Basic principles of Paleoclimate and paleo Environmental analysis.

2. Paleoclimatology is the study of
ancient regional and global
climates.
This science is quite intriguing
considering the fact that the
means of measuring precipitation
and temperature were not
available.
Since it is not possible to go back
in time to see what climates were
like, how do scientists determine
these past climates?
… or can we?

3. For interpretation of paleoclimate and
paleoenviromental, the basic material is drawn from
geology but we have to take help of many diverse
branches of science.
Cold Climate: Tillites, glaciofluvial (dropstones),
varves (paired layers) i.g darker layers=Organic rich,
fine grained=Winter; Lighter layers=coarse grained
=spring and summer;
Glacial pavements, faciated, straiated boulders and
fresh feldspar grains.

4. Ratio of Oxygen 16 to Oxygen 18 (most oxygen in the
earth is in the form of oxygen 16 = 99.756% ; Oxygen
18 =0.205% ). During glaciation oceans become
relatively depleted in oxygen 16 and enriched in
oxygen 18 isotope [ water that is rich in oxygen 16 which
makes it lighter evaporate more readily than water with
more Oxygen 18. During glaciation, the clouds precipates
their oxygen 16 rich water on ice cap as snow, where it
remains locked up for long time. As a result, the oceans
become relatively depleted in oxygen 16 and enrich is
oxygen 18 during period of glaciation]. Measurement of
oxygen isotope in calcite of shells of marine organism
(foraminifera etc) and chemical sediments, limestone
and cherts etc.

5. Coal= Moist climate = At various temperature,
except Arid hot and cold climate;
Arid /semiarid: 1) Sand dunes =hot or cold arid
or semiarid ;
2) Evaporites: Chemical precipitate; minerals, calcite,
halite, sodium carbonate, sodium sulphate, potasium
ppt etc.
3) Red Beds: FeO3 cemented sandstone and shales
oxidising atmosphere in arid/semiarid.
4) Dark brown/black coloured-iron and Mn oxides
coatings on sediments/pebbles etc “Desert varnish”
from evaporating moisture-rises to surface due to
capillary action.

6.  Hot Humid Climate: Laterites and Bauxite=
deeply weathered tropical soils in hot, humid
climate.