| ABSTRACT
When they were graphically
correlated against a composite standard database, paleontologic data sets
from the Carboniferous and Lower Permian of the western Tarim basin revealed
a punctuated stratigraphic succession in which most of geologic time is
contained within regional hiatuses (up to 15 m.y. duration). These hiatuses
occur beneath rock packages of late Bashkirian-middle Moscovian, late Moscovian-early
Kasimovian, late Gzhelian-early Asselian, and early Sakmarian-Artinskian
ages. This interpretation differs from other views that hold that Permian-Carboniferous
deposition in the Tarim basin was continuous, or nearly continuous with
only minor breaks. The results suggest that late Paleozoic sedimentation
in the Tarim basin was controlled primarily by local processes, not by
third-order, global, sea level cycles (1-3 m.y. duration).
The graphic correlation technique is capable
of superior biostratigraphic resolution because it uses
©Copyright
1997. The American Association of Petroleum Geologists. All rights reserved. 1Manuscript
received June 3, 1996; revised manuscript received October 21, 1996; final
acceptance March 19, 1997.
2Amoco
Exploration and Production Technology Group, P.O. Box 3092, Houston, Texas
77253.
3Consultant,
1 Whistler Point Road, Westport, MA 02790.
Development
of the "Old World" composite standard was a collaborative effort involving
us and Amoco colleagues J. F. Baesemann, J. L. Carney, P. L. Diver, C.
H. Kreger, M. K. LaCoe, M. Nguyen, J. A. Stein, G. P. Wahlman, and G. D.
Wood. We benefited from discussions on fusulinacean biostratigraphy with
G. P. Wahlman, I. Nilsson (Saga Petroleum), and V. I. Davydov (VSEGEI,
St. Petersburg), and from discussions on Tarim geology with C. Heubeck
(Amoco). C. B. Foster (Australian Geological Survey Organization) provided
a prepublication copy of AGSO's Phanerozoic time scale. We thank S. A.
Graham, G. H. Blake, and P. O. Yilmaz for their thoughtful reviews of the
manuscript, which was released for publication by Amoco Orient Petroleum
Company. |
| the ranges of all fossils within
a data set, not just guide fossils or those associated with zonal definitions.
Moreover, a composite standard that is linearly calibrated to geologic
time makes possible inferences regarding rates of rock accumulation within
stratigraphic sequences and the durations of sequence-bounding hiatuses.
The resulting chronostratigraphic framework enables and constrains sequence
stratigraphic and seismic stratigraphic interpretations.
INTRODUCTION
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