Origin of Peridotites and Chromitites in the Pozanti‐kar Santi Ophiolite, Turkey
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2017-05-01 |
| Journal | Acta Geologica Sinica - English Edition |
| Authors | Dongyang Lian, Jingsui Yang, Michael Wiedenbeck, Yıldırım Dilek, Alexander Rocholl |
| Institutions | Miami University, Chinese Academy of Geological Sciences |
| Citations | 1 |
| Analysis | Full AI Review Included |
Technical Analysis and Documentation: Diamond for Extreme Geochemical Analysis
Section titled “Technical Analysis and Documentation: Diamond for Extreme Geochemical Analysis”Executive Summary
Section titled “Executive Summary”This geological study analyzing the Pozanti-Karsanti ophiolite highlights the natural formation of microdiamond and moissanite (SiC) under ultra-high pressure and ultra-high reducing conditions. This research directly validates the need for high-performance diamond materials in replicating and analyzing extreme geological and physical processes.
- Key Discovery: Over 200 grains of microdiamond and 100 grains of moissanite (SiC) were successfully separated and analyzed from Turkish podiform chromitites.
- Analytical Demand: High-precision analysis of carbon ($\delta^{13}\text{C}{\text{PDB}}$) and nitrogen ($\delta^{15}\text{N}{\text{AIR}}$) isotopic compositions was conducted using advanced Secondary Ion Mass Spectrometry (SIMS).
- Isotopic Range: Natural diamond exhibited a wide carbon isotopic range (-28.4 ‰ to -18.8 ‰), demonstrating variability essential for mantle studies.
- Material Relevance: Replicating these analyses or simulating these extreme formation conditions requires robust, high-ppurity Single Crystal Diamond (SCD) or customized Polycrystalline Diamond (PCD).
- 6CCVD Value Proposition: 6CCVD specializes in custom MPCVD diamond, including isotopically enriched or depleted standards vital for calibrating SIMS, EDX, and Laser Raman equipment used in this research.
- Capabilities Match: We offer the precise materials (optical quality, low nitrogen) and customization (dimensions, polishing, metalization) necessary to support high-P/T experimentation and deep Earth geochemistry.
Technical Specifications
Section titled “Technical Specifications”The following hard data points were extracted from the analysis of natural microdiamond and moissanite (SiC) conducted using CARMECA 1280-HR SIMS. This data defines the necessary precision required for geological reference standards.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Diamond Grains Analyzed | > 200 | grains | Quantity separated from podiform chromitite |
| Moissanite Grains Analyzed | > 100 | grains | Quantity separated (identified as SiC) |
| Diamond Carbon Isotope Range ($\delta^{13}\text{C}_{\text{PDB}}$) | -28.4 to -18.8 | ‰ | Range derived from 61 total results |
| Moissanite Carbon Isotope Range ($\delta^{13}\text{C}_{\text{PDB}}$) | -30.5 to -27.2 | ‰ | Range derived from 31 total results |
| Moissanite Carbon Isotope Mean ($\delta^{13}\text{C}_{\text{PDB}}$) | -29.0 | ‰ | Average isotopic composition |
| Diamond Nitrogen Isotope Range ($\delta^{15}\text{N}_{\text{AIR}}$) | -19.1 to 16.6 | ‰ | Reflects a relatively large variation across 40 results |
| Conditions of Formation | High-pressure, Ultra-high reducing | N/A | Inferred genesis environment for diamond and moissanite |
Key Methodologies
Section titled “Key Methodologies”The study relied heavily on separating and characterizing unusual minerals found within the chromitites, employing state-of-the-art analytical tools that benefit directly from 6CCVD’s engineered diamond products.
- Mineral Separation: Extensive heavy mineral separation work was performed to isolate microdiamond, moissanite, rutile, zircon, monazite, and various sulphides from the chromitite host rock.
- Initial Mineral Identification:
- Energy Dispersive X-ray Spectroscopy (EDX) was used for elemental composition.
- Laser Raman analyses were performed to confirm the crystal structure of diamond and moissanite (SiC).
- High-Precision Isotopic Analysis:
- Both separated diamond and moissanite were analyzed for carbon and nitrogen isotopic composition.
- Analysis utilized the CARMECA 1280-HR large geometry Secondary Ion Mass Spectrometer (SIMS) at the Helmholtz Zentrum Potsdam.
- Geochemical Interpretation: Data was interpreted to support the genesis of ophiolitic materials under extreme high-pressure and ultra-high reducing conditions, involving melt-rock reactions and magma mixing.
6CCVD Solutions & Capabilities
Section titled “6CCVD Solutions & Capabilities”This research demonstrates a critical need for high-purity, isotopically controlled diamond materials for use as SIMS standards, high-pressure cells, and optical components. 6CCVD’s advanced MPCVD synthesis capabilities are perfectly aligned to meet these precise requirements.
Applicable Materials for Geochemical Research
Section titled “Applicable Materials for Geochemical Research”To replicate or extend this research, focusing on high-pressure synthesis or highly sensitive analytical techniques (SIMS, Raman), 6CCVD recommends:
- Isotopic Control Grade SCD: Critical for calibrating SIMS instruments (like the CARMECA 1280-HR) used for $\delta^{13}\text{C}$ analysis. We offer single crystal diamond with customized 12C/13C ratios to create primary reference standards across the geochronological range.
