Influence of Deformation and Fluids on Ti Exchange in Natural Quartz

Michel Bestmann; Giorgio Pennacchioni; Bernhard Grasemann; Benjamin Huet; Michael W.M. Jones; Cameron M. Kewish

doi:10.1029/2021JB022548

Influence of Deformation and Fluids on Ti Exchange in Natural Quartz

Michel Bestmann (Corresponding author)
, Giorgio Pennacchioni
, Bernhard Grasemann
, Benjamin Huet
, Michael W.M. Jones
, Cameron M. Kewish

Publications: Contribution to journal › Article › Peer Reviewed

Abstract

Using a combination of microstructural, spectroscopic, and geochemical analyses, we investigate how subgrain rotation recrystallization and fluid migration affect Ti concentration [Ti] in naturally deformed quartz veins from the Prijakt Nappe (Austroalpine Unit, Eastern Alps). These coarse-grained quartz veins, that formed at amphibolite facies conditions, were overprinted by lower greenschist facies deformation to different degrees. During the overprint, subgrain rotation recrystallization was dominant during progressive deformation to ultramylonitic stages. The initial [Ti] (3.0–4.7 ppm) and cathodoluminescence (CL) signature of the vein crystals decrease during deformation mainly depending on the availability of fluids across the microstructure. The amount of strain played a subordinate role in resetting to lower [Ti] and corresponding darker CL shades. Using a microstructurally controlled analysis we find that the most complete re-equilibration in recrystallized aggregates ([Ti] of 0.2–0.6 p.m.) occurred (a) in strain shadows around quartz porphyroclasts, acting as fluid sinks, and (b) in localized microshear zones that channelized fluid percolation. [Ti] resetting is mainly observed along wetted high angle boundaries (misorientation angle >10–15°), with partial [Ti] resetting observed along dry low angle boundaries (<10–15°). This study shows for the first time that pure subgrain rotation recrystallization in combination with dissolution-precipitation under retrograde condition provide microstructural domains suitable for the application of titanium-in-quartz geothermobarometry at deformation temperatures down to 300–350°C.

Original language	English
Article number	e2021JB022548
Number of pages	26
Journal	Journal of Geophysical Research: Solid Earth
Volume	126
Issue number	12
DOIs	https://doi.org/10.1029/2021JB022548
Publication status	Published - Dec 2021

Funding

This work was funded by the Deutsche Forschungsgemeinschaft DFG (BE 2413/3-1). GP acknowledge funding from the University of Padova (BIRD175145/17). Access to the SEM-EBSD facilities was provided by the Department of Werkstoffwissenschaften WW1, FAU Erlangen-N?rnberg, Germany. The Oxford Instruments CMOS-Symmetry EBSD detector was funded by the DFG (JA 2718/3-1). Jay Thomas is thanked for providing the synthetic Ti-doped quartz standard (QTiP-38, Ti 380 ppm), Djordje Grujic for the natural standard (TN-06, 0.3 ppm) and Steven Kidder for the Herkimer ?Diamond? used as a Ti blank. Cees-Jan De Hoog is thanked for conducting SIMS measurements and processing at the School of Geosciences of the University of Edinburgh. We acknowledge Holger St?nitz for discussion and providing access to the SEM-CL spectra facilities at the Department of Geosciences at the Arctic University of Norway (Troms?), and Amicia Lee and Tom-Ivar Eilertsen for their assistance. Christoph E. Schrank and Nicholas W. Phillips are thanked for their contribution with respect to the synchrotron data set. Part of this research was undertaken on the XFM beamline at the Australian Synchrotron, part of ANSTO. Rene Romer is thanked for support during electron microprobe analysis (chlorite thermometry) and Friederike Urban and Raphael Njul for sample preparation. Alexis Plunder is thanked for the chlorite thermometry blind test. We are grateful for constructive reviews of Steve Kidder and Leif Tokle and the assessment of an anonymous associated editor of JGR-Solid Earth. Open access funding enabled and organized by Projekt DEAL. This work was funded by the Deutsche Forschungsgemeinschaft DFG (BE 2413/3‐1). GP acknowledge funding from the University of Padova (BIRD175145/17). Access to the SEM‐EBSD facilities was provided by the Department of Werkstoffwissenschaften WW1, FAU Erlangen‐Nürnberg, Germany. The Oxford Instruments CMOS‐Symmetry EBSD detector was funded by the DFG (JA 2718/3‐1). Jay Thomas is thanked for providing the synthetic Ti‐doped quartz standard (QTiP‐38, Ti 380 ppm), Djordje Grujic for the natural standard (TN‐06, 0.3 ppm) and Steven Kidder for the Herkimer “Diamond” used as a Ti blank. Cees‐Jan De Hoog is thanked for conducting SIMS measurements and processing at the School of Geosciences of the University of Edinburgh. We acknowledge Holger Stünitz for discussion and providing access to the SEM‐CL spectra facilities at the Department of Geosciences at the Arctic University of Norway (Tromsö), and Amicia Lee and Tom‐Ivar Eilertsen for their assistance. Christoph E. Schrank and Nicholas W. Phillips are thanked for their contribution with respect to the synchrotron data set. Part of this research was undertaken on the XFM beamline at the Australian Synchrotron, part of ANSTO. Rene Romer is thanked for support during electron microprobe analysis (chlorite thermometry) and Friederike Urban and Raphael Njul for sample preparation. Alexis Plunder is thanked for the chlorite thermometry blind test. We are grateful for constructive reviews of Steve Kidder and Leif Tokle and the assessment of an anonymous associated editor of JGR‐Solid Earth. Open access funding enabled and organized by Projekt DEAL.

