A transient, perched aquifer model for banana hole formation: Evidence from San Salvador Island, Bahamas
A transient, perched aquifer model for banana hole formation: Evidence from San Salvador Island, Bahamas
复制标题
香蕉洞形成的瞬态栖息含水层模型：来自巴哈马圣萨尔瓦多岛的证据
DOI：
10.1002/esp.5276
复制
发表时间：
2022
影响因子：
3.3
通讯作者：
Fullmer, Shawn M.
中科院分区：
文献类型：
--
作者：
Breithaupt, Charles I.;Gulley, Jason D.;Bunge, Eric M.;Moore, Paul J.;Kerans, Charles;Fernandez‐Ibanez, Fermin;Fullmer, Shawn M.
香蕉洞是喀斯特洼地，主要是在巴哈马群岛的海滨平原上发现的。香蕉洞已被假设为形成向下溶解在渗流带和潜水带通过混合溶解和/或空间变异的有机碳输入到地下水位。渗流模型无法解释香蕉洞中常见的悬垂屋顶，而潜水模型需要非常高的溶解速率。在这项研究中，我们开发了一个新的模型香蕉孔形成的基础上，现场观测，机载激光雷达（光探测和测距）调查，并发表在圣萨尔瓦多岛，巴哈马的地球化学数据。我们在LiDAR数据中检测到3356个凹陷，这些凹陷与海洋同位素子阶段（MIS）5e和MIS 9/11 strandplains中的香蕉孔形态一致。在全新世滨海平原没有发现香蕉洞。所有的香蕉洞都是在山脊之间的洼地里发现的。在MIS 5e strandplains发现的香蕉洞中，有109个的底部海拔在海平面以上6至19米之间。这些香蕉洞不可能形成于潜水带，因为MIS 5e淡水透镜达到了高于现代海平面6米的最大高度。我们还观察到香蕉洞充满了水在潮湿的季节。虽然香蕉洞旁边的威尔斯井是潮汐的，但香蕉洞里的水池不是，这表明水池是栖息的。我们的观察，水文模型的支持下，香蕉洞可能会形成在渗流区在短暂的，栖息的含水层暴露区。来自山脊的径流通过渗流快速流动路线渗透，直到遇到低渗透暴露区，在那里流动是横向的。通过停留在暴露区溶解将产生从注射点辐射的薄的、横向延伸的腔室。随后的顶板塌陷导致其曲面表达。由于溶解发生时，沃茨成为栖息，商会可能会形成整个低看台，因此可能不会反映快速潜水溶解。
Banana holes are karst depressions that have primarily been reported from strandplains within the Bahamian archipelago. Banana holes have been hypothesized to form by downward dissolution in the vadose zone and in the phreatic zone by mixing dissolution and/or spatial variability in organic carbon inputs to the water table. While vadose models have been unable to explain overhanging roofs common in banana holes, phreatic models require anomalously high dissolution rates. In this study, we develop a new model for banana hole formation based on field observations, an airborne LiDAR (light detection and ranging) survey, and published geochemical data on San Salvador Island, Bahamas. We detected 3356 depressions in LiDAR data consistent with banana hole morphologies in Marine isotope substage (MIS) 5e and MIS 9/11 strandplains. No banana holes were detected in Holocene strandplains. All banana holes were found in swales between ridges. Of the banana holes found in MIS 5e strandplains, 109 had floor elevations between 6 and 19 m above sea level. These banana holes could not have formed in the phreatic zone because the MIS 5e freshwater lens reached a maximum elevation of 6 m above modern sea level. We also observed banana holes filled with water during wet seasons. While wells next to banana holes were tidal, pools in the banana holes were not, indicating pools were perched. Our observations, supported by hydrological models, suggest banana holes may form in the vadose zone in transient, perched aquifers on exposure zones. Runoff from ridges infiltrates through vadose fast‐flow routes until encountering low permeability exposure zones, where flow is directed laterally. Dissolution by perching on exposure zones would create thin, laterally‐extensive chambers radiating from injection points. Subsequent roof collapse results in their surface expression. Because dissolution occurs when waters become perched, chambers could form throughout low stands and may therefore not reflect rapid phreatic dissolution.
登录
查看更多内容
DOI：
--
发表时间：
1977
期刊：
影响因子：
--
作者：
H. T. Mullins;G. W. Lynts
通讯作者：
G. W. Lynts
影响佛罗里达州奥兰多地区新天坑开发的水文地质因素
影响因子：
2.6
作者：
W. Wilson;B. Beck
通讯作者：
B. Beck
根据降雨和径流数据预测石灰石溶解率：一些评论
影响因子：
3.3
作者：
J. Gunn
通讯作者：
J. Gunn
碳酸盐序列古土壤解释中的一些陷阱
影响因子：
1.4
作者：
J. Carew;J. Mylroie
通讯作者：
J. Mylroie
巴哈马大埃克苏马全新世滩涂平原下淡水透镜体的水文地质学
影响因子：
6.4
作者：
T. N. Wallis;H. Vacher;M. Stewart
通讯作者：
M. Stewart