Geology Vocab!

Being out on the JOIDES Resolution is a learning experience for me! I teach high school marine science and Advanced Placement Environmental Science, so being here, in the world of geochemistry, geophysics, and volcanology (just to name a few disciplines) is taking me out of my zone of familiarity.

One job for the scientists on board is to describe the cores- this sounds like a pretty straightforward task, right? Not so much! Some parts of core description include:

  • Macroscopic visual description of split cores
  • Microscopic observations from thin sections
  • Description and measurement of structures
  • Data collection & analysis of digital images, diffuse color reflectance, and magnetic susceptibility

All of the above means there’s lots of discussion and collaboration by the scientists- they all have their own individual tasks, but then have to assemble all the data into a coherent unit. Reading up on their reports has shown me that there’s a whole world of terms that I am unfamiliar with. It seems as though I’m learning new definitions every day! A few examples include:

  1. Vug: a small cavity in a vein or in rock, usually lined with crystals of a different mineral composition from the enclosing rock.
  2. Breccia: a course-grained clastic rock, composed of angular broken rock fragments held together by a mineral cement or fine-grained matrix.  Basically, it translates to “broken stones”. 
  3. Clastic: pertaining to a rock or sediment composed principally of fragments derived from pre-existing rocks or minerals and transported some distance from their places of origin.
  4.  Fluid Inclusion: a tiny cavity in a mineral, 1.0-100.0 microns in diameter, containing liquid and/or gas, formed by the entrapment in crystal irregularities of fluid, commonly that from which the rock crystallized.
  5. Thin Section: a fragment of rock or mineral mechanically ground to a thickness of approximately 0.03mm, and mounted between glasses as a microscope slide. This reduction makes renders most rocks & minerals transparent or translucent, thus making it possible to study their optical properties.

**All of the above definitions attributed to: Bates, Robert L., and Julia A. Jackson. Dictionary of Geological Terms, Doubleday, 1984.

So, for someone who doesn’t have much of a background in the subject, I really am enjoying learning as the expedition progresses. Hopefully I’ll be able to take my newly expanded vocabulary back to my classes and teach MY students about it!

 

 

 

 

 

 

Author:
Tammy
About:
Hello there! My name is Tammy Orilio and I am sailing on board the JOIDES Resolution, Expedition 376: Brothers Arc Flux as an Education & Outreach Officer. I look forward to sharing both science and shipboard life with you! In my other life, I teach Marine Science and Advanced Placement Environmental Science at Marjory Stoneman Douglas High School in Parkland, FL. I love being able to share these experiences with my school community!
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