Basalt

Basalt

　　In the Jingpo Lake mountain area, Bohai Town, and Shalan Township, basalt can be found everywhere. It not only forms unique landforms such as basalt lava plateaus, underground lava caves, and volcanic crater forests, but also provides valuable information from deep within the Earth. Additionally, due to the special uses of this type of rock, it is attracting more and more attention.

Basalt is a dense or vesicular structured rock formed when magma ejected from a volcano cools and solidifies. In geological classification, it is categorized as an igneous rock (also called magmatic rock). The magma that erupts during a volcanic explosion can reach temperatures as high as 1,200 degrees Celsius. Due to its certain viscosity, the magma flows very slowly on flat terrain—only a few meters per minute. When encountering steep slopes, the flow rate increases significantly. As it flows, it carries large amounts of water vapor and bubbles. Upon cooling, it forms various altered shapes. North of Jingpo Lake, there are waterfall-like and wavy formations; around Yinggeling, there are round bun-shaped and pagoda-shaped formations; between Bohai Town and Shalan Township, there are massive python-like shapes and lava tunnels. The geological and geomorphological structures here are novel, diverse, and richly varied.

The color of basalt is commonly black, dark brown, or dark green. Due to its dense texture, it has a higher specific gravity than common rocks such as granite, limestone, sandstone, and shale. However, some basalts, because they contain a particularly high number of pores, are lighter in weight and can even float on water. Such porous, lightweight basalt is referred to as "pumice." Some artists use the porous and wrinkled, leaky characteristics of pumice to create rockeries in gardens or to sculpt delicate potted landscapes.

According to analysis and identification by geological scientists, the main components of basalt are silicon dioxide, aluminum oxide, iron oxide, calcium oxide, magnesium oxide (along with small amounts of potassium oxide and sodium oxide), among which silicon dioxide is the most abundant, accounting for about 45% to 50%.

Basalt is an excellent raw material for producing "cast stone." Cast stone is a material made by melting, casting, crystallizing, and annealing basalt. It is harder and more wear-resistant than alloy steel, and more corrosion-resistant than lead and rubber. Basalt also serves as a "lubricant" in an advanced casting process, extending the life of casting molds. Additionally, basalt can be drawn into glass fibers, which have stronger alkali resistance and better high-temperature performance than ordinary fiberglass cloth.

Vesicular basalt (pumice), due to its many pores and considerable hardness, when mixed into concrete, can reduce the weight of the concrete while still maintaining strength, and also offers soundproofing and thermal insulation properties, making it an excellent aggregate for lightweight concrete in high-rise buildings. Pumice is also an outstanding abrasive material, used for grinding metal and stone materials; industrially, it can also be used as a filter, dryer, catalyst, and more.