Structural Geology

Free papers on Chile and Haiti provided by The Geological Society of London

2010-03-06T22:30:00.003Z

The Geological Society of London has made freely available two sets of papers at their website, related with the earthquakes ocurred in Haiti and Chile in the past weeks and months. Together with these papers, you can also download a series of publications related with the bicentenary of Charles Darwin:

http://www.geolsoc.org.uk/gsl/publications/lyellcollection/page7188.html

These papers will be available for free until the end of March (Darwin and Haiti topics) and until the end of April, in the case of Chile.

¡Arriba Chile!

2010-03-01T07:23:00.000Z

More than 700 casualties have been counted so far due to the earthquake of last Saturday. Now is the moment to contribute with any help you can give: Remember that any amount of money is useful. "A beach is made of grains of sand".

If you want to help contributing online, use the Google Crisis Response site dedicated to this earthquake:

http://www.google.com/relief/chileearthquake/

You can also visit your local/national Red Cross organisation:

http://www.icrc.org/

Please, help and forward this message to your contacts and friends.

http://www.boston.com/bigpicture/2010/02/earthquake_in_chile.html
AP Photo/Roberto Candia

Link of the month: Ron Schott's blog

2010-02-27T19:47:00.007Z

I have decided to create a series of monthly posts/awards (...) in this blog where I will comment on blogs, websites and Twitters that I find both interesting and useful. I actually think I can find once a month a really good site. If I don't, or I just forget about it... well... Just let me know candidates!

So, here it goes the winner of February'10:

Ron Schott's website

Do you want to keep informed about what is going on in geology?
Do you want several updates a day?
Would you like to find interesting links about our favourite science?

If you have answer YES to at least one of the previous three questions, then you are interested in the blog and TWITTER of Ron Schott. Ron won last week (in an impressive couple of hours period) the "Where on (Google) Earth #187" that Dan suggested here, in StructuralGeology.org (Dan was sooo dissapointed... but his next image will be hard to find...)

If you don't know Ron, he is Assistant Professor of Geology at Fort Hays State University. Well, you better visit his personal website and you can find out more about him:

http://ron.outcrop.org/

His blog is great, by the way.

http://ron.outcrop.org/blog/

And, if you use twitter, you will just love his feeds:

http://twitter.com/RonsGeoPicks

By the way, Ron is an active user of the game "What on Google Earth". The "Schott rule", as you can imagine, is named after him. No wonder why... grrrr. And his last WOGE, number 188, is still waiting for your answer!!

Earthquake in Chile, 8.8 Mw

2010-02-27T09:06:00.004Z

Chile has been shaken this night by a 8,8 Mw earthquake, as reported by www.usgs.gov (http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/us2010tfan/#details). There is not much information so far. Bachelet, president of Chile, has reported 6 casualties already. USGS informs of potential several structural damages in central and southern Chile.

The epicenter has been located at 35 km offshore Concepción, and Santiago de Chile, at more than 300 km, has been left in a blackout. In Valparaiso, the quake has been felt, but apparently no major damages have been reported.

Chile has been always, and will be, one of the most seismologically active areas in the world. In 1960 a 9.5 Mw earthquake devastated the region of Valdivia, killing 1655 people.

http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/us2010tfan/#scitech

Where on (Google) Earth? No. 187.

2010-02-18T20:53:00.005Z

Having won the last round of Where on (Google) Earth it is my turn to suggest a location for others to find. The image below has an eye altitude of roughly 23km, and that’s all the help you lovely people get I’m afraid.

As with previous episodes, what we need to know is the Longitude and Latitude of the image, a general locality name and an explanation of the geological feature(s) shown. Also as with previous episodes, the first person with the correct answer gets to host the next edition.

Good Luck!

Podcasts in Geology

2010-02-16T15:22:00.000Z

I like podcasts. They are a good companion at work, in the car or doing sports. But being a geologist, there is not much choice about what we can listen if we want something relating with our field of expertise.

Some years ago I discovered the “Corecast” of the USGS, but to be honest, it is quite light and … disappointing. The program is well done, is good, but only if you don’t know much of geology. Its target audience is the general public. Obviously that is fine because that is the task of the USGS: to educate general public about our work.

From time to time, in programs like “Radio 4 Choice”, of the BBC, they include content related with geology and this is great. But that doesn’t happen very often.

So, what do we have? Well, thanks to The Geological Society we have a few episodes of a geology podcast. Few means three so far! But their quality is quite good.

Sarah Day, the Earth Scientist Communicator of GSL, conducts the program where she interviews the speaker of the popular Shell Lectures, which are carried out on a monthly basis (montly…ish).

http://www.geolsoc.org.uk/podcasts

So far, the episodes are (description take from the GSL website):

Episode 3: The Present is the Key to the Past

Listen to the podcast - 'The Present is the Key to the Past' (.mp3 11894 Kb)

Charles Lyell’s Principles of Geology was published between 1830-1833, and introduced the famous maxim, ‘the present is the key to the past’. Bruce Levell, Chief Geologist at Shell, explains the relevance of this principle to the oil and gas industry today, and why it might be hindering, rather than helping the search for energy resources.

One of the biggest consequences of our use of fossil fuels is its effect on sea level, which is continuing to rise. Is sea level rise natural, or are humans playing a part? And how can geologists help protect our coastlines? Lynne Frostick, Professor of Geography at the University of Hull and Geological Society President, explains what rising tides mean for our future, and how an understanding of our geological past can help us prepare for the future.

Episode 2: Spider Webs and Seamounts

Listen to the podcast - 'Spider Webs and Seamounts' (.mp3 10927 Kb)

Sarah visits Professor Martin Brasier at the University of Oxford, who made the news last month when he published reports of the world’s oldest fossilized spider webs. Preserved in amber dating back to the early Cretaceous, the webs are 135 – 140 million years old, and capture a crucial period in spider evolution.

