Research Projects

Dating Paleoindian sites in Brazil and elsewhere

Dating of ceramics and fire-modified rock

Dating rock alignments in the Rocky Mountains and Great Plains


 
 
 
 

 

We are exploring the potential of luminescence to date construction episodes of prehistoric architecture.  We have in the past dated construction materials such as bricks and mortar.  But we have also tried to date paleo-surfaces beneath architectural remains in order to estimate when the architecture was put there.  This relies on the ability of luminescence to date paleosols to the time of their burial.  Grains in active soils become exposed to sunshine by cycling to the surface via turbation.  This process effectively ends with the placement of something over the surface, so that by dating the youngest grains in the paleosol, luminescence should be able to estimate the date of the placement.  We initially applied this principle to dating the construction of earthen mounds in the Southeast.  We are currently involved in a NSF-funded project to date the placement of rocks in “tipi rings” and other anthropogenic rock arrangements in the Rocky Mountains and Great Plains.  To make the data assessable, we have provided links to various data files. The luminescence data files can be accessed at http://dagorlad.anthropology.washington.edu/~ftpuser/Rock_Alignment_Dating/. In order to navigate through the various files we have also provided a spreadsheet directory containing information about sample numbers, bin files, and dates of measurement: luminescence file directory.

  1. Samples: Prehistoric rock arrangements are ubiquitous throughout the Rocky Mountains and adjacent high Plains.  Despite the remarkable record of settlement and subsistence practices that these arrangements provide, their use has been limited by the difficulty in dating them.  As a pilot project, we have collected several sites from five sites in Montana and Wyoming.  Kutoyis is a multi-dimensional site in northern Montana on the plains just east of Glacier National Park.  It includes linear arrangements of cairns forming bison drive lines that lead to a cliff as well as several concentrations of tipi rings.  The Whitewater sites are a series of small tipi-ring sites located north of Malta, Montana, on the high plains.  Below is the list of samples:

 

UW lab #

Sample

type

provenience

Kutoyis, Montana

UW1910

OSL 1

Surface control

South drive line

UW1911

OSL 2

cairn

South drive line

UW1912

OSL 3

cairn

South drive line

UW1913

OSL 4

cairn

North drive line

UW1914

OSL 5

Tipi ring

North camp site

UW1915

OSL 6

Tipi ring (same as UW1914)

North camp site

UW1916

OSL 7

Tipi ring

North camp site

UW1917

OSL 8

Tipi ring

North camp site

UW1918

OSL 9

Tipi ring

North camp site

UW2437

OSL 10-1

cairn

South drive line

UW2438

OSL 10-2

cairn

South drive line

UW2439

OSL 10-3

cairn

South drive line

UW2440

OSL 10-4

Large ring (medicine wheel)

Memorial monument

UW2441

OSL 10-5

Large ring

Memorial monument

UW2442

OSL 10-6

Large ring

Memorial monument

UW2443

OSL 10-7

cairn

North drive line

UW2444

OSL 10-8

cairn

North drive line

UW2445

OSL 10-9

Tipi ring

Upper campsite

UW2446

OSL 10-10

Tipi ring (two samples)

Upper campsite

UW2447

OSL 10-11

Tipi ring

Upper campsite

UW2448

OSL 10-12

Tipi ring

Upper campsite

Whitewater sites, Montana

UW2152

OSL 1

Tipi ring 1

24PH762

UW2153

OSL 2

Tipi ring 1

24PH762

UW2154

OSL 3

Surface control

24PH762

UW2155

OSL 4

Tipi ring 11

24PH3773

UW2156

OSL 5

Tipi ring

24PH3773

UW2157

OSL 6

Tipi ring 1

24PH3775

UW2158

OSL 7

Tipi ring

24PH3775