While working on a lab assignment in the basement of Krebs, I became very frustrated with the lack of organization that exists in the collection of books we have.  The literature is never in the same spot (which I am partially responsible for) and the books themselves seem to have little order about them.  Now, I do not mean to complain, yet I constantly find myself flipping through the pages hoping that my eye catches a picture resembling the shapes and colors of the current thin section I’m looking at.  And so, I found myself wanting and wishing for a quick and easy way to identify the minerals I was looking at in an organized and accurate manner.  I then found this website from the “Royal Ontario Museum Polarized-Light Microscopy Laboratory.”

http://rbmason.ca/databank/mineral/index_mineral.html

On this site, all of the minerals are grouped together with their respective families, and equipped with full descriptions of their properties as well as a few nice big photos.  I found this website very useful, and I hope someone else might do the same.  The chances of that happening may be slim however, because the lab I am working on is already passed its due date and will inevitably be handed in late.  But if there is another procrastinator out there like me, you’re welcome.

     I was looking for interesting blog articles and came across the a piece of the puzzle as to the origin of petrology.

   Scandinavian and British petrologists initiated a new international journey that brought the attention of petrology to many.  The whole range of subjects that come under a liberal definition of petrology were to  be published in the journal.  The journal would only accept only those papers that could withstand the most critical review and were well documented, of lasting value, and highest scientific merit.  Petrology has been growing very fast since WWII especially with technological advances allowing intense studies and experiments to be performed.   

This lead the two petrologists to begin a journal dedicated to the science of petrology.

http://petrology.oxfordjournals.org/cgi/pdf_extract/21/1/1

     It wouldve been nice to see Crater Lake in October while on the national GSA meeting, but unfortunetly our group didnt get a chance to go. Instead this article will have to quench my thirst for petrologic knowledge of Crater Lake

     The rocks belong to calcic-igneous series as defined as Peacock. The alkali-lime index is a silica percentage at which the content of lime equals that of the alkalis combined.  the magma types of the Crater Lake region are mainly quartz dioritic (peleitic), dioritic, and trondhjemitic.  he acid effusive rocks and the Mesozoic intrusives of the Sierra Nevada also show high k values, the magma types tending toward the granodioritic

     The Pliocene and younger rocks of the High Cascades are richer in A1₂0₃ in the range above 53.5 per cent SiO₂, in lime above 55 per cent SiO₂, and in Na₂O above 65 per cent and below 56 percent SiO₂, and are generally richer in magnesia.

This article continues explaining the variation diagrams as well as the rest of the data collected for this publication. 

http://www.craterlakeinstitute.com/online-library/geology-crater-lake/microscopic13.htm

I was searching through Google online books and came across this interesting article. Outside of Georgetown near the Omai-Potaro Mariaba region, the Bartica formation  consists of leucocratic biotitegneisses, amphibolitic gneisses and course-grained horneblende-biotite gneisses, representing high-grade equivilents of the overlying low-grade greenstone belts. 

The petrology of this region is interesting and helps me understand more about petrology. For example: Zircons from acid volcanics of the northern part of the Barama-Mazaruni greenstone belt in Guyana.

Here is the link http://books.google.com/books?id=h9XOfYxnnT0C&pg=PA102&lpg=PA102&dq=petrology+in+guyana&source=bl&ots=WeVc6dL_G6&sig=y-OKwDAB0VSgeeE0X7LNyJ9rCbY&hl=en&ei=xjEYS7jkD8KtlAfngKHiAg&sa=X&oi=book_result&ct=result&resnum=6&ved=0CBUQ6AEwBQ#v=onepage&q=petrology%20in%20guyana&f=false

There is an article in yesterday’s New York times about the Johnstown Flood and some of the research that Carrie, Neal, Uldis, and Reed have begun.

(And yes, I know there has been a large gap in posts here–my hope is to soon post several items about the field trips that we’ve gone on this fall.)

This is a good article explaining the coorelation with radium and the surrounding various types of granitic rocks in Finland

Finland is composed of pre-cambrian rocks located on the Fenno-Scandanavian shield.  It is believed that several chain mountain building events took place by evidence found within the strata.  Several folds were found and chronologically dated.  The paper goes on to deconstruct theories put forth to explain the several granites found in Finland.    I suggest reading  reading this article to get furthur insight into igneous petrology in Finland.

I read a good article about the geology of the antarctic peninsula and the facts discovered surrounding the mesozoic-cenezoic subduction of the pacific ocean floor.  The rocks found are similar to the Andean rocks of south america, which contain calcareous-alkaline remnants of now fragmented western margin of Gondwana extending from south america to the antarctic peninsula. The paper attempts to assess the compositional variation of amphibole in relations to host rock composition since amphibole is commonly found in all members of the magma present on the peninsula.

check out the article at google books

Ol Doinyo Langai is a volcano in Tanzania that erupts with natrocarbonatite lava, which is rich in calcium, sodium, and potassium, and low in silica.  Because this volcano is low in silica the lava is cool.  It alternates between effusive eruptions and explosive eruptions that build large cinder and ash cones.

For the effusive erutpions, the 1983 lava filled the crater of an ash cone that formed during an eruption in 1966.  Since then the lava filled the crater.

The dark areas on the previous picture show recent lava flows while the white color shows older lava flows that have reacted with rain and moisture.

For the explosive erutpions, in September 2007 an eruption threw ash thousands of meters into the air.  Ash also covered the landscape which forced residents to leave.  The eruption built a cone over 300 feet high with a steep walled crater, which can be seen in the following picture:

In Colorado and Wyoming Diamonds have been found in 40 known diamond containing kimberlite pipes. Diamonds are very rare because the conditions suitable for their formation are also rare. The kimberlite pipes are vertical columns that were squeezed up from great depths(over 150 km deep) within the mantle, and these kimberlites have been deeply eroded (possibly 2000- 4000 feet) for hundreds of millions of years, so there must be plenty more diamonds within the nearby river and stream channels, but few have looked for them. The conditions suitable for the formation of a diamond is that it must be at extreme temperatures and pressures at great depth, and also carbon is needed because diamond is pure carbon. Diamonds have high symmetry and are isometric, and they have many crystal habits including, cubic, octahedron, dodecahedron. Diamonds have perfect cleavage in four directions that are parallel to ther octahedral faces. They are usually colorless but can rarely occur in many different colors. Diamonds are hydrophobic thus they repel water, they also are unaffected by acids. They usually concentrate in black sands in the river beds of the Wyoming and Colorade regions and can be panned for just like gold.

http://www.wsgs.uwyo.edu/Publications/OnlinePubs/docs/IP-12new.pdf

All right, this might not make your day, but I have to say that finding the http://www.waterproof-paper.com/graph-paper/ made me really, really happy.   I’ve searched high and low for ternary paper on occasion, but now I have a pdf!   Unfortunately, all of their grid paper is in inches not mm, but you can’t have everything…

So, here’s a challenge for my students: can you find an internet site that will help you with petrology?