November’s Shell London Lecturer, Professor Tony Watts, explains the importance of his research into sea mounts – mountains under the sea. Potential causes of geological hazards, they are also focal points of biological diversity. Earth Scientists remain divided as to their cause, with some critical of the increasingly prevalent ‘hotspot’ theory.

Episode 1: Climate on Earth and Mars

Listen to the podcast - 'Climate on Earth and Mars' (.mp3 10655 Kb)

In our very first podcast, Dr Matt Balme explains how he uses his knowledge of Earth to understand the Martian climate. And Dr Rosalind Rickaby tells of a tiny marine organism that’s facing a big climate challenge.

The ocean’s ability to absorb co2 is vital to reducing the impact of carbon emissions on climate. Approximately one quarter of Co2 emissions caused by human activity are absorbed by the ocean, which is becoming increasingly acidic as a result. By carrying out photosynthesis, marine phytoplankton such as the coccolithophore are an important part of this process, but can struggle to build their shells and skeletal structure as waters become more acidic.

Whilst the ‘paradigm view’ is that the ocean acidification will make it harder for the coccolithophore to build its calcium carbonate shell, recent research suggests they are in fact responding by calcifying even more. Understanding how these tiny marine organisms will respond to rising levels of atmospheric co2 is crucial to predicting how climate will evolve in the future

Besides, the GeolSoc.org.uk website also includes the links to the podcast of NERC Earth science, the Planet Earth series: http://www.geolsoc.org.uk/gsl/site/GSL/lang/en/page6262.html

A whole list of Planet Earth podcasts is available at: http://planetearth.nerc.ac.uk/multimedia/index.aspx

Enjoy the podcasting!

Microtectonics course in Mainz

2010-02-10T15:10:00.000Z

If you are interested in microtectonics, then you know Passchier and Trouw and their classic textbook on that topic. Now you have the opportunity to enrol in a course in Mainz (where a large collection of microstructures is hosted) conducted by C. Passchier and D. Koehn.

Topics covered in the course are deformation mechanisms, veins and strain fringes, mylonitic fabrics and porphyroblasts. Participants are encouraged to bring their own thin-sections for discussions, in addition to the large collection available in the University of Mainz

Course fees are 280 euro, and will take place from Monday 29^th of March to Thursday 1^st of April of 2010. For further information, contact Sabine Fohrmann [fohrmann (at) uni-mainz (dot) de]. Appclations should be submitted before 1^st of March of 2010.

(Information adapted from an email sent by Daniel Koehn to the Geo-tectonics mailing list)

Institut für Geowissenschaften Tektonophysik: http://www.tekphys.geo.uni-mainz.de/

Haiti quake relief

2010-01-15T09:20:00.000Z

Posted in the Geo-tectonics list by Shan Sathar:

Dear colleagues,

As we all know, a devastating earthquake struck Haiti on the 12^th of January. Thousands are dead and many are seriously injured. Please do whatever you can do today to help thousands of people in desperate need.

I am posting the link for the British Red Cross to make things easy..

https://www.redcross.org.uk/emergencysite/campaign.aspx?id=88917

If you are not a fan of Red Cross, a simple Google search will list many other charities worldwide.

Many of us might have already donated for this cause.

My apologies if you are not interested.

Best regards,

Shan

Please, help and contribute.

Structural geology techniques (I)

2010-01-05T19:20:00.004Z

There is a few websites about structural geology that I visit once a week or more often. I would like to start a series of articles for briefly presenting them.

The first of this sites is "Structural Geology Techniques", in charge of Steven Dutch, professor of the University of Wisconsin. (http://www.uwgb.edu/dutchs/structge/labman.htm).

In the website of Dutch, a neat and organised page, you can find many examples and diagrams explaining a good range of geometric problems related with structural geology. There are from basic level problems (e.g., calculatina fold axis given the limbs of the structure) to not so fundamental problems (e.g., how to construct a down-plunge cross section).

As Dutch explaines in his homepage (http://www.uwgb.edu/dutchs/index.html), he does not like fancy graphics, and his website is an example of efficient diagrams, which isn't always the same as beautiful. However, they are clear and functional.

Visit the place if you didn't know it yet. You will be surprise with how many things you have forgotten of structural geology and geometry :-).

TSG meeting programme 2010

2010-01-04T11:16:00.001Z

Carl Stevenson has released the programme for the TSG meeting in Birmingham this week. If you are attending, we’ll meet up there. If you aren’t… well, that is what you are missing!

Tuesday 5^th January

18 30 onwards Wine reception in the Lapworth Museum

Registration desk open in Lapworth Museum

Poster hanging

Wednesday 6^th January

08 00 – 09 15 Registration desk open in Lapworth Museum (until lunch)

Arrival tea, coffee and refreshments

09 15 Welcome – Professor Tim Reston

09 30 Technical programme day 1 – talks and posters

Session 1: Reducing uncertainty and risk
09 30 – 09 45	The Freyja project: uncertainty analysis of geological interpretations	*Euan Macrae, Clare Bond, Zoe Shipton
09 45 – 10 00	The influence of Structural and Stratigraphic uncertainties on fault seal analysis and reservoir compartmentalisation of deep water fan systems	Wood, A., Paton, D, Cook, A.
10 00 – 10 15	‘De-risking the prospect’ Incorporating structural uncertainty in petroleum systems modelling: A case study from the Judd Basin, U.K.	S. M. Clarke, H. Johnson & J. Rodriguez
10 15 – 10 30	Test-driving the Virtual Seismic Atlas – finding analogues and authoring content	Rob Butler and Taija Torvela
10 30 – 10 45	The number of km-scale impact craters yet to be found on Earth is c. 800	Stewart, S. A.
10 45 – 11 00	Discussion period

