Of the ten randomly dispersed placers studied along the oast, geologist found they all contained small concentrations of these heavy radioactive minerals. The minerals studied in the placers were in layers between 1 and 2. 5 feet thick and located near the beach surface along with others buried in sand dunes. They believe the placers were formed with or by a combination of waves, wind, and the natural down flow of creeks/rivers. Due to the difference of each separately located placer, geologists noticed grain sizes and the sorting of the minerals differ from placer to placer.
They discovered the lenses with the majority of eavy minerals is finer grained, better sorted, and better rounded and contains magnetite. In the pacer at the northernmost tip, they found it differs from the others. It had black sand as opposed to white and it laid on top of a mud platform. Also, according to the survey, geologists found this placer to be less radioactive than the rest of placers researched. All of the placers are oblong in shape and are very large. Each placer is tens of hundreds of feet wide and can stretch out to be several miles long. The geologists surveyed the placers using an airborne radiometric survey.
After ll of the research the geologists and scientists found that all of the placers contain radioactive minerals as well as non-radioactive minerals. Reasoning and Application I specifically chose this article because I find radioactive minerals, and anything geological related to the ocean, interesting. I grew up surfing in a small beach town near Santa Barbara so any type of geology related to the oceans and beaches interest me. Also, one of the more interesting topics learned in my geology class were the different types of minerals and how their individual physical structure can be altered due to earths natural forces.
After studying geology this semester I was able to fully understand how these placers were formed along with why these heavy minerals formed in layers and were denser than the sand and other rocks. It helped me understand why and how geologists surveyed these radioactive minerals. Also, I completely understood how these minerals were sorted and the different physical structure of these well and poorly sorted minerals. I can honestly say that before taking this class I would have no idea what this article was about. Now I was fully able to grasp all of the information provided in the article. USGS Geology Report By gomer5