Geologic Framework and Consolidation Settlement Potential of the Lafourche Delta, Topstratum Valley Fill; Implications for Wetland Loss in Terrebonne and Lafourche Parishes, Louisiana.
Geologic Framework and Consolidation Settlement Potential of the Lafourche Delta, Topstratum Valley Fill; Implications for Wetland Loss in Terrebonne and Lafourche Parishes, Louisiana.
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拉富什三角洲、表层谷填土的地质框架和固结沉降潜力；
DOI：
10.31390/gradschool_disstheses.5734
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发表时间：
1994
影响因子：
--
通讯作者：
G. Kuecher
中科院分区：
文献类型：
--
作者：
G. Kuecher
在路易斯安那州的特雷博讷和拉福什教区，湿地的损失，主要是由于两个地下过程：1）巩固最近沉积的三角洲物质，和2）活动断层。每一个的影响都得到了解决。利用低温取样技术从大密西西比河三角洲平原的七（7）个现代三角洲环境中获得原位沉积物样品。固结仪测试确定泥炭相为最受固结沉降，其次是前三角洲和海湾泥相。来自其他测试环境的桑迪相不受显著固结沉降的影响。此处生成的压缩指数值用于计算P-190和P-6S-93钻孔处垂直叠加的沉降。结果表明，大多数沉降发生在截面的最上面两（2）米处，尽管在密度研究中确定了最上面的十（10）米。数据表明，泥炭相覆盖最近被遗弃的拉福什三角洲的厚度和目前的沿海土地流失模式之间有直接关系。在局部地区，易固结泥炭质沉积物厚度大的地方固结沉降高，反之亦然。分流间地区含有厚厚的泥炭沉积物，这些地区优先失去了更大的扩张。
Wetland loss in Terrebonne and Lafourche Parishes, Louisiana, largely results from two subsurface processes: 1) consolidation of recently deposited deltaic materials, and 2) active faulting. The impact of each is addressed. Cryogenic sampling techniques were utilized to obtain in-situ sediment samples from seven (7) modern deltaic environments in the greater Mississippi River delta plain. Consolidometer testing identifies peaty facies as mostsubject to consolidation settlement, followed by prodelta and bay mud facies. Sandy facies from the other tested environments are not subject to significant consolidation settlement. Compression index values generated here are used to calculate settlement in a vertical stack at the P-l90 and P-6S-93 borings. Results indicate most settlement occurs in the uppermost two (2) meters of section, although the uppermost ten (10) meters are identified in density studies. Data indicate a direct relationship between the thickness of peaty facies capping the recently abandoned Lafourche Delta and present patterns of coastal tract land loss. Locally, consolidation settlement is high where the thickness of consolidation-prone peaty sediments is great and vice versa. Interdistributary areas contain thick deposits of peaty sediments, and these areas are preferentially being lost to the expansion of greater