PACKRAT (Neotoma) MIDDEN ANALYSIS:

"Middens" are organic deposits of plant debris and feces cemented by dried urine (amberat).

First used in Quaternary Paleoecology introduced by Phillip Wells (Wells and Jorgensen, 1964), a zoologist doing vegetation reconnaissance on the Nevada Test Site.

Packrats are widespread in arid western North America, and have been collected as far north as British Columbia. They are foliavores, primarily getting their water from the vegetation they eat. (Wells, 1976).

Similar cave deposits left by other small mammals have been collected in caves of Australia, South America and the Near East.
'Trashy' + 'Mittens'


PRINCIPLES

METHODS

Each "unit" of a midden must be radiocarbon dated

Ideally, a large rock-shelter can provide middens of several different ages. Otherwise, the interpretations must take into account SITE DIFFERENCES.

Sample Selection:
Macrofossil Processing:
Identification
Quantification: Presentation:

INTERPRETATION

PLANT MACROFOSSILS:

PALYNOLOGY

MIDDEN POLLEN TRANSPORT = f(A,V,B,F)
    Air
      Organ Pipe Cactus National Monument, 17% of the pollen in modern middens from plants not found in the local vegetation.
    Vegetation
      Trapped in hairs and sticky surfaces.
    Body
      Very abundant, body wash.
    Feces
      Ave. 174,354 grains gm-1 (Davis and Anderson, 1987)



OTHER BIOGENIC CAVE DEPOSITS
    Porcupine (Echinoprocta dorsatum) Betancourt et al., 1986
    Hyrax (Procavia) urine, Louis Scott [link]
    Stick-nest Rat (Leporillus) urine, [link]

packrat Readings

HOMEWORK

LINKS
Desert Lab
Ken Cole [link]
NOAA Slide Set
USGS Database