Open AccessA Global Data Set of Present‐Day Oceanic Crustal Age and Seafloor Spreading Parameters
Author(s) -
Seton Maria,
Müller R. Dietmar,
Zahirovic Sabin,
Williams Simon,
Wright Nicky M.,
Can John,
Whittaker Joanne M.,
Matthews Kara J.,
McGirr Rebecca
Publication year - 2020
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2020gc009214
Subject(s) - geology , crust , seafloor spreading , oceanic crust , tectonics , subduction , seismology , paleontology
We present an updated oceanic crustal age grid and a set of complementary grids including spreading rate, asymmetry, direction, and obliquity. Our data set is based on a selected set of magnetic anomaly identifications and the plate tectonic model of Müller et al. (2019, 10.1029/2018TC005462 ). We find the mean age of oceanic crust is 64.2 Myr, slightly older than previous estimates, mainly due to the inclusion of pockets of Mesozoic aged crust in the Atlantic and Mediterranean and improvements to the Jurassic Pacific triangle. This older crust is partly compensated by additional Cenozoic‐aged back‐arc basin crust not included in previous models. The distribution of spreading modes based on area of preserved crust is relatively equal between slow (20–55 mm/yr) and fast (75–180 mm/yr) spreading systems at 33% and 39%, respectively. Crust transitional between fast and slow, or intermediate systems (55–75 mm/yr), cover 20% of the preserved ocean floor with much smaller proportions of crust formed at ultraslow (5%) and super‐fast (3%) spreading systems. Slow and intermediate spreading systems exhibit the most stable behavior in terms of spreading asymmetry and obliquity, with the widest distribution of obliquities occurring at ultraslow spreading systems, consistent with present‐day observations. Our confidence grid provides a complementary resource for nonexperts to identify those parts of the age grid that are least well constrained. Our grids in 6, 2, and 1 arc min resolution as well as our python workflow, isopolate , used to compute our data sets are freely available in online repositories and on the GPlates data portal.