Silicate mineralogy

In continuity of mineralogical observations about alkaline massif on Ditrău, begun in 1975, this study deals with the study of feldspars-minerals with the largest spread and with a sensible petrogenetic signification, within the massif. After ample studies (Ianovici, 1933, 1938; Codarcea, Ianovici, Codarcea, 1954, Streckeisen, 1954, 1960, 1974), which outlined a general image about the petrogenesis of the massif, our recent researching revealed several particularities, which enhance the mineralogical and petro-graphical diversity of Ditrău occurrence. The massif represents as complex unit, with two structural compartments: a) Jolotca-Putna, north of Jolotca Valley; b) Valea Mare-Gudutz-Belcina, south of Valea Mare-Ditrău, differentiated by the nature of petrographic members, by their extension and succession. In the northern compartment, Jolotca-Putna, the petrographic members, younger from West to East, are represented by: a) ultramafites and mafites; b) diorites; c) monzodiorites and monzonites; d) syenitoides; e) granitoides. The foidic rocks, such as nepheline-bearing syen-ites, are subordinated and occur as marginal apophyses with circular contour. In the south compartment, Valea Mare-Güdutz-Belcina, the miscellaneous foidic rocks-foidic syen-ites, foidic monzonites, essexites-occupy the central part and marginally includes mafites and ultramafites. The foidic members are dis-continuously bordered by monzonites, syeni-toides and granitoides (Fig.1). The study of plagioclase feldspars-present in all petro-graphic types of the massif, excepting ultra-mafites-deals with their frequency and morphology , the intergrowth types, optical and chemical-structural elements and several aspects related to petrogenetic evolution of the massif. Being a continuation of the research on K-feldspar (Anastasiu, Constantinescu, 1978) this study is based on a similar number of sam-Published in: Studii şi cercetări de Geologie, Academia Română, tom 26-1981, pp. 83-95, Bucureşti The plagioclases from the alkaline massif of Ditrău are albite and oligoclase-andesine. Grain size and crystal morphology, intergrowths (twins, antiperthites, myrmekites), optical (2V) and structural (XR), (IR) parameters were established as well as high order of plagio-clases and low temperatures of crystallization. A petrologic genesis model was assumed. The plagioclases represent late crystallization minerals from alkaline natural melt; oligo-clase-andesine was separated earlier than microcline but albite was formed both during pla-gioclase decalcification and during exsolution of alkaline feldspars.

Abstract for a study on mineralogical infrared spectroscopy, currently out for review at Spectrochimica Acta A.  If you are interested in reviewing this paper, feel free to contact them.  This paper has 20 points of new discovery encapsulated in a new model of mineralogical infrared.

Zunyites, Al13Si5O20(OH,F)18Cl, have been studied by Raman and infrared microscopy. The infrared spectrum (700–4000 cm−1) is characterised by a band near 720 cm−1 and a quintet of bands at 890, 992, 1062, 1130 and 1176 cm−1. The first two bands are assigned to Al–OH deformation modes with the 992 cm−1 mode being infrared inactive and the latter three bands as Si–O symmetric stretching modes. The IR hydroxyl-stretching region shows three Al–OH stretching modes at 3313 cm−1 with a shoulder at ±3200 cm−1 and a low intensity band at ±3623 cm−1. The Raman hydroxyl-stretching region reveals seven bands corresponding with Al–OH modes at ±3634, 3431, 3374, 3354, 3337, 3320 and 3306 cm−1. The corresponding Al–OH deformation modes are observed at 930, 950 and 994 cm−1. In the Raman spectral region of 1000–1300 cm−1, Si–O–Si symmetric stretching modes are observed at 1067, 1101 and 1126 cm−1, from which the middle band is infrared inactive and therefore assigned to the 180° intertetrahedral Si–O–Si bond. The remaining bands at 1141, 1176, 1207, 1239 and 1295 cm−1 are assigned to (i) Al–O symmetric stretch modes (3x) from the Al octahedra and (ii) the AlO4 tetrahedron in the Al13 unit and (iii) Al3+ substituting Si4+ in the Si5O16 unit. The low frequency Raman region is characterised by the symmetric bending modes of Si–O–Si at 202 cm−1 and Si–O–Al at 213 cm−1 in the Si5O16 unit. The third symmetric stretching mode at 271 cm−1 is assigned to Al–O–Al in the Al13 unit. The five bands between 275 and 425 cm−1 are assigned to Si–O bending modes and the bands at 444 and 467 cm−1 to Al–O bending modes. The broad bands at 612 and 701 cm−1 are assigned to the Si–O–Al deformation modes, the latter of which is infrared inactive.

