Wednesday, September 24, 2014

Geosonnet 11

For fifty million years, ‘tis understood
A vanished forest froze in permafrost.
The isotopes of carbon in the wood
Tell secrets of the climate we have lost.
Then brackish duckpond, now a frozen sea,
Ex-crocodiles where Franklin did maroon.
Those Rains of Castamere, we can’t agree:
Cold drizzle or a tropical monsoon?
Extinct sequoia yearns for rain no more
Yet in its fossil rings it has preserved
A dryad’s weather journal, yielding lore
of summer rain and winter drought observed
  The Arctic Ocean’s lost half of its ice
  What happens when it’s gone? We need advice.

Geology 40 523

Other geosonnets: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

Tuesday, September 23, 2014

Geopoetry disclaimers

 A few notes on the Geosonnet series
I will try to keep them going on Wednesdays as long as I can manage, but I have some travel coming up, so they might be a few misses if my queue runs down.

Selection of a paper for poetry does not constitute an endorsement of the methodology, or agreement of the conclusions; basically, it means that the paper caught my eye and I read it (Reading and understanding the paper is generally the biggest timesink here).

I mentioned in the science week poetry wrap-up post that I can take several approaches to the sonnets- explaining the geology, explaining why the methodology was cool, or just waxing poetic about the broader impacts. I’ll continue to pick whichever approach takes my fancy at the time I write them. I generally blog from the paper copies, so don’t expect to see anything from online previews straight away.


Please feel free to comment.  It is fantastic that some people have been commenting in verse, but don’t feel compelled to do so if you can better express your thoughts in prose comments.

They can all be found under the label of "Rheologic Rhymes" (because they are strained).

Wednesday, September 17, 2014

Geosonnet 10

The Ediacaran saw creatures grow
Diversify as animals evolved.
But Cambrian descendants do not show
A lineage, preserved or else dissolved.
A missing fossil yearns to be dug up.
The flinders ranges burn to tell their tale
Trace fossils, both a spicule and a cup
Mean evolutionary theories can prevail.
Coronacollina was once a sponge
With opaline supports to hold it flat
Choia’s ancestor, before the plunge
Into the Cambrian destroyed the mat
  On which it lived, before it then evolved.
  Another fossil puzzle has been solved

Geology 40 307

Other geosonnets: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

Wednesday, September 10, 2014

Geosonnet 9

The vast caldera of the Yellowstone
Erupts siliceous ash from time to time.
It’s far from the Cascade subduction zone
Therefore, a mantle plume’s the suspect prime.
But magma conducts electricity
Conductors in the mantle lie out west
The tomographic maps are very pretty
But show no melt where theory would suggest
A plume, with mantle source below the crust
Should yield a seismic and conductive trace.
Because we can’t detect deep melt we must
Explain resistance far below this place.
   A pulsed hotspot, or plate-related stall?
   Or maybe plumes do not exist at all.

Geology 40 447

Other geosonnets: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

Sunday, September 07, 2014

Friday, September 05, 2014

Effect of impact energy on SIMS U–Pb zircon geochronology

I have a paper out in pre-publication online availability. The basic gist of it is that we are investigating exactly why SHRIMP is so good at geochronology.  It is a short format conference proceedings paper, so there isn't that much to it.  Basically, we investigated the oxide formation used to calibrate relative U/Pb ionization yields by bombarding natural zircon with a primary ion beam made of 18O2ions.  This way, all the molecular oxide ions were isotopically labeled- 16O if the oxygen originated in the sample, 18O if it was from the primary beam.  We then varied the ion impact energy to see what effect this had on the overall collection efficiency.

One of the other different things about this paper is that I co-wrote it with my dad.  He doesn't know any geology, but since I was about five he has been using SIMS (not SHRIMP, other brands) analysing semiconductors.  He still lives in America, so I don't get to see him much any more, and he's not getting any younger.  So it was nice to have a structured activity to work on together.  The middle author, Jim Ferris, did the atomic force microscopy. Unfortunately due to the short format, we didn't have space for any of his pictures, but he measured the sputter crater volumes, which we needed to calculated useful yields.



Magee C. Jr., Ferris J. and Magee C. Sr. (2014), Effect of impact energy on SIMS U–Pb zircon geochronology, Surface and Interface Analysis, DOI: 10.1002/sia.5629



Wednesday, September 03, 2014

Geosonnet 8

The sunset lion, as Britannia aged
Survived, with every man, the frigid waste.
Industrial hostility upstaged
The sanctity of souls, their wreck encased
In icy seas and grinding floes made cold
By deep Antarctic circumpolar flow.
Dark isolation froze this land, how old
Are continental glaciers, ceaseless snow?
Six desp'rate heroes sailed the Scotia Sea
Dead arc, live backarc ridge beneath their keel
Tectonic forces pulled their goal to lea,
Deflected currents, begat their ordeal.
  Endurance sank, endurance overcame
  Asylum, dawn, and cause were all the same.

Geology 42 299

Other geosonnets: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47