Chair: Nicola De Paulo

11 00 – 11 30 Break with tea, coffee and refreshments

Session 2: Neotectonics and active basins
11 30 – 11 45	Afterslip on the L’Aquila earthquake (M6.3) surface rupture captured in 4D using a Terrestrial laser scanner (TLS)	*Wilkinson M., McCaffrey K.J.W., Roberts G., Cowie P.A., Phillips R.J. & Michetti, A.
11 45 – 12 00	High resolution monitoring of creep of the Mam Tor landslip, Derbyshire	Ernest Rutter and Sam Green
12 00 – 12 15	Fault Lubrication and Earthquake Propagation in Thermally Unstable Rocks	N. De Paola,T. Hirose, T. Mitchell, G. Di Toro, C. Viti and T. Shimamoto
12 15 – 12 30	Late Cenozoic reactivation of polydeformed basement in the Chinese Beishan region north of Tibet	Cunningham Dickson and Jin Zhang
12 30 – 12 45	Normal-Fault Architecture and Deformation Processes in Poorly Consolidated Sediments within an Actively Extending Basin, Gulf of Corinth, Greece	*Sian Loveless, Victor Bense and Jenni Turner
12 45 – 13 00	Discussion period

Chair: Steve Jones

13 00 – 14 30 Lunch and posters

Session 3: Palaeostress and brittle tectonics
14 30 – 14 45	Combination of paleostress and paleomagnetic data: case studies from the Pannonian Basin	Fodor, L.I., Márton, E
14 45 – 15 00	Seismites reveal long-term earthquake behavior of the Dead Sea Fault	Shmuel Marco
15 00 – 15 15	The stress state of the brittle upper crust during early Variscan tectonic inversion and its influence on high-pressure compartments	Van Noten, K., Muchez, P. & Sintubin, M.
15 15 – 15 30	Characterising brittle reactivation in basement: an example from the Lewisian Gneiss Complex, NW Scotland	*J. C. Martin, R. E. Holdsworth, K. W. J. McCaffrey, A. Conway& M. Krabbendam
15 30 – 15 45	Palaeostress reconstruction in the Lufilian Arc and the Kundulungu foreland (Katanga, Democratic Republic of Congo): in search of evidence of incipient active rifting	Kipata, M.L., Delvaux, D., Sebagenzi, M.N., Cailteux, J.-J.* & Sintubin, M.
15 45 – 16 00	Discussion period

Chair: Steve Rippington

16 00 – 16 30 Break with tea, coffee and refreshments

Session 4: Posters

16 30 – 17 30

Thursday 7^th January

08 00 – 09 15 Registration desk open in Lapworth Museum (until lunch)

Arrival tea, coffee and refreshments

09 15 Technical programme day 2 – talks and posters

Session 5: Mapping and remote sensing
09 15 – 09 30	The origin and evolution of the Cretaceous northwest Sirt Basin, Libya, based on remote sensing interpretation and well data analysis	*Khalifa M. Abdunaser, Ken J.W. McCaffrey
09 30 – 09 45	InSAR mapping of an active Iranian salt extrusion	Ian Alsop, Pedram Aftabi, Mahasa Roustaie, Christopher J. Talbot
09 45 – 10 00	Geology of the Ordovician Tyrone Igneous Complex, Northern Ireland	*Cooper, M. R.,* Crowley, Q. G., Hollis, S. P., Noble, S. R., Roberts, S., Chew, D., Earls, G, & Herrington, R..
10 00 – 10 15	Polyphase deformation in the Lake Hazen region, at 82^o north on Ellesmere Island: implications for the tectonic evolution of the High Arctic	Stephen Rippington, Robert Scott, Helen Smyth, Simon Kelly
10 15 – 10 30	A ruck, a ramp and imbricate stack, but no culmination – the Dundonnell sector of the Caledonian Moine Thrust Belt, Northwest Highlands of Scotland.	Leslie, A.G., Goodenough, K.M.& Krabbendam, M.
10 30 – 10 45	Discussion period

Chair: Sam Spendlove

10 45 – 11 15 Break with tea, coffee and refreshments

Session 6: Margins
11 15 – 11 30	Evidence for Quaternary convergence between the North American and South American plates, east of the Lesser Antilles	Patriat M., Pichot T., Westbrook G.K., Umber M., Deville E., Bénard F., Roest W., Loubrieu B.and the ANTIPLAC cruise party
11 30 – 11 45	Thermal weakening localizes intraplate deformation along the southern Australian continental margin	Simon P. Holford, Richard R. Hillis, Martin Hand, Mike Sandiford
11 45 – 12 00	Structural Controls on the Evolution of the Southeastern Brazilian Continental Margin	*Ashby, D.E., McCaffrey,K.J.W., Holdsworth, R.E., Almeida, J.C.H., Oliver, J.
13 00 – 12 15	Detachment faults during continental breakup and beyond	Tim Reston
12 15 – 12 30	Cenozoic history of Britain and Ireland: Implications of modern dynamic support for the Paleocene underplating idea, and quantification of plate boundary drivers of Cenozoic structural inversion	Stephen M Jones
12 30 – 12 45	Discussion period

Chair: Ken McDermott

12 45 – 14 15 Lunch and posters

Session 7: Novel approaches and applications I
14 15 – 14 30	Calculated petrophysical properties of rocks from CPO analysis by EBSD in a section across the Moho in Cabo Ortegal (N Spain)	Sergio Llana-Fúnez, Dennis Brown,Ramón Carbonell, Joaquina Álvarez-Marrón, David Martí,Matthew Salisbury
14 30 – 14 45	Linking sill morphology to emplacement mechanisms	*Nick Schofield, Carl Stevenson, Tim Reston
14 45 – 15 00	Cone sheet emplacement in sub-volcanic systems: a case study from Ardnamurchan, NW Scotland	*Craig Magee, Carl Stevenson and Brian O’Driscoll²
15 00 – 15 15	Contrasting magnetic susceptibility fabrics on opposite fold limbs: cause and implications	Debacker, T.N.., Seynaeve, N., Sintubin, M. & Robion, P.
15 15 – 15 30	Characterising the role of basin margin structure on finite strain patterns across a ‘cleavage’ front from the Variscides of southern Ireland	*Parker, C., Meere, P., Stevenson, C.,Mulchrone, K.
15 30 – 15 45	Discussion period

