ACTA GGM DEBRECINA Geology, Geomorphology, Physical Geography Series DEBRECEN Vol. 3,

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1 ACTA GGM DEBRECINA Geology, Geomorphology, Physical Geography Series DEBRECEN Vol. 3, Methodology of archaeometric investigation of archaeological rock raw-material (stone tools, building material): case studies Régészeti k zetnyersanyagok (k eszközök, épít anyagok) archeometriai vizsgálatának módszertana esettanulmányok alapján Anna Farkas-Pet Department of Mineralogy and Geology, University of Debrecen, H-4032, Debrecen, Egyetem tér 1, farkasanna74@fre .hu Abstract It has been known for almost 150 years that certain fields of archaeology could not operate without palaeoenvironmental investigations based on geology and the associated mineralogical-geological, building material etc. examinations. Therefore archaeometry and archaeological geology developed in the past few decades receive more-and-more attention nowadays. The author the present paper has been working with archaeologist Tünde Horváth since 1997 on the complex archaeological and geological investigation of the stone tools of the Vatya-Nagyráv Bronze Age culture including examination of more than 1000 stone tools. This is the first Hungarian project that focused on Bronze Age stone tools. Considering stone tools both traditional and modern analytical technologies can involve problems therefore a new non-destructive technology preserving the original form of the stone tools has been worked out. Categorizing in order to assess grade of identifiability and identification investigations applying comparison standards from different presumable localities were introduced. Characteristic values of studied stone tools were recorded in a computer database called lithotheca enabling us to perform various queries. Present paper outlines the methodology of such investigations on the basis of some Hungarian examples. Összefoglalás Közel 150 éve ismert az a tény, hogy a régészet bizonyos területei nem nélkülözhetik a geológiai típusú skörnyezet elemzést és a kapcsolódó ásvány-k zettani, épít anyag stb. vizsgálatokat. Az erre alapozott archeometria és régészeti geológia az utóbbi évtizedekben fejl dött ki és napjainkban egyre nagyobb hangsúlyt kap. Horváth Tünde régésszel 1997-t l dolgozunk együtt a vatyanagyrévi bronzkori kultúra k eszközeinek komplex régészeti-geológiai feldolgozásán, mely több mint 1000 k eszköz feldolgozását jelentette. Ez egyben az els olyan hazai munka, mely bronzkori k eszközökkel foglalkozott. K eszközök esetében mind a hagyományos, mind a korszer anyagvizsgálati módszerek alkalmazása problémát jelenthet, ezért egy új, a k eszközök formáját meg rz roncsolásmentes mintavételi technológiát dolgoztunk ki. Bevezettük az azonosíthatóság fokát min sít kategorizálást és a különböz feltételezhet lel helyekr l származó összehasonlító etalonokkal történ azonosító vizsgálatokat. A feldolgozott k eszközök jellemz it egy többoldalú lekérdezést lehet vé tév számítógépes adatbázisban, litotétkában rögzítettük. Jelen munka e vizsgálatok módszertanát mutatja be konkrét példák segítségével. Keywords archaeometrics, stone tools from the Bronze Age, building stones, methodology, locality identification Tárgyszavak archeometria, bronzkori k eszközök, épít kövek, módszertan, lel helyazonosítás Archaeometry in archaeology Investigating archaeological findings from different ages with physical scientific relations came to the fore only in the 1970s (AITKEN 1961, BUTZER 1977, DAVIDSON & SCACKLEY 1976, T. BÍRÓ 1984, T. DOBOS 1978.). Since then almost all of the modern mineralogical-petrographic, geochemical and other mainly physical material investigation methods have been applied in studying archaeological findings regarding ceramics, building material, metal material and stone tools as well (e.g. ICP- MS, REE, electric microprobe, isotope and thermal analyses, metallography, radiometric age determinations, palaeomagnetic and micro-palaeontologic examinations) (HERTZ & GARRISON 1998, RAPP & GIFFORD 1982, RAPP & HILL 1998, SÜMEGI 2003). This lead to the development of a new interdisciplinary science called archaeometry with which new relationships can be revealed regarding character development and efficiency of artificial activities, potential conditions of the geological environment and their interrelationship (HORVÁTH 2004, PET & KELEMEN 2000). Methods of archaeological stone tool and building material investigation Petrological, archaeometric and source research of archaeological stone materials includes several investigations that are based on each other. During these numerous problems may arise (PET 1999). Methods of archaeological research are described below with techniques that could solve some problems associated with this kind of research. First, detailed in-situ (at fining locality or in a museum) macroscopic description of the findings is performed during which stone types of similar character and of similar origin are separated. Then typifying regarding material is made more accurate by studying a small surface created by removing the patina cover. Among the pieces of the thus defined groups already damaged ones are used for further analysis. When there are no such samples others are chosen from the different material and function groups in agreement with the archaeologist for destructive material analyses. Generally those samples are chosen that are available in several copies and represent adequately their own groups. These samples are regarded as etalon ones and generally as many analyses are performed on them as possible and spare samples are also created from them that can be used for comparison. If homogeneity of certain groups is doubtful the material of several tools is analysed. Technology of sampling from the tools depends on its uniqueness and size (complete application, flipped, chopped material) (Fig. 1). As these tools are usually unique ones it is important to obtain the samples from them with techniques causing least damage. In order to this microcrown driller with diamond wing is applied (Figs. 2, 3) that can extract a few cm long cylindrical sample cutting 95

2 ACTA GGM DEBRECINA Geology, Geomorphology, Physical Geography Series Vol partially or completely the tool if it is fastened to a workpad. If required several samples can be taken from one tool. It is important that the diameter of the core exceeds that of the largest particle composing the tool material. However, it was not always possible in the case of intrusive igneous rocks, conglomerates and rocks of coarse porphyric texture. The place of the extracted core can be filled by coloured gypsum, plastic, etc. hiding the traces of the cut. slash partly or completely penetrating micro-head core drilling chopped piece of stone complete application macroscopic analyses microscopic analyses Main and trace element analysis XRD scanning SAM-EDAX DTA Figure 1 Sampling methods and analyses applied 1. ábra Mintavételi módszerek és alkalmazott anyagvizsgálatok rock driller grain Figure 2 Technical plan of the polycrystalline diamond micro crown drill 2. ábra Gyémántvágóéles mikrokoronafúró m szaki rajza Figure 3 Sampling by polycrystalline diamond micro crown drill 3. ábra Mintavétel gyémántvágóéles mikrokoronafúróval 96

3 Farkas, A.: Methodology and description of archaeometric ARCHAEOLOGICAL GEOLOGY, ARCHAEOMETRICS In order to identify possible sources of raw-material in the case of stone findings literature sources were used. After this, material for comparison was collected from the outcrops of the most probable source areas. Comparison in the case of two stone samples can be regarded as reliable if all technologies of analysis are available (because of objective and subjective reasons) and performed that can characterise the samples generally and specifically and can identify their facies and compare the specific characters of the samples. Regarding this, reliability of identification in the case of archaeological stone tools and building materials is limited by the following factors: - characteristics and representativity of the sample; - sufficient quantity of the sample; - possibility and financial feasibility of required analyses; - detection limits, accuracy and representativity of analytical methods. Regarding stone tools, limited number, quantity and destructibility of samples present the limits while in other cases the relative frequency or special characters of the rocks give the limits of investigation. Therefore it has to be noted objectively that the reliability of conclusions and identification is how strong considering the given accuracy of the examinations and the results compared to the ideal ones. Studied and analysed tool and material groups together