Austrian Fields of Science 2012

105124 Tectonics

Keywords

cathodoluminescence
correlative data workflow
geochemical re-equilibration
Quartz
recrystallization processes
TitaniQ thermobarometry
AUSTROALPINE BASEMENT
ALPINE
TITANIUM
CHLORITE
PRESSURE
TEMPERATURE
DYNAMIC RECRYSTALLIZATION MECHANISMS
CONSTRAINTS
DIFFUSION
FAULT

Access to Document

10.1029/2021JB022548Licence: CC BY-NC-ND 4.0

Cite this

@article{2e4768dc39e84d0f843fdb2c26130b4f,

title = "Influence of Deformation and Fluids on Ti Exchange in Natural Quartz",

abstract = "Using a combination of microstructural, spectroscopic, and geochemical analyses, we investigate how subgrain rotation recrystallization and fluid migration affect Ti concentration [Ti] in naturally deformed quartz veins from the Prijakt Nappe (Austroalpine Unit, Eastern Alps). These coarse-grained quartz veins, that formed at amphibolite facies conditions, were overprinted by lower greenschist facies deformation to different degrees. During the overprint, subgrain rotation recrystallization was dominant during progressive deformation to ultramylonitic stages. The initial [Ti] (3.0–4.7 ppm) and cathodoluminescence (CL) signature of the vein crystals decrease during deformation mainly depending on the availability of fluids across the microstructure. The amount of strain played a subordinate role in resetting to lower [Ti] and corresponding darker CL shades. Using a microstructurally controlled analysis we find that the most complete re-equilibration in recrystallized aggregates ([Ti] of 0.2–0.6 p.m.) occurred (a) in strain shadows around quartz porphyroclasts, acting as fluid sinks, and (b) in localized microshear zones that channelized fluid percolation. [Ti] resetting is mainly observed along wetted high angle boundaries (misorientation angle >10–15°), with partial [Ti] resetting observed along dry low angle boundaries (<10–15°). This study shows for the first time that pure subgrain rotation recrystallization in combination with dissolution-precipitation under retrograde condition provide microstructural domains suitable for the application of titanium-in-quartz geothermobarometry at deformation temperatures down to 300–350°C.",

keywords = "cathodoluminescence, correlative data workflow, geochemical re-equilibration, Quartz, recrystallization processes, TitaniQ thermobarometry, AUSTROALPINE BASEMENT, ALPINE, TITANIUM, CHLORITE, PRESSURE, TEMPERATURE, DYNAMIC RECRYSTALLIZATION MECHANISMS, CONSTRAINTS, DIFFUSION, FAULT",

author = "Michel Bestmann and Giorgio Pennacchioni and Bernhard Grasemann and Benjamin Huet and Jones, \{Michael W.M.\} and Kewish, \{Cameron M.\}",

year = "2021",

month = dec,

doi = "10.1029/2021JB022548",

language = "English",

volume = "126",

journal = "Journal of Geophysical Research: Solid Earth",

issn = "2169-9313",

number = "12",

}

TY - JOUR

T1 - Influence of Deformation and Fluids on Ti Exchange in Natural Quartz

AU - Bestmann, Michel

AU - Pennacchioni, Giorgio

AU - Grasemann, Bernhard

AU - Huet, Benjamin

AU - Jones, Michael W.M.