Chair: Carl Stevenson

15 45 – 16 15 Break with tea, coffee and refreshments

Session 8: Posters

16 15 – 17 30

17 30 – 18 00 AGM Chaired by Professor John Wheeler

18 00 – 18 30 Wine and posters

19 00 TSG conference dinner, Noble Room, 2^nd floor, Staff House

Friday 8^th January

08 00 – 09 30 Registration desk open in Lapworth Museum (until lunch)

Arrival tea, coffee and refreshments

09 15 Technical programme day 3 – talks and posters

Session 9: Novel approaches and applications II
09 15 – 09 30	Fault stepping and drainage evolution in the Corinth basin rift, Greece	Turner, J.A., Leeder, M.R. and Finch E.
09 30 – 09 45	A geological investigation into fault weakening mechanisms revealed in deep drill core from the San Andreas Fault Observatory at Depth (SAFOD)	Bob Holdsworth, Esther van Digglen, Hans De Bresser, Steve Smith
09 45 – 10 00	K-white mica thermo-barometry, conodont colour alteration index and vitrinite reflection: methods to distinguish nappes in a complex diagenetic to low-grade metamorphic nappe pile	Kövér, S. & Fodor, L. I.
10 00 – 10 15	3D Pulsating flow and possible strain pattern in general shear zones	David Iacopini, Rodolfo Carosi, Paris Xypolias
10 15 – 10 30	Fault and fracture patterns in low porosity chalk	David Sagi, Nicola De Paola, K.J.W. McCaffrey & R.E. Holdsworth
10 30 – 10 45	Discussion period

Chair: Tim Reston

10 45 – 11 15 Break with tea, coffee and refreshments

Session 10: Modelling and strain analysis
11 15 – 11 30	Spatial analysis, structural geology and mineral exploration	Julian Vearncombe and Susan Vearncombe
11 30 – 11 45	Reconciliation of contrasting theories for joint spacing in layered sequences	Schöpfer, M.P.J., Arslan, A., Walsh, J.J., & Childs, C.
11 45 – 12 00	3D numerical modelling of the evolution of fault zone internal structure	Schöpfer, M., Childs, C. & Walsh, J.J.
12 00 – 12 15	Structural modelling of possible contaminant pathways below nuclear installations	*Richard Haslam, Stuart Clarke, Peter Styles & Clive Auton
12 15 – 12 30	Strain analysis from point fabric patterns: A new objective method	Lisle, Richard J
12 30 – 12 45	Discussion period

Chair: John Wheeler

12 45 – 14 15 Lunch and posters

Session 11: Seismic analysis, interpretation and integration
14 15 – 14 30	Length-throw relationships in an evaporite-detached extensional fault array: The Bremstein Fault Complex, offshore mid-Norway	Wilson, P.., Elliott, G. M^., Gawthorpe, R. L.., Jackson, C. A-L. & Hansen, S.
14 30 – 14 45	Geological and structural evolution of the Rosaria Mare intraplatform Basin and its tectonic implications (Adria/Apulia plate boundary, SE Italy)	Felici, F., Turco, E., Pierantoni, P. P., & Milia A.
14 45 – 15 00	Linking fault geometry with wall-rock deformation: 3-D seismic investigation deepwater Niger Delta	*Jibrin, B., Turner, J.P., Westbrook G.K., Bretan, P.
15 00 – 15 15	Different interpretations of thrust trajectories and strain distribution in a fold-and-thrust belt	Torvela, T., Butler, R. W. H. & Bond, C.
15 15 – 15 30	Discussion period

Chair: Nick Schofield

15 30 – 16 00 close

16 00 – 16 30 Departing tea, coffee and refreshments

Saturday 9^th January

Post meeting workshop: Move2010 for teaching and research

In collaboration with Midland Valley Exploration Ltd.

Midland Valley Exploration’s Academic Initiative’s began three years ago and now, between the Field Mapping Initiative and the Academic Software Initiative, nearly 200 academic geosciences departments worldwide are using Move.

This workshop aims to introduce Move2010 to academic users and to highlight a few potential uses in teaching and research. We will go through some hands-on exercises from the Move2010 tutorials and discuss some current uses in academic teaching and research including field mapping.

Contact Carl Stevenson: c.t.stevenson@bham.ac.uk

Midland Valley will be represented by Dr Ruth Wightman

Workshop itinerary:

09.00 - 09.20 Introduction to Move and the rationale behind the ASI

09.20 - 11.00 Move2010 hands-on exercise - 2DMove

11.00 - 11.30 Refreshment break

11.30 - 12.30 Move2010 hands-on exercise - 3DMove

12.30 - 13.30 Lunch (Lapworth Museum)

13.30 - 14.00 Introduction to structural analysis - 4DMove

14.00 - 15.00 Examples of using Move in teaching and research

15.00 - 16.00 Examples of using Move in field mapping

16.00 - 16.30 Refreshment break

16.30 - 17.30 Participant Examples / Q&A

Cost - £7.50 (on arrival)

Places are limited to 30

Posters

The Origin and Nature of Cenozoic Faulting in North East Ireland

*Anderson, H., Walsh, J.J. & Cooper, M.R

The impact of strain, bedding plane friction and overburden pressure on joint spacing

Arslan, A., Schöpfer, M. P. J., Walsh, J. J., Childs, C.

Influence of deep transverse fault zones on the prospectivity, geometry and spatial arrangement on some hydrocarbon-related structures, Zagros fold and thrust belt, northern Iraq

Banks, G.J.

Analysis of structural lineaments and their relationship with paleotension fields responsable for the formation of cenozoic brittle structures, Espirito Santo State (SE Brazil)

*Bricalli, L.L., Cianfarra, P., Salvini,F. & Mello,C.L.

3D modelling of ore deposits geometry in the Variscan basement of SE Sardinia (Italy).

Cristina Buttau, Antonio Funedda, Andrea Dini,Stefano Naitza.

