Applying Thick-skinned Tectonic Models to the Apennine Thrust Belt of Italy—Limitations and Implications
Applying Thick-skinned Tectonic Models to the Apennine Thrust Belt of Italy—Limitations and Implications
复制标题
将厚皮构造模型应用于意大利亚平宁冲断带——局限性和启示
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
V. Zucconi
中科院分区：
文献类型：
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作者：
R. Butler;S. Mazzoli;S. Corrado;M. Donatis;D. Bucci;R. Gambini;G. Naso;C. Nicolai;D. Scrocca;P. Shiner;V. Zucconi
褶皱冲断带通常被解释为薄皮构造，发育在剥离之上，下伏基底保持不变。然而，在许多地区，特别是在挤压构造作用之前有裂谷作用的地区，基底断层再活化的模型可能更合适。利用意大利亚平宁山脉的一个历史案例，研究了薄皮构造和深根构造、逆冲构造主导的变形之间的对比。选取了3个扇区来代表逆冲带中构造样式的横向变化。Marche的外部部分（在北部）与南部的卢卡尼亚亚平宁山脉和中部亚平宁的Molise地区形成对比。Marche构造很容易用反演来解释，这种模型与陆上新的深层地震数据和亚得里亚海附近的常规地震数据一致。反演模型隐含的位移比现有的薄皮解释少五倍。然而，这些风格并不适用于整个亚平宁。卢卡尼亚亚平宁山脉南部的井资料显示了大规模的薄皮逆冲作用，自上新世早期以来水平位移达57公里。其中包括14公里的缩短段，这段缩短段穿过埋藏的阿普利亚台地碳酸盐岩。这些较深的构造可以利用斜坡主导的逆冲几何形状来恢复。莫利塞板块显示出与卢卡尼亚大致相同的构造样式：异域浅水碳酸盐岩和远洋盆地单元位于阿普利安地台的碳酸盐岩之上，主要区别在于，这里的远洋盆地单元是在渐新世-中新世下阿吉尔瓦科洛里水平分离的。在这种情况下，阿普利亚碳酸盐岩只需要5公里的位移就可以恢复。自上新世早期以来，上覆的外来生物可能已经容纳了大约45公里的位移。因此，亚平宁山脉表现出不同的构造样式，沿其长度方向有不同的位移。厚皮逆冲模型可应用于马尔凯和埋藏的阿普利亚单元中的构造。
Fold-thrust belts are commonly interpreted as thin-skinned structures, developed above a detachment, with the underlying basement remaining undeformed. However, in many areas, particularly where compressional tectonism was preceded by rifting, models of basement fault reactivation may be more appropriate. The contrasts between thin-skinned and deep-rooting, inversion-dominated deformation in building fold-thrust complexes are investigated using a case history from the Italian Apennines. Three sectors were chosen to represent the marked lateral variations in structural style e vident in the thrust belt. The outer portion of the Marche (in the north) is contrasted with a section through the Lucanian Apennines in the south and with the Molise district of the Central Apennines. The Marche structures are readily explained in terms of inversion, a model that is consistent with new deep seismic data onshore and conventional seismic from the nearby Adriatic Sea. The displacements implicit for the inversion model are a factor of five less than for existing thin-skinned interpretations. However, these styles are not applicable throughout the Apennines. Well data in the Southern Apennines of Lucania demonstrate large-scale thin-skinned thrusting, with 57 km of horizontal displacement since earliest Pliocene time. This includes 14 km of shortening that ramps up through the buried Apulian Platform carbonates. These deeper structures may be restored using ramp-dominated thrust geometries. The Molise sector shows broadly the same structural style as for Lucania: allochthonous shallow-water carbonates and pelagic basin units overlie the carbonates of the Apulian Platform, with the major difference being that here, the pelagic basin units are detached at the level of the Oligocene–lower Miocene Argille Varicolori. In this setting, the Apulian carbonates may be restored using only 5 km of displacement. The overlying allochthon probably has accommodated about 45 km of displacement since the earliest Pliocene. Therefore, the Apennines show differing structural styles with differing displacements along their length. Thick-skinned thrusting models may be applied to the Marche and to structures in the buried Apulian units.