Coastal dune ridge systems as chronological markers of palaeoseismic activity: a 650-yr record from southwest New Zealand
Coastal dune ridge systems as chronological markers of palaeoseismic activity: a 650-yr record from southwest New Zealand
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沿海沙丘山脊系统作为古地震活动的年代标记：新西兰西南部 650 年的记录
DOI：
10.1191/0959683606hl949rp
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
J. Goff
中科院分区：
文献类型：
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作者：
A. Wells;J. Goff
对新西兰西南部两个海岸平行沙丘脊序列的研究表明，至少自公元1450年以来，构造活动一直是其形成的主要控制因素。哈斯特河和奥库鲁河河口沙丘形成的时间是根据殖民树木的年龄确定的。情节沙丘的形成表明明显的不连续性的树的年龄，不同的队列殖民连续的，新形成的，沙丘岭洼地单位。在这两个地点，自公元1450年以来形成了四个沙丘脊-洼地单元，每个单元都是在阿尔卑斯山断层破裂之后形成的。公元1460年，c.公元1615年，公元1717年，公元1826年）。在这两个地点发生地震后的20-46年内，殖民树木开始生长，所有已知的主要区域地震都导致了沙丘形成。两个地点都没有其他沙丘。沿岸沙丘系统具有作为古地震研究工具的潜力。在沉积物输送的高背景水平，以限制沙丘的侵蚀/掩埋和几乎没有同震沉降的地区，沙丘系统可能会保留一个空间离散的记录，主要地震引起的沉积事件在全新世。地震是这一构造活动区古环境变化和沿海平原发展的关键驱动力。
A study of two shore-parallel dune ridge sequences in southwest New Zealand shows that tectonic activity has been the primary controlling influence in their formation since at least AD 1450. The timing of dune-building episodes at the mouths of the Haast and Okuru Rivers was determined using the ages of colonizing trees. Episodic dune formation was indicated by clear discontinuities in tree ages, with distinct cohorts having colonized successive, newly formed, dune ridge-swale units. At both sites, four dune ridge-swale units have formed since AD 1450, with each unit closely postdating an Alpine fault rupture (c. AD 1460, c. AD 1615, AD 1717, AD 1826). Colonizing cohorts of trees started growing within 20-46 years after an earthquake at both sites, and all known major regional earthquakes have resulted in a dunebuilding episode. No other dunes are present at either site. Progradational coastal dune systems have potential as a tool for palaeoseismic studies. In regions with high background levels of sediment delivery to limit erosion/burial of dunes and with little coseismic subsidence, dune systems may preserve a spatially discrete record of major earthquake-induced sedimentation events over the Holocene. Earthquakes are a key driver of palaeoenvironmental change and coastal plain development in this tectonically active region.