TS
Tectonics and Structural Geology

Tectonics and Structural Geology

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]

TS Must-Read – England and Molnar (1990) Surface uplift, uplift of rocks, and exhumation of rocks

September 20, 2021
TS Must-Read – England and Molnar (1990) Surface uplift, uplift of rocks, and exhumation of rocks

With this paper, England and Molnar (1990) shed light on the recurrent confusion in the uses of terms ‘uplift’ and ‘exhumation’. The main focus is to clarify the difference between surface uplift, uplift of rocks, and exhumation by explaining the differences and the relations between these processes (Fig. 1). The manuscript also illustrates how other processes, such as changes in climate, can be m ...[Read More]

TS Must-Read – Dahlen (1990) Critical Taper Model Of Fold-and-thrust Belts And Accretionary Wedges

September 13, 2021
TS Must-Read – Dahlen (1990) Critical Taper Model Of Fold-and-thrust Belts And Accretionary Wedges

Dahlen 1990‘s paper presents a synthesis of all theoretical work on accretionary wedges that had begun more than a decade earlier, with the fold and thrust belts research of Elliott (1976), Chapple (1978), and model by Davis et al., (1983). Dahlen expanded previous views with a more sophisticated treatment of pore-fluid pressure using volume-averaged Stokes-equations for both solids and flui ...[Read More]

TS Must-Read – Lister and Davis (1989) The origin of metamorphic core complexes and detachment faults formed during Tertiary continental extension in the northern Colorado River region, USA

September 6, 2021
TS Must-Read – Lister and Davis (1989) The origin of metamorphic core complexes and detachment faults formed during Tertiary continental extension in the northern Colorado River region, USA

Lister and Davis (1989) is a seminal article for core complexes and detachment faults, cited well over a thousand times. The authors describe geometry and kinematics of core complexes, cropping out in the USA, which result from lithosphere extension. The paper carefully describes the main detachment fault separating lower plate from upper extending plate and discusses the role of granitoid intrusi ...[Read More]

Tektonika Diamond Open Access Journal

September 1, 2021
Tektonika Diamond Open Access Journal

In a nutshell Tektonika is a community-led Diamond Open Access journal (DOAJ) for tectonics and structural geology launching in early 2022. The journal will publish high quality peer-reviewed research that is free for authors and readers, offering an alternative to long-standing publishing models that conceal knowledge dissemination behind paid subscriptions. Community involvement is at Tektonika’ ...[Read More]

Mind your Head: Five tips on mindful productivity at work

July 15, 2021
Photo from the page of a book, with an out of focus green background. The text on the page reads: 'Productivity, making the hours in the day go further. The main thing is to keep the main thing the main thing - Steven Covey'.
Productivity. 'The main thing is to keep the main thing the main thing' - Steven Covey. Credit: Krisna Iv. Distributed via Unsplash

This Mind your Head blog post is a follow-up from Maria Scheel’s talk during the latest short course around mental health at #vEGU21. Before guiding a wonderful mindfulness pop-up event, Maria talked about how she struggled with unrealistic expectations, feeling insufficient and alone as a PhD student during the last lockdown. She turned this around by radically redefining her motivation, goals an ...[Read More]

TS Must-Read – Sylvester (1988) Strike-slip faults

June 30, 2021
TS Must-Read – Sylvester (1988) Strike-slip faults

Strike-slip faults by Arthur Sylvester (1988) is a must-read paper for anyone, and more so for those who want to understand the mechanisms of strike-slip faulting. Although it mostly refers to the San Andreas fault, the most studied strike-slip fault at the time (and possibly to date), the contribution is a comprehensive review of the state of the art about strike-slip faults in general. Sylvester ...[Read More]

TS Must-read – Dewey (1988) Extensional collapse of orogens

June 25, 2021
TS Must-read – Dewey (1988) Extensional collapse of orogens

After building orogens with Dewey and Bird (1970) and extending them during building with Platt (1986), Dewey (1988) explores the lifetime of orogens in their last breath: their extensional collapse. Simple considerations on how to form a normally-thick continental crust (30-40 km) from a thickened continental domain (50-60 km) indicate that erosion of the topography alone is far from being suffic ...[Read More]

Features from the Field: Stretching Lineations

and June 21, 2021
Features from the Field: Stretching Lineations
Measuring stretching lineations is the base to understanding the kinematics of large structures, like this protomylonitic metasandstone from a shear zone in the Glengarry Basin (Western Australia). Rocks slid past each other either up or down along this lineation. Which way? We need to look at a section oriented parallel to this lineation. Photo by Rolinator via wikimedia.org.

Deep beneath our feet, deformation of rocks at high temperature produces impressive structures such as shear zones, that localize the movement of two volumes of rock with respect to one another. Shear zones are strongly deformed bands with strongly foliated structures (i.e., with rocks that look like a pile of leaves) and kinematic indicators, such as S-C fabrics, that tell us geologists which way ...[Read More]