Linking the northern Alps with their foreland: The latest exhumation history resolved by low-temperature thermochronology

The evolution of the Central Alpine deformation front (Subalpine Molasse) and its undeformed foreland is recently debated because of their role for deciphering the late orogenic evolution of the Alps. Its latest exhumation history is poorly understood due to the lack of late Miocene to Pliocene sediments. We constrain the late Miocene to Pliocene history of this transitional zone with apatite fission track and (U-Th)/He data. We used laser ablation inductively coupled mass spectrometry for apatite fission track dating and compare this method with previously published and unpublished external detector method fission track data. Two investigated sections across tectonic slices show that the Subalpine Molasse was tectonically active after the onset of folding of the Jura Mountains. This is much younger than hitherto assumed. Thrusting occurred at 10, 8, 6–5 Ma and potentially thereafter. This is contemporaneous with reported exhumation of the External Crystalline Massifs in the central Alps. The Jura Mountains and the Subalpine Molasse used the same detachments as the External Crystalline Massifs and are therefore kinematically coupled. Estimates on the amount of shortening and thrust displacement corroborate this idea. We argue that the tectonic signal is related to active shortening during the late stage of orogenesis

Memory Phenotype CD4 T Cells Undergoing Rapid, Nonburst-Like, Cytokine-Driven Proliferation Can Be Distinguished from Antigen-Experienced Memory Cells

Contrary to the current paradigm that nearly all memory T cells proliferate in response to antigenic stimulation, this paper shows that an important population of CD4 T lymphocytes achieves memory/effector status independent of antigenic stimulation

Late Miocene to present deformation and erosion of the Central Alps — Evidence for steady state mountain building from thermokinematic data

We present new apatite fission track and apatite (U–Th)/He data from the Alpine orogenic front, the Austrian Subalpine Molasse. We show that the cooling signal reported from the Swiss part of the basin since 10 Ma is also present farther east. Hence, it appears to be independent of the kinematic relation to thrusting in the external thrust belt present further west, the Jura Mountains. By reconstructing the Central Alpine pro-wedge geometry at 10 Ma, we show that the taper of the Central Alps has not changed significantly and presumably remained close to the critical state since then. From cooling offsets at faults, the present day shortening rate of the pro-wedge ranges between 1.0 and 2.0 mm/a and appears to have been constant since at least the Late Miocene. In conjunction with the observations of repeated out-of-sequence thrusting in the Subalpine Molasse, a stationary deformation front, constant shortening and erosion rates and the constant taper, we argue that the Central Alpine pro-wedge is at kinematic, as well as at mass flux steady-state since 10 Ma. Our results suggest that distinct climate-driven erosion events – in contrast to more continuous erosion – are not distinguishable in the deformation record of the last 10 Ma. Hence, kinematic and mass flux steady state in the Central Alpine pro-wedge along with stable localization of deformation restricted to the Subalpine Molasse may indicate a feedback between ongoing shortening and erosion at low rates during the Late Neogene to present