The southern passive margin of the oceanic Western Black Sea Basin consists
of two tectonic units, the istanbul Zone and the Central Pontides. These u
nits are delimited by a Fundamental, north-south Arac-Daday shear zone juxt
aposing totally different basement rock groups and covering later Mesozoic
sedimentary rocks. To the west of this shear zone the istanbul Zone is cove
red by a sedimentary succession deposited in a southerly deepening continen
tal margin basin. This basin was bisected lengthwise during the Maastrichti
an forming the Zonguldak Basin in the northwest and the Ulus Basin in the s
outhwest. Both of these basins were deformed in the Early Cainozoic. To the
east of the Arac-Daday shear zone, the northerly deepening Sinop Basin dom
inates the architecture of the Pontides in the north. It began forming by e
xtension in the Barremian and was destroyed by a single-phase north-south c
ompression in the Late Eocene-Oligocene. After the juxtaposition of the Cen
tral Pontides and the istanbul Zone, an E-W trending extensional magmatic a
re was established on these sedimentary basins in response to northward-sub
ducting Neotethys to the south. This magmatic are, which began during the T
uronian, gave rise to the Western Black Sea oceanic back-are basin,
None of the basins in the Pontides is simple. They show a complex evolution
responding to different rifting and closure events with much, as yet unspe
cified, strike-slip movement. Copyright (C): 1999 John Wiley & Sons, Ltd.