Tuesday, May 12, 2009

Tools Geologists Use To Gather Rock Samples

Geologists use high to low technology tools, like this shovel.


Geology is a science that is highly evolved, but uses traditional tools at the same time. This being the case, geologists use as many tools as they can to study the earth. These vary in range from ultra-high-technology modern tools to traditional low-tech tools such as pickaxes and shovels.


Picks and Shovels


At the low end of the tool spectrum are the traditional rock-hunting tools. These include pickaxes, shovels and hammers. A geologist may see an interesting rock formation. She chips away at the rock with a pickaxe, then uses a shovel to put the samples into a bucket. She takes the samples to the lab for further analysis. This method is pretty low-tech, but it works well, so it's still being used today.


Core Drilling


If a geologist wants to see a rock sample that is deep below the earth, a core drill is used. A core drill is a hollow steel tube about three inches in diameter. It has industrial diamonds bonded to the edge, and it is spun into the ground by a derrick assembly. As the drill plunges into the earth, a section of soil, rock and other material is collected inside the tube. The tube is brought up and the trapped sample is pushed out by a steel rod.


A core drill can be driven for thousands of feet into the earth. For example, the U.S. Geological Survey sank a core drill 1,500 feet deep near Savannah, Georgia while drilling a deep geologic test well. The project was completed in April of 2010, and it allows geologists to study rocks 60 million years old.


Wireline Logs


A wireline log is actually a group of tools housed inside a robotic capsule-shaped tool called a log. A hole is drilled deep into the earth. A variety of tools, such as a small camera, scrapers and small scoop buckets, is housed inside the capsule. The geologists control the log from the surface. A scraper collects a sample at the bottom of the hole, and it is brought up for analysis. According to Innovations Report, wireline logs provide an accurate way of looking at the samples collected from deep underground.


Chemistry


Geologists do not work in a vacuum. They rely on the expertise of other professionals, such as chemists. A good example of this is the diamond exploration effort in northern Canada, as described on the Earth Explorer website. Core samples (acquired by core drilling) were brought up by geologists. Chemists analyzed the samples and discovered a lot of garnet rock in many of the samples. Garnet is usually found side-by-side with diamonds. However, the chemical analysis of some garnet samples revealed the earth conditions were not right to create diamonds in some areas.







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