Incorporating structural uncertainty into petroleum systems modelling to reduce exploration risk

S. M. Clarke, M. Littler, H. Johnson, M. Quinn, J. Rodriguez, S. Stoker & P. Ware

The Fluid Flow Evolution During the Seismic Cycle Within Overpressured Fault Zones in Evaporitic Sequences

N. De Paola, C. Collettini, D.R. Faulkner

The Cantabrian Thrust Belt: basin history of the North Gondwana passive margin - rifting, glaciation? more rifting then collision.

*Helen Doherty, Tim Ferriday, Michael Kelly, Michael Montenari, Steven Rogers & Graham Williams

Structural evolution and fluid flow in the Wealden and Hampshire basins, southern England, U.K.

*Salah Eldin M. Elgarmadi, Graham Potts, and Richard Worden

A geometrical relationship between imbricate thrust structures and their generated topography of mass-transport deposits (MTD’s); implications for the accommodation of sediment laden gravity-driven flows.

*Fairweather, L. I. D. & Kneller, B. C.

A layer cake model as a stratigraphic classification of mass-transport deposits (MTDs); from palaeo-flow directions and macro-scale structures, Paganzo basins, Argentina.

*Fairweather, L. I. D., Kneller, B.C., Dykstra, M. & Milana, J.P.

Characterising fracture systems within upfaulted basement highs in the Hebridean Islands: an onshore analogue for the Clair Field

*Franklin,B. S. G.,2^nd Holdsworth R. E., McCaffrey K.J. W., Krabbendam M., Conway A. & Jones R

Modelling continental margin extension using combined rigid/deformable plate tectonic reconstructions

Munoz, A.A., Glover, C.T., Harris, J.P., Goodrich, M., Hudson, L. & Ady, B.

Laccolithic emplacement of the Northern Arran Granite, Scotland: a new model based on Anisotropy of Magnetic Susceptibility

*Grove, C and Stevenson, C. T

Consequences of Anisotropic Poroelasticity due to Fluid-Saturated Damage

Healy, D.

Structural analysis of fold and thrust structures from deepwater west Niger Delta.

Iacopini D., Grimaud J-L., Butler R.W.H.

Application of dip-related seismic curvature attributes to map surface fault geometry: Examples from deepwater Niger Delta

*Jibrin, B., Turner, J.P., Westbrook G.K., Huck, A., & Hemstra, N.

Magma plumbing in the Judd Basin, North Atlantic, from opacity rendered 3D seismic data

*Adam Linnell, Carl Stevenson, Nick Schofield

Fault-related fracturing in carbonate damage zones: field analysis and modeling from Central Apennines (Italy)

*Mannino I., Salvini F., Cianfarra P.

How to Form a Rifted Margin – Fault, Fault and Fault Some More

*Ken McDermott , Tim Reston & Jonathon Turner

Examining the low-angle normal fault system of north-west Kea based on a new geological map

Müller, M.., Grasemann, B. & Iglseder, C.

Interactions between strike-slip faults, Westward Ho!: domino vs conjugate

*Casey W. Nixon, David J. Sanderson, Jonathan M. Bull and Stephen Dee

Quantification of Curvature and Fracture Distributions in Outcrop-Scale Periclines

Pearce, M.A., Jones, R.R., Smith, S.A.F. & McCaffrey, K.J.W.

The Sardic Phase.

Puddu C.

The interpretation of major fault zone properties using three integrative approaches

Taylor, R.L., Rutter, E. H. & Faulkner, D.R.

The effects of crystallographic anisotropy on fracture development and acoustic emission in quartz

Timms, N.E., Healy, D., Reyes Montes, J.M., Collins, D., Prior, D.J., & Young, R.P.

The Virtual Seismic Atlas – utilising web-based material in Earth science research.

Torvela, T. & Butler, R. W. H.

Visualising and understanding structural geology from the field to the lab: using Move as an aid in teaching and research.

Wightman, R.H., Bond, C.E., Scherrenberg, A., Similox-Tohon, D.

(*student presentation)

Terrane Map of Europe

2010-01-03T11:52:00.004Z

For the first post of the year, I would like to include a link to an interesting map containing the major terranes of Europe, as it has been compiled by Martin S. Oczlon.

http://www.geobib.uni-hd.de/terranemap/index.html

Martin has used more than 2600 references for this outstanding work, and you will appreciate that when you will see the detailed mapping labour.

From the website of the terrane map of Europe:

WHAT CAN THIS MAP TELL YOU?
The aim of this map is to provide a view on the growth of Europe throughout its billions of years of evolution, applying a self-explanatory colour scheme. It is designed to allow also readers without much background on the geology of Europe to access the basic concepts on the assembly and accretionary history of the continent. At the same time, it provides in-depth information and key arguments for the various assignments.

Every part of the European crust with the same provenance, accreted at the same time or in one diachronous event, is given the same colour. Following Late Palaeozoic accretion of Gondwana-derived terranes, almost all of the crust that currently makes Europe was already assembled by ca. 280 million years. Therefore, terrane-description focuses mainly on their Palaeozoic and older pre-/syn-accretionary evolution. The younger sutures and ophiolite belts of southern Europe are the result of Meso-Cainozoic opening and closure of small oceanic basins within the previously accreted crust. These sutures are shown with a line-framework that outlines the boundaries of the major Alpine tectonic units.
For a better understanding of terrane-provenance, palaeogeographic reconstructions of Earth at 543, 444, 375, 299, and 195 million years are shown on the right-hand side of the map. Colours of the various palaeo-continents and terranes are the same as on the Terrane Map, allowing easy recognition of the past position of continental fragments that now form part of Europe.

And, before I forget it...

Happy 2010!!

Interview with Dr. Randy Marrett

2009-11-22T19:01:00.005Z

If you regularly read this blog (I guess that is something boring, because I don't regularly upgrade it...), you have noticed that I have changed, once again, the layout of the page. Well, this time is quite a definitive change, I like it now, finally. It is clear and neat. Please, allow me a few days to make all work properly!.

