer, Ylona van Dinther, ...[Read More]