## 2 Geological and Petrographic Overview of Norite
### Influence of Petrographic Properties on Mechanical Behavior  
The mineralogical attributes of rocks have a significant impact on their mechanical qualities. [PERSON] et al. [31] (2024) state that the mechanical properties of a rock, which are influenced by its mineral composition, determine whether it is weak, strong, ductile, stiff, or brittle. [PERSON] et al. [32] (1999) examined grain size as an important petrographic characteristic, suggesting that the initial cracking stage occurs due to stress load irrespective of the average grain size. This occurs in rocks with a uniform mineral composition and consistent grain size distribution. [PERSON] et al. [31] (2024) further discuss that the presence of quartz strengthens rocks, while altered feldspar, mica, and biotite weaken rocks. Weaker or altered minerals, like mica and feldspar, can weaken a rock, making it more vulnerable to fracturing, whereas minerals such as quartz help to increase the strength of rock [14]. The medium grain size texture in norite balances strength and workability, preventing excessive brittleness or ductility, while coarser textures may lead to lower strength and cracking resistance [31]. Generally, smaller grains are stronger and more resistant to crack propagation because they have more grain boundaries that prevent cracks from spreading. Figure 3: A norite specimen displaying its coarse texture. However, very fine grains may lead to higher porosity, potentially weakening the rock. In contrast, larger grains or coarse-grained rocks may have fewer grain boundaries, making them more inclined to fracture under stress [33]. According to [PERSON] et al. [31] (2024), the uniaxial compressive strength (UCS) of felsic norite varies between 142.6 MPa and 217 MPa, with an average of 188.6 MPa. Additionally, the study showed that the tangent Young's modulus of elasticity ranges from 62.17 to 71.4 GPa, averaging to 67.4 GPa. Additionally, the Poisson's ratio ranges from 0.19 to 0.28, with an average of 0.19 based on the norite samples used by [PERSON] et al. [31] (2024). In order to determine the influence of the petrographic characteristics on the mechanical properties, the ratio of quartz to plagioclase and the grain size were correlated with the engineering properties using regression analyses [34]. A strong correlation was observed between the UCS, point load strength, and tensile strength in the study of [PERSON] and [PERSON] [34] (2013), focusing on the strength of granitic rocks, which is significantly influenced by mineral composition. According to [PERSON] et al. [31] (2024), the UCS can only be estimated by using the average value obtained from testing other samples of the same rock type. Grain boundaries can act as weak points where cracks start and propagate, while alterations in mineral composition can reduce cohesion, increase porosity, and promote crack growth. The study by [PERSON] et al. [35] (2024) highlights the significant role of rock texture in microcrack formation, emphasizing its importance in rock engineering applications. Grain texture characteristics (shape, size, orientation, and heterogeneity) are a key parameter governing the response to stress. Grain texture controls the strength and ductility of crystalline rock; however, it can be challenging to incorporate these factors in a quantitative manner [36]. [PERSON] et al. [37] (2017) additionally emphasized the fact that brittleness indices are based on the concept that rock breaks with increases in tensile strength, implying that as the compressive-to-tensile-strength ratio decreases, the rock is more prone to brittle behavior and breaking. Norite is a coarse-grained mafic intrusive rock primarily composed of orthopyroxene and plagioclase feldspar, often accompanied by clinopyroxene and olivine (Figure 4). The petrographic image displays a coarse grain size, and it tends to have reduced strength due to easier fracture propagation. The study of [PERSON] [38] (1974) supports this by showing that adding finer textures improves rock durability and resistance.