McINTIRE 37 



have withstood both time and the elements. Although limited, these artifacts provide a relative 

 scale when classified, whereby the sequence of time is measured by culture change. In order 

 to ferret out the culture changes and consequently apply them to the changing river, archaeo- 

 logical methods have been used to order, collect, and classify the material. 



Fortunately a competent group of archaeologists has worked out a chronological time 

 scale for the Lower Mississippi Valley. This chronological scale was used as the basis for 

 sorting and classifying the ceramic remains recovered during the project. At the present time, 

 the following periods are recognized for the Lower Mississippi Valley: 



Youngest . . . Natchez Period 



Plaquemine Period 



Coles Creek Period 



Troyville Period 



Marksville Period 

 Oldest Tchefuncte Period 



The periods were usually named after the localities where the pottery complex was first recog- 

 nized. For the purposes of this discussion these cultural divisions will be used to designate 

 time periods. 



It was in the shell middens that much of the cultural remains left by the aborigines was 

 recovered. After the collections were made, the potsherds were classified according to type 

 of design and means of manufacture and then segregated into a particular time period. 



Figure 1, a cross section of an ancient submerged shell heap deposited by the Indians, is 

 a good example of the sites visited. The shell heap is based on an old natural levee that has 

 subsided beneath the marsh level to a depth of eight feet. The only feature that remains to in- 

 dicate the presence of a natural levee is the top of the shell heap deposited there by early man. 



This remnant feature is a frequent one throughout the deltaic area and is often the only 

 clue to the location of former streams. Hence it was necessary to scrutinize the aerial photos 

 of the area to locate trees and vegetation variations which almost inevitably indicate old Indian 

 sites. After the site was located, bore holes were drilled to determine whether the site was 

 resting on an old natural levee or an abandoned beach. 



In addition to the identification of physical features, the Indian mounds and middens also 

 suggest ecological environments of the surrounding water bodies. The cross section of the 

 mound (Fig. 1) shows a layer of fresh-water clam shells ( Unio ) directly above the levee; cap- 

 ping this is a deposit of brackish-water clam shells ( Rangia ). This general stratification pic- 

 ture is found in many of the shell heaps in the area and indicates that a change in water condi- 

 tions must have taken place. Salinity change is caused either by encroachment of Gulf waters 

 due to subsidence or to the influx of fresh water due to active deposition of streams. 



The sites investigated are indicated on Fig. 2 and show the widespread distribution 

 throughout the area. Various ages of the pottery are indicated by different patterns on the map. 

 Clusters of sites suggest areas or streams which were active during a phase of the cultural 

 continuum and thereby indicate different shifts of the master stream. A very brief summary 

 of the cultural periods from oldest to youngest is all that is possible in this limited discussion. 



Tchefuncte is the oldest culture isolated in coastal Louisiana and pottery of this complex 

 is found in both eastern and western Louisiana. The sites are usually associated with stranded 

 beaches or Pleistocene terrace material. Subsidence and burial of Tchefuncte sites by more 

 recent movements of the major streams has likely obliterated the record in the flood plain and 

 it is doubtful that much information about this early period will be recovered from the central 

 area. 



Cultural remains of the Tchefuncte period give little definite information about the loca- 

 tion of the master stream, but Marksville sites in the flood plain show more definite correla- 

 tions. It has been established by competent geomorphologists that the Mississippi River 

 occupied the Teche- Mississippi channel prior to its diversion to the eastern side of the alluvial 



