By Josh Bimm

Once upon a time, approximately 320,000 years ago, an enormous eruption of the basaltic lava family occurred from what is known as the Swan Lake Flat Basalt, a part of the today's Yellowstone National Park, in Wyoming, U.S.A.[1] Our basalt lava family had been waiting thousands and thousands of years to burst out of the ground, out of the interior of the earth. The basalt family was very lucky; our heritage was composed of approximately 52% silica (SiO2), which allowed us to match up with various minerals. As well we tend to be very viscous: flow easily, therefore makeing moving from one place to another hassle free[2]. All that this basaltic lava family wanted to do was to re-locate on the exterior of the earth as rocks.

 

          Born and raised in the upper mantle, rock that has become uncomfortable and begins to move around, releases pressure and partially melting[3]. The basaltic family is the result of this melting rock in the form of lava. This is how it is conceived[4]. After spending thousands of years locked in the belly of the earth, the basaltic family found escape by the easiest route: hot spots and at rift zones[5]. New life could now begin!

 

          Just before our basaltic family began their journey toward the exterior of the earth, a huge going away party was thrown for us. Both sides of the basaltic family attended: the Pahoehoe lava, which is the part of the family who are smooth, and rope-like, and the A’a’ lava, who are often rough, often spiny, and can sometimes have a block-like surface[6]. Both branches of the family came from Hawaii, where they originate[7].  After much discussion, it was decided that both parts of the family travel together to unite one very large basaltic family. They agreed only to separate once they were settled outside of the earth.

 

          After a very long journey from the upper mantle, with no stops, rushing to the exterior of the earth, through hot spots and rift zones[8], the basaltic lava family finally found themselves at their new home, the Sheepeater Cliff.

 

          Time passed, and this basalt lava family had become basalt rock. Reforming into hard, black rock, our basalt family changed to suit their surroundings, and went through vigorous stresses to become a part of a column where they live[9].  They were jointed into the column by being shown how to contract when they first arrived. They began to cool off[10]. They knew of course that every basalt family who had ever lived there had been fractured apart into these columns[11]. In order to be accepted into this column of houses, the basalt conformed, like all of their basalt lava ancestors did, into hexagonal shapes, allowing them to fit right in[12]. Now any set of basalt’s new in town could be re-united with their cousins.

 

          Now on the exterior of the earth, the basalt rocks knew that they were a vital rock to the earth’s make-up. As the basalts grow, every rock, like their parents and grandparents before them, become igneous rocks, an occupation only known to those rocks who have solidified from magma[13]. This very important job is particular to the basalt family due to their extensive ability to perform properly. While solidifying, they produce magnificent ferromagnesian minerals, such as olivine or pyroxene. This is due to their make-up of silica meeting iron and magnesium[14]. These minerals make the basalt rocks turn green or stay black[15]. Some basalt rocks also unite their silica content with calcium and aluminum to produce plagioclase feldspar[16]. These rocks are dark grey[17]. However, the basalt family does not particularly like to produce quartz; they would rather match their silica up with the previous minerals[18].

 

          After going to university and learning just what there is to learn about geology, pieces of the basalt rock knew that they were useful and needed in other parts of the world. Some of the basalt rocks moved to the ocean floor when they were needed to fill the cracks and gaps[19]. They knew that along with granite, they covered most of the world’s ocean floor[20]. Since the ocean cools the rock especially quickly, when there is an eruption the rock solidifies in the fracture of the seafloor crust at an ever greater rate than if on the continental crust[21].

 

          For the most part our basaltic family has continued to grow within the formation known as the Sheepeater Cliffs. Generations of people have described us as a geological gem. Vistors arrive every year to take in the beauty created by our family. Now you know our story.

 

 

Seen here, Sheepeater Cliff is in the upper west side of Yellowstone National Park. It is evident that it is merely a spec in the geological wonder that is Yellowstone!

Seen in this map, the yellow indicates basalt rock as well as rhyolite that is embedded within Yellowstone National Park.

• Shield volcanoes are made almost entirely of basalt!
• The mantle, where the basaltic magama begins, is approximately 30-50 kilometers below continents.
• Most of the oceanianic crust is composed of basalt.

Source:U.S. Department of the Interior, U.S. Geological Survey, Menlo Park, California, USA, Photo Glossary of Volcano Terms, http://volcanoes.usgs.gov/Products/Pglossary/basalt.html.