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首页> 外文学位 >Holocene evolution of the intermontane Tasek Bera peat deposit, Peninsular Malaysia: Controls on composition and accumulation of a tropical freshwater peat deposit.
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Holocene evolution of the intermontane Tasek Bera peat deposit, Peninsular Malaysia: Controls on composition and accumulation of a tropical freshwater peat deposit.

机译：马来西亚半岛山间Tasek Bera泥炭矿床的全新世演化：控制热带淡水泥炭矿床的组成和积累。

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摘要

The evolution and structure of a dendritic peat deposit in the interior lowland of tropical Peninsular Malaysia is investigated as a viable archive of paleoecological and paleoclimatological changes. The project was initiated due to the lack of understanding fundamental processes of intermontane peat accumulating systems mainly because previous studies have focused exclusively on coastal lowland deposits. Peat stratigraphy, mineralogy, organic petrography and geochemistry are some methods utilized in this study.; The modern depositional environment of the Tasek Bera Basin includes lowland dipterocarp forest, swamp forest, Cyperaceae/Pandanaceae swamp and open water areas. Widespread peat deposition in the basin started about 5300 years BP, when Holocene climate changes led to the evolution of a wetland system. Peat accumulation progressively expanded by processes of terrestrialization of channels and subbasins and paludification of the riparian part of the lowland forest zone. Stratigraphic facies can be distinguished in the field and combined with the ash yield, which indicates rapid and cyclic changes of frequency and magnitude of runoff events, demonstrating that hydrologic and in turn climate dynamics dictate peat evolution.; Although tropical peat deposits are widespread, few classification systems exist that recognize the distinctive characteristics specifically of tropical peats. A three-group field classification (fibric, hemic, sapric) for organic soils based on texture and fiber content is proposed. In addition, a new classification of organic soils based on loss of ignition and carbon content for geological, engineering, agricultural and economical studies of tropical peatlands is developed. Peat is defined as having a loss of ignition of 45 to 100 wt-%, muck 35 to 45 wt-%, organic-rich soils/sediments 20 to 35 wt-%, and mineral soils/sediments 0 to 20 wt-%.; Abundant and unique Al-Si bioliths exist in the mire system of Tasek Bera. These Al- and Si-hydroxides and the opaline silica from diatoms and sponges represent a repository of Al and Si, which may contribute to mineral transformation, neoformation and alteration processes during coalification of the peat deposits. Most plant-essential nutrients are biocycled within the top 150 cm of the organic deposits causing an upward migration of plant-essential elements, such as Mg, Ca, or P, during mire evolution. Hence, incorrect paleoclimatic and paleodepositional interpretation may result from utilizing geochemical data (e.g. normalization of elements with Al, interpretations of major element data) of tropical peat deposits.; With burial, the deposits of Tasek Bera Basin would yield a dendritic sediment pattern of sandstone, shale, carbonaceous shale and low to high ash coal, overlain by carbonaceous shale. Because of the dendritic nature of the basin, coal seams would most likely have a similar pattern as the Carboniferous coal deposits of the Black Warrior Basin in Alabama (USA). The peat deposits of southern Tasek Bera reveal that thick, low-ash, low sulfur peat may originate in narrow tributary valleys with moderately steep flank gradients. The deposits may be favorable precursors to dulling-upward coals, in that they contain high wood and low-ash content at depth and medium wood and slightly increasing ash content in the upper parts.*; *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirement: Analytical Data.
机译：研究了马来西亚热带半岛内陆低地树突状泥炭沉积的演化和结构，作为可行的古生态和古气候变化档案库。该项目之所以启动，是因为对山间泥炭聚集系统的基本过程缺乏了解，主要是因为先前的研究仅集中在沿海低地沉积物上。泥炭地层学，矿物学，有机岩石学和地球化学是这项研究中使用的一些方法。塔塞克贝拉盆地的现代沉积环境包括低地龙脑香林，沼泽林，莎草科/熊猫科沼泽和开阔水域。全新世气候变化导致湿地系统的演变，盆地中泥炭的广泛沉积始于大约BP 5300年。通道和子流域的陆地化和低地森林带河岸部分的光化作用使泥炭积累逐渐扩大。可以在该地区区分地层相，并与灰分产量相结合，这表明径流事件的频率和大小发生快速而周期性的变化，表明水文和气候动力学决定了泥炭的演化。尽管热带泥炭的沉积很普遍，但很少有分类系统能够识别热带泥炭的独特特征。提出了一种基于质地和纤维含量的有机土壤三组田间分类（纤维，半腐殖酸，癸酸）。此外，还针对热带泥炭地的地质，工程，农业和经济研究，开发了一种基于燃烧损失和碳含量的有机土壤新分类方法。泥炭的定义是燃烧损失为45至100重量％，渣土为35至45重量％，富含有机物的土壤/沉积物为20至35重量％，矿物土壤/沉积物为0至20重量％。 ; Tasek Bera的泥潭系统中存在大量独特的Al-Si生物岩。这些铝和硅的氢氧化物以及硅藻和海绵中的不透明二氧化硅代表了铝和硅的储存库，在泥炭沉积的煤化过程中，可能有助于矿物转化，新形成和蚀变过程。大多数植物必需的养分在有机沉积物的顶部150厘米内进行生物循环，从而导致泥泞过程中植物必需元素（例如Mg，Ca或P）向上迁移。因此，利用热带泥炭矿床的地球化学数据（例如，用Al进行元素归一化，主要元素数据的解释）可能会导致古气候和古沉积的解释不正确。通过埋藏，塔塞克贝拉盆地的沉积物将形成由碳质页岩覆盖的砂岩，页岩，碳质页岩和低灰分至高灰分煤的树状沉积物模式。由于该盆地的树枝状性质，煤层极有可能与美国阿拉巴马州黑武士盆地的石炭系煤矿床具有相似的模式。 Tasek Bera南部的泥炭沉积表明，厚，低灰分，低硫的泥炭可能起源于狭窄的支流谷，其侧翼梯度中等。这些沉积物可能是上沉煤的有利前体，因为它们在深处和中层木材中含有较高的木材和较低的灰分含量，而在上部则含有稍高的灰分含量。 *本论文是复合文件（作为论文的一部分，包含纸质副本和CD）。 CD需要满足以下系统要求：分析数据。

著录项

  • 作者

    Wuest, Raphael Andreas Josef.;

  • 作者单位

    The University of British Columbia (Canada).;

  • 授予单位 The University of British Columbia (Canada).;
  • 学科 Geology.
  • 学位 Ph.D.
  • 年度 2001
  • 页码 478 p.
  • 总页数 478
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 地质学;
  • 关键词

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