New Mexico Geological Society Annual Spring Meeting
April 7, 2017
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Assessing Uranium Concentration in Stream Sediment on the Laguna and Isleta Pueblos
As a summer internship through a New Mexico EPSCoR funded STEMAP program. Myself and another intern worked with the uranium team at New Mexico Tech. We collected sediment samples from streams and washes on Laguna and Isleta Pueblo lands. Samples were collected from the Rio Puerco, San Jose, Del Valle, and Paguate washes to analyze the heavy metal content washing down from upstream uranium mines. Knowing the type and quantity of heavy metals washing down these washes, could help with further clean up or reclamation efforts in the area.
The samples needed to be dried, sieved, ground into a fine powder, then digesting in acid. Analysis of heavy metals was done using an ICP-MS for heavy metal content. We also performed a mass fraction of grain size on each sample to get a course sand content vs. the finer grain content.
Our hypothesis being that uranium particle adheres to the larger surface area by volume of the clay material better than course sand.
Uranium concentrations were present on samples we collected from the washes downstream of the main uranium mines. Our data also supported our hypothesis when we correlated the amount of finer grained material a sample had with the concentrations of uranium that was present in that same sample. Sites G,H,I the fine grain fraction of C and the course grain fraction of B held the highest concentration of uranium. Which was above the average Earth’s background uranium concentration of 3 mg/kg.
uranium concentration, ICP-MS
2017 New Mexico Geological Society Annual Spring Meeting
April 7, 2017, Macey Center, New Mexico Tech campus, Socorro, NM