In the Mănăila alpine area, the soil layer developed in situ on top of the sericite-schists, which belong to the Tulghes 3 metamorphic unit. The aim of the present work was to determine the degree of soil formation using both mineralogical and geochemical exploration methods. XRD, FTIR and SEM-EDS results showed that the soil constituents were dioctahedral 2:1 minerals, quartz, chlorite, Na-feldspar, rutire and ilmenite. Mainly illite and secondarily mixed-layer minerals were considered to be the most likely minerals resulting from the transformation of sericite and chlorite under acidic alpine conditions. Geochemical modeling inferred the dominance of illite and the presence of smectite as a chlorite alteration product. The weathering indices supported the moderate stage of the soil development agreeing with mineralogical observations. Because of the abundance of sericite and quartz in the parent material, the soil formation was retarded, and its present composition is still related to the bedrocks.

A carbonate-bearing, fluorine-overcompensated fluorapatite (F = 4.42 wt.% as compared with 3.77 wt.% F in the Ca₅(PO₄)₃F end-member), was identified in forsterite-bearing skarns from Valea Rea (N 46°39′48″, E 22°36′43″), located near the contact of the granodiorite laccolith from Budureasa, of Upper Cretaceous Age, with Anisian dolostones. The chemical structural formula (with carbonate not included) is: (Ca_4.989Mn_0.001Fe²⁺_0.003Mg_0.003Ce_0.001La_0.001)(P_2.992Si_0.008)(O_11.894F_1.202Cl_0.001). No major structural distortions due to (CO₃F)^3--for-(PO₄)^3- replacement were identified by single crystal X-ray diffraction, Raman or FTIR. The mineral crystallizes in space group P6₃/m, having as cell parameters a = 9.3818(1) Å and c = 6.8872(1) Å. The indices of refraction are: ω = 1.634(2) and ε = 1.631(1). The calculated density is D_x = 3.199 g/cm³ and the measured density is D_m = 3.201(3) g/cm³. Calculation of the Gladstone–Dale compatibility indices gave in all cases values indicative of superior agreement between physical and chemical data. In the infrared spectra, the multiplicity of the bands assumed to phosphate modes (1ν₁ + 2ν₂ + 3ν₃ + 3ν₄) agrees with the reduction of the symmetry of PO₄³⁻ ion from T_d to C₆. Chemical peculiarities and textural relations agree with a hydrothermal origin of the mineral, crystallized from F-rich fluids originating from the granodiorite intrusion.

A rich association of primary guano minerals, including taranakite, hydroxylapatite, brushite and gypsum with relicts of illite, kaolinite, alpha (low) quartz and calcite, was identified in the fossil bat guano deposit from Gura Dobrogei Cave, Dobrogea County, Romania. Gypsum and Ca phosphates developed preferentially on the carbonate bedrock or on fallen carbonate blocks in the guano mass, whereas taranakite was identified in the clay-rich, detritic sequences. The mineral species from the cave were characterized by optical methods, scanning electron microscopy, X-ray powder diffraction, Fourier-transform infrared and inductively coupled plasma–atomic emission spectrometry analysis. Chemically induced local dehydration of primary minerals, characterized by low temperatures (up to 100 ^∘C or even lower) and critically depending on exothermal reactions in the guano mass, prompted the formation of a secondary association, consisting of francoanellite, bassanite and monetite. Topotactic substitutions were observed in the cases of francoanellite on taranakite, bassanite on gypsum and monetite on brushite. In its turn, ardealite was partially replaced by monetite and bassanite. The sequential dehydration process seems driven by the degradation of organic matter by microbial action and also, presumably, by other exothermic reactions at local scale (e.g., oxidation of ammonia, allogenic pyrite or other organic compounds).

A shallow-level monzodioritic to quartz-monzodioritic pluton of the Upper Cretaceous age caused contact metamorphism of Tithonic–Kimmeridgian reef limestones at Măgureaua Vaţei (Metaliferi Massif, Apuseni Mountains, Romania). The preserved peak metamorphic assemblage includes gehlenite (Ak 33.64–38.13), monticellite, wollastonite-2M, Ti-poor calcic garnet, and Ca-Tschermak diopside (with up to 11.15 mol.% Ca-Tschermak molecule). From the monzodioritic body to the calcitic marble, the periplutonic zoning can be described as: monzodiorite/agpaitic syenite-like inner endoskarn/wollastonite + perovskite + Ti-poor grossular + Al-rich diopside/wollastonite + Ti-poor grossular + diopside + vesuvianite/gehlenite + wollastonite + Ti poor grossular + Ti-rich grossular (outer endoskarn)/wollastonite + vesuvianite + garnet (inner exoskarn)/wollastonite + Ti-rich garnet + vesuvianite + diopside (outer exoskarn)/calcitic marble. Three generations of Ca garnets could be identified, as follows: (1) Ti-poor grossular (Grs 53.51–81.03 mol.%) in equilibrium with gehlenite; (2) Ti-rich grossular (Grs 51.13–53.47 mol.%, with up to 19.97 mol.% morimotoite in solid solution); and (3) titanian andradite (Grs 32.70–45.85 mol.%), with up to 29.15 mol.% morimotoite in solid solution. An early hydrothermal stage produced retrogression of the peak paragenesis toward vesuvianite, hydroxylellestadite (or Si-substituted apatite), clinochlore, “hibschite” (H₄O₄-substituted grossular). A late hydrothermal event induced the formation of lizardite, chrysotile, dickite, thaumasite, okenite and tobermorite. A weathering paragenesis includes allophane, C-S-H gels and probably portlandite, unpreserved because of its transformation in aragonite then calcite. Overprints of these late events on the primary zoning are quite limited.

An ammonium-bearing fluorapophyllite-(K) occurs as a late hydrothermal product in the outer endoskarn zone from Aleului Valley (N 46°37′04″, E 22°35′22″), located at the contact of the granodiorite laccolith from Pietroasa, of Upper Cretaceous age, with Anisian dolostones. Associated minerals are wollastonite, K feldspar, diopside, fluorapatite, talc, and pectolite. The chemical structural formula is [K_0.985Na_0.012(NH₄)_0.076]_Σ=1.073(Ca_4.009Mn_0.001Fe²⁺_0.003Mg_0.002Ba_0.001)_Σ=4.016(Si_7.953Al_0.047) O_20.029[F_0.899(OH)_0.101]·8.059H₂O. The structure was successfully refined as tetragonal, space group P4/mnc, with cell parameters of a = 8.9685(1) Å and c = 15.7885(5) Å. The indices of refraction are ω = 1.534(1) and ε = 1.536(1). The calculated density is D_x = 2.381 g/cm³, in good agreement with the measured density, D_m = 2.379(4) g/cm³. The thermal analysis shows that the mineral completely dehydrates at up to 450 °C (endothermic effects at 330, 371, and 448 °C) and loses ammonium at 634 °C. In the infrared spectra, the multiplicity of the bands assumed to be silicate modes (1ν₁ + 3ν₃ + 2ν₂ + 3ν₄) agrees with the reduction in the symmetry of the SiO₄⁴⁻ ion from T_d to C_δ. Fluorapophyllite-(K) from Aleului Valley is of late hydrothermal origin and crystallized from F-rich fluids originating from the granodiorite intrusion, which mobilized K, Ca, and Si from the pre-existing feldspar.