The Adena culture built conical mounds in which single- or multiple-event burials, often cremated, were interred along with rich grave goods including copper bracelets, beads, and gorgets, art objects made from mica, novaculite, hematite, banded slate, and other kinds of stone, shell beads and cups, and leaf-shaped "cache blades". This culture is believed to have been core to the Meadowood Interaction Sphere, in which cultures in the Great Lakes region, the St. Lawrence region, the Far Northeast, and the Atlantic region interacted. The large area of interaction is indicated by the presence of Adena-style mounds, the presence of exotic goods from other parts of the interaction spheres, and the participation in the "Early Woodland Burial Complex" defined by William Ritchie   Pottery was widely manufactured and sometimes traded, particularly in the Eastern Interior region. Clay for pottery was typically tempered (mixed with non-clay additives) with grit (crushed rock) or limestone. Pots were usually made in a conoidal or conical jars with rounded shoulders, slightly constricted necks, and flaring rims. Pottery was most often decorated with a variety of linear or paddle stamps that created "dentate" (tooth-like) impressions, wavy line impressions, checked surfaces, or fabric-impressed surfaces, but some pots were incised with geometric patterns or, more rarely, with pictorial imagery such as faces. Pots were coiled and paddled entirely by hand without the use of fast rotation such as a pottery wheel. Some were slipped or brushed with red ochre. Pottery, agriculture, and permanent settlements have often been thought of the three defining characteristics of the Woodland period. However, it has become evident that, in some areas of North America, prehistoric cultural groups with a clearly Archaic cultural assemblage were making pottery without any evidence of the cultivation of domesticated crops. In fact, it appears that hunting and gathering continued as the basic subsistence economy and that subsistence horticulture/agriculture did not occur in much of the Southeast for a couple of thousand years after the introduction of pottery, and in parts of the Northeast, horticulture was never practiced. This research indicated that a fiber-tempered horizon of ceramics greatly predates 1000 BCE, first appearing about 2500 BCE in parts of Florida with the Orange culture and in Georgia with the Stallings culture.