The Archaeology of the Cahokia Mounds ICT-II: Site Structure James M. Collins fU Mound 72 Illinois Cultural Resources Study No. 10 Illinois Historic Preservation Agency JLUNOIS HISTORICAL SURVEY The Archaeology of the Cahokia Mounds ICT-II: Site Structure James M. Collins 1990 Illinois Cultural Resources Study No. 10 Illinois Historic Preservation Agency Springfield THE CULTURAL RESOURCES STUDY SERIES The Cultural Resources Study Series was designed by the Illinois State Historic Preservation Office and Illinois Historic Preservation Agency to provide for the rapid dissemination of information to the professional community on archaeological investigations and resource management. To facilitate this process the studies are reproduced as received. Cultural Resources Study No. 10 reports on the features and structural remains excavated at the Cahokia Mounds Interpretive Center Tract-II. The author provides detailed descriptions and interpretations of household and community patterns and their relationship to the evolution of Cahokia 's political organization. This repwrt is a revised version of a draft previously submitted to the Illinois Historic Preservation Agency. The project was funded by the Illinois Department of Conservation and, subsequently, by the Illinois Historic Preservation Agency. William 1. Woods served as Principal Investigator. The work reported here was financed in part with federal funds provided by the U.S. Department of the Interior and administered by the Illinois Historic Preservation Agency. However, the contents and opinions do not necessarily reflect the views or policies of the U.S. Department of the Interior or the Illinois Historic Preservation Agency. Funds for preparation of this report were provided by a grant from The University of Iowa, Office of the Vice President for Research. Thomas E. Emerson, Chief Archaeologist of the Illinois Historic Preservation Agency serves as general editor for the Cultural Resources Study Series. International Standard Book Number 0-942579-10-0. This work is dedicated to Susan and Kathleen TABLE OF CONTENTS LISTOFnGURES vi LISTOFTABLES viii PREFACE '''i ACKNOWLEDGMENTS x"i CHAPTER I PROJECT HISTORY, DESIGN, AND METHODS Introduction 1 The Interpretive Center Tract-Location II 3 Recommendations Based on 1984 Testing 3 ICT-n Mitigation—1985 5 Research Topics 5 Methods 6 ICT-II Mitigation and Testing—1986 16 CHAPTER n SITE STRUCTURE EM THE AMERICAN BOTTOM: ca. A.D. 900-1250 Emergent Mississippian Settlement Patterns in the American Bottom 27 Mississippian Settlement Patterns in the American Bottom 29 Mississippian Developments at Cahokia 30 CHAPTER ni ICT-n CULTURAL FEATURES—ANALYTICAL APPROACH Introduction 35 Methods 36 CHAPTER IV FEATURE CLASSmCATION 46 Feature Class 1 —Pit Features of Indeterminate Function Feature Class 2—Cache/Storage Facilities 48 Feature Class 3—Fire-Related Features 58 Feature Qass4—Postmolds and Post Pits 65 Feature Class 5—Enclosed Wall Trench Structures 67 Feature Class 6—Other Structures 81 Feature Class 7—Other Features 87 CHAPTER V DESCRIPTIONS OF COMPONENT FEATURE ASSEMBLAGES Concepts of Household 103 Component Descriptions 104 Late Archaic Component Features 104 Indeterminate Mississippian Component Features 105 Lohmann Component Features 105 Lohmann-Stirling "Component" Features 1 19 Stirling Component Features 121 Early Stirling Component Features 123 Late Stirling Component Features I'^l General Stirling Component Features 160 Moorehead Component Features 166 CHAPtER VI SUMMARY COMPARISON OF FEATURES, FEATURE CLUSTERS, AND COMPONENTS Feature Classes: A Diachronic Perspective 220 Feature Clusters and Components: A Diachronic View 228 REFERENCES ^^ LIST OF FIGURES Figure 1.1 Location of museum related investigations conducted prior to 1984 2 Figure 1.2 Cahokia site showing location of Interpretive Center Tract-Location IT 4 surface collection Figure 1 .3 Surface density distribution of chert artifacts recovered during 1985 8 Figiu-e 1.4 ICT-Il block showing limits of 1985 excavation 9 disturbances Figure 1 .5 Northern portion of ICT-II excavation block showing historic to Mississippian features 10 Figure 1.6 ICT-II excavation block showing location of Stratigraphy Trenches and Archaic Block. 13 Figure 1.7 Profile of north-south Stratigraphy Trench 14 Figure 1.8 Profile of east-west Stratigraphy Trench 15 Figure 1.9 Final configuration of ICT-II excavation block showing feature distribution 17 Figure 1.10 Composite of ICT-II mitigation and testing procedures 19 Figure 1.11 Surfacedensity distribution of artifacts from parking area collection 20 Figure 1.12 Utility corridor showing locations of Sample Areas 1-7 and Deep Backhoe Trenches 1 and 2 22 Figure 1.13 Sample Areas 1-7 showing sub-plowzone feature distribution 23 Figure 1.14 Profile of Deep Backhoe Trench 1 24 Figure 1.15 Profile of Deep Backhoe Trench 2 26 Figure 2.1 Composite of proposed cultural chronologies for Cahokia and the American Bottom.... 