Rock weathering experiment kit

Abstract

This provides a rock weathering experiment kit that can easily reproduce the environment that causes salt weathering. [Solution] The rock weathering experiment set 100 comprises a rock sample 110 formed from tuff into a columnar shape, magnesium sulfate powder 120, a container 130 capable of holding the lower part of the rock sample immersed in an aqueous magnesium sulfate solution obtained by dissolving the magnesium sulfate powder in water, and a lid 140 that fits over the opening of the container. The lid has a through hole 140a that fits over the rock sample and allows the upper part of the rock sample to protrude outside the container. This makes it possible to reproduce an environment that causes salt weathering with a simple configuration, to continuously observe the progression of cracks and collapses in the rock sample, and to provide a tangible understanding of the weathering phenomenon of the rock sample.

Description

Technical Field

[0001] This specification discloses a technology related to a rock weathering experiment set.

Background Art

[0002] Rocks are known to become brittle and break over a long period of time due to the action of substances such as water, and this phenomenon is called weathering. In particular, the phenomenon in which an aqueous solution containing salts such as magnesium sulfate and sodium sulfate rises inside a rock due to capillary action and the rock is broken by the pressure generated when the salts recrystallize during the drying process is known as salt weathering (see Non-Patent Document 1). It has been reported that salt weathering is likely to occur when an aqueous solution of magnesium sulfate or sodium sulfate is applied to tuff (see Non-Patent Documents 2 and 3).

Prior Art Documents

Patent Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] As mentioned above, weathering is known as a phenomenon of rock deterioration, and there is a need to deepen understanding of it in educational settings. However, it is difficult to truly grasp the progression of weathering based solely on descriptions in textbooks. [Means for solving the problem]

[0005] One embodiment disclosed herein is a rock weathering experiment kit. This rock weathering experiment kit comprises a rock sample formed from tuff into a columnar shape, magnesium sulfate powder, a container capable of holding the lower part of the rock sample immersed in an aqueous magnesium sulfate solution obtained by dissolving the magnesium sulfate powder in water, and a lid that fits over the opening of the container. The lid has a through hole that fits over the rock sample and allows the upper part of the rock sample to protrude outside the container. This form of rock weathering experiment kit allows for the reproduction of an environment that causes salt weathering with a simple configuration. As a result, the progression of cracks and collapse in the rock sample can be continuously observed. Therefore, it is possible to provide a tangible understanding of the weathering phenomenon of rock samples. [Brief explanation of the drawing]

[0006] [Figure 1] This is an explanatory diagram showing the individual parts that make up the rock weathering experiment kit. [Figure 2] This is a perspective view showing the rock weathering experiment kit in use. [Figure 3] This is an explanatory diagram illustrating the temporal changes in the progression of salt weathering in rock samples. [Modes for carrying out the invention]

[0007] Figure 1 is an explanatory diagram showing the individual parts that make up the rock weathering experiment kit 100. Figure 2 is a perspective view showing the rock weathering experiment kit 100 in use. The rock weathering experiment kit 100 comprises a rock sample 110, magnesium sulfate powder 120, a container 130, and a lid 140.

[0008] The rock sample 110 in the rock weathering experiment kit 100 is made by shaping tuff into a columnar form. Specifically, the rock sample 110 can be made from Oya stone, a green tuff from Utsunomiya City, Tochigi Prefecture, which is prone to salt weathering. The rock sample 110 can be, for example, a rectangular prism shape of 4cm x 4cm x 15cm. The mass of a rock sample 110 of these dimensions is approximately 800g. With a rock sample 110 of these dimensions, the progress of weathering can be clearly observed in about two months, making it suitable as teaching material. The rock sample 110 may also be shaped to the specified dimensions by a stone supplier. Each face of the rock sample 110 is approximately flat. However, the dimensions of the rock sample 110 are not limited to those described above. The width, height, and length can be changed as appropriate. The shape of the rock sample 110 is not limited to a rectangular prism; it may be a prismatic, cylindrical, or other columnar shape. Furthermore, the material of the rock sample 110 is not limited to Oya stone, but may be other rocks that are prone to salt weathering (for example, sandstone).