with the rocks collected for comparison are documented in detail and their samples are placed in a new type lithotheca (Table 1) formed for this purpose the basis of which was given by the Lithotheca formed in the National Museum by Katalin T. Bíró (T. BÍRÓ 1991, T. BÍRÓ et al. 2000). This is an access based information set that is clear, manageable, extendable for both the archaeologist and the geologist. The data source serves the basis for multiple queries and enables the relative and statistic comparison of the stone material of older and younger cultures. Internet access for the database is under construction. The database is composed of two parts. The first is given by the archaeological data of the tools (locality, record numbers, type of tool, its function, current location, name of culture, archaeological description of the tool, other data, drawing of the tool, macroscopic photo, etc.). Second is the petrological data of the tool (e.g. type of material, location specific characteristics, microscopic thinsection photos, data of geochemical research). The two parts complement each other, however, they can be used individually as well. It is important to determine the finding locality of the materials where possible. If it is not possible potential alternatives are listed. Probability of the finding locality of the material types a subjective reliability index is given that depends on numerous factors like possibility of sampling, quantity of the sample, analyses performed, type of rock material, specialities of the rock material, etc. Locality of origin of some material types can be given based on the available data while those of uncertain origin receive lower values. Identification of the material can be regarded as good in the case of 50 80% of the samples while it shows great variety in the case of the rest. In the following particular examples are used to show the application of the method described above in the case of stone tools and building stones. Locality identification case studies Archaeometry of the Bronze Age stone tools of the earthworks in Százhalombatta (Vatya-Nagyrév culture) Study of the stone tools, especially flipped stone tools from the Palaeolithic and Mesolithic in Hungary was highly important and accurate from the beginning of archaeological studies. However, studying stone tools (e.g. polished axe) from the Neolithic got out of the focus of research. There are no Hungarian publications on Bronze Age tools despite the fact that there are high numbers of findings of tools and ornaments of rock material from this age. In order to substitute this lack archaeological, geological and archaeometric investigation of the flopped and polished stone tools from the settlements of the Vatya- Nagyrév culture from the Bronze Age was started by us with the archaeologist Tünde Horváth (HORVÁTH 1997, HORVÁTH 2004, PET 1999). One of the first result of this work was the investigation of the Vatya findings (435 pieces of stone tools) found in the area of the Sánchegy around Százhalombatta. The majority of the stone tools (292 pieces) were chipped stone tools (saw, arrow heads, blades, scrapers, etc.) the raw-material of which was flintstone and chert originated from the Transdanubian Mts., however, in subordinate amount jaspilite, radiolarite and other quartzite and opal varieties were also represented. Identification of their origin was impossible due to the small size and the type of material of the tools. Large number of grinding stones was found among the findings at Százhalombatta that were used primarily for grinding crop. These are composed of two parts. The upper part is rubbing stone the material of which is mainly metamorphic quartzite while the lower part is an almost elliptic shaped flat sheet produced from a wide range of stones, e.g. granite (Velence Mts.), coarse grained sandstone, fine grained conglomerate (Hárshegy Sandstone Formation), subordinately andesite (Visegrád Mts.). Number of stone axes (chisel, last, trapeze shaped and hollowed handle axes) was significant (40 pics.) among polished stone tools (Fig. 4). The material of these is mainly andesite (amphibole andesite) that shows similarities to the neutral Miocene (Badenian) volcanites of the Visegrád and the Börzsöny Mts. (Mátra Andesite Formation). Most exotic part of the axes was a group of variable ophiolites that was classified into the metabasics and tectonite serpentinites of the greenschist facies ophiolitic association based on the preliminary macroscopic and microscopic analyses. It had to be decided whether this group was of East Alpine, Dinaric or West Carpathian origin and for this, further petrographic and geochemical investigations were necessary. Stones were altered in variable extent by dynamometamorphic and hydrometasomatic effects. Brush and sheaf like aggregations and foliation can be observed (Fig. 5). Most typical appearance is characteristic for the net like chrysotile. One part of them is subophitic textured and 97

