The role of silica precipitation kinetics in determining the rate of quartz pressure solution

1991 ◽  
Vol 96 (B6) ◽  
pp. 10007 ◽  
Author(s):  
Andrew M. Mullis
Keyword(s):  
Pressure Solution ◽  
Precipitation Kinetics ◽  
Silica Precipitation

scholarly journals Role of pressure solution in the formation of bedding-parallel calcite veins in an immature shale (Cretaceous, southern UK)

2018 ◽  
Vol 156 (5) ◽  
pp. 918-934 ◽  
Author(s):  
QINGFENG MENG ◽  
JOHN HOOKER ◽  
JOE CARTWRIGHT
Keyword(s):  
Critical Role ◽  
Maximum Principal Stress ◽  
Feedback Mechanism ◽  
Black Shales ◽  
Pressure Solution ◽  
Overburden Pressure ◽  
Axis Orientation ◽  
Calcite Veins ◽  
Fibre Growth

AbstractBedding-parallel fibrous calcite veins in black shales (Cretaceous, southern UK) were investigated using a combined field, stable isotopic geochemistry, petrographic and crystallographic method to examine their formation mechanism. Calcite veins occur in all shale beds and are most abundant in the bituminous shales of the Chief Beef Beds. The calcite fibres in these veins exhibit either an antitaxial fibre growth with curvy stylolites as the median zone, or a predominantly syntaxial, upwards growth. The calcite veins range from –0.49 to 1.78‰ of δ13C values, and –6.53 to –0.03‰ of δ18O values, which are both similar to those of their host shales. Our petrographic observations demonstrate that subhorizontal and interconnecting microstylolite networks commonly occur within the calcite veins. Equant calcite grains in the median zones exhibit indenting, truncating and also interpenetrating grain contacts. It is interpreted that the fibrous calcite veins were sourced by neomorphic calcite from their host shales, with evidence from the δ13C signatures, pressure-solution features (stylolites, microstylolites and grain contact styles) and embedded fossil ghosts within the veins. The diagenetic fluids, from which calcite was precipitated, were a mixing of the original seawaters and 18O-depleted meteoric waters. Development of bedding-parallel calcite veins is considered to have been enhanced by pressure solution as a positive feedback mechanism, which was facilitated by the overburden pressure as the maximum principal stress. Calcite fibres, with a predominant subvertical c-axis orientation, exhibit a displacive growth in porous shales and a replacive growth at vein-limestone contacts. This study highlights the critical role of pressure solution in the formation of bedding-parallel calcite veins during burial and diagenesis of immature black shales.

Imidazole catalyzed silica synthesis: Progress toward understanding the role of histidine in (bio)silicification

2009 ◽  
Vol 24 (5) ◽  
pp. 1700-1708 ◽  
Author(s):  
Mei-Keat Liang ◽  
Siddharth V. Patwardhan ◽  
Elena N. Danilovtseva ◽  
Vadim V. Annenkov ◽  
Carole C. Perry
Keyword(s):  
Molecular Weight ◽  
Silicic Acid ◽  
Catalytic Mechanism ◽  
Synthetic Polymers ◽  
Precipitation Process ◽  
Silica Precipitation ◽  
Silica Synthesis ◽  
Different Molecular Weight

Histidine is an amino acid present in proteins involved in biosilica formation and often found in peptides identified during phage display studies but its role(s) and the extent of its involvement in the silica precipitation process is not fully understood. In this contribution we describe results from an in vitro silicification study conducted using poly-histidine (P-His) and a series of different molecular weight synthetic polymers containing the imidazole functionality (polyvinylimidazole, PVI) for comparison. We show that the presence of imidazole from PVI or P-His is able to catalyze silicic acid condensation; the effect being greater for P-His. The catalytic mechanism is proposed to involve the dual features of the imidazole group—its ability to form hydrogen bonds with silicic acid and electrostatic attraction toward oligomeric silicic acid species.

Role of electrochemical reactions in pressure solution

2009 ◽  
Vol 73 (10) ◽  
pp. 2862-2874 ◽  
Author(s):  
George W. Greene ◽  
Kai Kristiansen ◽  
Emily E. Meyer ◽  
James R. Boles ◽  
Jacob N. Israelachvili
Keyword(s):  
Electrochemical Reactions ◽  
Pressure Solution

The role of silicate surfaces on calcite precipitation kinetics

2014 ◽  
Vol 135 ◽  
pp. 231-250 ◽  
Author(s):  
Gabrielle J. Stockmann ◽  
Domenik Wolff-Boenisch ◽  
Nicolas Bovet ◽  
Sigurdur R. Gislason ◽  
Eric H. Oelkers
Keyword(s):  
Precipitation Kinetics ◽  
Calcite Precipitation

The Role of Excess Vacancies on Precipitation Kinetics in an Al-Mg-Sc Alloy

2008 ◽  
Vol 39 (10) ◽  
pp. 2297-2305 ◽  
Author(s):  
F. Fazeli ◽  
C.W. Sinclair ◽  
T. Bastow
Keyword(s):  
Precipitation Kinetics
Sign in / Sign up

Export Citation Format

Share Document