- High-Purity Optical Grade SCD: Necessary for components requiring high transparency and low nitrogen content (e.g., nitrogen substitution is measured in the paper). Used for windows in DACs (Diamond Anvil Cells) or as ultra-low background Raman substrates.
- Polycrystalline Diamond (PCD) Substrates: Excellent thermal management and mechanical stability for large-scale analytical equipment or sample mounting systems, especially where large areas (up to 125mm) are required.
Customization Potential for Research Replication
Section titled “Customization Potential for Research Replication”6CCVD offers extensive engineering services to tailor diamond properties to the most rigorous scientific applications, surpassing the requirements of commercial stock material.
| Required Specification | 6CCVD Capability | Direct Research Relevance |
|---|---|---|
| Isotopic Control | Custom synthesis enabling enrichment or depletion of 13C and control of trace nitrogen/N-aggregation states. | Essential for creating calibration standards for SIMS $\delta^{13}\text{C}$ and $\delta^{15}\text{N}$ analysis. |
| Mechanical Strength (DAC) | SCD plates up to 500µm thickness, optimized for high-pressure Diamond Anvil Cell applications. | Replicating the high-pressure genesis conditions inferred for the ophiolitic diamond. |
| Dimensions | Custom Plates/wafers up to 125mm (PCD) and specialized geometries via laser cutting. | Providing custom window shapes or anvils tailored to specific CARMECA or Raman instrument geometries. |
| Surface Finish | SCD polished to Ra < 1nm; Inch-size PCD polished to Ra < 5nm. | Minimizing background signal interference for highly sensitive Laser Raman analyses and improving optical clarity. |
| Metalization Services | Internal capability for Au, Pt, Pd, Ti, W, Cu layers. | Enabling patterned electrodes or stable bonding interfaces for electrical or heating experiments within high-P/T cells. |
Engineering Support
Section titled “Engineering Support”6CCVD’s in-house PhD team provides specialized material science support for projects targeting extreme conditions. We can assist researchers replicating the high-pressure and ultra-high reducing environment identified in the Pozanti-Karsanti Ophiolite study by selecting the optimal MPCVD diamond grade for optical transmission, thermal management, and mechanical durability in DAC systems.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
The Pozanti‐Karsanti ophiolite (PKO) in Turkey’s eastern Tauride belt comprises mantle peridotites, ultramafic to mafic cumulates, isotropic gabbros, sheeted dikes and pillow lavas. The mantle peridotites are dominated by spinel harzburgites with minor dunites. The harzburgites and dunites have quite depleted mineral and whole‐rock chemical composition, suggesting high degrees of partial melting. Their PGEs vary from Pd‐depleted to distinct Pd‐enriched patterns, implying the crystallization of interstitial sulphides from sulphur‐saturated melts (e.g. MORB‐like forearc basalt). U‐shaped or spoon‐shaped REE patterns indicate that the PKO peridotites may have also been metasomatized by the LREE‐enriched fluids released from a subducting slab in a suprasubduction zone. Based on the mineral and whole‐rock chemical compositions, the PKO peridotites show affinities to forearc peridotites. Chromitites occur both in the mantle peridotites and the mantle‐crust transition zone horizon (MTZ). Chromitites from the two different horizons have different textures but similar mineral compositions, consistent with typical high‐Cr chromitites. Chromitites hosted by mantle harzburgites generally have higher total platinum‐group element (PGE) contents than those of the MTZ chromitites. However, both chromitites show similar chondrite‐normalized PGE patterns characterized by clear IPGEs, Rh‐enrichments relative to Pt and Pd. Such PGE patterns indicate no or only minor crystallization of Pt‐ and Pd enriched sulphides during formation of chromitites from a sulphur‐undersaturated melt (e.g. boninitic or island arc tholeiitic melt). Dunite enveloping chromitite lenses in the hosting harzburgite resulted from melt‐rock reaction. We have performed mineral separation work on samples of podiform chromitite hosted by harzburgites. So far, more than 200 grains of microdiamond and more than 100 grains of moissanite (SiC) have been separated from podiform chromitites. These minerals have been identified by EDX and Laser Raman analyses. The diamonds and moissanite are accompanied by large amounts of rutile. Additionally, zircon, monazite and sulphides are also common phases within the heavy mineral separates. Both diamond and moissanite have been analyzed for carbon and nitrogen isotopic composition using the CARMECA 1280‐HR large geometry Secondary Ion Mass Spectrometer at the Helmholtz Zentrum Potsdam. In total, 61 δ 13 C PDB results for diamond were acquired, exhibiting a range from −28.4 ‰ to −18.8 ‰. 31 δ 13 C PDB results for Moissanite vary between −30.5 ‰ to −27.2 ‰, with a mean value of −29.0 ‰. Diamond has relatively large variation in nitrogen isotopic composition with 40 δ 15 N AIR results ranging from −19.1 ‰to 16.6 ‰. The discovery of diamond, moissanite and the other unusual minerals from podiform chromitite of the Pozanti‐Karsanti ophiolite provides new support for the genesis of ophiolitic peridotites and chromitites under high‐pressure and ultra‐high reducing conditions. Considering the unusual minerals, the high Mg# silicate inclusions, and the needle‐shaped exsolutions in the PKO chromitites, the parental melts of these chromitites may have been mixed with deep asthenospheric basaltic melts that had assimilated materials of the descending slab when passing through the slab in a subduction zone environment. We suggest melt‐rock reactions, magma mixing and assimilation may have triggered the oversaturation of chromites and the formation of PKO chromitites.