With the three-dimensional (3D ) geological modeling problem of the'funnel'crater with ring-like inclination, a method was proposed based on geological cross sections.Firstly, the surface geological boundary and section data of the crater was matched to extract the 3D geological boundary.Then, different geological modeling schemes were proposed according to the'gentle'or'steep'shape of the extracted 3D geological boundary.Taking the Fujian Shimen crater as an example, the interface of the brecciated rhyolite constructed by the common method has a'sharp point'and did not go through the original geological boundary.The geological interface obtained in Biharmonic spline modeling was smooth and with good fitting effects, but it was only effective for modeling the gentle breccia rhyolite interface;for steep volcanic breccia interface modeling, the abrupt change of the geologic interface will occur.Therefore, we constructed the 3D steep geological boundary data in the form of spatial triangulation and adopted the improved Clough-Tocher algorithm based on triangulation to model the geological interface.Finally, the crater geological body model was constructed by the geological interface combined with the topography and the bottom constraints.%针对围斜内倾的"漏斗"状火山口三维地质建模问题, 提出了基于地质剖面进行火山口三维地质建模的方法.首先对火山口地表地质界线和剖面数据进行匹配提取三维地质界线, 然后根据三维地质界线"平缓"或"陡峭"等特点提出不同的地质界面建模方案.具体以福建镇前幅石门火山口为例, 用常规方法建立的角砾流纹岩界面存在"尖点"现象, 且不经过原始的地质界线.采用Biharmonic样条模拟得到的地质界面光滑且贴合效果较好, 但发现其对平缓的角砾流纹岩界面建模有效, 对于陡峭的火山角砾岩界面建模会出现形态突变的情况, 为此提出将陡峭的三维地质界线数据按照空间三角网的形式组织, 采用基于空间三角网的改进Clough-Tocher算法进行空间建模.最后, 地质界面加上地形和底面约束封闭成火山口地质体模型.
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