Holmquistite is a lithium-bearing orthorhombic amphibole , named after the Swedish petrologist Per Holmquist. It typically occurs at the contact of lithium rich pegmatites with surrounding rocks and is associated with metasomatic processes. The bands around 3660, 3645, 3635 and 3615 cm- 1 have been assigned to (3Mg)-OH, (2Mg + Fe2+)-0H, (Mg + 2Fe2+)-0H and (3Fe2+)-0H, respectively. Based on the ratio between
the 3645 and 3660 cm- 1 bands in the Raman spectrum the Fe2+ /(Fe2+ + Mg2+) ratio in the M1 and M3 sites has been determined to be 0.4 [14]. A similar calculation on the infrared OH-stretching bands indicate a slightly lower ratio around 0.3, but this value is less precise due to the presence of a broad background signal of adsorbed water.A limited number of vibrations are only infrared active, such as the bands
at 649, 737, 873, 923, and 1011 cm-1, while bands at 751 , 998, 1041 and 11 27 cm- 1 are only Raman active. All other bands are both infrared and Raman active. From the theoretically 86 possible vibrations in the infrared and Raman spectra in this region below 1200 cm-1 fo rty-four bands are observed. The 950--11 30 cm- 1 region represents the antisymmetric Si-0-Si and 0 - Si-O stretching vibrations. In the region
between 650 and 800 cm-1 bands are observed attributed to the symmetrical Si-0-Si and Si-0 vibrations. The region below 625 cm-1 is characterized by vibrations related to the deformation modes of the silicate chain and vibrations involving Mg, Fe, Al and Li in the various M sites. The 499 cm- 1 band is a Li-0 deformation mode while the bands at 448-454 and 557- 558 cm- 1 are Al-0 deformation modes. OH-libration and translation modes are observed around 302, 534, 587 and 6 12 cm-1.

Storage of carbon dioxide in geological formations involves changes in wettability to the host formation during injection and ultimately the formation of inorganic carbonates through mineral trapping. Sequestration locations will be at high pressure and high temperature, thus providing a challenging environment for in-situ study. However, infrared spectroscopy (FTIR) with the use of photons is not limited in temperature or pressure and therefore is applicable to study chemical changes to minerals occurring during carbon sequestration. Through the commission of a high pressure/high temperature in-situ FTIR cell and the subsequent spectroscopic following of carbonation reactions in synthesised silicate mineral analogues, we document fundamental chemical changes occurring at the nanoscale during carbon storage. Speciation, coordination of carbonate ions to the surface of silicate mineral analogues and changes in surface hydroxyl coverage are observed and discussed, in the context of CO2 injection and dissolution/mineralisation reactions of reservoir silicate minerals.

Course name: Earth Systems I: Solid Earth

Saint Louis University, Madrid Campus, Faculty: Science and Engineering

Semester:  Spring 2005.

Course description: On the structure of our planet and the forming processes: plate tectonics, crustal evolution, rocks, surface and groundwater hydrology, and so on. Focus on volcanic activity in the Canary Islands, where students will carry out field studies during a long-weekend visit.
Mandatory trip: Lanzarote (Canary Islands); unpaid fees result in automatic removal from class.

Course Objectives: 
By end of the course the student should:
• Know the basic types of rocks and understand the basic principles of the rock cycle.
• Know and understand the basic principles of plate tectonics and volcanism.
• Know and understand the most important processes on the earth´s surface.
• Achieve a foundation on the basic principles underlying the patterns and dynamics of the earth´s surface and interior.

Textbook: Following textbook is absolutely necessary for the course:
PRESS, Frank, & SIEVER, Raymond (2001): Understanding Earth. 3rd edition. – New York (W. H. Freeman and Company).

