Geological Quarterly, 1998,42 (2): 209-220 Water soluble salts in degradation processes of stony architectural monuments in the Upper Silesia Malgorzata LABUS Labus M. (1998) - Woter soluble sails in dcgrndation processes of stony nrchiteehuui monuments in the Upper Silcsia. Geol. Quill1., 42 (2): 209-220. WnrsUlwa. The study goals were aimed 111 obtaining infonnation on corrosion products of rocks used in architectural monuments in the Upper Silesia. Samples from four monume ntal buildings located 01 margins of the Upper Silesia were IlSCd in the study. Three of them nrc located in the western pill1 of the region: a castle at Tasuk, a grain elcvatorat Stare Gliwice and castle ruins III Chud6w, and one is located in the eastern part (a cn.~ tle 01 6(;dzill). Samples of rocks from area significantl y lcss affected by atmospheric COlltnmillDtion (castle ruins at MimII' in the 1um Kmkowsko..czC5tochowska region) were analp.ed for comparison. Samples of sandstone, limestone and granitoids were analY1.ed with X-ray dirfraCLornetry and microstructurnlll1lalyscs. Cnemical analyses were conducted for aqucOllS solutioos of powdered rock samples. The following compounds wert detected in the sltJdicd snmples: sulphates, chlorides, nitrntes and carbonates. Total snUnilY in the samples of sandstone lind limcslone Wll.~ calculated, based on the resulls ofche mical analyses and X-my difCractolTlCtry . The highest salinity was detected in the samples from lhe castle ruins al Chud6w. Mu/gunil/U LahU.f, Irmifu/e ofAppli ed Geology, Silesilln Tu/micul University, Akodemicko 2, 44- /00Gliwice. Poland (reuived: 3.02./998; ocupltd; 22.02.1998). Key words: Upper Silesia, architectural monuments, air pollution, building stone detcriOl1ltion, wfttersoluble salts. INTRODUCTION fonn various types of incrustations: hard and dense (i.e. calcium carbonate), fluffy (sodium sulphate) or glassy (potas­ sium sulphate). Aqueous solutions of salts migrating in the stony elements Rock corrosion causes increased crystallization salt press­ of buildings significantly affect weathering processes of these ure. Degradation results from crystal formation and growth, structures. Corrosion mechanisms are based on physical and and from hydration and hydration pressure. Intensity of these chemical processes, with water being their important compo­ processes, as degrading forces, is associated with salt solution nent, dissolving and Iransporling salts, and occasionally their concentrations, crystallographic form, salt aqueous solubility hydrolysis (S. Skibinski, 1989). Salts soluble in water are coefficient, temperature and frequency of rock wetting and natural components of many rocks, they also fonn in the drying (P. A. Baedecker etal., 1992; B. O. Fobe et al., 1995 ; hazardous amounts in reactions between gaseous atmospheric R. U)fvendahl el ai., 1992; H. Sweewers, R. van Gricken, pollutants and primary components of rocks. Separations 1992). within the rock structure are the most hazardous symptoms of degradation caused by dissolving salts. Presence of dissolvi ng salts reduce rock cohesiveness and compactness, and cause loss of mechanical strength of rocks resulti ng from chemical STUDY SCOPE AND METHODS decomposition of mineral components. The most noticeable symptoms of salt activity are their crystalline efflorescence on rock surfaces, which depending on salt type and quantity, The study was conducted using samples of four monumental objects located at margins of GOP (the Upper Table 1 Samples of construction rucks were collected, so that they possibly represent all lithologic types used in the studied List of samples anatpad uslngspecific methods objects. Additionally, samples of exposed and of protected, for example by vegetation (assuming that affecting processes depend on degree of wetness and rate of rock drying), wall fragments were collected. Outer layers of weathered surfaces, which sover some rocks, and grout were also sampled. Sarnp- Iing of all objects was accompanied by lithological inventory of construction materials. Samples in all objects were col- lected at elevation oC0.5-2.0 rn above the land surface. Some samples collected at Chud6w were collected at elevation of 0.3 m (lw, 15p, I lg and 18g). Symbols which include sample number and lithological type were used for sample designa- tion. Sandstone samples were designated with letters "p", limestones as letter "w", and eratic blocks as letter "g" (grani- toids). Samples of grout were designated with letter "2". List of analyzed samples is presented in Table 1. Because of the specificity of construction materials, in many cases, the amount of colIected samples was insufficient for all planned analyses. This fact complicated interpretation of the msuIts and caused necessity of application