ABSTRACT

Ultrasonic pulse velocity (UPV) measurement has previously been determined to be a good proxy for rock weathering intensity. As such, it has the potential to be useful for the establishment of relative weathering rates in culturally sensitive artefacts such as tombstones. This is the first study that makes use of an ultrasonic proxy in this manner to be carried out in South Africa, where many tombstones are constructed from locally produced gabbro stone. However, the delimitations of ultrasonic equipment have not been appropriately established for use on this particular lithology. This study investigates the relationship between UPV and the amount of time various tombstones have spent in situ at Cullinan Main Cemetery in South Africa, with the aim of determining if UPV can accurately be used to assess relative weathering rates for the tombstones there. Ultrasonic measurements were taken with two different transducer packages on 34 tombstones that had remained in the cemetery for between 15 and 100 years. The results show that there is a measurable, statistically significant positive relationship between inscription age and ultrasonic pulse velocity (UPV), supporting the hypothesis that UPV is a valid proxy for rock weathering with respect to South African gabbro tombstones.

摘要

超声波脉冲速度 (UPV) 测量先前已被确定为岩石风化强度的良好代表。因此，它有可能有助于确定文化敏感文物（如墓碑）的相对风化率。这是在南非进行的第一项以这种方式使用超声波代理的研究，那里的许多墓碑都是用当地生产的辉长石建造的。然而，超声波设备的界限还没有适当地确定用于这种特殊的岩性。本研究调查了 UPV 与各种墓碑在原地停留的时间之间的关系在南非的库里南主公墓，目的是确定 UPV 是否可以准确地用于评估那里墓碑的相对风化率。使用两个不同的换能器包对 34 块墓碑进行了超声波测量，这些墓碑在墓地中保留了 15 到 100 年。结果表明，铭文年龄和超声脉冲速度 (UPV) 之间存在可测量的、统计学上显着的正相关关系，支持这样的假设，即 UPV 是南非辉长岩墓碑岩石风化的有效代表。