Post by: Madeline Foutch, Sabine Dickerson, and Iana Train

Figure 1: This art installation is located on the University of Oregon campus. The front view shows that it is made up of eight individual pieces of basalt all strategically placed together. Note: 20 centimeter scale for reference.

GPS Coordinates: 44.04548°, -123.07428° (Site 3)

Location and General Description: The campus feature, Figure 1, is mounted on the outside of the south side of Columbia Hall on the University of Oregon campus. The artwork installment is made up of eight slabs of basalt, with six grouped together and two further to the side acting as outliers. Created by artist Steve Gillman in 1979 (University of Oregon Libraries, 2022), the piece is a significant contributor to the University of Oregon’s public art collection and acts as an accessible link between geology, art, and student life. Our group was first interested in this piece due to its color contrast and everyday relevance. Placed at the intersection of Erb Memorial Union and Columbia Hall, hundreds of students pass by it everyday as they travel to get between classes. 

Geological Observations: Basalt is a mafic, extrusive igneous rock rich in magnesium and iron, which give it its dark color and fine-grained texture. Although, the basalt pieces in the installment vary in texture, with the matte areas being crumbly and loose. The glossy, darker portions of the exhibit, although having visible cracks, do not flake at the touch. The matte surfaces are a lighter grey compared to the glossy ones, suggesting a difference in mineral composition or weathering process. Mineral composition is what makes up a rock, including different proportions, types, and sizes of minerals. The slabs of basalt have consistent widths ranging from 20 – 25 centimeters, while their heights vary greatly from approximately 20 – 80 centimeters. Additionally, each block is hung about two centimeters away from the wall. 

How Do Communities Respond To Crises Involving Basalt Lava Flows?

Contributed by: Madeline Foutch

Figure 2: Front view of one of the basalt slabs within the installation with a 20 cm scale for reference. Note the discoloration and difference in surface textures. 

Geological Question: The more I learn, the more intrigued I am about how the world is impacted by geology. Where we build our lives is influenced by the rocks, mountains, and bodies of water that are included in the terrain. What happens when geology negatively impacts our lives? How should we react? When a volcano erupts, its basalt lava can cause devastation, and I am eager to understand how communities respond to this disaster, leading me to ask: How do communities respond to crises involving basalt lava flows?

Description of Scientific Article: To begin exploring this question, I read about 38 basalt lava flow crises over the last 70 years (Tsang & Lindsay, 2020). The comparison of how different communities around the world prepare for, respond to, and recover from the lava flows allows for patterns to form instead of simply looking at one case study. Tsang and Lindsey (2020) state their main goal to be learning from past history lessons to improve prevention methods. This investigation connects directly to geology because it explains how factors like monitoring systems, hazard models, and cultural values influence the decisions people make when faced with volcanic eruptions. 

Intersection Between Peer-Reviewed Research and Observations on Campus: Figure 2 shows two different textures: a smooth, shiny surface on the left and a rough, grainy surface on the right. These differences are due to how the lava cools, with the outside cooling quick and the inside cooling more slowly. Tsang and Lindsey (2020) observe that the cooling pattern is key to note during active lava flows because it could appear solid on the surface, but can still be moving underneath. This makes the flow of the path difficult for communities to predict. Many basalt eruptions create flows with smooth crusts (seen on the left side of figure two) and molten interiors which can break open, forming new lava routes (Tsang & Lindsay, 2020). These hidden molten cores have been issues in the past like in the 2018 Kilauea eruption where the breakout paths flowed through neighborhoods even when the earlier flows had already hardened (Tsang & Lindsay, 2020). The rougher texture in Figure 2 resembles the inside of an a’ā flow which is typically thicker and more forceful. During the 1991 Mount Etna eruption, the flow pushed through walls and damaged homes (Tsang & Lindsay, 2020). This example helps to explain how lava flows can differ within short distances, a contributing factor when trying to predict whether a lava flow will slow or keep advancing. Before an eruption occurs, communities create hazard maps, which are visual representations of areas susceptible to lava flows, and are able to use their data and zoning methods to reduce the amount of people that live in high-risk areas (Tsang & Lindsay, 2020). While a crisis occurs, scientists and press officials publish scientific quotes and information to influence the public’s trust as well as reporting on live updates. Evacuations are common and can be either voluntary or mandatory, and evacuation data such as time left, transportation method, and time of return can be useful for improving efficiency for future crises. Tsang and Lindsey (2020) learned that communities with greater knowledge of how to handle basalt lava flow crises show better preparedness. By making their understanding more accessible, less negative impacts of lava flows will occur.

An Answer to the Question? Tsang and Lindsey (2020) helped answer my question by providing numerous case studies that describe how places reacted to eruptions. By connecting the basalt installation on campus to their descriptions, I was able to further understand how properties of basalt influence how impactful a lava flow will be. 