28 Figure 2.2 American Bottom showing physiography ca 1800 and locations of major Mississippian sites 31 Figure 3.1 Standard formulas used in detennining ICT-II feature volumes 37 Figure 3.2 ICT-II excavation block showing composite of excavated features 39 Figure 4.1 Representative examples of Sub-class 1.1 pit features 47 Figure 4.2 Representative examples of Sub-class 1.2 pit features 49 Figure 4.3 Representative example of Sub-class 1.3 pit features 50 Figure 4.4 Representative examples of Sub-class 2.1 exterior cache/storage pits 51 Figure 4.5 Representative examples of Sub-class 2.2 interior cache/storage pits 54 Figure 4.6 Representative examples of Sub-class 2.3 small cache pits 56 Figure 4.7 Sub-class 2.4 burial pit. Feature 423 57 Figure 4.8 Representative examples of Sub-class 3.1 hearths 59 Figure 4.9 Representative examples of Sub-class 3.2 fu^pils 60 Figure 4.10 Representative examples of Sub-class 3.3 fu-epits with posts 62 Figure 4.11 Representative example of Sub-class 3.4 smudge pits 63 Figure 4.12 Representative examples of Sub-class 3.5 pit ovens (Type 1) and roasting/steaming faciUties (Type 2) 64 Figure 4.13 Representative examples of Sub-class 4.1 free-standing post features 66 Figure 4.14a Sub-class 5.1 rectangular wall trench structure (Fea. 233) 69 Figure 4.14b Sub-class 5.1 rectangular wall trench structure (Fea. 324) 70 Figure 4.15a Sub-class 5.2 small, rectangular wall trench suiicture (Fea. 344) 72 Figure 4.15b Sub-class 5.2 small, rectangular wall trench stiiicture (Fea. 12) 73 Figure 4.16a Sub-class 5.3 square, or nearly square, wall U^nch structure (Fea. 143) 74 Figure 4.16b Sub-class 5.3 square, or nearly square, wall trench structure (Fea. 367) 75 Figure 4.17a Sub-class 5.4 unusual-shaped wall trench structure (Fea. 8) 77 Figure 4.17b Sub-class 5.4 unusual-shaped wall trench structure (Fea. 287) 78 Figure 4.17c Sub-class 5.4 unusual-shaped wall trench structures (Fea. 131) 79 Figure 4. 17d Sub-class 5.4 unusual-shaped wall trench stioictures (Fea. 332) 80 Figure 4.18 Representative examples of Sub-class 6.1 features 82 Figiu-e 4.19 Representative examples of Sub-class 6.2 features 84 Figure 4.20 Representative examples of Sub-class 6.3 features 86 Figure 4.21 Representative examples of Sub-class 6.5 post structures 88 Figure 4.22 Representative examples of Sub-class 7.4 features 90 Figure 5.1 Distribution of Indeterminate Mississippian features 106 Figure 5.2 Distribution of Lohmann component features 107 Figure 5.3 Locations of Lohmann component Feature Clusters 1-3 108 Figure 5.4 Lohmann Feature Cluster 1 110 Figure 5.5 Lohmann Feature Cluster 2 113 1 Figure 5.6 Lohmann Feature Cluster 3 116 Figure 5.7 Distribution of Lohmann-Stirling "component" features 120 Figure 5.8 Distribution of Stirling component features 122 Figiu^ 5.9 Distribution of Early Stirling component features 124 Figure 5.10 Location of Early Stirling component Feature Clusters 1-7 125 126 Figure 5.11 Early Stirling Feature Cluster 1 Figure 5.12 Early Stirling Feature Cluster 2 128 Figure 5.13 Early Stirling Feature Cluster 3 130 Figure 5.14 Early Stirling Feature Cluster4 133 Figure 5.15 Early Stirling Feauire Cluster 5 135 Figure 5.16 Early Stirling Feature Cluster 6 137 Figure 5.17 Early Stirling Feature Cluster 7 138 Figure 5.18 Distribution of Late Stirling component features 142 Figure 5.19 Location of Late Stirling component Feature Clusters 1-6 143 Figure 5.20 Late Stirling Feature Cluster 1 144 Figure 5.21 Late Stirling Feature Cluster 2 147 Figure 5.22 Late Stirling Feature Cluster 3 149 Figure 5.23 Proximity of Mound 107 to ICT-II excavation block 151 Figure 5.24 Detailed plan and profile of Late Stirling Structural Feature 178 152 Figure 5.25 Late Stirling Feature Cluster 4 154 Figure 5.26 Late Stirling Feature Cluster 5 157 Figure 5.27 Late Stirling Feature Cluster 6 159 Figure 5.28 Distribution of General Stirling component features 161 Figure 5.29 Detail of proposed hide processing activity area 164 Figure 5.30 Distribution of Moorehead component features 167 Figure 5.31 Location of Moorehead component Feature Clusters 1 and 2 168 Figure 5.32 Moorehead Feature Cluster 1 169 Figure 5.33 Moorehead Feature Cluster 2 174 Figure 6. Comparison of structure floor area means from the ICT-II and selected FAI-270 project sites 227 Figure 6.2 ICT-II Lohmann Component 231 Figure 6.3 ICT-II Stirling Component 232 Figure 6.4 ICT-II Moorehead Component 233 LIST OF TABLES 41 Table 3.1 ICT-II Cultural Feature Inventor>' Table4.1 Sub-class 1.1 Pit Features 92 Table4.2 Sub-class 1.2 Pit Features 93 Table4.3 Sub-class 1.3 Pit