Contrasting deformation styles along an active thrust belt front - the external Dinarides and Hellenides

沿活跃冲断带前缘的对比变形样式 - 外部 Dinarides 和 Hellenides

• 批准号: 269913092
• 负责人: Professor Dr. Klaus Reicherter
• 金额: --
• 依托单位: Lehr- und Forschungsgebiet für Neotektonik und Georisiken (NUG)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/269913092?language=en
• 关键词: Contrasting; deformation; styles; along; active

The fold-and-thrust belt of the Dinarides-Hellenides on the Balkan Peninsula is a rare example of active continental subduction. We propose to study its active tectonics in an area of transient kinematics between southern Croatia, Montenegro and northern Albania. Several anomalous features characterize this area and need clarification: (a) northward-diminishing seismic moment release, (b) northward disappearance of a continental lithospheric slab and (c) northward end of syn-collisional extension related to subduction rollback. The study area hosted numerous historical earthquakes as well as one of the strongest instrumentally recorded earthquakes in Europe (Montenegro 1979, MW 7.1). GPS studies indicate convergence between Adria and Eurasia at rates of 4-5 mm yr-1, largely accommodated within the external thrust belt. Long-term convergence rates, by contrast, remain unconstrained. We aim to characterize the structural basis of this transient kinematic behaviour in a two-fold approach: (1) Balanced cross sections in two regional transects on either sides of the orogen-perpendicular Skutari-Pec Fault, which delimits syn-collisional extension to the north, will allow quantifying the overall Cenozoic crustal shortening as well as the contribution of rollback-triggered extension in the transect south of the Skutari-Pec Fault. (2) Presently active structures will be identified by tectonic geomorphological and paleoseismological studies. Emphasis will be given to quantifying rates of surface uplift and active folding in the adjacent coastal areas by dating Quaternary aggradational river terraces affected by river incision and fold growth. In combination with constraints on geometries of active faults, this will allow estimating fault slip rates on a 10-100 kyr time scale. These slip rate estimates will provide average values across many seismic cycles compared to GPS-derived convergence rates that are valid only for the last 1-2 decades, i.e., a seismically quiet period since the 1979 event. The comparison of long-term and short-term slip rates can potentially highlight locked faults and is hence of relevance for assessing the seismic hazard. Our study will also contribute towards a better understanding of continental subduction and thrust belt propagation in areas characterized by low plate convergence rates.

巴尔干半岛上的Dinarides-Hellenides的褶皱带是活跃大陆俯冲的一个罕见例子。我们建议在克罗地亚南部，黑山和阿尔巴尼亚北部之间的短暂运动学区域研究其主动构造。几个异常特征表征了该区域，需要澄清：（a）北向降低的地震矩释放，（b）大陆岩石圈板的北面消失，（c）与俯冲回滚相关的汇总扩展的北端。该研究区域举办了许多历史地震，也是欧洲最强的乐器地震之一（Montenegro 1979，MW 7.1）。 GPS的研究表明，阿德里亚和欧亚大陆之间的收敛速度为4-5 mm yr-1，很大程度上容纳在外部推力带内。相比之下，长期收敛率仍然不受限制。 We aim to characterize the structural basis of this transient kinematic behaviour in a two-fold approach: (1) Balanced cross sections in two regional transects on either sides of the orogen-perpendicular Skutari-Pec Fault, which delimits syn-collisional extension to the north, will allow quantifying the overall Cenozoic crustal shortening as well as the contribution of rollback-triggered extension in the transect south of the Skutari-pec故障。 （2）目前活跃的结构将通过构造地貌和古杂种学研究来识别。通过与河流切口和褶皱生长影响的第四纪浓缩河流露台约会，将重点是量化相邻沿海地区的表面隆升和主动折叠率。结合对活动故障的几何形状的限制，这将允许在10-100 kyr时尺度上估计断层滑移速率。与GPS衍生的收敛速率相比，这些滑动率估计值将提供许多地震循环的平均值，而GPS衍生的收敛速率仅在过去1-2年中有效，即自1979年事件以来的地震安静时期。长期和短期滑动率的比较可能会突出显示锁定的断层，因此与评估地震危险相关。我们的研究还将有助于更好地了解以低板收敛速率为特征的区域的大陆俯冲和推力带的传播。