A New Southern North Atlantic Isochron Map: Insights Into the Drift of the Iberian Plate Since the Late Cretaceous

Abstract

This paper presents a new southern North Atlantic plate model from Late Cretaceous to present, with the aim of constraining the kinematics of the Iberian plate during the last 83.5 Myr. This model is presented along with a detailed isochron map generated through the analysis of 3 aeromagnetic tracks and ~400 ship tracks from the National Centers for Environmental Information database. We present a new technique to obtain well‐constrained estimates of the Iberia‐North America plate motions from magnetic anomalies, overcoming the scarcity of large‐offset fracture zones and transform faults. We build an integrated kinematic model for NW Africa, Morocco, Iberia, Europe, and North America, which shows that the deformation is partitioned between Pyrenees and Betic‐Rif orogenic domain during the Late Cretaceous‐Oligocene time interval. In the Eastern Betics domain, the calculated amount of NW Africa‐Iberia convergence is ~80 km between 83.5 and 34 Ma, followed by ~150 km since the Oligocene. The motion of Iberia relative to Europe in the Central Pyrenees is characterized by overall NE directed transpressional motion during the Campanian and the Paleocene, followed by NW directed transpressional movement until the Lutetian and overall NNW directed convergence from Bartonian to Chattian. This motion occurs along the axis of the Bay of Biscay from the Santonian–Campanian boundary to the middle Priabonian, subsequently jumping to King's Trough at Anomaly 17 (36.62 Ma).

Insights Into the Crustal‐Scale Dynamics of a Doubly Vergent Orogen From a Quantitative Analysis of Its Forelands: A Case Study of the Eastern Pyrenees

“…Their model predicts the highest convergence rates in Ypresian and Lutetian times (~3.6 mm/yr), slightly slower convergence during Bartonian and Priabonian times (~2.8 mm/yr), followed by rapid convergence during the Oligocene (~3.9 mm/yr). The good agreement between our results and those obtained from completely independent methods and data (Macchiavelli et al, ) shows that our approach gives good results and can be applied to other natural systems to better constrain their evolution.…”

Thermochronological Evidence of Early Orogenesis, Eastern Pyrenees, France

“…Second, assuming a constant convergence rate along the orogen, it would have taken longer to close the wider rift to the west, thus preserving the thermal perturbation for longer. A faster convergence rate in the east as documented recently by Macchiavelli et al () would further promote this trend.…”

“…The Pyrenean orogen was generated from late Santonian–early Campanian to middle Miocene by N‐S convergence of the Iberian and European plates (Choukroune, ; Muñoz, ; Macchiavelli et al, ). External orogenic zones and foreland basins record two distinct periods of low but accelerating tectonic shortening and subsidence, latest Santonian–Danian and Thanetian–Oligocene, separated by a quiet (very low to near‐zero subsidence) period during the Paleocene (Ford et al, ).…”

Unraveling the Mesozoic and Cenozoic Tectonothermal Evolution of the Eastern Basque‐Cantabrian Zone–Western Pyrenees by Low‐Temperature Thermochronology

“…At that time, however, oceanic crust was being created in the center of the Bay of Biscay (up to chron A33o, 80 Ma; e.g., Sibuet et al, ), implying simultaneous lithospheric extension toward the west. A very detailed kinematic model recently proposed by Macchiavelli et al () predicts this behavior, with nearly nor convergence or extension in the intermediate zone (the Basque‐Cantabrian zone) until the beginning of the Eocene. Around the Cinco Villas massif and the Marble Unit, we interpret the high cooling rates observed in the early to middle Eocene as the expression of exhumation by thrusting (curves for LZ2 and CV2 in Figure ).…”

“…It is widely accepted that the onset of convergence in the Pyrenees s.s. occurred in the Late Cretaceous, at ~83–84 Ma (Macchiavelli et al, ; Teixell et al, , and references therein). At that time, however, oceanic crust was being created in the center of the Bay of Biscay (up to chron A33o, 80 Ma; e.g., Sibuet et al, ), implying simultaneous lithospheric extension toward the west.…”