AU - Kewish, Cameron M.

PY - 2021/12

Y1 - 2021/12

N2 - Using a combination of microstructural, spectroscopic, and geochemical analyses, we investigate how subgrain rotation recrystallization and fluid migration affect Ti concentration [Ti] in naturally deformed quartz veins from the Prijakt Nappe (Austroalpine Unit, Eastern Alps). These coarse-grained quartz veins, that formed at amphibolite facies conditions, were overprinted by lower greenschist facies deformation to different degrees. During the overprint, subgrain rotation recrystallization was dominant during progressive deformation to ultramylonitic stages. The initial [Ti] (3.0–4.7 ppm) and cathodoluminescence (CL) signature of the vein crystals decrease during deformation mainly depending on the availability of fluids across the microstructure. The amount of strain played a subordinate role in resetting to lower [Ti] and corresponding darker CL shades. Using a microstructurally controlled analysis we find that the most complete re-equilibration in recrystallized aggregates ([Ti] of 0.2–0.6 p.m.) occurred (a) in strain shadows around quartz porphyroclasts, acting as fluid sinks, and (b) in localized microshear zones that channelized fluid percolation. [Ti] resetting is mainly observed along wetted high angle boundaries (misorientation angle >10–15°), with partial [Ti] resetting observed along dry low angle boundaries (<10–15°). This study shows for the first time that pure subgrain rotation recrystallization in combination with dissolution-precipitation under retrograde condition provide microstructural domains suitable for the application of titanium-in-quartz geothermobarometry at deformation temperatures down to 300–350°C.

AB - Using a combination of microstructural, spectroscopic, and geochemical analyses, we investigate how subgrain rotation recrystallization and fluid migration affect Ti concentration [Ti] in naturally deformed quartz veins from the Prijakt Nappe (Austroalpine Unit, Eastern Alps). These coarse-grained quartz veins, that formed at amphibolite facies conditions, were overprinted by lower greenschist facies deformation to different degrees. During the overprint, subgrain rotation recrystallization was dominant during progressive deformation to ultramylonitic stages. The initial [Ti] (3.0–4.7 ppm) and cathodoluminescence (CL) signature of the vein crystals decrease during deformation mainly depending on the availability of fluids across the microstructure. The amount of strain played a subordinate role in resetting to lower [Ti] and corresponding darker CL shades. Using a microstructurally controlled analysis we find that the most complete re-equilibration in recrystallized aggregates ([Ti] of 0.2–0.6 p.m.) occurred (a) in strain shadows around quartz porphyroclasts, acting as fluid sinks, and (b) in localized microshear zones that channelized fluid percolation. [Ti] resetting is mainly observed along wetted high angle boundaries (misorientation angle >10–15°), with partial [Ti] resetting observed along dry low angle boundaries (<10–15°). This study shows for the first time that pure subgrain rotation recrystallization in combination with dissolution-precipitation under retrograde condition provide microstructural domains suitable for the application of titanium-in-quartz geothermobarometry at deformation temperatures down to 300–350°C.

KW - cathodoluminescence

KW - correlative data workflow

KW - geochemical re-equilibration

KW - Quartz

KW - recrystallization processes

KW - TitaniQ thermobarometry

KW - AUSTROALPINE BASEMENT

KW - ALPINE

KW - TITANIUM

KW - CHLORITE

KW - PRESSURE

KW - TEMPERATURE

KW - DYNAMIC RECRYSTALLIZATION MECHANISMS

KW - CONSTRAINTS

KW - DIFFUSION

KW - FAULT

UR - https://www.scopus.com/pages/publications/85121684202

U2 - 10.1029/2021JB022548

DO - 10.1029/2021JB022548

M3 - Article

AN - SCOPUS:85121684202

SN - 2169-9313

VL - 126

JO - Journal of Geophysical Research: Solid Earth

JF - Journal of Geophysical Research: Solid Earth

IS - 12

M1 - e2021JB022548

ER -

Influence of Deformation and Fluids on Ti Exchange in Natural Quartz

Abstract

Funding

Austrian Fields of Science 2012

Keywords

Access to Document

Other files and links

Fingerprint

Cite this