4 ACTA GGM DEBRECINA Geology, Geomorphology, Physical Geography Series Vol Table 1 Datasheet of the new type lithoteca 1. táblázat Új típusú litotéka adatlapja 98

5 Farkas, A.: Methodology and description of archaeometric ARCHAEOLOGICAL GEOLOGY, ARCHAEOMETRICS relatively fresh, the other part is strongly altered tectonite serpentinite. Chloritic and carbonate alterations can be detected at places and high Mg content was measured in one sample (Table 2) that is associated to the large content of baumite (= a mixture of several serpentines and chlorites) shown by X-ray analysis. Resilification grade of the samples show differences, silification can be observed occasionally and clayey decay has started in two samples. Additionally tremolite, albite, chlorite and muscovite become abundant. Significant cummingtonite (30%) and clinozoisite (34%) contents were measured in several samples. Figure 4 Sketch of the stone axe (Szhb-Kb. 17.) from the Bronze Age, found in Százhalombatta-Földvár (Vatya-Nagyrév culture) 4. ábra Százhalombatta-Földvár területér l el került bronzkori (vatyanagyrévi kultúra) k balta (Szhb-Kb. 17.) rajza Szhb-Kb. % 17. analysed value SiO Al 2 O Fe 2 O FeO 2.12 MnO 0.07 CaO 0.29 MgO (!) K 2 O 2.00 Na 2 O 0.10 TiO P 2 O H 2 O (!) -H 2 O 0.19 (100 C) Elemezte/Analysed by: Dr. Barta István Table 2a Main element composition of the stone axe (Szhb- Kb. 17.) from the Bronze Age, found in Százhalombatta-Földvár 2. a, táblázat Százhalombatta-Földvár területér l el került bronzkori (vatya-nagyrévi kultúra) k balta (Szhb-Kb. 17.) f elem összetétele Figure 5 Thin-section image of the stone axe (Szhb-Kb. 17.) from the Bronze Age, found in Százhalombatta-Földvár (Vatya-Nagyrév culture) 5. ábra Százhalombatta-Földvár területér l el került bronzkori (vatyanagyrévi kultúra) k balta (Szhb-Kb. 17.) mikroszkópi vékonycsiszolati képe chrysotile XRD data (%) Szhb- Kb- 17. amorph. chlorite maghemite baumite Elemezte/Analysed by: Dr. Kovács-Pálffy Péter Table 2b XRD data of the stone axe (Szhb-Kb. 17) 2.b. táblázat a k balta (Szhb-Kb. 17.) RTG elemzési adatai ICP data (ppm) B Ba Cr Cu Li Rb S Sr V Szhb-Kb Elemezte/Analysed by: Kiss Erzsébet Beatrtix 2.c. táblázat a k balta (Szhb-Kb. 17) ICP nyomelem-vizsgálati adatai Table 2c ICP trace element data of the stone axe (Szhb-Kb. 17) In conclusion, the association can be identified as representative of the greenschist facies ophiolitic formations of the Penninic Unit exposed in the Rehnitz (Rohonc) Window (Figure 6) (HÖCK & KOLLER 1987, 1989). Material of the same group was also identified in other localities of the Vatya culture (e.g. Bölcske). 99

6 ACTA GGM DEBRECINA Geology, Geomorphology, Physical Geography Series Vol Cross-section/Szelvények: a:w Bernstein Window b: E Bernstein Window c. N-Bernstein Window d: Rehnitz Window (S-Glashütten) e: Rehnitz Window (N-Glashütten) f: Rehnitz Window (Rumpersdorf) g: Eisenberg Window (Vaskereszt) Tertiary sediments Upper Eastern Alps Lower Eastern Alps serpentinite greenschist metagabbro metasediments faults thrusts Figure 6 Geological surrounding of the Penninic basement, Austrian Alps and schematic cross-section of ophiolites (HÖCK & KOLLER 1989) 6. ábra Az Osztrák Alpok Pennini alapjának földtani környezete és vázlatos ofiolit szelvények (HÖCK & KOLLER 1989) Archaeometric study of the building stones of a Middle Age church (Balatonszárszó Kis-erdei way) Archaeological investigations prior to the construction of the M7 motorway were performed between 2000 and 2003 along the southern shore of the Balaton between Zamárdi and Ordacsehi (BELÉNYESI et al. 2007) (Fig. 7). The investigation revealed the base and the building stones of a Middle Age church in the vicinity of Balatonszárszó (Kis-erdei way) (Fig. 8). The former church was built on the border of two small landscapes (Somogy coastal flat and western Outer Somogy) (MAROSI et al. 1990) in the area of the latter dissected by meridional ridges and valleys. It is located in the marginal part of a mountain ridge (Alma Hill) that is bordered by steep sides except for the southern part. 100

7 ARCHAEOLOGICAL GEOLOGY, ARCHAEOMETRICS Farkas, A.: Methodology and description of archaeometric siliceous sandstone; 3.57% (Tertiary) calcareous sandstone; 15.82% (Tertiary) pred sandstone; 0.51% (Perm) metapelite; 4.08% (Mesozoic) tuffaceous sandstone; 3.06% (Upper Pleistocene) tdolomite; 2.04% (Triassic) limestone; 3.57% (Miocene) bazaltic tuff; 67,35% (Upper Pliocene) Figure 9 The material of the building stones of the Middle Ages church at Balatonszárszó 9. ábra A balatonszárszói középkori templom épít köveinek k zettípus szerinti megoszlása. Figure 7 Space image of the vicinity of the locality 7. ábra A lel hely környékének!rfelvétele ( Figure 8 Aerial image of the excavation of the Medieval church (Balatonszárszó, Kis-erdei way) (Belényesi et al. 2007) 8. ábra A középkori templomkörzet (Balatonszárszó, Kis-Erdeid!l ) ásatásának légifotója (Belényesi et al. 2007) Our task was to investigate the petrography of natural raw-material, stones used for the building of the church. During this 200 building stones were studied, the size of which ranged from a few cm large fragments to m sized blocks. In the course of macroscopic and microscopic investigations, 8 petrographic groups were separated types and rates in % of which are presented in Figure 9. Most of the building stones are carved out of less resistant, variously grained, dominantly carbonate, subordinately zeolite cemented basalt tuff (Fig. 10) deposited in water and easy to work with. On the microscopic photo (Fig. 10) the isolation of the fragments by the cementing material is visible. Figure 10 Macroscopic (above) and microscopic thin-section image (below) of basalt tuffs (XN) 10. ábra Bazalttufa makroszkópi (felül) és mikroszkópi vékonycsiszolati (lent) fotója (XN) 101

8 ACTA GGM DEBRECINA Geology, Geomorphology, Physical Geography Series Vol. 3 Tiny and angular character of the grains gives a breccia appearance to the rock, however, this is only visible under the microscope. Material of the frequently irregular or slightly rounded basalt lapilli with ash like, altered edges are frequently vesicular, strongly glassy with orientated texture. Its feldspar laths are acicular in appearance and orientated into the flow direction suggesting rapid crystallization. Certain pores are filled by calcite others by zeolite. The matrix suffered slight palagonitic alteration indicated by the pale brownish colour. The rock group considering its macroscopic and microscopic characteristics shows great similarities with the pyroclastic rocks occurring in uneven distribution and 2008 quantity in the Balaton Uplands, indicating the start of the Upper Pliocene volcanic activity (BUDAY & GYALOG 2009, DEÁK 1972, JUHÁSZ 1987). Regarding the basalt tuff cones here, the outcrop in the Tihany peninsula is located closest to the studied church (Fig. 11), thus it can be assumed that the majority of the building material of the church is a relatively solid raw material that is easy to work with and originated from the western part of the Tihany peninsula. It forms, among others the foundation of the undercroft of the national monument church in Tihany and the monk dwellings were also burrowed in the northern shores of the peninsula. Figure 11 Geological map of the vicinity of the locality (BUDAI & GYALOG 2009) 11. ábra A lel hely környékének földtani térképe (BUDAI & GYALOG 2009) Legend/jelmagyarázat: Qh2 Fluvial clay, silt, sand, gravel (Holocene)/folyóvízi agyag, k zetliszt, homok, kavics (holocén); Qh4 Fluvial sand, gravel (Holocene)/folyóvízi homok, kavics (holocén); Qh8 Paludal clay, silt, sand, calcareous mud (Holocene)/tavi agyag, k zetliszt, homok és meszes iszap (holocén); Qph3 Fine grained slope sediment (Pleistocene Holocene)/finom szem! lejt üledék (pleisztocén holocén); Qph5 Slide sediment (Pleistocene Holocene) /Csuszamlásos üledék (pleisztocén holocén); MPl3 Tapolca Basalt (Effusive basalt, basaltpyroclastite, subvolcanic basalt (Miocene Pliocene)/Tapolcai Bazalt (kiömlési bazalt, bazaltpiroklasztit, szubvulkáni bazalt (miocén pliocén); MPl4 Tapolca Basalt, geyserite Hot spring sediment: post volcanic geyserite (Miocene Pliocene)/Tapolcai Bazalt, gejzirit forrásüledék: utóvulkáni gejzirit (miocén pliocén); M3 Tihany Formation Lacustrine clay marl, silt, fine-grained sand; carbonaceous clay, variegated clay, lignite, dolomite (Miocene)/Tihanyi Formáció Tavi agyag, márga, k zetliszt, finomszem! homok; meszes agyag, tarkaagyag, lignit, dolomit (Miocene) Based on the above methods a real image is may formed on the demands, distribution and technology of the user of the stone tools and building material together with other research data, completing the knowledge on the given culture and on its influencing effects as shown by particular examples. Conclusions Complex archaeological-geological investigation of the stone tools of the Bronze Age Vatya-Nagyrév culture can be regarded as an investigation model that contributed with several new elements to the modern archaeometric study of these findings. The new sampling technology makes it possible to carry out analyses on tools that have not been studied yet due to potential deterioration during sampling. In the case of building material this generally presents no problem. Data recorded in the new and continuously extended database are easy to access, assess, and compare to material of other cultures by both archaeologists and geologists. Identifying finding locations, general description and origin research of association can be performed, however, they are variable in detail. Therefore subjective reliability indexes can be given for the particular stone groups and their place of possible origin. Irodalom AITKEN, M.J. 1961: Physics in Archeology. New York, Interscience, 296 p. BELÉNYESI K., HONTI SZ., KISS V. (ed.) 2007: Gördül id. Régészeti feltárások az M7-es autópálya Somogy megyei szakaszán Zamárdi és Ordacsehi között. Directorate of Somogy County Museums, Archaeological Institute, HAS, p. 332 BUDAI T., GYALOG L. (ed.) 2009: Magyarország földtani atlasza országjáróknak 1: Publication of the Geological Institute of Hungary, Budapest 102

9 Farkas, A.: Methodology and description of archaeometric ARCHAEOLOGICAL GEOLOGY, ARCHAEOMETRICS BUTZER, K.W. 1977: Geo-archeology in Practice. Review of Anthropology, 4, DAVIDSON, D.A., SCHACKLEY, M.L. (ed) 1976: Geoarcheology. Duckworth Press, 408 p. DEÁK M. (ed.) 1972: Magyarázó Magyarország es földtani térképsorozatához L-33-XII. Veszprém. Geological Institute of Hungary, MÁFI, Budapest HERTZ, N., GARRISON, E.G. 1998: Geological methods for archeology. Oxford University Press, Oxford, 343 p. HÖCK, V., KOLLER, F. 1987: The Idalp Ophiolite (Lower Engadin Window, Eastern Alps) its Petrology and Geochemistry). Ofioliti, 12(1), HÖCK, V., KOLLER, F. 1989: Magmatic evolution of the Mezozoic ophiolites in Austria. Chemical Geology, 77, HORVÁTH T. 1997: Százhalombatta-Földvár bronzkori rétegeinek k anyaga. ELTE, Budapest, 63 p. HORVÁTH T. 2004: A Vatyai Kultúra Településeinek K anyaga - Komplex régészeti és petrográfiai feldolgozás. unpublished PhD theses, Budapest, 167 p. JUHÁSZ Á. 1987: Évmilliók emlékei, Magyarország földtörténete és ásványi kincsei. Gondolat Press, Budapest, 511 p. MAROSI S. (ed.) 1990: Magyarország kistájainak katasztere I-II. GRI, HAS, Budapest, 1023 p. PET A. 1999: Régészeti k eszközök geológiai vizsgálati lehet ségei és eredetkutatása egy hazai bronzkori kultúra példáján. Unpublished diploma theses University of Debrecen, 96 p. PET A., KELEMEN É. 2000: A földtan, archeometria és petroarcheológia szerepe a régészeti értékek feltárásában. Földtudományi Szemle, 1, RAPP, G.J., GIFFORD, J.A. 1982: Archeological Geology. American Scientist, 70, RAPP, G.J., HILL, C.L. 1998: Geoarchaeology. Yale University Press, London RENFREW, C. 1969: Trader and Cultural Process in European Prehistory. Current Antropology, 1., SÜMEGI P. 2003: A régészeti geológia és a történeti ökológia alapjai. JATE Press, Szeged, 223 p. T. BÍRÓ K. 1984: Az sk kori és k kori k eszközök nyersanyagai Magyarországon. Unpublished PhD theses, Geological Institute of Hungary. T. BÍRÓ K. 1991: Lithotheca Comparative Raw Material Collection of the Hungarian National Museum. MNM, Budapest, 268 p. T. BÍRÓ K., T. DOBOSI V., SCHLÉSER Zs. 2000: Lithotheca II. Comparative Raw Material Collection of the Hungarian National Museum MNM, Budapest, 332 p. T. DOBOSI V. 1978: A pattintott k eszközök nyersanyagairól. Folia Arch., 29,