کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4684420 1635425 2014 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Impact of wind erosion on detecting active tectonics from geomorphic indexes in extremely arid areas: a case study from the Hero Range, Qaidam Basin, NW China
ترجمه فارسی عنوان
تأثیر فرسایش باد بر تشخیص ساختارهای فعال زمین شناسی از شاخص های ژئومورفیک در مناطق بسیار خشک: مطالعه موردی از محدوده قهرمان، حوضه قیدام، چینی نروژ
کلمات کلیدی
حوزه قیدام، فرسایش باد، منحنی هایسومتری، شاخص جریان گرادیان جریان، تجزیه و تحلیل زهکشی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
چکیده انگلیسی


• The impact of wind erosion on geomorphic indexes is evaluated.
• The case study was developed on Hero Range in the western Qaidam Basin.
• Wind erosion makes geomorphic indexes showing higher activities.
• Wind erosion affects the indexes by base-level lowering and lateral erosion.

Geomorphologic analysis has been used widely to detect active tectonics in regions where fluvial incision is the major erosional process. In this paper, however, we assess the feasibility of utilizing these frequently-used geomorphic indexes (e.g., hypsometric curves, longitudinal channel profiles, normalized stream length-gradient (SLK) index) to determine active tectonics in extremely arid areas where wind erosion also plays an important role. The case study is developed on the Hero Range in the western Qaidam Basin, one of the driest regions on Earth with severe wind erosion since late Pliocene. The result shows that in the west and south sectors, as well as the western part of the east sector, of the Hero Range where fluvial incision prevails, these geomorphic indexes are good indicators of active faulting and consistent with the geological result based on study of fault traces, scarps, faulted Holocene fans and historical seismicity within the past four decades. In contrast, along the northeastern margin (the NE and the SE parts of the east sector) of the range where wind erosion is also important, the results from the geomorphic indexes show quite active tectonics, contrary with the geological evidence favoring weakly active tectonics. Moreover, the positive SLK anomaly lies oblique to the fault trace and the anticline axis but parallel to the wind direction. To reconcile the contradiction, we propose that wind erosion caused by northwestern winds has a tendency to make geomorphic indexes exhibit anomalous values that indicate higher activities, by way of (1) lowering the base-level to generate knickpoints on the longitudinal channel profiles and therefore positive SLK anomalies, and (2) lateral erosion of the mountain front making the hypsometric curves and even the longitudinal channel profiles more convex, and producing obvious slope breaks.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Geomorphology - Volume 224, 1 November 2014, Pages 39–54
نویسندگان
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