There is N-MORB ("Normal" mid-ocean ridge basalt), E-MORB ("Enriched" ya-da-ya-da*)
and T-MORB ("transitional" ya-da-ya-da). What I find fascinating is the basalts at the divergent plate boundaries are still controversial in that geologists really don't know for sure at what depths of the mantle is coming up and why the variations (however slight). Lab experiments geologists mimic as closely as possible is believed to be going on say 150+ km down into the mantle. Thanks to smart guys like petrologist, Norman L. Bowen...we geology students have a model we use that helps us to image fractional crystallization of magma although Bowen initially wanted to show why certain minerals were found together.
Deeper into the chapter, I discover that geologists have more types of diagrams and graphs than Carter has pills (old saying) regarding Earth's mantle. My head is swimming at trying to delve into the data before me. Most of it I actually get, but once in a while you get a diagram that has numbers only but is not labeled as to what the numbers mean, so you cannot interpret the data. Grrrrrrrr! I'm tired.
Okay so here is the part where I sit back in my office chair, look away from the textbook, see my Godzilla toy, and ask myself..."what would Godzilla do?" Godzilla is my favorite monster since childhood...I LOVE Godzilla...so much we had to play "Godzilla" by Blue Oyster Cult in my cover band many moons ago. The only thing that continues to run through my head over and over are the lyrics...
"History shows again and again how nature points up the folly of man...GODZILLA!"
I stop reading and taking notes. I put down my Pilot G-2 pen, I start to think about "our folly". I know my professor from MJC dislikes a certain movie that came out with a machine made of "unobtainium" that could drill down to the core. I, on the other and love Hollywood's imagination (despite how stupid it may be)! Problematic however is that Hollywood needs to come up with another name for an element that is unearthly. "Unobtainium" has been used in at least two movies I have seen..."Avatar" (Sam Worthington - yay!) when actor Giovanni Ribisi holds up a hand sample of galena and claims it to be a valuable resource they want to mine on the moon, Pandora. The problem is the source is under the home of the Na'vi. The second time is when Delroy Lindo (who plays Dr. Ed Brazzleton) says his "machine" is made of "unobtainium" and can drill down to the core.
Okay, then. First kids there is NO such thing as "unobtainium" that is why they call it that. Hollywood has its share of folly, but what about us geologists? I personally feel geologists today (and those in the past) have done an excellent job in trying to explain the Earth rock processes with restrictions of the human body.
There is still much to study and learn, but what a great and fascinating field geology is. Geologists use their knowledge to come up with scenarios in the lab for explanations of processes we are not privileged in seeing (due to extreme pressure and temperatures of the mantle for example). Planetary geologists also have to rely on observation, learned knowledge and research to come up with the best scenarios they can regarding other planets and moons - millions of miles away. Intense stuff!
So, that being said, I am going to go offline, and I am so done with reading my homework...time to watch Sam Worthington go blue... :)
BTW, Godzilla movie schedule for May 16th release....cannot wait! GO GO GODZILLA! The trailer is promising...http://www.fandango.com/movie-trailer/godzilla2014-trailer/157230
* Ya-da-da is NOT a technical nor scientific word...it just means "and so on".