I have thought that it would be interesting to put in the right side bar some videos from time to time related with structural geology. I will start this series of videos with an interview with Dr. Randy Merrett, associate professor in the Department of Geological Sciences at the University of Texas.

As the introduction of the video states:

Dr. Marrett's research concentrates on deformation processes in the upper continental crust where folds, faults, and opening-mode fractures are the most important products. This work is applicable to a wide range of human concerns such as natural hazards (e.g., earthquakes, volcanoes) and the flow of fluids through rock (e.g., hydrocarbons, water, contaminants). Some common themes that relate his disparate interests are quantitative field observations and analysis, especially using techniques that address spatial and size scaling of structures. Dr. Marrett currently has on-going projects that address active faulting and geyser eruption patterns in the Central Andes of Argentina and Chile, detachment folding and curved orogenic belt development in the Sierra Madre Oriental of Mexico, and opening-mode fracturing in numerous areas.

Quite basic, but always useful for forwarding it to people who want to know more about what we do.

Enjoy it!

Geo-Logic Systems, bought by Halliburton

2009-11-21T20:57:00.002Z

Halliburton has recently acquired Geo-Logic Systems, the producers of Lithotect, the balancing and restoring software. It has been announced in several E∓P websites, and also in the corporative websites of both companies:

On Tuesday, October 27, Halliburton announced its acquisition of Geo-Logic Systems, LLC. “The industry faces increasingly difficult exploration and drilling scenarios,” said Paul Koeller,Hal liburton’s vice president of Software and Asset Solutions. “The integration of Geo-LogicSystems offers ge oscientists advanced modeling solutions to address the technical challenges of exploring in complex petroleum regimes such as overthrust belts and the pre-, syn- (including sub-salt) and post-ri ft portions of extensional basins. In these complicated, poorly imaged plays risk reduction is of paramount importance.”

That is probably a big step for Lithotect, a great piece of software. Now, being part of such a huge company like Halliburton, surely the rivarly with MVE's Move (formerly know by its different components: 2DMove and 3DMove) will tight up, and this will be clearly in benefit of the customers.

Halliburton owns already the giant of seismic software, Landmark, and this acquisition points out to the direction that E&P is taking in the last years: Structurally complex scenarios, fold and thrust belts, deep water belts, sub-salt environments, etc, which need serious expertise on structural geology and risk reduction. Well, let's revisit our notes and books because there is a lot of hard work waiting for us...

Recording planes with strike or dip? The problem of the right-hand rules

2009-11-02T08:00:00.001Z

When we want to record the orientation in space of a geological surface (e.g. a stratigraphic body), we have two different ways of doing it:

a) Dip direction and dip angle: Dip direction is just the direction toward which the plane is inclined. Dip angle is the angle of inclination of the plane. In the example included in this article, we would write it down as 090/45; the plane is inclined 45º towards the east (090º). Easy.

b) Strike and dip angle: Strike is the direction of the imaginary line which would represent the intersection between the plane and a horizontal surface. But here it comes the problem: the strike, as we know, can be represented by two different conjugated angles, and we need to follow some kind of convention; typically, the strike is expressed as the acute angle between the intersection line and the north direction. In our example, it would be 0ºN. But how which convention we take for indicating towards which direction is dipping the bed? For that we use the right hand rule.

(click on the image to enlarge it)

There are two different right hand rules... Did you know that? Oh, that is not very convenient...

American right hand rule: Looking to the strike direction, the bed dips to the right. In our example, that would fit with 000/45. So, looking to the north, the bed dips to the right, to 090 (east).

British right hand rule: The thumb of the right hand indicates the dip direction, and the heal points to the strike direction. So in our example, we would record the orientation as 180/45. That is: Strike towards 180 (perfect south bearing), and dip of 45º towards 090.

Usually, if the person who took the measurements knew that other people MAY HAVE different criteria expressing the same results, the data can be recorded as

180/45E

Which would mean, no doubt, a strike of 180 and a dip direction towards the east, with a magnitude (dip angle) of 45. If you use strike, please remember to write always as a companion of the dip angle the quadrant where the dip direction would be. For example, 045/56SE. In this case we are talking of 120/56 (dip direction/dip angle). 045/56NW; now we would be talking of 315/56 (dip direction/dip angle).

But what happens with measures like:

45W/34

What does that mean? I have seen it. Does it mean 45º from north towards west, so 315? or does it mean strike of 045 and an a dip angle of 34 towards W? Is that? Uh, I don't think so.

The truth is that, besides right-hand rules, many geologists use other conventions, sometimes personal ones, and maybe in a wrong way. Perhaps using only NW and NE quadrants for the strike. Perhaps not.

It is clear that using strike values when representing the orientation of a bed we are introducing a risk factor if we don't state clearly which right hand rule we are using. Of course, for some people in some situation the usage of strike/dip angle may be very useful:

When we speak of general trends in a big area (e.g. an orogen, in order to show that a trend is parallel or not to the structure).
In a mine, in order to visualise quickly if the strike direction is the same as certain mineralisation or lineaments.
In engineering geology, for the same reason, in order to know if the bedding/joints have the same orientation than a well, a tunnel, etc.

I would suggest another right hand rule... If you use strike for describing the attitude of a plane, your right hand should be cut!.

But perhaps that is very extreme... so far.

Structural Geology @ Facebook

2009-10-02T19:31:00.003+01:00

I am totally absorted with my renewal work in another website (about Poland, if you are interested, although it is in Spanish), and I am planing to write up some articles for this blog about basic structural geology. Perhaps I should say "not so basic stuff but something we should have always in mind".

And something I have realised now is that I totally forgot to post here the creation, some months ago, of a "Structural geology and tectonics" group in Facebook. Raik and I are the administrators of the group.

If you are an user of this social network (you are in another planet, or perhaps you are still resisting to join it... now is the moment to do it!), you are invited, encouraged, to join us there. I wonder how I can do a more direct link between this blog and the group, but first things first: writing about geology!

