Travitonics:: using travertines in active fault studies
Travitonics:: using travertines in active fault studies
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DOI：
10.1016/s0191-8141(99)00061-9
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发表时间：
1999-08-01
影响因子：
3.1
通讯作者：
Çakir, Z
中科院分区：
文献类型：
--
作者：
Hancock, PL;Chalmers, RML;Çakir, Z
温泉沉积的晚第四纪钙华能够揭示很多有关新构造属性和构造历史的信息。基于在爱琴海地区（土耳其和希腊）、亚平宁山脉北部（意大利）以及盆地与山脉省（美国）的实地研究，我们得出以下具有预测价值的关系：
（i）钙华沉积优先沿着断裂痕迹分布，要么就在张性裂隙正上方，要么在正断层的上盘；
（ii）许多钙华裂隙脊沉积的位置与断层段之间的阶跃区（转换斜坡）重合；反映在这种环境下所经历的复杂应变的交叉张性裂隙网络可能是增强热液流动的原因；
（iii）覆盖在张性裂隙之上的钙华沉积形态受下伏物质的流变性控制；在以前和现在的湖岸，当裂隙位于未固结沉积物之下时会形成石灰华锥（塔、尖峰），而当裂隙在地表切割基岩时则会形成裂隙脊；
（iv）裂隙脊由向外倾斜的层状钙华组成，其两侧是一条被垂直条带状钙华填充的中央张性裂隙；裂隙可用于推断局部拉伸方向；
（v）对于那些可以用铀系法测定年代的钙华，有可能计算出单个裂隙的时间平均扩张和横向扩展速率；
（vi）大多数切割裂隙脊的裂隙由自相似的角状段组成，其分形维数在1.00 - 1.12范围内，层状钙华的特性加上裂隙尖端的应力扰动可能是导致从如此广泛的地点推断出这种相似分形维数的原因。随着深度增加宽度逐渐增大的裂隙是连续断裂扩张的产物，这与在间歇性扩张期间形成的、宽度随深度呈阶梯式增加的裂隙形成对比；
（vii）沿着断层带从泉水中沉积的钙华堆积在泉线下坡的阶地状土丘中；
（viii）许多切割钙华沉积的沉积后裂隙在局部与沉积边缘成直角方向排列；
（ix）钙华中的系统性节理仅限于那些已被剥露的侵蚀板状沉积部分。（C）1999年由爱思唯尔科学有限公司出版。保留所有权利。
Late Quaternary travertines deposited from hot springs can reveal much about the neotectonic attributes and histories of structures. On the basis of field studies in the Aegean region (Turkey and Greece), the northern Apennines (Italy) and the Basin and Range province (USA) we conclude that the following relationships are of predictive value: (i) travertine deposits are preferentially located along fracture traces, either immediately above extensional fissures or in the hanging walls of normal faults; (ii) the locations of many travertine fissure-ridge deposits coincide with step-over zones (relay ramps) between fault segments; networks of intersecting tensional fissures reflecting the complex strains experienced in such settings are probably responsible for enhancing hydrothermal flow; (iii) the morphology of travertine deposits overlying extensional fissures is controlled by the rheology of the underlying materials; tufa cones (towers, pinnacles) form on former and present lake hoots where fissures underlie unconsolidated sediments, whereas fissure-ridges develop where fissures cut bedrocks at the surface; (iv) fissure-ridges comprise outwardly dipping bedded travertine flanking a central tensional fissure filled by vertically banded travertines; fissures can be used to infer local stretching directions; (v) where there are travertines datable by the U-series method it is possible to calculate time-averaged dilation and lateral propagation rates for individual fissures; (vi) most fissures cutting fissure-ridges comprise self-similar angular segments with fractal dimensions in the range 1.00-1.12, the properties of bedded travertine combined with stress perturbations at fissure tips probably being responsible for such similar fractal dimensions being inferred from such a wide range of locations. Fissures gradually increasing in width with depth are products of continuous fracture dilation in contrast to those that form during episodic dilation which display stepped increases of width with depth; (vii) travertine deposited from springs along fault zones accumulate in terraced-mounds sited down slope of the spring line; (viii) many post-depositional fractures cutting travertine deposits are locally oriented at right angles to deposit margins; and (ix) systematic joints in travertines are restricted to those parts of eroded sheet deposits that have been exhumed. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.