Structure from Motion (SfM) photogrammetry, on-site hardness and water absorption tests, and petrographical and porosimetric analyses on targeted samples were carried out on representative areas within six different locations of Maltese fortifications affected by salt weathering. The objective was to quantify the limestone loss over the last half-millennium and to attempt to identify the controlling factors of durability. The results highlight the existence of a two-rate weathering regime within the Miocene Globigerina Limestone which is the main building stone of the Maltese Islands. With a median stone recession of 1.4 mm/century, the subtype locally called Franka has resisted atmospheric aggression on average 36 times better than the Soll subtype (median stone recession of 50 mm/century). The Oligo-Miocene Coralline Limestone has also resisted well, with a stone recession of on average 1.3 mm/century. Two main controls of the varying durability of these limestones have been identified. First, the water uptake capacity of the least durable, already weathered limestone (Soll) is two to three times higher than that of the weathered but more resistant Franka and Coralline Limestone (6.3 g.m⁻².s⁻¹ against 2.5 g.m⁻².s⁻¹). Second, there is a marked difference in cohesiveness between these limestones. Whereas the weathered, susceptible Soll facies is poorly-cemented or microcracked, the exposed durable Franka displays an abundant micritic and microsparitic matrix. The statistical relationship between durability and surface hardness is not straightforward, and other controls such as the clay content of limestones should be explored. Investigating a larger number of sites would allow the refining of the limestone durability scale inferred from the present study.

运动（SfM）摄影测量的结构，现场硬度和吸水率测试以及目标样品的岩石学和孔隙率分析是在受盐分风化影响的六个马耳他设防地点内的代表性区域进行的。目的是量化最近半千年的石灰石损失，并试图确定耐久性的控制因素。结果表明，中新世Globigerina石灰石是马耳他群岛的主要建筑石料，存在两种速率的风化作用。石头凹陷的中位数为1.4毫米/世纪，当地称为Franka的亚型抵抗大气侵害的能力平均比Soll强36倍亚型（中位数石材后退50毫米/世纪）。Oligo-中新世珊瑚色石灰石的抵抗力也很好，石材平均凹进程度为1.3毫米/世纪。已经确定了这些石灰石的不同耐久性的两个主要控制方法。首先，最不耐用的，已经风化的石灰石（Soll）的吸水能力是风化但更耐腐蚀的Franka和Coralline石灰石（6.3 gm ^-2 .s ^-1对2.5 gm ^-2）的两到三倍。 s ^-1）。第二，这些石灰石之间的内聚力存在明显差异。而风化，容易索尔胶结物胶结性差或微裂，暴露的耐用弗兰卡（Franka）显示出大量的微晶和微散晶基质。耐久性和表面硬度之间的统计关系并不直接，应探索其他控制方法，例如石灰石的粘土含量。研究更多的地点将使根据本研究推断出的石灰石耐久性标度得以提炼。