DRT 2009 conference in Liverpool

2009-07-17T09:50:00.000+01:00

As it has been communicated in the Geo-Tectonics mailing list, the “Deformation, rheology and tectonics” conference in Liverpool will take place this September, between the 7^th and the 9^th.

In their own words, “In 2009, DRT is a joint venture between the universities of Liverpool and Manchester, and is to be held in the contemporary cityscape of the rejuvenated Liverpool Docklands.

As many of you are aware, 2008 was shrouded by the untimely loss of Dr. Martin Casey. This meeting is dedicated to Martin, and events and sessions will be organised in his memory.”

The conference includes two fieldtrips: A pre-conference trip to the Mam Tor Landslide (Derbysire, England) on the 6^th of September 2009 and a post-conference trip to the Isle of Anglesey (north Wales) from the 9^th to the 11^th of September of 2009. (http://www.liverpool.ac.uk/PDMearth_sciences/dept/drt2009/fieldtrips.html)

The site is www.liverpool.ac.uk/earth/drt2009, and you can see the programme in here: www.liverpool.ac.uk/earth/drt2009/programme.

M6.3 earthquake in Taiwan

2009-07-13T20:11:00.004+01:00

If you have been listening to the news in the last hours, you probably know already that a M6.3 earthquake has struck offshore Taiwan. As usual, the best information comes from the USGS.

The event happend at 18.05 UTC, and we don't yet have a focal mechanism solution for it. Anyway, in the attached figure you can have an idea of what is going on in there.

Taiwan is located in the boundary between the Phillipine Sea and the Eurasian plates. There is an approximated convergence rate of 80 mm/yr to the SE. What is really especial about this island is the presence of two subduction zones: One, where the South China Sea subducts beneath Eurasia, and another one, where Eurasia subducts beneath the South China Sea, forming both zones approximately a right angle.

You can see a great introduction (including the previous explanation) to the geology of Taiwan in the dedicated website of the California Institute of Technology:

http://www.tectonics.caltech.edu/taiwan/regional.htm

Sources:

- http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/us2009jabu.php
- http://www.tectonics.caltech.edu/taiwan/regional.htm

Comments available again!

2009-07-12T21:55:00.003+01:00

In the last days I have been trying to fix the problem we had with the comments, which now they work again!

The problem was fairly simple: although we have our own domain, the blog is enginereed by www.blogger.com, and it seems they don't fit as nicely as we expected.

Probably, if you have been visiting this website in the few days, you have been we have been trying some fancy designs... I promise the final one will have a geological look, just give me a couple of days!!

So... post your comments, they are more than welcome!

Download ASTER GDEM

2009-07-01T14:04:00.000+01:00

On Monday 29^th of June of 2009, NASA and Japan’s Ministry of Economy, Trade and Industry, released the Global Digital Elevation Model (GDEM) created from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data. That has involved the processing of more than a million ASTER scenes, in order to cover Earth’s land surface between 83 degrees North and 83 degrees South.

The result is a 30-m resolution digital elevation model available from the following URL: ASTER GDEM . In this website the GDEM can be downloaded selecting by tiles, by polygon, by shapefile and of course, by coordinates.

So far the standard DEM was the SRTM data, obtained during a flight of the Space Shuttle in 2000. Its resolution is approximately 90 m (30 for USA), and has proven to be a very valuable resource in structural geology, hydrocarbon exploration, geohazard analyses, etc. GDEM will predictably become a new standard, with a commercial resolution and global availability.

Important links:

http://www.gdem.aster.ersdac.or.jp/index.jsp

http://www.nasa.gov/topics/earth/features/20090629.html

Problems with the comments

2009-06-23T08:59:00.000+01:00

I apologise for the error in the web that doesn’t let you to leave comments in the articles. I will try to fix that in the next days. Apparently it is just a small bug in the template I am using, nothing else! I’ll keep you updated about that.

Thanks for reading this humble place :)

Jorge

Move and LithoTect for free

2009-06-22T10:19:00.000+01:00

Dr. Alan Gibbs, director of Midland Valley Exploration, has announced in the Geo-Tectonics list that their software Move2009 (which includes 2DMove, 3DMove and 4DMove) is now available for free to universities for teaching and research.

He recommends contacting MVE through their website or using this email: help@mve.com

Move2009, as described by MVE, is “fundamentally different from other geo-modelling and model building software as it incorporates geological time into the modelling process. Other modelling tools simply create good-looking models from the present day interpretations, ours turn the modelling process into a rigorous analytical activity involving geological time, with interoperability support of modelling environments and the ability to easily transfer files between all Move components. Using our products geoscientists can continually challenge and test their assumptions and thereby gain a far deeper understanding into the structural geology they are modelling”.

Is that the only geo-modelling software available for building and balancing cross sections and general structural modelling? No. In the same list, Dr. Robert Ratliff, development director of Geo-Logic Systems, reminds that their software LithoTect is also available for free for universities (as it has been for many years). This software combines the power of geological modelling with a very attractive conditions in terms of available platforms and licensing conditions.

Well, the choice is in your hands. Perhaps you want to make a comment comparing both suites?

Earthquakes in Google Earth

2009-06-19T19:03:00.008+01:00

A good habit I have acquired during the last months is to take a look to the recent seismic activity of a region before starting to work in there, in order to get a quick idea of what is going on. This habit can be more illustrating that it initially seems.

USGS provides a KMZ file with a very friendly and attractive interface for Google Earth. It loads the major earthquakes in our planet for the last 7 days, classified by time (Last hour, Last day, Last week), and by magnitude (from 1 to 8). If you click on each individual earthquake, you will open a box with its basic information and the url link for opening in your browser the complete information about it.

You can load this file in your Google Earth from the dedicated USGS website for seismology:

http://earthquake.usgs.gov/

It is on the left, "Google Earth KML". Anyway, the direct link to the file is:

http://earthquake.usgs.gov/eqcenter/catalogs/eqs7day-age.kmz

The interface also loads plate boundaries and convergence rates, measured in mm/year. I haven't found the source of the rates, but let's accept that if the data comes from USGS, should be fine. The plate boundaries included in the KMZ file are:

- Subduction zone.
- Oceanic transform fault.
- Oceanic spreading rift.
- Oceanic convergent boundary.
- Continental transform fault.
- Continental rift boundary.
- Continental convergent boundary.

