气候变化领域集成服务门户(CCPortal): A Late Cretaceous-Eocene Geomagnetic Polarity Timescale (MQSD20) That Steadies Spreading Rates on Multiple Mid-Ocean Ridge Flanks

CCPortal

DOI	10.1029/2020JB020034
	A Late Cretaceous-Eocene Geomagnetic Polarity Timescale (MQSD20) That Steadies Spreading Rates on Multiple Mid-Ocean Ridge Flanks
	Malinverno A.; Quigley K.W.; Staro A.; Dyment J.
发表日期	2020
ISSN	21699313
卷号	125 期号:8
英文摘要	Magnetic anomalies over mid-ocean ridge flanks record the history of geomagnetic field reversals, and the width of magnetized crustal blocks can be combined with absolute dates to generate a Geomagnetic Polarity Timescale (GPTS). We update here the current GPTS for the Late Cretaceous-Eocene (chrons C33–C13, ~84–33 Ma) by extending to several spreading centers the analysis that originally assumed smoothly varying spreading rates in the South Atlantic. We assembled magnetic anomaly tracks from the southern Pacific (23 ship tracks), the northern Pacific (35), the southern Atlantic (45), and the Indian Ocean (51). Tracks were projected onto plate tectonic flow lines, and distances to magnetic polarity block boundaries were estimated by fitting measured magnetic anomalies with a Monte Carlo algorithm that iteratively changed block model distances and anomaly skewness angles. Distance data from each track were then assembled in summary sets of block model distances over 13 ridge flank regions. We obtained a final MQSD20 GPTS with another Monte Carlo algorithm that iteratively perturbed ages of polarity chron boundaries to minimize the variability of spreading rates over all ridge flanks and fit an up-to-date set of radioisotopic dates. The MQSD20 GPTS highlights a major plate motion change at 50–45 Ma, when spreading rates decreased in the Indian Ocean as India collided with Eurasia while spreading rates increased in the South Atlantic and Northern Pacific and the Hawaii-Emperor seamount chain changed its orientation. ©2020. The Authors.
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187719
作者单位	Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States; Department of Physics, Brown University, Providence, RI, United States; Dipartimento di Scienze della Terra, Università Statale di Milano, Milan, Italy; Now at Department of Earth and Environment, Boston University, Boston, MA, United States; Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France
推荐引用方式 GB/T 7714	Malinverno A.,Quigley K.W.,Staro A.,et al. A Late Cretaceous-Eocene Geomagnetic Polarity Timescale (MQSD20) That Steadies Spreading Rates on Multiple Mid-Ocean Ridge Flanks[J],2020,125(8).
APA	Malinverno A.,Quigley K.W.,Staro A.,&Dyment J..(2020).A Late Cretaceous-Eocene Geomagnetic Polarity Timescale (MQSD20) That Steadies Spreading Rates on Multiple Mid-Ocean Ridge Flanks.Journal of Geophysical Research: Solid Earth,125(8).
MLA	Malinverno A.,et al."A Late Cretaceous-Eocene Geomagnetic Polarity Timescale (MQSD20) That Steadies Spreading Rates on Multiple Mid-Ocean Ridge Flanks".Journal of Geophysical Research: Solid Earth 125.8(2020).