The University of Iowa Office of the State Archaeologist: Ceramic Analysis

The most distinctive artifact category of Great Oasis is undoubtedly ceramics. The original basis for assigning Great Oasis sites as a separate entity by Lloyd Wilford in the early 1940s were the ceramics. In one of the earliest published accounts describing Great Oasis Wilford states "The pottery complexes of the three sites [Humphrey, Great Oasis, Cambria] are so different that each site must be assigned to a different aspect. The vessels have very few features in

common . . . . In the decoration of the external rim area from lip to throat, the Great Oasis pottery is unique. . . . Great Oasis pottery has no near relatives among already defined cultures" (Wilford 1945:34, 36, 39). Great Oasis ceramics have since been described by Anfinson (1979, 1997), Edwards (1983, 1993), Henning and Henning (1978), Henning and King (1982, 1996a), Johnson (1969), and Johnston (1967).

The typical Great Oasis vessel is a globular jar that exhibits grit tempering (often crushed igneous rock), and a rounded shoulder, constricted neck, and out-flaring rim. No handles are present. An anvil and cord-wrapped paddle were utilized in the manufacture of the vessels, with the cord marking often completely or partially smoothed over. Decorative elements are mainly confined to the rim exterior and are linear as opposed to curvilinear. Trailing is utilized for the decorative elements, and some designs on Great Oasis High Rim ceramics are trailed versions of cord-impressed designs found to the east and west (Benn 1990a:141-142; Henning and Henning 1978:15; Johnston 1967:71; Tiffany 1991:188; Wood 1962:33).

Based upon differing rim and neck forms, Great Oasis ceramics have been divided into two wares: Great Oasis High Rim and Great Oasis Wedge Lip (Henning and Henning 1978). Great Oasis High Rim ware, as the name implies, consist of vessels exhibiting long, usually parallel-sided rims with usually flattened lips. Great Oasis Wedge Lip ware exhibit rims which are short, thick, and beveled toward the exterior. Lips are in most cases flattened.

Drawing of the metric attributes recorded for high rims and wedge lips during the Cowan ceramic analysis
Metric attributes recorded for High Rims (left) and Wedge Lips (right) during the Cowan ceramic analysis.

A major difference between the two wares, besides the lip and rim profile, is the amount and type of decoration. Because Great Oasis High Rim ceramics exhibit more of a rim area that can be decorated as compared to Wedge Lip ceramics, High Rim vessels are often more elaborately decorated than the Wedge Lip. Decorative elements on High Rim ceramics occur in two or three bands or zones. The upper band is that area of the rim extending downward approximately 1 cm from the vessel's lip. Decorative elements found within this band usually include oblique lines, elongated punctates, or crosshatching. Occasionally this band is plain.

The lower band is that area of the rim which adjoins the upper band and extends downward toward the rim-shoulder juncture. The lower band can best be seen as consisting of a field, or background, to which decorative motifs have been applied (Henning and Henning 1978). This field can be plain or decorated with horizontal or diagonal lines. Decorative motifs which are applied to this field include triangles (zigzags) (apex pointing up), pendant triangles (apex pointing down), oblique lines, trapezoids, and diamonds, as well as designs which have been interpreted as running deer (sometimes termed "flag and dot"), turkey tracks, and inverted turkey tracks. Other motifs, interpreted as representing arrows, maize, and trees also occur but are rare.

Occasionally a middle band is also present on High Rim ceramics. This band is located between the upper and lower bands and is either plain or contains horizontally or diagonally trailed lines.

Decorative elements on Great Oasis Wedge Lip ceramics occur on the lip-rim exterior margin or the flattened lip surface. Designs include crosshatching, tool impressions, or a combination of both. Usually, however, Wedge Lip ceramics are plain. The bodies of Wedge Lip vessels are sometimes decorated with horizontally parallel lines which encircle the vessel primarily from the neck to the shoulder area.

The ceramic assemblage is one of the largest artifact assemblages at the Cowan site (32,000+ sherds) and represents the largest analyzed Great Oasis ceramic assemblage in Iowa. This sample provides the opportunity to closely examine Great Oasis wares and decoration and to add insights into intrasite patterning.

Wedge Lips are the most common vessel form at Cowan, accounting for 54 percent of the rim assemblage, followed by High Rims at 41 percent. While the majority of the Wedge Lips are undecorated, the most common lower band motif found on High Rims is triangles and pendant triangles, with other motifs such as diamonds, running deer, inverted turkey tracks, and spaced oblique lines also occurring. A previously unreported treatment of the lower band field was noted at Cowan, that of dividing the field into rectangular panels. Three D-shaped rims were recovered from the Phase III investigation, with one additional D-shaped rim found during the Phase I survey. These four sherds fit into the range defined as Mill Creek Chamberlain rims. Based in part upon the lack of other diagnostic Mill Creek artifacts from Cowan, however, these rims are considered to be part of the Great Oasis assemblage. No Middle Mississippian influences are seen on the Cowan ceramics.

A previously unrecognized Great Oasis ware has been named at Cowan. This ware is represented by S-shaped rims and appears to represent an earlier stage of development of Foreman ware. S-shaped rims are a minor ware at both Great Oasis and Mill Creek sites, accounting for 1-2 percent of the assemblage at Great Oasis sites and 2-5 percent at Mill Creek sites.

Photograph of a woman holding an intact decorated wedge lip vessel

Crew member holding excavated intact decorated
Wedge Lip Vessel from feature 67.

While the lower band decorative motifs, such as triangles, pendant triangles, and the various life forms, are meant to convey specific messages to those viewing the ceramics, the middle band on High Rims is decorative and was not meant to communicate specific messages. It is suggested that three hierarchical levels of ceramic decoration are visible at Cowan. First is the village style, which at Cowan consists of the triangle and pendant triangle motifs, as well as dividing the field into panels. Second is the household style, which may correlate to a clan or lineage style. At Cowan, these motifs include the running deer, diamond, spaced oblique lines right, and the inverted turkey track. Lastly is the individualistic style, which represents an artist's idiosyncrasies. This would involve using three lines to outline a triangle as opposed to one or two, or the use of cross-hatching in the upper band in conjunction with specific lower band motifs.

It would be beneficial to subject extant collections from both Great Oasis and Mill Creek sites to the same type of analysis conducted at Cowan. Presumably, different village styles will emerge for each site, and sites in close proximity to one another will possess more similar styles than sites located great distances apart. If the household style can be correlated to a clan or lineage style, insights to the social organization of both the Great Oasis and Mill Creek would be possible.

Cowan | General Contracts Program

Webpage originally by Tim Reed March 19, 1999.

Updated by Mary De La Garza, August 2007.
Designed by Tricia R. Bender

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