Integrated Geological, Geochemistry and Geophysical Analysis Dataset of the Tan-Lu Fault Zone (XRD, XRF, Mössbauer Spectroscopy, Magnetic Susceptibility)
Description
This dataset is a comprehensive collection of geochemical and geological analysis data, with its core focus on the study of fault gouge from the Tan-Lu Fault Zone. It systematically integrates four major types of analytical data: mineral composition data from X-Ray Diffraction (XRD), geochemical element data from X-Ray Fluorescence (XRF), iron phase and valence state data from Mössbauer Spectroscopy, and rock magnetic property data from Magnetic Susceptibility. These multi-method datasets complement each other, providing detailed mineralogical and geochemical constraints for an in-depth understanding of the tectonic activity and fluid-rock interaction within the Tan-Lu Fault Zone.
Files
Steps to reproduce
X-ray powder diffraction (XRD) analyses were conducted using a Rigaku D/max-2500 PC diffractometer. Samples preparation involved: (1) cryogenic drying of fault rocks and gouges, (2) mechanical crushing to 40-60 mesh, (3) manual removal of country rock fragments under a stereomicroscope, and (4) fine grinding with corundum mortar to <200 mesh. Operational parameters comprised: Cu target, Kα radiation, 1 mm/8 mm/2.5°/Ni filter, slit system: DS (divergence slit): 1°, wavelength: 1.540 Å, operating voltage 40 kV, operating current 100 mA, continuous scanning mode, scanning range 2.5°~65° (2θ), step size 0.02°, scan speed 2°/min (Wang & Zeng, 2025). After testing, the diffraction data were processed using Jade 9 software to obtain mineral composition test results. Analyses were conducted using a Shimadzu Sequential 1800 wavelength-dispersive X-ray fluorescence (XRF) spectrometer, following the procedures detailed by Ma et al. (2012). To ensure data quality and instrumental stability, one replicate sample was analyzed for monitoring purposes after every batch of approximately 10 samples. The analytical uncertainties for most elements were 3-5%, as verified by repeated measurements of certified reference materials (e.g., GBW07112, GBW07101, GBW07401). Loss on ignition (LOI) was measured by heating the samples at 1000 °C for 1.5 hours in a muffle furnace, followed by cooling to 400 °C and then to room temperature in a desiccator, with the LOI value calculated from the weight loss. The measurements employed a constant-acceleration Mössbauer spectrometer (Model WSS-10) with a 25 mCi ⁵⁷Co(Rh) radioactive source. Prior to measurement, the fault gouge and fault breccia samples were ground in an agate mortar to pass through a 200-mesh sieve. To optimize the signal-to-noise ratio, the optimal mass for each sample was estimated; a mass of 70 mg was used for the 20 mm diameter sample holders. All spectra were collected at room temperature. Doppler velocity calibration was performed using a 25 μm-thick α-Fe foil. The data acquisition time for each spectrum was ≥ 72 hours (Wang et al., 2025). Spectral fitting was performed using Lorentzian line shapes within the Mosswinn 4.0 software. The resulting reduced chi-square values (χ²) ranged between 0.913 and 1.141, indicating reliable fitting results for the Mössbauer spectra. The measurements were conducted using a KLY-3S kappa bridge susceptibility meter (AGICO, Czech Republic) with a precision of 3×10⁻⁸ SI and an applied field of 300 A/m. Given the diamagnetic property of water and its potential influence on susceptibility measurements (Ramdhani et al., 2016), the samples were freeze-dried prior to analysis. Subsequently, they were ground in an agate mortar to pass through a 200-mesh sieve. The ground samples were weighed and then wrapped in non-magnetic plastic film for storage. The measured susceptibility values were normalized to sample mass to obtain mass-specific magnetic susceptibility (χ).
Institutions
- China University of GeosciencesHubei, Wuhan