TY  - GEN
N2  - Passive continental margins are extraordinary geo-archives that result from processes related to continental rifting, breakup, sea-floor spreading, post-breakup, and climate changes. Whereas the South Atlantic passive continental margins (SAPCM?s) in Brazil, Namibia, and South Africa are partly high-elevated margins (~2,000m a.s.l.), the SAPCM in Argentina and Uruguay is of low elevation. The northern part of the Argentinean passive margin is represented by the Sierras Septentrionales (Tandil Hills or Sierras Tandil) and the Sierras Australes (Ventana Hills or Sierra de la Ventana). They are key areas to unravel the thermal and exhumation history of the low-elevation SAPCM. In addition, this area has been part of the Gondwanides Orogeny. During the Permo-Triassic both areas were influenced by compressive deformation and diagenetic to low grade metamorphism. Thermochronological data from the Sierras Australes are characterized by apatite (U-Th-Sm)/He ages between 107.4 (3.5) Ma and 163.0 (9.8) Ma. Apatite fission-track ages range from 129.2 (9.3) Ma to 242.7 (17.1)Ma, zircon (U-Th-Sm)/He ages show values from 206.6 (16.5) Ma to 343.6 (27.5) Ma. AHe-ages from the Sierras Septentrionales range between 121.2 (7.3) Ma and 163.0 (9.8) Ma, AFT-ages between 104.0 (7.1) Ma and 228.9 (22.3) Ma, ZHe-ages between 167.8 (10.1) and 272.7 (16.4) Ma and ZFT-ages between 218.1 (79.4) Ma and 262.4 (36.1) Ma. The AFT-ages from SE-Uruguay range between 200.2 (19.3) Ma and 325.7 (24.8) Ma. This indicates that all dated samples are younger than the corresponding formation-, intrusion- or sedimentation-age. 
The Time-Temperature models from the Sierras Australes lead to a differentiated thermal evolution throughout the region, whereas 
the thermal history in the Sierras Septentrionales, seems to be very homogeneous. Thermal overprint related to Jurassic volcanism is very reasonable and supported by thermokinematic HeFTy-models. Thermal modelling for SE-Uruguay revealed, that also this area was covered by thick late Jurassic extrusive layers (depending on the assumed geothermal gradient 1000 to 2000 m). 

UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/19168/
A1  - Kollenz, Sebastian
ID  - heidok19168
Y1  - 2015///
TI  - Long-term landscape evolution, cooling and exhumation history of the South American passive continental margin in NE Argentina & SW Uruguay

CY  - Heidelberg
AV  - public
ER  -