FN Archimer Export Format PT J TI Seismic Crustal Structure and Morphotectonic Features Associated With the Chain Fracture Zone and Their Role in the Evolution of the Equatorial Atlantic Region BT AF MARJANOVIC, Milena SINGH, Satish C. GREGORY, Emma P. M. GREVEMEYER, Ingo GROWE, Kevin WANG, Zhikai VADDINENI, Venkata LAURENCIN, Muriel CARTON, Helene DE LA PENA, Laura Gomez FILBRANDT, Christian AS 1:1;2:1;3:1;4:2;5:3;6:1;7:1;8:1;9:1;10:2;11:2; FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;10:;11:; C1 Univ Paris, CNRS, Inst Phys Globe Paris, Paris, France. GEOMAR Helmholtz Ctr Ocean Res Kiel, RD4 Marine Geodynam, Kiel, Germany. Rhein Westfal TH Aachen, TU Delft, ETH Zurich, Appl Geophys Program, Aachen, Germany. C2 UNIV PARIS, FRANCE IFM GEOMAR, GERMANY ETH ZURICH, GERMANY IF 3.848 TC 21 UR https://archimer.ifremer.fr/doc/00690/80171/83239.pdf https://archimer.ifremer.fr/doc/00690/80171/83240.docx LA English DT Article CR ILAB-SPARC BO Pourquoi pas ? AB Oceanic transform faults and fracture zones (FZs) represent major bathymetric features that keep the records of past and present strike-slip motion along conservative plate boundaries. Although they play an important role in ridge segmentation and evolution of the lithosphere, their structural characteristics, and their variation in space and time, are poorly understood. To address some of the unknowns, we conducted interdisciplinary geophysical studies in the equatorial Atlantic Ocean, the region where some of the most prominent transform discontinuities have been developing. Here we present the results of the data analysis in the vicinity of the Chain FZ, on the South American Plate. The crustal structure across the Chain FZ, at the contact between similar to 10 and 24 Ma oceanic lithosphere, is sampled along seismic reflection and refraction profiles. We observe that the crustal thickness within and across the Chain FZ ranges from similar to 4.6-5.9 km, which compares with the observations reported for slow-slipping transform discontinuities globally. We attribute this presence of close to normal oceanic crustal thickness within FZs to the mechanism of lateral dike propagation, previously considered to be valid only in fast-slipping environments. Furthermore, the combination of our results with other data sets enabled us to extend the observations to morphotectonic characteristics on a regional scale. Our broader view suggests that the formation of the transverse ridge is closely associated with a global plate reorientation that was also responsible for the propagation and for shaping lower-order Mid-Atlantic Ridge segmentation around the equator. PY 2020 PD OCT SO Journal Of Geophysical Research-solid Earth SN 2169-9313 PU Amer Geophysical Union VL 125 IS 10 UT 000604458900004 DI 10.1029/2020JB020275 ID 80171 ER EF