PREFACE

f. Samples should not be exposed to excessive heat (over 100 degrees Celsius), or to direct sunlight,ultraviolet, infrared, X-rays, gamma-rays, or beta radiation.g. Collect multiple samples from a given provenience when possible.2. Laboratory Methodsa. Samples that appear to have been refired should not be submitted.b. Submit multiple samples from the same provenience and from different ceramic vessels.c. Give highest priority to samples from proveniences with other datable materials.d. When sending samples in for analysis, be sure to include all written information asrequested by the TL laboratory.DendrochronologyDendrochronology is another method to use for absolute dating. Tree-ring dates have a potentialresolution of one year to a few decades, so it is clearly the most reliable method for determining whethersites or features within a site are contemporaneous. Tree-ring dates are best when recovered from sitesdating to the seventh century or later. Although dendrochronology is a well known botanical datingtechnique in the Southwest, there has been only limited success with this technique in southeast NewMexico owing to complacent growth of riparian species, and a lack of tree species over wide areas of theregion. Prior to collecting dendrochronological samples, it is best to check with the Tree-Ring Laboratoryin Arizona to determine if the samples are viable.As with radiocarbon samples, dendrochronology samples are collected in the field. Samples should haveintact outer rings in order to obtain cutting dates. Samples should be tied with a string to maintainstability.Once back in the laboratory, highest priority should be given to samples from proveniences with otherdatable materials. As many samples as possible from a given provenience will be submitted in order toincrease precision. All dendrochronology samples will be sent to the Laboratory of Tree Ring Research atthe University of Arizona, Tucson.1. Field Methodsa. Try to obtain samples with intact outer rings in order to get cutting dates.b. Collect as much as possible of a single beam in order to obtain enough rings. Take the largestbeams and collect as many samples as possible. Unsuitable samples should be retained forEthnobotanical Studies.c. Avoid pretreatment of samples with paraffin and gas to the extent possible so as to allow forpossible radiocarbon dating later.d. To maintain sample stability tie with string.e. Obtain as many different samples as possible from a given provenience.f. Collect all tree species present. All woody species, including sagebrush, oak, cottonwood,pinyon, and juniper are potentially datable.2. Laboratory Methodsa. Submit as many samples as possible from a given provenience in order to increase precision.b. Send samples as soon as possible - tree ring lab has a huge backlog.c. Give highest priority to samples from proveniences with other datable materials, e.g.,radiocarbon, obsidian, archaeomagnetic, thermoluminescence.d. Submit all samples collected.6-26