Of course, don't expect a very precise location for the plate boundaries! It is just an indication of the global tectonics of each area, in order to put the earthquakes in a correct geodynamic context.

Personally I find this KML file very useful, not only for the very up-to-the-date information given, but also for the boundaries, the rates... Useful thing when we have to prepare a simple figure in Corel or Freehand for a report.

Again, the links:

http://earthquake.usgs.gov/
http://earthquake.usgs.gov/eqcenter/catalogs/eqs7day-age.kmz

There are more KML's and KMZ's providing similar information, but that will be for another day.

Enjoy!

Graphical templates for Structural Geology

2009-05-27T09:28:00.001+01:00

We all need from time to time to print a stereographic projection net, a Kalsbeek counting net or a rose diagram. Courtesy of Holcombe, Coughlin & Associates (http://www.holcombecoughlin.com) today we bring you a document (pdf format) with several graphical templates for structural geology (and mineralogy too!):

http://www.holcombecoughlin.com/downloads/HCA_templates_for_structural_geologists.pdf

The content of the document includes the following diagrams:

Stereographic projection nets (several sizes, 20 cm, 15 cm, 10 cm and 5 cm):

- Lambert equal area projection (Schmidt net).

- Polar equal area projection.

- Equal angle projection (Wulff net).

Rose diagram net

Kaalsbeek counting net

A simple but very useful document, as we can have in a single pdf all the basic diagrams we can need in the field. Now print it and start to plot data!

Obituary of Prof. Maurice Mattauer

2009-04-15T16:46:00.001+01:00

I have read today in the Geo-Tectonics distribution list the obituary of Prof. Maurice Mattauer, who passed away on the 8^th of April of 2009. I copy it here, and please accept my apologises for the late posting, but I just read that this morning:

Homage to Professor Maurice Mattauer *

** Holding the latest scientific advice that he wanted to give on the earthquake of Aquila in Italy, to appear in the "Gazette de Montpellier", 9 April of this year, Professor Maurice Mattauer died accidentally at his home April 8 2009.

Born in 1928 in Sentheim (Alsace), he makes his higher education in Besançon, he joined the CNRS in 1951, to conduct a thesis in Ouarsenis Algérien, then it will work for the service of the Card. He returned to France, appointed Professor at the University of Montpellier in 1959 where he became the leader of the team of Structural Geology. It will remain at his post as leader of Geology montpelliéraine until 1996, then Professor Emeritus of the University of Montpellier 2 until 2003. It will continue until the last few days, to come to the meeting of young researchers and former students to give its advice and criticism.

Motivated and dynamic teacher, he brought his passion for geology, rocks and fossils, to generations of students, who followed his footsteps and then raised his voice and his methods in other universities.

His books and numerous publications in the direction of specialists in the discipline "Tectonics" or the general public to share his love of the mountains and rocks all have a huge national and international success.

The mountains were his passion, and has published numerous works in "écumant " first outcrops around Montpellier, discovering in himself, with his legendary flair, fossils largest in the region such as dinosaur eggs from the Upper Cretaceous. It will launch here the foundations of the modern tectonic mapping is special for students awarded by Montpellier. It shows the importance of observing the microstructures in the understanding of mountain ranges.

After the Pyrenees, the Alps and the Massif Central where he will propose the first coherent tectonic models, he embarked on the visit of the mountains of South America and Asia, in cooperation with the Andean countries and China. He will also visit the Mountains of North America, but also the Mediterranean for which he published in 2008, the last scientific article, full of new ideas and always served by the quality of its graphics innate.

All persons who have approached Maurice Mattauer and all students have recognized him quickly an outstanding scientist and passionate living for his Science.

It forms part of this, these few men, leading others by communicating their passion to advance or to excel. It was, ultimately, a chance to have met!

During his career Maurice Mattauer has received numerous awards and honors, especially the prices of Geological Societies of France and Belgium and the Academy of Sciences.

He was also promoted to the rank of Officer of the Legion of Honor.

Pr. Maurice Brunel, Montpellier

* His funeral have been held in Grammont-Montpellier on Tuesday 14 April *

Mw 6.3 Earthquake in Italy

2009-04-06T14:26:00.000+01:00

We got up this morning with the terrible news from Italy, where last night an earthquake affected significantly the location of L’Aquila in the Central Apennines region resulting in more than 90 killed (so far, at 14.00 GMT, and surely the number will increase in the next hours).

The Apennines are an accretionary wedge formed as consequence of the subduction of the Adriatic microplates under Italy from east to west, whilst from the south to the north the convergence of Africa against Europe builds the Alpine orogen and opening the Tyrrhenian sea to the west of the Italic peninsula.

I won’t extend much in this entry; you can read better and more updated information in the news:

Powerful Italian quake kills many (BBC website)

Magnitude 6.3 – Central Italy (USGS website)

"Eine verlässliche Vorhersage war es auf keinen Fall“ (Tagesschau.de, in German)

Sadly an Italian geophysicist predicted the event –kind of–. We cannot rely on predictions. We cannot expect –yet– to trust correlations between indirect measurements and seismic phenomena. What we can do?

What we can do as geologist is help the authorities educating people, promoting the knowledge of geohazards and how to behave in the case of an Earthquake. Authorities have in their hands the power of approve correct standards for construction. A 6.3 earthquake shouldn’t have caused any fatality in a rich country like Italy. Why it has been like that? Seismicity in the Central Apennines is not new. Historic earthquakes include the one of 1997 (Mw 6.0) which includen in a period of 2 months several M5.0 events (the Umbria-Marche seimic sequence).

Our support to the people in despair for this earthquake.

(Later I will update this article with some images and corrections... I am sending this from my email!)