Geology in the Wild - Roadside Faults

While traveling home a couple of years ago, I happened to notice some nice faults along the side of the road. So, like any good geologist, I got out to take a few pictures.


The location is in Utah, within the Eocene Green River Formation east of the Tie Fork Rest Area between Price and Provo along Route 6. It's the fancy newish rest area that has a bunch of train displays.


The image below was taken along Route 6 facing north, with the west to the left and east to the right. You can get a pretty good view of it within Google Street View Here.

West                                                                                                                                      East

Taking a closer look at the western fault above.


And an even closer look with the fault highlighter. The beds show significant offset by matching up that double bed located just above the arrows in the image below.

 This type of fault is what is known as a Normal Fault, as illustrated in the image below. It results from extensional forces where each side of the fault are moving away from each other. A Reverse Fault would be where the two blocks are being pushed towards each other.

Looking at the eastern portion of the top image.

We can see there are two, nearly vertical, faults lying very close to each other.

The bend in the fault line above is just due to the degree of erosion revealing the fault at a weird angle and also the perspective from which I am viewing the fault. In actuality, the fault is not bent like that.

Both of these faults are also Normal Faults because of the same extensional activity as to the west. This makes sense because if the fault to the west resulted from extensional activity, it would be highly likely the entire area, if not the region, had undergone extensional pressures. This means that these couple of faults here would probably not be the only normal faults in the area and there are  more normal faults spread throughout the area and/or region.

This is what is known as a scientific hypothesis. We looked the available data on the region and came up with a testable hypothesis based on it.

Geology Through Literature - Idylls of the King

The next up on my Geology Through Literature thread is Idylls of the King by Alfred Lord Tennyson published between 1859 and 1885. You can get my complete thoughts on the book/story over at my blog - The Remnant, but for here I will just go into the geological or basic scientific aspects that are brought up in the story.

The story is an epic poem based on the life of King Arthur. There is only one geological instance worth noting in the story itself.

"Chapter": Gareth and Lynette

"In dewy grasses glistened; and the hair 

All over glanced with dewdrop of with gem 

Like sparkles in the stone Avanturine."

Avanturine, more commonly spelled Aventurine, is a gemstone variety of quartz (SiO2). However, unlike the typical varieties of quartz like amethyst, smokey quartz, or milky quartz (to name a few), aventurine contains flecks of mica and other materials incorporated into the crystal. It is these flecks that give the crystal a "sparkle" as the poem states (geology.com).

A green variety of aventurine. 

Aventurine was named after the Italian words "a ventura", meaning by chance. This is in reference to the chance creation of the artificial aventurine variety now referred to as goldstone where flecks of copper were incorporated into a bit of glass creating a similar, but much more dazzling, appearance (mindat.org).

Goldstone, an artificial "gemstone" similar to aventurine in appearance, except it is often made with glass and copper flecks or other metals (wikipedia).

Geology in Pop Culture - Activity Rocks Kit

Recently while at Death Valley National Park, my wife purchased a geology activity for me to do with our daughter. And since this is a fairly fun and easy activity to do with kids I figured I would pass along the information. You can get the Activity Rocks kit at Amazon right now as well.

Above you have the four rock/mineral based activities that comes with the kit. The rocks/minerals are:

• Magnetite - and a paperclip for magnetic properties
• Pumice - for a floating rock
• Quartz pebbles - for a sparking rock activity
• Dolomite - With a penny for a dissolving and recrystallization activity.

Many, if not all, of these rocks are available to most geologists, however this kits gives them in nice kid friendly sizes with instructions (below) for what to do with them, 

Here is everything at the start. The pumice is floating, the dolomite is sitting in vinegar, the magnetite is magnetizing, and the quartz pebbles are just sitting there. The best part about this kit is after you are done with it you can pass it on to a friend for them to experiment with as well. 

Besides the pumice and the magnetite, which are neat, but you can't really do anything beyond float or stick something to it, the real science comes with the dolomite and the quartz.

Here is the dolomite after it had been sitting in vinegar for about a week. The crystals recrystallized nicely on top of the rock. There is also a penny in the solution, which was supposed to turn the crystals blue (due to oxidation of the copper). They did turn blue at first, but only slightly and not really noticeable after a while.