[0009] Magnesium sulfate powder 120 is a powder used to produce an aqueous magnesium sulfate solution by dissolving it in water. Specifically, magnesium sulfate heptahydrate can be used. Epsom salt, which is sold commercially as a bath additive, may also be used. Epsom salt is relatively inexpensive and therefore suitable as teaching material. Magnesium sulfate powder 120 is not limited to powder form, but may also be granular or crystalline. In addition to Epsom salt (heptahydrate), magnesium sulfate may also be Keithrite (monohydrate). Epsom salt is more soluble in water than Keithrite and therefore suitable as teaching material. Magnesium sulfate powder 120 can be approximately 250g per bag, for example, but is not limited to this. The amount can be changed as appropriate. Multiple bags may be included in the set. An aqueous magnesium sulfate solution can be produced by dissolving magnesium sulfate powder 120 in approximately 700mL of water in container 130. The amount of water is not limited to the above. The concentration of the aqueous magnesium sulfate solution should be close to saturation. For example, at a concentration of 1 / 10th of the saturation level, it takes about six months for clear cracks to develop due to weathering, making it unsuitable for student observation. The solubility of magnesium sulfate changes with temperature. For example, it is known to be approximately 38.5 g / 100 g of water at 25°C. On the other hand, sodium sulfate, calcium sulfate, and sodium chloride are known to cause salt weathering. However, research by the inventor has revealed that these salts do not easily cause clear cracks to develop in rock sample 110, and their effectiveness as teaching materials is weaker than that of magnesium sulfate.

[0010] As shown in Figure 2, container 130 is capable of holding the lower part of the rock sample 110 immersed in an aqueous magnesium sulfate solution obtained by dissolving magnesium sulfate powder 120 in water. Container 130 is a plastic container. Its capacity is, for example, 1350 mL. Container 130 has an opening at the top. The opening is shaped to accommodate a lid 140. Container 130 has a bottom and side walls. The bottom is formed flat. The side walls are formed in a roughly cylindrical shape. Container 130 has an internal space capable of containing the aqueous magnesium sulfate solution. The material of container 130 may be transparent or translucent resin. The capacity of container 130 is not limited to 1350 mL. It may be in the range of 1000 mL to 2000 mL. The shape of container 130 is not limited to cylindrical; it may be rectangular or other container shapes.

[0011] The lid 140 fits into the opening of the container 130. The lid 140 is made of plastic. The lid 140 is made of a plate-like material. The outer circumference is shaped to engage with the opening edge of the container 130. A through hole 140a is formed in the center of the lid 140. The through hole 140a is sized to allow the rock sample 110 to pass through. The through hole 140a fits into the rock sample 110 and allows the upper part of the rock sample 110 to protrude outside the container 130. It is preferable that the shape of the through hole 140a substantially matches the cross-section of the rock sample 110. If the gap between the rock sample 110 and the through hole 140 is large, the recrystallization of magnesium sulfate occurs on the rock surface rather than inside the rock, making it difficult to observe cracks and other surface changes, and thus unsuitable for observation. The lid 140 may be formed integrally with the container 130, or it may be constructed as a separate component.

[0012] The rock weathering experiment set 100 according to this embodiment consists of multiple parts, as shown in Figure 1. Specifically, it includes an Oya stone sample (4cm x 4cm x 15cm) as the rock sample 110, magnesium sulfate powder 120 (approximately 250g per bag), a plastic container (capacity 1350mL) as the container 130, a lid as the lid 140, and a recording medium 150 containing time-lapse video of the progress of salt weathering. The recording medium 150 may or may not be included in the set as needed.

[0013] A time-lapse video is a video created by taking photographs of the weathering process of a rock sample at regular intervals. The recording medium 150 may be a DVD or other recording medium.

[0014] (How to use) As an example of how to use the Rock Weathering Experiment Kit 100, first put about 700 mL of water into container 130. Next, add about 250 g of magnesium sulfate powder 120 and stir to produce a magnesium sulfate aqueous solution.

[0015] Next, the lid 140 is attached to the container 130. The rock sample 110 is inserted into the through hole 140a of the lid 140, and the lower part of the rock sample 110 is immersed in the aqueous solution.

[0016] Subsequently, the container 130 is left undisturbed for a predetermined period of time while the rock sample 110 remains standing approximately perpendicular to the surface of the aqueous solution.