of analogies observed macroscopically. Detailed identification of phase composition of rocks and coatings at external surfaces was conducted, based on the results of X-ray diffractometry. X-ray diffractometry was conducted on powdered samples. Analyses were conducted using TUR-61/HZG-4 diffractometer, with monochmmatic, Fe-filtered CoKa radiation in the range of 5-35 0.X-ray diffraction was also used to identify the precipitates formed on glass slides by drying the extracts of soluble components of the rock samples. The XRD patterns were obtained with GEIGERFLEX diffractometer (Rigaku-DenkG using Fe-fil- trated CoKa radiation, Phases were identified based on the reference data in Mineral Powder Diffraction File (1986) and V. I. Mikheev (1957). Precipitates on glass slides were also examined in po- larized light using Reichert MF2 optical microscope. Scan- ning electron microscopy (SEW with chemical analyzer was used for seIected samples to characterize composition of subsurface layers. Samples were prepared as cuts both per- pendicular and parallel to the external, weathered part of rock sampIes. SarnpIes were carbon-coated. Samples 1w, 1Zp and 3g were analyzed with ISM-5300 SEM equipped with WNK- ISISdetector which allowed to identify light elements (atomic number 24). Other samples were examined with JEOL Super- probe 733 electron microscope equipped with JC XA 733 microprobe. Elements heavier than Z = 8 were identified using w -limestones, p -srmdsmnes, g- eratic bIocks (granitoids), z -gm~ ts energy-dispersive spectrometer. Carbon and nitmgen were analyzed with wavelengthdispersive spectrometer. Quantita- tive analysis of carbon was of limited precision due to carb- on-coating on sample surfaces. Silesian Industrial Region), three of them located in western Qualitative chemical analyses included some of the ions part: a castle at Toszek, a grain elevator at Stare Gliwice and @, K', ca2', lMg2', NO?,SO$-, Cl3 in aqueous solutions castle ruins atChud6w and ane located in eastern part (acastIe at Bedzin). For comparison, rock samples from an object of powderd samples. These analyses were aimed at determi- located in a region of significantly less atmospheric pollution nation of soIuble substances, especially salts which are pro- were analyzed. Castle ruins at Mirdw (JucaKrakowsko-Czp- ducts of rock weathering. tochowska) is the object. Water soluble salts in degmdation of stony monuments 211 Fig. 1. XRD pattern: A - sample from a dark incrustation on dolomitic limestone (53~.Bqdzin castle), B - grout sample (62, Chud6w castle ruins), C - sandstone sample (I 4p, Toszek castle) C -calcile, D -dolomite. G -gypsum, Q -quarts Sn -syngenite, Br - brushite, F -frondelite, A - bloditc. Ki -kiiscritc, N - nitmnatrite, R - rulile Dyfdtogmm rentgenowski:A - pr6bki cicmnego nashpienia na wapieniu dolomitycznym (53w, zarnek w Bqdzinie), B - pr6bki zapwy (bz, ruiny zamku w Clrudowie). C - pr6bki piaskowca (14p, 7ame.k w Toszku) C - Ucyt, D -dolornit, G - gips, Q -kwarc, Sn -syngenit, Br- brushyt, F-frondelit, A-astrachanit, Ki-kizwyS Irl -nitron~tryt, R -mtyl X-RAY DETRACI'OMETRY of thick black incrustation on the rock surface (sample 53w) was analyzed. FoIlowing minerds were identified: dolomite, caIcite, gypsum, quartz and syngenite (&SO4 .CaS04. HzO) various lithological types (Fig. 1A). In &per parts ofa sample 56~only dolomite and differentmonumental objmtsg weeanalyzed with calcite, and ina sample 5Zw - dolomite and small diffractometry. Samples of dolomitic limestones were coI- ofgypsum were identified, respectively. Iecttd in the Bedzin castle. Mineral composition of a sample Fig. 2. Total elemcnt composition: A -dark incrustation on nn external dolomitic limestone surface (54w,Bedzin castle), B -external zone in a dolomitic limestone sample (54w) in a distance oF250 pm rmm the surface (B~dzincastlc), C - polyhalile crystal MgK2Cm(S@)4 4 2H70,with admixturn of iron and mangancsc oxides in a sandstone mple(2p, Chud6w ca~tlcruins), D -incrustations on sandstone (6p. Chud6w castle ruins). 1E - incrustations in a limcstane sample (9w, Chuddw castle ruins), F- external surface oClimestone (I I w, Taszek castle), 6: -surface in sandsione (45~.Mjr6w castle ruins) Zbimy sklad pienvimtkowy: A - ciemnego naskorupienia na zewwtrznej powierzchni wapienia dolomitycznego (54w, zamek w Bedzinie). B - zewnetnnejstrery pr6bki wapieniadolomityuncgo(S4w)w odteg4o$ci25(3podpowienchni (mrnckw Bedzinie),C-krysaalu polihlihalitu MgK2&2(S04)4 2H20 wnz z dornieszkumi 1lenk6w Fe i Mn w prdbae piaskowca (2p, miny mmku w Chudowie), D - naskompiefi na piasknwcu (6p, ruiny zamku w Chudowie), E - naskompieit w pr6bce wapienia (9w. miny zamku w Chudowie), F - zewn~umejpowienchni wapienia (I lw, zamek w Toszku), C - puwierzchni piaskowctl(45p, ruiny