Number 31 January 1998 Newsletter of the Subcommission on ...

to meetings <strong>of</strong> <strong>the</strong> 9 th International Congress on Carboniferous
Stratigraphy and Geology that was held in Urbana, Illinois.
Physical and chemical nature <strong>of</strong> <strong>the</strong> Permian/Triassic boundary
and <strong>the</strong> distribution <strong>of</strong> rocks and fossils in China formed <strong>the</strong>
primary bases for discussion.
Subsequent activities <strong>of</strong> <strong>the</strong> <strong>Subcommission</strong> are covered in
<strong>the</strong> 30 issues <strong>of</strong> SPS <strong>Newsletter</strong>s/Permophiles published 1979-
<strong>1998</strong>.
Brian F. Glenister
Department <strong>of</strong> Geology
University <strong>of</strong> Iowa
Iowa City, IA 52242, U.S.A.
Reference
Van Der Plas, L. and Tobi, A.C., (1965). A chart for judging <strong>the</strong>
reliability <strong>of</strong> point counting results. American Journal <strong>of</strong> Science,
vol. 263, p. 87-90.
Michael T. Dunn
Department <strong>of</strong> Geosciences
Boise State University
Boise, ID 83725 USA
mdunn@trex.idbsu.edu
W. W. Nassichuk
Geological Survey <strong>of</strong> Canada (Calgary)
3303 - 33rd Street NW
Calgary, Alberta T2L,2A7 Canada
Preliminary Palynological Assessment <strong>of</strong> Selected
Horizons Across <strong>the</strong> Carboniferous/Permian
Boundary, Aidaralash Creek, Kazakhstan.
by Michael T. Dunn
An abundant, diverse, and well-preserved palynological
assemblage has been obtained from several horizons <strong>of</strong> strata
across <strong>the</strong> Carboniferous/Permian Boundary in Aidaralash Creek,
Kazakhstan. The samples span 50.2 meters <strong>of</strong> section, from 24.2
meters below to 26.0 meters above <strong>the</strong> base <strong>of</strong> Permian (base <strong>of</strong>
bed 19, Fig. 1). The assemblage is dominated by disaccate
pollen grains. Palynomorph populations have been assessed
from a count <strong>of</strong> 300 palynomorphs per slide after Dan Der Plas
and Tobi (1965).
Percentage occurrences for <strong>the</strong> sample recovered from 26.0
MAB are shown on Figure 2. Disaccate pollen grains constitute
51 percent <strong>of</strong> <strong>the</strong> sample (Table 1); common genera include
Hamiapollenites, Protohaploxypinus, and Pityosporites.
Taeniate polyplicates are second in abundance at 17.6 percent,
with Vittitina <strong>the</strong> most common genus <strong>of</strong> this group.
Monosaccate pollen grains are <strong>the</strong> third most abundant group
at 11.3 percent <strong>of</strong> <strong>the</strong> population; Cordaitina uralensis and
several species <strong>of</strong> Potonieisporites have thus far been identified.
Trilete spores make up 10.6 percent <strong>of</strong> <strong>the</strong> sample and
common genera <strong>of</strong> this group include Punctatisporites, and
Leiotriletes. Trilete zonate spores are <strong>the</strong> least numerous group
at 8.3 percent and include Densosporites, Grandispora, and
Knoxisporites. Several representatives <strong>of</strong> <strong>the</strong> latter two groups
<strong>of</strong> spores include reworked Devonian and Carboniferous forms
(Utting, <strong>1998</strong>, personal communication).
Acknowledgments
I would like to thank Brenda Davies and John Utting, Institute
for Sedimentary and petroleum Geology, Geological Survey
<strong>of</strong> Canada, Calgary, Alberta, for assistance in preparation
and identification <strong>of</strong> samples and The Geological Society <strong>of</strong>
America for funding travel to Calgary.
10
Figure 1. Stratigraphic column <strong>of</strong> portion <strong>of</strong> <strong>the</strong> section at Aidaralash
Creek, Aktöbe region, Kazakhstan. Carboniferous/Permian boundary proposed
on <strong>the</strong> basis <strong>of</strong> conodonts, fusulinaceans, and ammoniods, is indicated.
Bed numbers (e.g., 19) and subdivisions (e.g., 19.5) represent
designations widely used in recent Soviet/Russian literature; “a”, “f”, and
“c” indicate ammoniod, fuslinacean, and conodont occurrences. Palynological
horizons are indicated by “p”. Zero meters marks <strong>the</strong> point
defining <strong>the</strong> base <strong>of</strong> <strong>the</strong> Permian System.
Figure 2. Percentage <strong>of</strong> major palynomorph groups from sample at 26.o
MAB, Aidaralash Creek, Kazakhstan. Di-sac = disaccate pollen grains;
Taen poly = taeniate polyplicate pollen grains; Mono-sac = monosaccate
pollen grains; Tri-rad = trilete radial spores; Tri-zone = trilete radial
zonate/cingulate spores.