Now the really interesting thing (that I had not realized before), was that when two "tumbled" quartz pebbles (crystal quartz in this instance) are struck together they produce an electrical shock that lights up the pebbles. This was a little hard to picture so I had my daughter take some photos while I struck the pebbles together. Below are the sequence of photos and a very brief video that shows the results.

All in all a fun activity to get your kids interested in the joys of geology and science. Also, if buying a kit like this isn't your style, this post will give you info on how to build a kit of your own from your own supplies.

Geology Through Literature - Candide

The next up on my Geology Through Literature thread is Candide by Voltaire published in 1759. You can get my complete thoughts on the book/story over at my website - Dinojim.com, but for here I will just go into the geological or basic scientific aspects that are brought up in the story.

I had heard about the geological content of Candide many years ago after I had read the story. So, I had it on my list to eventually go back and find the information in order to present it here. Within the story of Candide, the titular character comes upon the shores of Lisbon, just as an earthquake begins. This is a historical event that took place on November 1st, 1755 (just four years prior to publication).

Chapter 5

     "Scarcely had they set foot in the city (Lisbon), still weeping over the death of their benefactor, than they felt the earth quake beneath their feet. In the port a boiling sea rose up and smashed the ships lying at anchor. Whirlwinds of flame and ash covered the streets and public squares: houses disintegrated, roofs were upended upon foundations, and foundations crumbled.

Thirty thousand inhabitants of both sexes and all ages were crushed beneath the ruins. The sailor said with a whistle and an oath: 

'There'll be some rich pickings here.' 

'What can be the sufficient reason for this phenomenon?' wondered Pangloss.' 

The end of the world is come!' Candide shouted."

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 ...'This earthquake is nothing new,' replied Pangloss. 'The city of Lima felt the same tremors in America last year. Same causes, same effects. There must be a vein of sulphur running underground from Lima to Lisbon.' 

'Nothing is more probable,' said Candide, 'but for God's sake get me some oil and wine.' 

'What do you mean, "probable"?' the philosopher retorted. 'I maintain that the thing is proven.'

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...'For all this is the best there us, If the volcanic activity is in Lisbon, it means it could not have been anywhere else. For it is impossible for things not to be where they are. For all is well.'"

Chapter 6

"After the earthquake which had destroyed three quarters of Lisbon, the wise men of the country had not been able to come up with any more effective means of preventing total ruin than to give people a splendid auto-da-fé. It was decided by the University of Coimbra that the spectacle of a few people being ceremonially burnt over a low flame is the infallible secret of preventing earthquakes.

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...A week later...the earth quaked once more.

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For my reading I had the Everyman's Library version of Candide and at the beginning of most Everyman's Library books is an Introduction. This introduction, by Roger Pearson talks about the actual earthquake which is portrayed in Candide and was experienced by Voltaire.

"...Voltaire's faith in God had been severely shaken by the Lisbon Earthquake on 1 November (All Saints' Day) 1755, which killed 40,000 or more people; and his poem on the subject, published in 1756, is a devastating cri de coeur against Pope and Leibniz, not to mention the Almighty. Subtitled 'An Examination of the Axiom: All is well', the poem begins by asking, first, how such carnage can be in accordance with the eternal laws of a good and free God and, second, how it can be a punishment from God. Why Lisbon, Why not London or Paris ('Lisbon lies in ruins, while in Paris they dance.') Did the volcanic activity that caused the earthquake really have to be part of the Creation?"

The Great Lisbon Earthquake is well known as one of the widest felt earthquakes ever on record. It was felt from its epicenter off the shores of Portugal, up through Great Britain and well into Africa (see image below). 

Shakemap of the Great Lisbon Earthquake. (Gutscher et al., 2006)

Best estimates are that between 10,000 and 15,000 people died within the city of Lisbon. Many died later due to injuries, fires, and tsunamis and outside the city limits, hence giving the higher numbers often cited elsewhere.  As to the damage, many of the finer buildings in the city were mostly ruined and smaller houses and shops were completely destroyed. Observers in ships were said to see the city swaying corn before the buildings collapsed. These estimates and observations are based on eyewitness accounts in The Lisbon Earthquake by  T. D. Kendrick.

