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Wednesday, July 29, 2015

Geologic Tools of the Trade: No Monkey Wrenches Here, Only Bruntonian Motion

     Thanks, Lego Joe, of Puzzleria! fame for the suggestion to write about geologic tools of the trade, an extension from the NPR Sunday Puzzle about auto mechanics' tools of the trade.

      My two favorite field geologic tools are my Brunton Compass:

and my Estwing rock hammer:

[It did look like this when it was new:]

          And now it looks like this (rock hammer, Brunton, and Brunton case):

     The Brunton compass is used primarily to take the strike and dip of rocks in an outcrop as described in this three-minute video.

    The Brunton compass (actually the Brunton Pocket Transit) is a precision compass made by Brunton, Inc. of Riverton, Wyoming. The instrument was patented in 1894 by a Canadian-born Colorado geologist, David W. Brunton. 

      Unlike most modern compasses, the Brunton Pocket Transit utilizes magnetic induction damping rather than fluid to damp needle oscillation. 

     From the Wikipedia article on the Brunton Compass:

      "With the advent of portable electronic devices a new generation of compasses has emerged, some again of specific interest to geologists. Unlike analogue compasses, a digital compass relies on an accelerometer and a teslameter, and may provide much information as to the reliability of a measurement (e.g. by repeating the same measurement and performing statistical analysis). Programmers of today's smartphones have responded with different geological compass apps. However, caution must be exercised: Because the Earth's magnetic field fluctuates rapidly, 'smartphone' 3 axis magnetometers can potentially measure noise. Furthermore, all smartphones create strong magnetic fields that must be corrected by computer algorithms. At present, all geological compass apps should be tested against traditional magnetic compass measurements."

     My trusty Brunton was also used for siting along with a plane table and alidade in barite mapping in Mexico. Here's a photo of Francisco who was my bodyguard and occasional rod man 

while I tromped around on the rocks, measuring strike and dip, sampling thick barite beds, and dropping acid 
(a mixture of Alizarin red S and potassium ferricyanide dissolved in a dilute hydrochloric acid solution)

 on rocks to determine if the carbonate was calcite (bright red or pink) or dolomite (white, brownish-grayish-greenish or clear). 

       I used my Brunton to measure the strike of metamorphic features in addition to sedimentary layers. The Brunton is still used by geologists, archeologists, and other scientists (though the price is now between $350-$700; I bought mine used for $75 and that was a really good deal.)

       My rock hammer has pounded on rocks from Spain to Mexico to all over the U.S. Field geology is a truly a blast!

       Two of my other favorite "tools?" A tractor and a backhoe used to dig trenches to get a better look at the thick barite beds beneath the surface in Cobachi, Sonora, Mexico. 

What's your most trusted tool?

Wednesday, July 22, 2015

DNA Ties between Indigenous People of Australasia and Amazon: Free Shipping Included?

     YesterdayHarvard University researchers published research in the journal Nature which shows close DNA connection between indigenous peoples of the Amazon Basin of South America and aboriginal people of Australasia (including Australia, New Zealand, Papua, New Guinea and surrounding islands).

       The researchers looked at the data several times because it differed from their previous models of the spread of the human population. Skoglund et al found the genomic evidence to be even stronger as they looked harder to show there was not a tie between the two population groups.

        This summary article from Science Daily includes these paragraphs:

        "Skoglund and colleagues from HMS, the Broad and several universities in Brazil analyzed publicly available genetic information from 21 Native American populations from Central and South America. They also collected and analyzed DNA from nine additional populations in Brazil to make sure the link they saw hadn't been an artifact of how the first set of genomes had been collected. The team then compared those genomes to the genomes of people from about 200 non-American populations."

      "The link persisted. The Tupí-speaking Suruí and Karitiana and the Ge-speaking Xavante of the Amazon had a genetic ancestor more closely related to indigenous Australasians than to any other present-day population. This ancestor doesn't appear to have left measurable traces in other Native American groups in South, Central or North America."

      "The genetic markers from this ancestor don't match any population known to have contributed ancestry to Native Americans, and the geographic pattern can't be explained by post-Columbian European, African or Polynesian mixture with Native Americans, the authors said. They believe the ancestry is much older--perhaps as old as the First Americans."

