Department or Program



An unusual deposit of Fe-rich hydrothermal nontronite was recovered by remotely operated vehicle (ROV) from Seamount 3 of the Wolf-Darwin lineament, Galapagos Marine Reserve. X-ray diffraction, ICP-MS/ICP-AES, and SEM-EDS analyses show that this deposit is chemically and mineralogically similar to other deep-sea hydrothermal nontronites, indicating a formation temperature of about 30o to 50o Celsius. These Fe-Si-oxides and Fe-rich Al-poor nontronite deposits contain about 38-51 weight % SiO2 and 40-50 weight % Fe2O3. Although hydrothermal nontronite has been sampled at a number of sites by coring and dredging, this is the first in situ documentation of its sinuous, tubular structure on the sea floor. Image-analysis of ROV imagery suggests that this unusual pattern might be controlled by fluid pathways in the underlying pillow lavas.

Level of Access

Restricted: Embargoed [Open Access After Expiration]

First Advisor

Genevieve Robert

Date of Graduation


Degree Name

Bachelor of Science

Number of Pages


Open Access

Available to all.