However, contrary to what was believed (at least by Candide at the time), this was not a result of volcanic activity. As you can see on the map below, there aren't even any even any volcanoes on the Iberian Peninsula. 

Active, dormant, and extinct volcanoes of the world.

Even with this blown up view of Europe showing any earthquake hazards in Europe, there isn't even a hazard within 1,000 km of Lisbon. And even that one has an uncertain eruption date.

Earthquake Hazard Map of Europe

My guess is that Candide is aware of the volcanic activity and their corresponding earthquakes in Italy and attributed this earthquake to those causes. However this does not have the hallmarks of a volcanic eruption.  As the seismograms below can illustrate, volcanic eruptions have a drawn out shaking due to the magma moving through the Earth called harmonic tremors. This provides a steady shaking over a long period of time. Earthquakes due to fault action have a sharp start and peter out fairly quickly (over the course of 1-3 minutes). 

Volcanic harmonic tremors

Fault based seismic tremors

The earthquake had to be a result of fault movement then and not volcanic activity, so let's looks at possible plate tectonic activity. Looking at a plate tectonic map of the Iberian Peninsula we have the following:

Fault slip rates along plate tectonic boundaries (http://diapiro.ictja.csic.es/gt/ivone/research_AFEU.html)

There is a plate boundary running right near Lisbon (which is located right about where the "5" is in 0.05 north of the plate boundary). So where would the earthquake epicenter have been? Looking at the map below, a recent study has pinpointed the likely epicenter to being within the Marques de Pombal (Zitellini et al., 2001).

Bathymetric map of the southwestern Iberia with location of seismic stations (Zitellini et al., 2001). 

It has also been determined that the cause of the earthquake was likely a shallow, eastward dipping thrust fault (Gutscher et al., 2006). This type of fault zone, along with it's location can cause the amount of damage caused in the fault as well as the following tsunamis that are associated with this fault. It is interesting to note that even though they compare this Lisbon earthquake to a Lima, Peru earthquake as both being caused by volcanic activity, both are actually caused by eastward dipping thrust faults. Lima, Peru was hit and destroyed by an earthquake and tsunami combo in 1746 (history.ac.uk). These events are so similar, that it is no wonder that Voltaire used this example in his writing. Although, he did have the date off, it wasn't "last year" from the Lisbon earthquake, but close enough (9 years prior).

It is estimated that the Lisbon Earthquake had the magnitude of 8.5-9.0 on the moment magnitude scale (the Richter Scale).  The Richter Scale measures the amount of energy released from an earthquake. This number is comparable to other earthquakes because it does not care about the amount of damage that occurs. However, this can only really be measured with modern day equipment. Any earthquakes that occurred before the advent of earthquake reading equipment needs to be estimated differently to gain an accurate estimate.

What we can measure without the direct scientific readings of the energy released from the fault is the amount of damage that had been recorded by contemporary media. This information is then translated into the Modified Mercalli Intensity Scale. It is on this scale that we are able to place estimates on the size of the earthquake. Based on this scale, the Lisbon earthquake would likely be at least a IX in the area of Lisbon (as shown on the first map above):

IX

Violent

Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations.

And due to the construction at the time (wooden and brick houses, high percentage of people living in poverty), this type of damage would wipe out an entire city.

As a final note, the text states that some shaking started about a week later (presumable a week after the original earthquake). These later earthquakes are what are known as aftershocks. Aftershocks are smaller earthquakes than the original, however they can cause just as much, if not more, damage due to the already susceptible state that the city is in from the original earthquake.  Aftershocks are fairly common after large earthquakes as the fault settles out from a large movement (USGS). This was the case for the Lisbon earthquake as well (drgeorgepc.com).

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References

https://www.researchgate.net/profile/M-A_Gutscher/publication/223469777_The_Gibraltar_Arc_seismogenic_zone_Part_2_Constraints_on_a_shallow_east_dipping_fault_plane_source_for_the_1755_Lisbon_earthquake_provided_by_tsunami_modeling_and_seismic_intensity/links/09e41507675e5267e8000000.pdf

https://archive.org/details/lisbonearthquake010555mbp

http://earth.rice.edu/mtpe/geo/geosphere/hot/volcanoes/volcanoes_b2.html

http://www.preventionweb.net/english/professional/maps/v.php?id=3832

http://diapiro.ictja.csic.es/gt/ivone/research_AFEU.html

https://www.researchgate.net/profile/Rinaldo_Nicolich/publication/250309865_Source_of_1755_Lisbon_Earthquake_and_Tsumani_investigated/links/54985a6f0cf2c5a7e342bc77.pdf

http://www.history.ac.uk/reviews/review/932

https://earthquake.usgs.gov/learn/topics/measure.php

https://www2.usgs.gov/faq/categories/9827/3346

http://www.drgeorgepc.com/Tsunami1755Lisbon.html

Dinos in Pop Culture - Paleontology Chocolate!

