Interactions of growing folds and coeval depositional systems
Interactions of growing folds and coeval depositional systems
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DOI：
10.1046/j.1365-2117.1996.00181.x
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发表时间：
1996-09
期刊：
影响因子：
3.2
通讯作者：
D. Burbank;A. Meigs;N. Brozović
中科院分区：
文献类型：
--
作者：
D. Burbank;A. Meigs;N. Brozović
现代和古代河流沉积体系的增长褶皱的反应可以解释在相互竞争的控制变量之间的相互作用，可以纳入简单的概念模型。沉积物堆积速率与构造抬升速率之比决定了褶皱是否在当地基准面之上形成地形。（a）水流功率和上游沉积速率与（B）基岩阻力以及顶部隆起和褶皱加宽速率之间的平衡决定了先行河流是否保持其路线或被生长的结构击败。现代排水配置在积极折叠景观往往可以解释在这些竞争的变量，并通过分析数字地形，这些褶皱的详细地形特征可以量化。生长褶皱的现代例子显示了失败和持久的先行河流，偏转排水和横向传播的结构。地形与失败的先行河在惠勒岭，加州，是一致的模型，其中失败的结果，从强制加积在背驮式盆地，而不需要改变流量或隆起率。要重建沉积体系与演化褶皱之间的长期相互作用，需要从地层学角度，例如与古褶皱和断层直接并列的同构造地层所提供的角度。西班牙东北部加泰罗尼亚海岸山脉边界的古近纪生长地层分析表明，在近端前陆盆地中，多重褶皱和断层的同步生长和运动学历史。虽然主要是横向河流穿过褶皱波峰，古河谷，扇间低，结构折返和鞍，和上升的背斜分流和影响当地的沉积。在古代记录中，排水网络事件，如横向河流的撕裂或失败，通常不能明确地归因于单一原因。然而，从地貌学的角度对古代同构造地层的研究，允许同造山期地形、地貌和沉积体系的连续重建。
Responses of both modern and ancient fluvial depositional systems to growing folds can be interpreted in terms of interactions among competing controlling variables which can be incorporated into simple conceptual models. The ratio of the rate of sediment accumulation to the rate of structural uplift determines whether a fold develops a topographic expression above local base level. The balance between (a) stream power and rates of upstream deposition vs. (b) bedrock resistance and rates of crestal uplift and of fold widening determines whether an antecedent stream maintains its course or is defeated by a growing structure. Modern drainage configurations in actively folding landscapes can often be interpreted in terms of these competing variables, and through analysis of digital topography, detailed topographic characteristics of these folds can be quantified. Modern examples of growing folds display both defeated and persistent antecedent rivers, deflected drainages and laterally propagating structures. The topography associated with a defeated antecedent river at Wheeler Ridge, California, is consistent with a model in which defeat results from forced aggradation in the piggyback basin, without the need to vary discharge or uplift rate. Reconstruction of the long-term interplay between a depositional system and evolving folds requires a stratigraphic perspective, such as that provided by syntectonic strata which are directly juxtaposed with ancient folds and faults. Analysis of Palaeogene growth strata bounding the Catalan Coastal Ranges of NE Spain demonstrates the synchronous growth and the kinematic history of multiple folds and faults in the proximal foreland basin. Although dominated by transverse rivers which crossed fold crests, palaeovalleys, interfan lows, structural re-entrants and saddles, and rising anticlines diverted flow and influenced local deposition. In the ancient record, drainage-network events, such as avulsion or defeat of a transverse stream, usually cannot be unambiguously attributed to a single cause. Examination of ancient syntectonic strata from a geomorphological perspective, however, permits successive reconstructions of synorogenic topography, landscapes and depositional systems.