this study is focused on do lomi te s of the
Chehel-Kaman Formation (Upper Paleocene) that is located in
NE Iran. Field and petrographic studies lead to distinguish dl
and d2 dolomites. dL is fine crystals (Ie.<;ser than 10 micron) and
is associated with t:vaporatic sed ime nts. and d2 in addition to
fint: crystals. contains coarser crystals (50-RO micron) without
evaporatic sediments. Also. oxygen isotope of ell is hCltvicr than
-2.5 %" PDB and oxygen isotope of d2 is lighter than
- 6.5 %0 PDB. C'lrbon isotope in these dolomites ranges
between + 1.8 %0 to +3.5 %0 PDB. These data along with CL
o bse rvation show that d l dolomites are formed in lower
temperature (calculated temperature is 26°C) within supratidal
environment, while d2 dolomites are formed in higher
temperature (calculated temperature is more than n °C) during
burial stage.