地质学报（英文版）2007，Vol.81Issue(6)：940-948,9.
Calibration of the Albian/Cenomanian Boundary by Ammonite Biostratigraphy: U.S. Western Interior
Calibration of the Albian/Cenomanian Boundary by Ammonite Biostratigraphy: U.S. Western Interior
摘要
Abstract
Calibration of numerical ages to the geological time scale is a long scientific pursuit that requires the integration of multiple data sets. A case study of the Albian/Cenomanian stage boundary,also the Lower/Upper Cretaceous series boundary, illustrates the calibration process. The numerical age of this boundary has shifted from 96 Ma to 99 Ma over a time span of nearly fifty years. Recalibration resulted first from improvements in radiometric dating, and later from inferences about ammonite phylogeny, and most recently from radiometric dates of newly discovered volcanic beds interbedded with diagnostic guide fossils. However, the calibration process continues with study of cosmopolitan dinoflagellates.关键词
Albian/Cenomanian, ammonite biostratigraphy, age calibrationKey words
Albian/Cenomanian, ammonite biostratigraphy, age calibration分类
天文与地球科学引用本文复制引用
..Calibration of the Albian/Cenomanian Boundary by Ammonite Biostratigraphy: U.S. Western Interior[J].地质学报（英文版）,2007,81(6):940-948,9.基金项目
This work is in part supported by the National Key Basic Research Program, the Ministry of Science and Technology of China (MOST 973 Program,2006CB701400), and is a contribution to IGCP 463/555. （MOST 973 Program,2006CB701400）