Supplementary reading: Following books may be interesting or helpful for some aspects of the course, but they are not necessary:
ANDEL, T. H. van, (1994): New views on an old planet. A history of global change. 439 pp.; Cambridge (Cambridge University Press).
ARAÑA, V., & CARRACEDO, J. C. (1979): Los volcanes de las islas Canarias. – Vol. I: Tenerife; Vol. II: Lanzarote y Fuerteventura.
BOLT, Bruce A. (1999): Earthquakes. – 366 p.; New York (W. H. Freeman and Company).
CUNNINGHAM, W.P., & SAIGO, B. Woodworth (1992): Environmental Science – A Global Concern. 2nd edition. – 622 p., Dubuque (Wm. C. Brown Publishers).
CUNNINGHAM, W.P., & CUNNINGHAM, M.A., & SAIGO, B. Woodworth (2002): Environmental Science – A Global Concern. 7th edition. – 646 p., Boston.
DECKER, Robrt & Barbara: Volcanoes. – 321 p.; New York (W. H. Freeman and Company).
MERRITTS, D., & WET, A. DE, & MENKING, K. (1998): Environmental geology. 452 pp.; New York (Freeman a. Co.).
SCARTH, Alwyn & TANGUY, Jean-Claude (2000): Volcanoes of Europe. – Oxford.
YARZA, Esperanza (1988): Volcanes de Iberoamerica. – 128 p.; Madrid (Anaya).

Course Calendar:
Tuesday, Jan. 18th: Introduction – Building a planet (Textbook chapter 1)
Thursday, Jan. 20th: Minerals (Textbook chapter 2)
Tuesday, Jan. 25 & Thursday, Jan. 27: Rocks (Textbook chapter 3)
Thursday, Jan. 27: End of DROP/ADD period
Tuesday, Feb. 1 & Thursday, Feb. 3: Igneous Rocks (Textbook chapter 4)
Tuesday, Feb. 8 & Thursday, Feb. 10: Volcanism (I) (Textbook chapter 5)
Tuesday, Feb. 15: Review & Preparation of first mid-term exam
Tuesday, Feb. 15: Deadline for the submission of the title of the paper
Thursday, Feb. 17: First mid-term exam
Tuesday, Feb. 22 & Thursday, Feb. 24: Volcanism (II) (Textbook chapter 5)
Tuesday, Mar. 1 & Thursday, Mar. 3: Volcanism (III) (Textbook chapter 5)
Saturday, Mar. 5, to Sunday, Mar. 13: SPRING BREAK
Tuesday, Mar. 15: Weathering and Erosion (Textbook chapter 6)
Thursday, Mar. 17, to Sunday, Mar.20: Field trip to the Canary Islands
Tuesday, Mar. 22: Sediments and Sedimentary Rocks (I) (Chapter 7)
Thursday, Mar. 24, to Sunday, Mar.27: Easter
Tuesday, Mar. 29: Review & Preparation of second mid-term exam
Thursday, Mar. 31: Second mid-term exam
Tuesday, Apr. 5: Deadline for the submission of papers and PowerPoint presentations
Tuesday, Apr. 5: Sediments and Sedimentary Rocks (II) (Chapter 7)
Thursday, Apr. 7: Metamorphic Rocks (Textbook chapter 8)
Thursday, Apr. 7: Deadline for the submission of the exercise
Friday, Apr. 8: Last day to drop a class and receive a grade of "W"
Tuesday, Apr. 12: The Rock Record and the Geologic Time Scale (Textbook chapter 9)
Thursday, Apr. 14: Rock Deformation (Textbook chapter 10)
Tuesday, Apr. 19 & Thursday, Apr. 21: The Hydrologic Cycle and Groundwater (Chapter 12)