Something Additional I Learned and Future Questions: Additionally, I learned that indigenous communities have cultural knowledge that is shared through the use of stories that explain their past experiences with volcanic eruptions. This tradition increases this community’s resilience to lava flows because they understand how to prepare for it in a safe way due to knowledge from their ancestors. This leads me to ask: How can indigenous beliefs be incorporated into modern hazard planning to improve community preparedness? 

Sources:

Tsang, S. W. R., & Lindsay, J. M. (2020). Lava flow crises in inhabited areas part I: lessons learned and research gaps related to effusive, basaltic eruptions. Journal of Applied Volcanology, 9(1). https://doi.org/10.1186/s13617-020-00096-y

 

“How does erosion affect the coloration of basalt rocks?”

Contributed by: Sabine Dickerson

Figure 3: This is an image of a piece of basalt that is a part of a larger installation outside of Columbia Hall at the University of Oregon. The image is zoomed in on a specific portion of the basalt that has been discolored by weathering. There is a 20 cm scale on the rock for zoom reference. 

Geological Question: In high school, I was given the opportunity to take an advanced science research class. The main requirement in this class was to conduct my own research project, I chose beach erosion. In order to collect my data I got to simulate erosion with sand and water. It was such an interesting experiment and it definitely sparked an interest in the earth sciences for me. Now getting to select my own research question again, I wanted to incorporate that knowledge, but more specifically with basalt rocks. I noticed on our basalt sculpture that there was different red and grey coloring throughout each rock, especially in places that had been damaged or chipped off. Ultimately, with my past experiences and current observation I chose the research question “How does erosion affect the coloration of basalt rocks?”. This question is related to geology because it specifically looks at weathering/erosion and its impact on basalt rocks, a large part of geology. 

Description of scientific article: To assist me in answering my question I will be utilizing Colman (1982). Colman (1982) is a peer-reviewed scientific article that delves specifically into chemical weathering of basalts and how their chemical composition is altered with severe weathering. I chose Colman (1982) because it provides multiple perspectives on how the coloration of basalt changes, and does not just focus on erosion. However, it still ties back to erosion and specifically dives into how erosion changes the chemical make up of the basalt. Ultimately, Colman (1982) will provide me facts and assist me in answering my research question due to both its specificity, and its variety of perspectives. My geological question will be further answered with Colman (1982) as Colman (1982) focuses directly on basalt rocks and how chemical transformations affect the coloring of basalt.

Intersection between peer-reviewed research and observations on campus: Figure 3 shows specific evidence of coloration occurring on basalt rocks. I noticed this discoloration and determined that weathering most likely occurred on the rock and ultimately led to a brown/red rust like color to appear on the originally dark grey basalt rock. Colman (1982) discovered that weathering is seen on basalt rocks through weathering rinds. Weathering rinds occur when the crust of the rock is physically eroded or altered, or when the rock has undergone chemical changes. Ultimately, Colman (1982) states that most of these changes come from weathering/erosion and result in discoloration. Through my observations, I recognized this. The basalt installation had various pieces of eroded rock that were changing color, a clear indication of chemical alterations. Colman (1982) also noticed that weathering rinds on basalt can actually provide a lot of information for scientists. Weathering rinds can show what material rocks are made out of (Colman, 1982). For example, Colman (1982) states that through thorough examinations of weathering rinds scientists can conclude what base material the rock is made out of, and whether there has been detrital contamination. Detrital contamination is when particles are found within a rock that were not there when the rock formed. Often this will change the composition of the rock or cause misunderstanding of what made up the original rock. This was not something I was able to observe on the basalt art formation when I was looking at the weathering, however, I did notice that besides the change in color, the eroded rock was unpolished and looked raw. Lastly, Colman (1982) observed that weathering rinds are able to preserve each individual layer of weathering that occurs. This means that the time it took for the weathering to erode the surface of the basalt to the core of the basalt can be found when studying the rinds (Colman, 1982). Without weathering rinds it can be difficult to observe the transformation of the rocks over time. 

An answer to the question? Colman (1982) assisted me in partially answering my initial question of: “How does erosion affect the coloration of basalt rocks?” Ultimately, I gained a lot of knowledge on how erosion and weathering affect basalt rocks, specifically around the topic of weathering rinds and how those help scientists. However, the portion of my question that remains somewhat unanswered is how coloration is affected. While I learned that erosion and weathering can alter the color of basalt, how that occurs was not further investigated, thus lacking a full answer to my question. While I found that erosion of basalt does lead to coloration and overall changes in the rocks appearance, mainly due to weather, the specific chemical processes were not specified. The “how” portion of my question remains unanswered. 

Something additional I learned and future questions: Additionally, through Colman (1982) I learned that both chemical and mineralogical changes can lead to weathering rinds. Mineralogical changes are transformations in the mineral makeup of a rock. Colman (1982) provided me with this new piece of information that gave me a better understanding of how processes other than erosion can affect basalt. Through my research and Colman (1982) I began to wonder if different kinds of weathering and/or erosion would lead to different colorations of rock. While I know that different minerals within the rocks lead to different colors being presented upon contact with water, I am curious if different kinds of erosion, wind, water, etc. would make the rock different colors, no matter its mineral composition. The question I would ask is: “How does different types of erosion impact the color the eroded rock becomes?” 

