i
Nontronite-bearing tubular hydrothermal deposits from a Galapagos seamount
-
2018
-
-
Source: Deep Sea Research Part II: Topical Studies in Oceanography, 150, 181-194
[PDF-191.06 MB]
Details:
-
Journal Title:Deep Sea Research Part II: Topical Studies in Oceanography
-
Personal Author:
-
NOAA Program & Office:
-
Description:A telepresence-enabled cruise using remotely operated vehicle (ROV) exploration discovered an unusual tubular deposit of Fe-rich hydrothermal nontronite on a young seamount, Mashi, of the Wolf-Darwin lineament in the Galápagos Islands. 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 likely formation temperature of about 30° to 50 °C by diffuse hydrothermal activity. These deposits contain mixtures of Fe-rich, Al-poor nontronite and poorly crystalline Fe-Si-oxyhydroxides with bulk compositions of 38–51 wt% SiO2 and 40–50 wt% Fe2O3*. The presence of filamentous and spherical structures in the samples suggests that mineral deposition was in part facilitated by chemosynthetic microbes. Although hydrothermal nontronite has been sampled at a number of seafloor sites by coring and dredging, this is the first in situ documentation of its unusual sinuous, tubular structure, on the seafloor. Quantitative image-analysis of ROV imagery indicates that hydrothermal fluid pathways, developed through an underlying pillow lava sequence, likely control the distinctive sinuous morphology.
-
Keywords:
-
Source:Deep Sea Research Part II: Topical Studies in Oceanography, 150, 181-194
-
DOI:
-
ISSN:0967-0645
-
Format:
-
Publisher:
-
Document Type:
-
Funding:
-
Rights Information:Accepted Manuscript
-
Compliance:Library
-
Main Document Checksum:
-
Download URL:
-
File Type:
