ÇATALHÖYÜK 1999 ARCHIVE REPORT

Artifact Conservation Final Report

Buluntu Konservasyonu Final Raporu

Kent Severson

Abstract

Artifact conservation included the treatment of ceramics, basket impressions, bone and iron. A wall painting and an infant burial were conserved and lifted as blocks for display in Konya Museum.

Özeti

Konservasyon çalışmaları çanak-çömlekte, sepet izlerinde, kemiklerde ve demirde yapılmıştır. Bir duvar resminde ve bir yetişkin mezarında konservasyon işlemi yapılmış ve Konya Müzesine sergi için gönderilmiştir.

Artifact conservation at Çatalhöyük during the extended 1999 season was undertaken by Kent Severson (Private Practice, Boston, Massachusetts), in conjunction with Frank Matero (Co-Director of Site Conservation, Çatalhöyük Research Project Graduate Program in Historic Preservation, Graduate School of Fine Arts, University of Pennsylvania). Severson worked at the site from 22 April to 19 June and again from 21 August to 27 September, with the intervening time spent at other projects in Turkey.

Conservation of artifacts consisted of assisting in recovery of movable from the excavations, stabilization of artifacts in the laboratory, and preparation of artifacts for depot storage or display in the Konya Museum. Some in situ work was undertaken in the absence of Matero toward the end of the season.

All conservation treatments undertaken were documented in writing in a newly established conservation database, linked to the main Çatalhöyük database. Each treatment received a Conservation Laboratory number (for example: 99.030, etc.) which is tied to that artifact’s GID unit number in the database. The conservation numbers were written on the identifying tags for each object (as, for example, "Cons. Lab. 99.23"). These records contain specific details of each treatment undertaken. An indexed hard copy of the records from 1998 and 1999 was printed and left at the site in a binder with collected reports from previous seasons. It is recommended that a hard copy also be printed for the Çatalhöyük archive at Cambridge University.

Conservation treatments undertaken this season, categorized by material, are summarized as follows:

Ceramics: sixteen ceramic or unfired clay objects were treated this season. These ranged from simple cleaning and repair to small figurines to a more elaborate treatment of a late Roman jug, found in a burial in West area in 1998 (Cons. Lab. 99.009).

Basket/phytolithic impressions: approximately nineteen samples of phytolithic basket impressions were treated this season. Treatments ranged from simple consolidation and packing to the more elaborate lifting and cleaning of a basket from an infant burial (Cons. Lab. 99.017, GID 4429.x1). This treatment demonstrates the feasibility of recovering more than just the two dimensional spiral impressions of baskets which commonly appear at the site. It is hoped that these samples can form the basic material for a detailed study of Neolithic basket construction techniques at Çatalhöyük. An outline proposal for such a study will be submitted under separate cover.

Bone, Human and Otherwise: ten bone artifacts or fragments were treated this year, either by the conservator or by staff under supervision of the conservator. These treatments included consolidation in the field and lifting. Work with human skeletons was highlighted by the recovery of a well preserved infant burial (Cons. Lab. 99.012, GID 4406.x1). The skeleton, with accompanying bead on the wrists and ankles, was lifted as a block, consolidated and cleaned in the laboratory, and installed in the Konya Museum. In addition, six horn cores were treated this season, including an elaborate consolidation and recovery of a very large aurochs horn (Cons. Lab. 99.005, GID 4121.x1).

Wall Painting: a small section of wall painting, discovered during cleaning operations, was cleaned and consolidated in situ, and then removed from the excavations (Cons. Lab. 99.002, GID 4223.x1). The fragment was backed, mounted and installed in the Konya Museum. Other work with wall paintings or wall plaster, included continuation of injection grout and stabilization measures after the departure of Matero (Cons. Lab. 99.042 and 99.060) and supervision of winterizing Building 17 in the South area. The latter consisted of preparation and installation of pearlite pillows against exposed wall plasters and installation of geotextile on floor surfaces.

Other Materials: one small iron artifact was treated this season along with simple treatments of other materials including consolidation of antler, phytolytic impressions of wood and grains, and a handful of corprolite samples.

Other activities undertaken by the conservator this season included preparation of a handout on conservation tips for excavators and presentation of this handout at a seminar for staff. A second handout on packing tips for storage in finds depots was likewise prepared and presented. These materials could be very useful to the project in both improving recovery and storage techniques for the artifacts and in providing some continuity in these activities from one season to the next. It is hoped that these handouts will be revised as necessary and redistributed at the beginning of each season.

In advance of this year’s extended season, there was considerable discussion of the possibility of finding waterlogged remains in the deep excavations and the effect of rising and falling water levels on those finds. These issues are discussed briefly in the attached Conservation Assessment Report. Based only on this conservator’s limited knowledge of this topic and observations made on site, it is recommended that every effort be made to maintain a stable level for the water table around the site, regardless of the specific elevation of that table.

In a comprehensive report on the artifact conservation program at Çatalhöyük, prepared at the end of the 1998 season, R. Beaubien called for greater integration of registration processing, conservation records, and specialists’ studies. Considerable progress was made this season in implementing these proposals. That report also outlined general guidelines for handling, treatment storage of each type of artifact found at the site. These guidelines formed the basis of this year’s artifact conservation program. It is hoped that the progress made this year will carry forward and be expanded in coming years. Budgets for supplies and equipment prepared at the end of the 1998 season can be updated and utilized should construction of a new, expanded conservation laboratory become a reality.

The presence of an artifact conservator on the site greatly enhances both the kind of material which can be recovered from the excavation and the preservation and presentation of those finds in the long term. Although minimal in past seasons, it is hoped that artifact conservation will become a regular part of the research program at Çatalhöyük.

ASSESSMENT statement

This statement reflects observations made at the end of the 1999 season; it is not based on particular measurements or on other specific collected data. The following refers only to materials which might survive as substantial artifacts; in many conditions, residues and charred materials may survive where waterlogged artifacts are distorted beyond recognition.

Waterlogged organic remains fall generally into two categories, proteinaceous and cellulosic/lignin (or skin, leather and other tissues, and wood and textiles):

Skin and leather.

The most dramatic mechanism of deterioration for skin and other protein based artifacts is biological deterioration, followed by the swelling and softening of the material while immersed in water. Dramatic distortion will occur in conditions of repeated wetting and drying, with destruction ultimately due to shrinkage during loss of water. In all likelihood, very few artifacts were deposited at Çatalhöyük directly into a wet environment (except possibly at the lowest levels near the surrounding swampy areas); most artifacts probably were degraded by biological activity within a relatively short period after deposition.

Wood and textiles

Wood, textiles and basketry are somewhat more resistant to rapid biological deterioration than protein based artifacts. In a truly waterlogged context, the cell structures of these materials are filled with water and the cell walls soft. Removal of that water leads to catastrophic collapse of the structures from which there is no recovery. While there is probably a somewhat greater chance that some artifacts survived as truly waterlogged in some areas beneath the mound, those artifacts which have been exposed to even a few cycles of wetting and drying will probably be distorted beyond recognition or recovery. The low probability of finding waterlogged remains is supported by the scant evidence seen in samples taken from deep sounding.

In soil structures like the mound at Çatalhöyük, moisture levels may be divided into the depth to which precipitation penetrates, the height to which moisture rises in soil, and the level of the water table or the level of true saturation. The depth of penetration is a function of the type of soil and remains relatively consistent with a moisture level that ranges from dry to slightly moist. It appears that the intervening layer at Çatalhöyük, that is the layer between the maximum penetration by rainwater and the rising damp from the water table, is a thick evenly graded stratum that retains a remarkable amount of water, but which is not waterlogged. It is unlikely that any truly waterlogged artifacts survive in this level. It is clear from other stuies that the interface between this layer and the truly saturated layer beneath fluctuates, and so will also contain few truly waterlogged artifacts.

Truly waterlogged remains at Çatalhöyük could only exist in the lowest levels of the mound at a level beneath which the water table has never fallen. Based on this year’s experience in the South area, where virgin marl deposits were at almost exactly the level of the water table, or in the case of the KOPAL excavation where the water table was below the marl, it is doubtful that such waterlogged remains exist.

More important than the survival of artifacts at Çatalhöyük is the effect of the swelling and contraction of the clays from which the walls and their decorations are made and which surround and fill all voids in artifacts. Observation and research has shown these clays to shrink dramatically with moisture loss. Repeated expansion and contraction can only lead to distortion and weakening of both structures and walls. Expansion and contraction of surrounding clays could also have a dramatic effect on preservation of charred organic remians, such as those found by Mellaart. Taking this phenomenon into account, this, it is recommended that moisture levels in the mound be maintained as steady as possible, regardless of the actual elevation of the water table.