Sources cited:

Colman, S. M. (1982). Chemical weathering of basalts and andesites; evidence from weathering rinds (No. 1246). USGPO,.

How does temperature affect weathering of basalt in inactive volcanic fields?

Contributed by Iana Train

Figure 4: Front facing view of basalt slabs located on the University of Oregon campus. Note the grainy vs shiny texture as well as the 20 cm scale for reference.

Geological Question:

Erosion affects the world on a daily basis. The process of weathering and erosion changes the surface we all stand on, and the changing and movement of rocks is what fascinated me. In Figure 4, there is clear weathering that has affected the basalt, whether this is artistic or natural. The process is something that is clearly defined on the face of the slabs. In terms of basalt, temperature is a large factor that determines how it is formed and how it cools to become basalt. This ultimately made me choose the research question: How does temperature affect weathering of basalt in inactive volcanic fields?

Description of Scientific Article:

To help me start answering this question, I read about 37 regions around the world that were tested to show the influence of climatic parameters on basalt weathering rates (Li et al. 2016). The peer reviewed article tested the implications of mean annual temperature as well as rates of CO2 consumption within inactive volcanic fields. These two factors helped examine how climate and temperature chemically break down basalt. This process of weathering allowed scientists to see the correlation of basalt breakdown and the reduction of CO2 levels in the atmosphere. This concludes that basalt is a key part in the negative feedback loop we call climate change, as basalt weathers CO2 is consumed, stabilizing the detrimental effects that carbon emissions have on the environment and the world around us. 

Intersection between peer reviewed research and observations on campus:

In Figure 4 it is clearly evident the weathering that has occurred on the basalt slab. The exterior’s texture is seen as grainy in some parts while in others the slab seems to have this smooth and shiny texture. Li et al. 2016 determines the positive relationship between warmer temperatures and faster weathering in basalt within inactive volcanic fields. Through testing, the higher the mean annual temperature led to more acceleration of weathering (Li et al. 2016). The art piece, “Beginnings” is displayed on the south side of Columbia Hall on the exterior of the building. Due to its location, the art piece receives more sunlight and moisture due to its orientation on the south side and its position located outside exposed to all elements at all times of the year. The art piece has been stationed in this position for the last 45 years since its installment. The weathering that has occurred over these past years won’t be significantly evident due to weathering occurring over a large time scale, but there is still an impact due to the constant temperature deviation that occurs on a daily basis. The mineral composition within the basalt also determines the differences in how the basalt weathers overall. Li et al. (2016) explain that basalt minerals break down at different rates depending on their chemistry, grain size, and how easily they react with water and moisture. The glossy areas have a mineral composition that seems to react against temperatures by cracking and breaking, while the grainy parts seem to flake off when reacting to higher temperatures. These compositions accelerate the chemical weathering that is taking place by having different methods of weathering: cracking or flaking off. Li et al. 2016 concludes that basalt with grainy textures are products of basalt dissolution as they were introduced to some sort of moisture or liquid that allowed them to weather. The shinier areas of the basalt begin to crack due to thermal expansion explained in the article (Li et al. 2016). 

An answer to the question:

Li et al. 2016 clearly answered my question: How does temperature affect weathering of basalt in inactive volcanic fields? It determined that there is a correlation between warmer temperatures and increased weathering. Temperature is a large factor when it comes to weathering, and it is extremely important to understand the true effect it has on surfaces like basalt. The data within the article showed that higher average temperatures sped up the chemical weathering process (Li et al. 2016). In inactive volcanic fields, climate is the main factor influencing weathering because there aren’t any active eruptions occurring in the volcano. Without these external factors it is easy to pinpoint how the weathering is occurring. Although throughout this article there were limitations because climate predictability is something that cannot be measured to the fullest extent, and there is no way to fully isolate one temperature to occur for the rest of time because seasons are always changing and developing. Through graphs and assumptions there will always be a correlation with temperature and weathering because it physically interacts to expand and contract materials eventually leading to the disintegration of the basalt altogether (Li et al. 2016).

Something additional I learned and future question:

Additionally through this article, I learned that active volcanic fields cannot factor into the statement that temperature determines weathering (Li et al. 2016). Reactivity of recently erupted basalt and hydrothermal reactions (Li et al. 2016) are some factors that weather active volcanic fields other than temperature which makes their consideration into this study invalid. This led to asking more questions about the weathering process and other materials like basalt and their timeline of weathering. I began to wonder: does the mineral composition of a rock influence the rate of weathering that occurs?

Source Citations:

Li, G., Hartmann, J., Derry, L. A., West, A. J., You, C. F., Long, X., … & Chen, J. (2016). Temperature dependence of basalt weathering. Earth and Planetary Science Letters, 443, 59-69.