Development of the southern Eastern Cordillera, NW Argentina, constrained by apatite fission track thermochronology: From early Cretaceous extension to middle Miocene shortening
Development of the southern Eastern Cordillera, NW Argentina, constrained by apatite fission track thermochronology: From early Cretaceous extension to middle Miocene shortening
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DOI：
10.1029/2005tc001894
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发表时间：
2006-11-18
期刊：
影响因子：
4.2
通讯作者：
Strecker, Manfred R.
中科院分区：
文献类型：
--
作者：
Deeken, Anke;Sobel, Edward R.;Strecker, Manfred R.
[ 1]对于阿根廷西北部的普纳高原和东科迪勒拉，变形和地表隆起的时间和空间模式仍然没有得到很好的限制。从垂直剖面沿着ESE趋势横断面从高原内部延伸到南东科迪勒拉在类似的25度S收集的完全和部分复位磷灰石裂变径迹样品的分析揭示了重要的制约变形和折返历史的这一部分的安第斯山脉。这些数据限制了东科迪勒拉山脉的新近纪安第斯山脉的发展，以及晚侏罗世/早白垩世一些采样地点的裂谷相关剥露。在东科迪勒拉南部的始新世-渐新世折返事件可能与地壳缩短有关。随后，该地区被安第斯前陆盆地地层重新掩埋，开始于3000万年至2500万年之间。沉积的幅度和持续时间，揭示了热模拟，不同的样品位置，指向一个向东传播的盆地系统。在东科迪勒拉山脉南部，安第斯山脉的变形开始于2250万~ 2100万年前，比推断的重要地形的形成早500万~ 750万年，比邻近新生代盆地的沉积物保存早650万~ 800万年。比较部分重置样本的计算结构深度表明，沿前萨尔塔裂谷边缘沿着新形成的西倾逆断层容纳了大部分新近纪构造运动。东部科迪勒拉山脉南部的晚新生代变形在西部开始较早，随后向东传播。造山带的横向生长与山脉前方的前陆盆地系统的发展相结合，随后被后来出现的地形所分隔。
[ 1] For the Puna Plateau and Eastern Cordillera of NW Argentina, the temporal and spatial pattern of deformation and surface uplift remain poorly constrained. Analysis of completely and partially reset apatite fission track samples collected from vertical profiles along an ESE trending transect extending from the plateau interior across the southern Eastern Cordillera at similar to 25 degrees S reveals important constraints on the deformation and exhumation history of this part of the Andes. The data constrain the Neogene Andean development of the Eastern Cordillera as well as rift-related exhumation for some of the sampled locations in the Late Jurassic/Early Cretaceous. An intervening Eocene-Oligocene exhumation episode in the southern Eastern Cordillera was probably related to crustal shortening. Subsequent reburial of the area by Andean foreland basin strata commenced between 30 and 25 Myr. Magnitude and duration of sedimentation, revealed by thermal modeling, differ between the sample locations, pointing to an eastward propagating basin system. In the southern Eastern Cordillera, Andean deformation commenced at 22.5 - 21 Myr, predating both the inferred formation of significant topography by 5 - 7.5 Myr and preservation of sediments in the adjacent Cenozoic basins by 6.5 - 8 Myr. Comparing the calculated structural depth of partially reset samples suggests that newly formed west dipping reverse faults along the former Salta Rift margin accommodated most of the Neogene tectonic movement. Late Cenozoic deformation at the southern Eastern Cordillera began earlier in the west and subsequently propagated eastward. The lateral growth of the orogen is coupled with a foreland basin system developing in front of the range and then becomes subsequently compartmentalized by later emergent topography.