『Abstract
Oil source rocks represent sequences with the Corg
content ranging from 3-5 to 15-20 %. Sedimentary sections of large
petroliferous basins usually include one or two such sequences,
which generated liquid and gaseous hydrocarbons (HCs) during their
long-term subsidence to the elevated temperature zone. The middle
episode of the Late Cretaceous was marked by the accumulation
of sediments with a high Corg content in
different areas of the World Ocean. However, truly unique settings
favorable for accumulation of the sapropelic organic matter (OM)
appeared at continental margins that primarily faced the Tethys
Ocean. The La Luna Formation is one of the best known source rock
sequences responsible for the generation of liquid HCs in basins
of the Caribbean region. In the Persian Gulf, the Kazhdumi Formation
composed of marls and clayey limestones is considered the main
oil-generating sequence. In the Paleogene after closure of the
Tethys, the Pacific continental margins became the main domains
that accumulated source rocks. The maximal deposition of sapropelic
OM in this region correspond to the early-middle Eocene. In the
Neogene, the accumulation of source sediments was associated with
deltas and submarine fans of large rivers and with upwelling zones.
In basins of the Californian borderland, the main oil-generating
sequences are represented by siliceous rocks of the Monterey Formation.
They were deposited in a regional upwelling zone related to the
cold California Current.』
Senonian-Paleocene interval
Terminal Paleocene -first half of the Eocene
Oligocene-Pleistocene interval
Conclusions
References