We analyzed the official yearly mortality data due to malignant pleural meso-thelioma (MPM) from 1995 to 2002 in all 107 Italian provinces, and we related them to provincial resident population in the same years. The resulting ratios are displayed as geographically referenced maps, which enhance the visual impact on how that fatal disease distributes over the country. The following results are statistically meaningful: (1) internal migration changed the Italian population distribution, with major increases in regions Lombardy, Trentino–Alto Adige, Veneto, and Emilia–Romagna, and moderate decreases in Piemonte, Liguria, and Friuli–Venezia Giulia. (2) MPM mortality is increasing overall, with five provinces largely exceeding the average Italian rate: Alessandria (Piemonte), Genoa and La Spezia (Liguria), and Gorizia and Trieste (Friuli–Venezia Giulia). (3) There is a substantial mortality rate increase in the same provinces which shows decreasing population. Results are discussed with reference to well-known cases of asbestos-polluted sites such as Balangero and Casale Monferrato (Piemonte), Genoa and La Spezia (Liguria), and Monfalcone and Trieste (Friuli–Venezia Giulia). General unquestionable conclusions are (a) occupational exposure, especially working conditions, increases MPM mortality; (b) non-occupational exposure data are scattered, as are male versus female data, and cannot be dealt with statistically on a nationwide scale; (c) natural environmental exposure may contribute to MPM mortality, but its effect is still statistically minor. The MPM mortality apex is currently reached at Trieste, a province free of asbestos minerals occurring in their natural setting, but where MPM affects workers in the marine industry strongly who operated in contact with insulating outfits. Information on content and type of amphibole present in the asbestos materials used for industrial applications is scattered and generally scarce, thus making the evaluation of the amphibole versus chrysotile relative impact on MPM mortality rates statistically unsound.

The biorelated degradability and clearance of siliceous nanomaterials have been questioned worldwide, since they are crucial prerequisites for the successful translation in clinics. Typically, the degradability and biocompatibility of mesoporous silica nanoparticles (MSNs) have been an ongoing discussion in research circles. The reason for such a concern is that approved pharmaceutical products must not accumulate in the human body, to prevent severe and unpredictable side-effects. Here, the biorelated degradability and clearance of silicon and silica nanoparticles (NPs) are comprehensively summarized. The influence of the size, morphology, surface area, pore size, and surface functional groups, to name a few, on the degradability of silicon and silica NPs is described. The noncovalent organic doping of silica and the covalent incorporation of either hydrolytically stable or redox- and enzymatically cleavable silsesquioxanes is then described for organosilica, bridged silsesquioxane (BS), and periodic mesoporous organosilica (PMO) NPs. Inorganically doped silica particles such as calcium-, iron-, manganese-, and zirconium-doped NPs, also have radically different hydrolytic stabilities. To conclude, the degradability and clearance timelines of various siliceous nanomaterials are compared and it is highlighted that researchers can select a specific nanomaterial in this large family according to the targeted applications and the required clearance kinetics.

Article published in the trade journal Solids & Bulk Handling about the dangers associated with respirable crystalline silica dust and suggested control measures based on compliance with the Control of Substances Hazardous to Health Regulations (COSHH).

Calculation of the properties of dislocations by computer simulations requires, among other things, the availability of accurate interatomic potentials, ideally with ab-initio quality. For crystals with large unit cells and complex crystal structures, such as most minerals, the number and size of the calculations may severely limit the applicability of a full ab-initio approach. In this paper we present an investigation of the dislocation properties of coesite, a mineral with a relatively large unit cell, carried out with a force field developed for silica based on a parametrization to ab-initio data. Two-dimensional generalized stacking fault energy surfaces for basal and prismatic planes are considered for a global search of the possible dissociation paths in partial dislocations. Test calculations show negligible differences between the energy surfaces calculated with the force field and with ab-initio methods. Five different coesite slip systems are investigated: [100](010), [001](010), [101](010), [010](001), and [010](¯ 101). Dislocation core structures and critical stresses are determined by using the Peierls-Nabarro-Galerkin approach. While [100] and [101] (screw) dislocations share a similar core structure, [001] differs substantially by showing a much larger split between partial dislocations. The lattice friction experienced by [001](010) is found to be close to those of [100](010) and [101](010), confirming the pseudohexagonal symmetry suggested by experiments.

the crystal structure of baghdadite,
ideally Ca3Zr(si2o7)o2, was refined using 1986
reflections to R = 0.034. Baghdadite is monoclinic,
space group P21/a, with cell parameters a 10.432(3),
b 10.163(2), c 7.356(2) Å, b 90.96(2)°. the refined
crystal structure is in agreement with the structure of
synthetic Ca3zrsi2o9. the structure is characterized
by the presence of walls of cation polyhedra, four
columns large, linked together by both direct
connection as well as by disilicate groups. Baghdadite
is the first phase in the cuspidine group in which the
Pauling’s fourth rule is violated.