I was pointed out by my friend Erin a while ago about a blog talking about this website which sold a chocolate T. rex tooth and a chocolate "Megalodon" tooth. Since I wasn't able to do anything about it at the time, I saved the information. Well, I have come back around to it and lo and behold, there is so much more than I thought.

The website is called "The Edible Museum" and it is run by The Sarah Hardy Confectionary. And not only do they have those teeth. They have so much more. I went for the largest item they had, which included all of their available fossils (that I am aware of): The Chocolate Fossil Hamper Box. Which runs for £75.00, and is shipped out of England. Below I have a breakdown of what was included in the box.

This is everything that came in the "case". It had about 18 individual "fossils" that ranged from white, milk, and dark chocolate to some with a combination of the milk and dark. 

 When it first arrived it came in a cardboard box, and inside was this awesome looking collector's item. I really never expected something like this. The papers are actually sticking out because I had opened it and mussed it up a little when I got it, but rest assured it was immaculate upon arrival. 

 Opening it up, everything was neatly packed away with tons of padding to keep everything safe.

 The first layer was the small fossils. Each set of chocolate was wrapped in plastic wrap to keep the chocolate fresh and each section had it's own pillow of bubble wrap below it.  But the best part is easier to see below. Each fossil includes a tag with the species, the age, and the location of the original fossil. This is a paleontologist's dream box for sure.

We'll start in the middle on the top.

SPECIES: Ammonite - Toxaceratiode

AGE: Cretaceous

LOCATION: Queensland, Australia

CHOCOLATE: dark chocolate

 The next box to the left had two sets of fossils and two tags associated with it.

SPECIES: Trilobite - Asaphus exponsus

AGE: Ordovician 

LOCATION: Sweden

CHOCOLATE: dark chocolate

 SPECIES: Brachiopod - Articulate

AGE: Ordovician 

LOCATION: ?

CHOCOLATE: milk chocolate

 SPECIES: Ammonite - perisphinctes

AGE: Jurassic

LOCATION: Madagascar

CHOCOLATE: white, milk, and dark chocolate, some with a gold like glaze.

 SPECIES: Trilobite - Calymene

AGE: Upper Ordovician 

LOCATION: Anti-Atlas, Morocco

CHOCOLATE: milk chocolate with some dark chocolate spots making it appear more realistic.

 SPECIES: Sharktooth - Otodus Obliquus

AGE: Ordovician 

LOCATION: Sweden

CHOCOLATE: white, milk, and dark chocolate

 SPECIES: Ammonite - perisphinctes

AGE: Ordovician 

LOCATION: Sweden

CHOCOLATE: milk chocolate with a gold like glaze making it appear more metallic.

 Here is a shot of the top drawer all cleaned up and unwrapped. Also the chocolates were delicious!

 But that's not all! Like a tackle box, the top shelf comes out revealing a large open area below.

 This bottom area contains the Tyrannosaurus rex tooth and the Carcharodon megalodon tooth (incorrectly labeled as "Megalodon" because that's the way everyone does it, even though you wouldn't call humans "Sapiens", you shouldn't call an animal by it's species name only but that's a side issue). My only gripe about the box is that there are no tags for the two bottom teeth anywhere in the box, trust me I looked. But if that is my only gripe, it is a very minor one. 

SPECIES: Tyrannosaurus rex and Carcharodon megalodon

CHOCOLATE: mix of milk and dark chocolate

Overall this box gets an A+ from this paleontologist. I recommend this as a good birthday, valentines, or other holiday gift for that fossil lover in your life. The presentation is beyond awesome and the chocolates with definitely delicious. Many of the fossils even included special coatings to make them appear more genuine.