Terrestrial Palaeoecology and Global Change

254 Valentin A. Krassilov. Terrestrial Palaeoecology
average with deforestation. A significance of these correlations may only be revealed
with a more exact chronology of the Tertiary cycles.
VII.6. Mid-latitude Tertiary cyclicity in eastern Asia
To account for both temperature and precipitation variables of climate changes, vegetation
responses inferred from fossil plant assemblages have to be added by depositional
and taphonomic evidence. It is also desirable to restrict the analysis by the less ambiguous
responses. In practice, the following set of palaeoclimatic criteria proved useful in
distinguishing the recurring combinations of temperature and precipitation over the Tertiary
climatic cycles (Table 3).
The stratigraphic sequence of plant assemblages is informative when related to a catenic
succession, as in the case of Fagus replacing Castanea upslope and upsection (below).
VII.6.1. Succession of plant assemblages
Geological setting. The Russian Far East east of the Siberian Platform is a mosaic
of cratonic blocks welded by ophiolitic fold belts. The pre-Cretaceous sedimentary ba-
Table 3. Indicators of Tertiary climate types in the Russian Far East.
Climate
Warm humid,
WH
Warm dry,
WD
Cool humid,
CH
Cool dry,
CD
Diversity High Moderate Moderate Low
Dominance
Non-arboreal
element
Poly
dominant
Poly
dominant
Olygo
dominant
Oligo/mono
dominant
Rare Common Rare Common
Taxodiaceae Common Rare Common Rare
Pinaceae Rare Rare Common Common
Typical leaf
morphology
Simple Compound Simple/
compound
Simple
Mean leaf width c. 60 mm c. 35 mm c. 45 mm c. 30 mm
Entire/serrate
leaf margin ratio
High Moderate Low Low
Leaf mats Lacking/rare Lacking Common Rare
Thick coal Present Lacking Present Lacking