[0017] If the water level of the aqueous solution decreases during observation, the water level can be adjusted by adding magnesium sulfate solution. For example, if the water depth decreases to about 1 cm from the bottom of the container, create an aqueous solution using additional magnesium sulfate powder and adjust the water depth to about 4 cm to 4.5 cm.

[0018] (The process of salt weathering) Figure 3 is an explanatory diagram of the time-dependent changes showing the progress of salt weathering of the rock sample 110. Next, the process of salt weathering of the rock sample 110 according to the present embodiment will be described while referring to Figure 3. This experiment started on April 27, 2024.

[0019] After the start, at the time of May 1, 2024, no significant change was confirmed in the appearance of the rock sample 110.

[0020] On May 10, 2024, discoloration was observed near the lower part of the rock sample 110.

[0021] On May 14, 2024, fine cracks were confirmed near the lower part.

[0022] On May 27, 2024, a plurality of cracks occurred in the lower part of the rock sample 110. The cracks were about a few millimeters wide.

[0023] At the time of June 5, about one and a half months after the start, three cracks about a few millimeters wide were confirmed. The height of the entire sample increased, and a slightly tilted state was confirmed. Fragments of about 5 mm in diameter were also confirmed.

[0024] As the number of days passed, the cracks further developed. Disintegration progressed mainly in the lower half of the rock sample 110.

[0025] In a humidity and temperature environment such as a corridor or a science laboratory, similar changes were confirmed in about two months regardless of the season.

[0026] Salt weathering is a phenomenon in which an aqueous solution containing salts such as magnesium sulfate and sodium sulfate rises inside the rock due to capillary action, and the rock is destroyed by the pressure generated when the salt recrystallizes during the drying process. This is a phenomenon that also occurs in familiar places such as block walls and the foundations of houses.

[0027] This experimental method was established based on Yamada and Matsukura (2000, 2001). It has been reported that Oya stone is susceptible to salt weathering by aqueous solutions of magnesium sulfate, sodium sulfate, etc. In this embodiment, the conditions for the size of the Oya stone sample and the type of salt were investigated. As a result, a size of 4 cm × 4 cm × 15 cm and conditions using magnesium sulfate were adopted. The solubility of magnesium sulfate varies in the literature. In this experiment, the value of 38.5 g / 100 g water at 25°C was adopted based on Babel, M. and Schreiber, BC (2014).

[0028] In current junior high school science textbooks, explanations of weathering are often limited to just a few lines of text or a photograph. Therefore, it has been pointed out that this makes it difficult for students to gain a sufficient understanding of weathering.

[0029] The advantage of this experiment is that it can be observed during breaks by leaving the equipment undisturbed in the science classroom or in the hallway outside the science classroom. Even with limited class time, it allows for continuous observation of phenomena that progress over several months.

[0030] As described above, the rock weathering experiment kit 100 allows for the reproduction of an environment that causes salt weathering with a simple configuration. As a result, the progression of cracks and collapse in the rock sample 110 can be continuously observed. Therefore, it becomes possible to provide a tangible understanding of the weathering phenomenon of the rock sample 110.

[0031] The technologies disclosed herein are not limited to the embodiments, examples, and modifications described above, and can be implemented in various configurations without departing from the spirit thereof. For example, the technical features of the embodiments, examples, and modifications described above that correspond to the technical features of each form described in the summary of the invention may be replaced and combined as appropriate to solve some or all of the above-described problems or to achieve some or all of the above-described effects. Furthermore, technical features not described as essential in this specification may be deleted as appropriate. [Explanation of symbols]

[0032] 100... Rock Weathering Experiment Kit 110…Rock samples 120... Magnesium sulfate powder 130...Container 140... Lid 140a...Through hole 150…Recording media

Claims

[Claim 1] This is a rock weathering experiment kit. Rock samples formed from tuff into columnar shapes, Magnesium sulfate powder and A container capable of maintaining a state in which the lower part of the rock sample is immersed in an aqueous magnesium sulfate solution obtained by dissolving the magnesium sulfate powder in water, A lid that fits into the opening of the aforementioned container and Equipped with, A rock weathering experiment set, wherein the lid has a through hole that fits onto the rock sample and allows the upper part of the rock sample to protrude outside the container.

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