Hydrothermal alteration of olivine in a flow-through autoclave: Nucleation and growth of serpentine phases
-
Charles Normand
,
Anthony E. Williams-Jones
Abstract
A single-pass flow-through experiment was conducted to induce serpentinization, and to relate serpentine mineralogy to reaction progress during open-system alteration of San Carlos olivine by air-saturated water. The fluid flowed at 300 °C and 300 bars for 1368 hours through crushed olivine contained in a tubular titanium reaction cell. Chemical analysis of the fluids indicated a steady-state composition with respect to Mg and pH after 550 hours, which was interpreted to reflect saturation with brucite and one or more serpentine-group minerals. The alteration products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). Nucleation and growth characteristics of serpentine phases on the fracture surfaces of olivine were studied by TEM using platinum/carbon replica techniques. After reaction, olivine fragments displayed clear signs of dissolution, and growth of neoformed phases. Brucite and magnetite were distributed uniformly through the reaction cell, although magnetite was more abundant. There is, however, a distinct zonal distribution of the serpentine phases from the inlet to the outlet of the reaction cell. Lizardite is the dominant serpentine phase at the inlet, whereas fibrous serpentines are predominant near the outlet. Lizardite crystals are more numerous (but smaller) in the middle of the cell, and are topotactically aligned along a single preferential crystallographic orientation of the olivine. Cylindrical chrysotile formed predominantly on the surfaces of lizardite, conical or polygonal serpentine. The morphology and sorting of the serpentine phases through the reaction cell suggest that crystallization of lizardite was controlled by heterogeneous nucleation on olivine under supersaturated conditions, and crystallization of chrysotile by nucleation on lizardite at higher levels of supersaturation.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- The chemical character of fluids forming diagenetic illite in the Southern Appalachian Basin
- Interpretation of K-Ar dates of illitic clays from sedimentary rocks aided by modeling
- Illite polytype quantification for accurate K-Ar age determination
- Characterization and modeling of illite crystal particles and growth mechanisms in a zoned hydrothermal deposit, Lake City, Colorado
- Characterization of the Waukesha Illite: A mixed-polytype illite in the Clay Mineral Society repository
- Exploring intra-crystalline B-isotope variations in mixed-layer illite-smectite
- Characteristics of mixed-layer smectite/illite density separates during burial diagenesis
- I-S precipitation in pore space as the cause of geopressuring in Mesozoic mudstones, Egersund Basin, Norwegian continental shelf
- Structural and chemical heterogeneity of illite-smectites from Upper Jurassic mudstones of East Greenland related to volcanic and weathered parent rocks
- Berthierine/chamosite, corrensite, and discrete chlorite from evolved verdine and evaporite-associated facies in the Jurassic Sundance Formation, Wyoming
- Weathering of ilmenite from granite and chlorite schist in the Georgia Piedmont
- The effects of grinding on the structure of a low-defect kaolinite
- Structure of heavy-metal sorbed birnessite: Part 1. Results from X-ray diffraction
- Structure of heavy-metal sorbed birnessite: Part 2. Results from electron diffraction
- Structure of synthetic Na-birnessite: Evidence for a triclinic one-layer unit cell
- New modeling of X-ray diffraction by disordered lamellar structures, such as phyllosilicates
- Identification of polytypic groups in hydrous phyllosilicates using electron backscattering patterns
- Orientational order-disorder of N(D,H)4+ in tobelite
- XPS evidence for Fe and As oxidation states and electronic states in loellingite (FeAs2)
- Hydrothermal alteration of olivine in a flow-through autoclave: Nucleation and growth of serpentine phases
- The influence of bulk composition on the diffusivity of carbon dioxide in Na aluminosilicate melts
- A combined rapid-quench and H2-membrane setup for internally heated pressure vessels: Description and application for water solubility in basaltic melts
- Letter. Crystal morphology of MV-1 magnetite
Articles in the same Issue
- The chemical character of fluids forming diagenetic illite in the Southern Appalachian Basin
- Interpretation of K-Ar dates of illitic clays from sedimentary rocks aided by modeling
- Illite polytype quantification for accurate K-Ar age determination
- Characterization and modeling of illite crystal particles and growth mechanisms in a zoned hydrothermal deposit, Lake City, Colorado
- Characterization of the Waukesha Illite: A mixed-polytype illite in the Clay Mineral Society repository
- Exploring intra-crystalline B-isotope variations in mixed-layer illite-smectite
- Characteristics of mixed-layer smectite/illite density separates during burial diagenesis
- I-S precipitation in pore space as the cause of geopressuring in Mesozoic mudstones, Egersund Basin, Norwegian continental shelf
- Structural and chemical heterogeneity of illite-smectites from Upper Jurassic mudstones of East Greenland related to volcanic and weathered parent rocks
- Berthierine/chamosite, corrensite, and discrete chlorite from evolved verdine and evaporite-associated facies in the Jurassic Sundance Formation, Wyoming
- Weathering of ilmenite from granite and chlorite schist in the Georgia Piedmont
- The effects of grinding on the structure of a low-defect kaolinite
- Structure of heavy-metal sorbed birnessite: Part 1. Results from X-ray diffraction
- Structure of heavy-metal sorbed birnessite: Part 2. Results from electron diffraction
- Structure of synthetic Na-birnessite: Evidence for a triclinic one-layer unit cell
- New modeling of X-ray diffraction by disordered lamellar structures, such as phyllosilicates
- Identification of polytypic groups in hydrous phyllosilicates using electron backscattering patterns
- Orientational order-disorder of N(D,H)4+ in tobelite
- XPS evidence for Fe and As oxidation states and electronic states in loellingite (FeAs2)
- Hydrothermal alteration of olivine in a flow-through autoclave: Nucleation and growth of serpentine phases
- The influence of bulk composition on the diffusivity of carbon dioxide in Na aluminosilicate melts
- A combined rapid-quench and H2-membrane setup for internally heated pressure vessels: Description and application for water solubility in basaltic melts
- Letter. Crystal morphology of MV-1 magnetite
