Spatial and Temporal Variations in Crustal Structure in the Eurasian Basin

Lihong Zhao,Pengyao Zhi,Tao Zhang,Mujie Li,Chaoyang Li,Zilong Ling,Renwei Ding

doi:10.3390/jmse10020157

Abstract

To understand the tectonic–magmatic history, crustal structure and crustal accretion mode of the Eurasian Basin in the Arctic, we calculated the crustal thickness, residual bathymetry (RB) and non-isostatic topography of the Eurasian Basin by using the latest bathymetry, free-air gravity anomaly, crustal age and sediment thickness data. The tectonic–magmatic process of the Eurasian Basin can be divided into two stages. During magnetic isochrons 24-13 (C24-C13), the crustal structure of the basin was characterized by regional variations, while the crustal structure of the basin was characterized by local variations during magnetic isochrons 13-0 (C13-0). On the whole, the western part of the basin had a thicker crustal thickness and higher RB than the eastern part of the basin during C24-C13, which should result from the northward movement of Greenland. During magnetic isochrons 24-20 (C24-C20), the crustal structure of the eastern part of the basin had abnormally strong asymmetry. We speculate that there may be mantle upwelling beneath the Kara Sea Shelf in the south of the Eastern Eurasian Basin, which provides a large amount of melt for the crustal accretion of the southern part of the Eastern Eurasian Basin. The melt focusing supply could generate abnormally thick crust (>7 km) during magma enhancement period. The Western Eurasian Basin had stronger spatial variability and more frequency asymmetric polarity reversal than the Eastern Eurasian Basin during magnetic isochrons 6-0 (C6-0). We attribute this to the inflow of the North Atlantic mantle.

Highlights

Publisher’s Note: MDPI stays neutralIn recent years, the global warming and potential natural resources led to the interest for studying the Arctic exponentially increase
In order to quantitatively analyze the spatial and temporal variations of crustal structure and tectonic–magmatic activity in the Eurasian Basin, we calculated the variations of crustal thickness, residual bathymetry and non-isostatic topography at different stages of the basin’s evolution (Figure 5a–c) according to the magnetic isochrone and flowline
Our results showed that the Eurasian Basin had an abnormally thin crust, low residual bathymetry, and non-isostatic lithosphere due to the fact that the Gakkel Ridge forming the Eurasian Basin is an ultra-slow spreading ridge

Summary

Introduction

Publisher’s Note: MDPI stays neutralIn recent years, the global warming and potential natural resources led to the interest for studying the Arctic exponentially increase. As the youngest tectonic province in the Arctic Ocean, the Eurasian Basin is the key to study the Arctic region. Some studies on the crustal structure have been conducted, they mostly focused on the Gakkel Ridge and the western part of the Eurasian Basin [1,2,3,4]. The Gakkel Ridge forming the Eurasian Basin is the ultra-slow spreading ridge (it has the slowest spreading rate in the world) that has a unique crustal accretion model and lithospheric characteristics; it is an ideal region to study the magmatic and tectonic behavior of the spreading ridges [2]. The study of the crustal thickness of the Eurasian

Results

Discussion

Conclusion