Secondary mineralogenesis in the gold-silver and polymetallic exploitation areas from Romania



The study of secondary mineralogenesis in the gold-silver and polymetallic exploitation areas from Romania will involve the study of secondary alterations (efflorescence and weathering crusts) and sediments/detritic material from mineralogical and geochemical point of view. Also, this project aims to study the acid mine drainage, a phenomenon which is mainly due to the alteration processes (oxidation, hydration-dehydration, neutralization) caused by metal sulfides typical to epithermal deposits operated in open pit mining type (open pits, waste dumps, tailing ponds). The present study also aims to integrate the results in an international database with distribution maps of identified minerals and minor elements in the investigated perimeters. To achieve its purpose, the following types of samples will be collected: efflorescence samples, ore samples showing alteration crust, acid water samples from temporary ponds and streams/rivers that cross the perimeter and sediment/detritic material samples. The analytical methods used in the proposed project are Raman spectrometry, Infrared spectrometry, X-ray diffractometry, X-ray fluorescence, scanning electron microscopy, micro- and macroscopic investigations and determinations of chemical parameters.


The specific objectives of the project are:

Elements of originality and innovation:


The main analytical methods used in this study are:

Raman spectrometry

  • Raman Spectrograph Horiba Jobin-Yvon RPA HE-532 with a multichannel air cooled (−70 °C) CCD detector, using a Nd-Yag laser 532 nm excitation source.
  • The spectral range is between 210 and 3400 cm−1 with a spectral resolution of 3 cm−1.
  • The Raman system includes a “Superhead” fiber optic Raman probe for non-contact measurements, with a 50× LWD Olympus objective, NA = 0.50, WD = 10.6 mm, and FIB50/10M optical fiber.
  • The laser spot diameter on the sample surface was approximately 2–3 µm (the minimum theoretical spot diameter is 1.3 µm).
  • Sulfur and ciclohexane were used for the calibration.

Infrared spectrometry

  • Bruker Vertex 70 Fourier-transform infrared (FT-IR) spectrometer with a spectral resolution of 2 cm−1 and the spectral range between 370-4000 cm−1.
  • The measurements were taken at room temperature using a KBr pellet technique.

Complementary analytical methods used in this study are: X-ray diffractometry, SEM, SEM-EDX and X-ray fluorescence.



Project website - 90% — http://geology.uaic.ro/mingen/
Building the geological maps of the studied perimeters and developing the GIS server - 55% — http://geologis.uaic.ro
Infrared database development - 50% — www.ft-ir.ro


Contact me and I'll get back to you soon.

Iasi, RO

andrei.apopei [at] uaic.ro