ABSTRACT |
The Sulu-Celebes-Banda Basins are lhree
poorly understood marginal basins
located
between northwest Australia and
southeast Asia. Analysis of magnetic
anomalies, heatflow
data, bathymetry and on-land geology has
led to the conclusion that these three
basins are
the remnants of a once-continuous ocean
basin (Lee and McCabe, 1986). ldentified
east-
west trending anomalies in all three of
these basins sugest the following ages:
Banda (119-
136 MaB.P.) (Lapouille et al.; recently
submitted manuscript; Celebes (65-72 Ma
B.P.)
(Less and McCabe, 1986); and Sulu (41-47
Ma B.P.) (Lee and McCabe, 1986). The
anomalies identified in each of these
basins become progressively younger
toward the north.
The on-land geology of this region is
complicated but stratigraphic and
paleomagnetic
studies on pre-Oligocence rocks by
numerous workers are consistent with the
interpretation
that the older landmasses that presently
dissect the basin were translated into
their present
position before late Miocene.
Stratigraphic studies from the Sula
Microcontinent, Buru,
Ceram and Tunor show close correlation
to the stratigraphy of north west
Australia or New
Guinea. Paleomagnetic studies from Timor
suggest that a portion of the island was
a part
of Australia since early Mesozoic.
Paleomagtettc and stratigraphic data
from Borneo and
Sulawesi suggest that these landmasses
share a common orign and that Sulawesi
rifted
eastward of Borneo during the Tertiary.
Paleomagnetic and stratigraphic data
from the
Philippines suggest that the Philippine
Arc is a composite of early Cretaceous
to Recent arcs
and oceanic crustal fragments that were
translated clockwise from the southeast.
The clock-
wise rotation of the Philippines,
coupled with paleo-inclination studies,
suggests that this
arc shares a common middle Tertiary
history with the West Philippine Sea.
Stratigraphic
and paleomagnetic data from the North
Palawan Continental Terrane are
consistent with
the interpretation that this terrane
rifted away from China during the middle
Tertiary.
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