        "The team named the mysterious ancestor Population Y, after the Tupí word for ancestor, 'Ypykuéra.' "

          The researchers propose that Population Y and First Americans came down from the ice sheets to become the two founding populations of the Americas.

       "About 2 percent of the ancestry of Amazonians today comes from this Australasian lineage that's not present in the same way elsewhere in the Americas," said David Reich, one of the contributing authors.

        An Australasian heritage for Amazonian people is one of the last connections that would come to my mind, given the geographical isolation of Australasia for such a long time period. What's your thinking about this migration pattern?

Two additional links on this topic from The New York Times and The Smithsonian.

Scratching my head over this one,

This world map projection is helpful:

     You can just about see Gilligan in the middle of the Pacific. . .

      And with the wind patterns:

Tuesday, July 14, 2015

If Only We Had Taller Been: New Horizons Makes the 3 Billion Mile Trip Past Pluto

       The startlingly clear images of dwarf planet Pluto's surface have captivated me all day. 

     Images from 3 billion miles from earth being transmitted by the New Horizons piano-sized probe have dominated nearly every news and science outlet. There's a Google doodle  and a New Yorker cartoon:

     Nine years after the 2006 launch we are treated to these false-color composite images of Pluto and Pluto's moon, Charon:

      There's even a New Horizons tribute with Ray Bradbury's voice reciting  If only we had taller been.

     For me, all of this spectacular imagery has me thinking about the U. S. space program's first probe of Mars on this very date (Bastille Day!) 50 years ago in 1965 . And, of course, the Moon Landing on July 20, 1969. 

       What is it about our space program and July?! Best time for good publicity? Best time for images? Other ideas?

All hail Pluto, the (round) dwarf planet and Happy Quatorze Juillet!


P.S. Hey. . .'Sup?

Thursday, July 9, 2015

Ethiopian Welo Opals, Oh Pals!

     Ethiopian opals from the Welo District include this spectacular specimen discovered in October 2013. 

     The Ethiopian Welo opal mines were first discovered in 2008 in the district north of the capital of Addis Ababa (although opal was said to have been discovered in the 1930's elsewhere in Ethiopia and minimal mining began in the 1990's):

       The USGS estimates 2012 production of Ethiopian Welo opal to be 14,000 kilograms or 31,000 pounds. This estimation would change Australia's purported 95-97 percent of the world's opal production. There is not much information currently available about the Ethiopian Welo opal mines. Perhaps my daughter, Zoe, can make a field trip to the north to discover more about their deposition (or I could visit her and the opal mines!). I am quite curious about the similarities between the depositional environments in Australia and Ethiopia. 

    Opal is a hydrated amorphous form of silica with a water content ranging from 3 to 21% by weight. Because of its amorphous character, it is classed as a mineraloid, unlike the other crystalline forms of silica, which are classed as minerals.

     Australian opal is generally of a higher water content than the Ethiopian Welo opal. It is also generally found in deeper environments. Opals which get too dry are said to "craze." Often gemologists store opals in water to keep them hydrated. I take mine swimming.

      This four minute long video of Welo opals is worth a look, oh pals!

       I like the fire and the setting of this Ethiopian opal.

     Speaking of Ethiopia, here's the Peace Corps group arrival at the airport in Addis Ababa. Where's Waldo (er, Zoe?!) What an enthusiastic bunch (especially just after a 13-hour plane ride)!

O pals, let me know your silica thoughts,

Wednesday, July 1, 2015

Lemony or Masculine: Olfactory "Fingerprints" (Noseprints?)

       New research by Secundo et al shows individuals have an olfactory "fingerprint" or "noseprint" ;-) which may be useful in early detection of Alzheimer's and Parkinson's diseases. The fingerprint may also be used in organ and bone marrow matching in a non-invasive manner.

     The researchers asked the subjects about a variety of smells (i.e., "is this smell lemony or masculine?") and mapped the results as above. They discovered that an individual's "noseprint" did not vary significantly over 30 days (as the two maps in the middle and on the right in the illustration above). However, the individual on the left has a very different olfactory noseprint or fingerprint.

     Additional information about the study is summarized at
this link

     Of course, some noseprints or fingerprints may take a little longer to map:

      What are you thoughts on this study? Are data points based on things like "lemony or masculine" good mapping markers?

Smell you later, ;-)


P.S Paul's comment about being prescient about smells and "Nostrildamus" made my day!