Rock of Ages – New Kentucky
This Earthcache is located at New Kentucky Park, Harris County, Texas. Since this is an Earthcache, there is no physical container to find. To earn a smiley for the cache, e-mail or message your answers to the questions to the cache owner BEFORE you log a find.
At GZ, you will observe a moderate monument to the New Kentucky, Texas community. Formed in 1831, about 30 miles northwest of Houston, the town was abandoned in 1840 for unknown reasons. The monument was erected in 1936 by the State of Texas with granite imported from Barre, Vermont.
Rock of Ages
Granite is a coarse-grained igneous rock made of primarily quartz, feldspar, micas, amphiboles, and a mixture of additional trace minerals. The abundance or variation of these minerals gives granite the numerous colors and textures we see today. Granite weighs about 170 pounds per Cubic foot.
Granite is formed when the Earth’s magma slowly cools and crystalizes long before it reaches the Earth’s surface. The texture of granite is determined by the rate at which it cools. Large mineral crystals in granite indicate they are slowly formed from the Earth’s magma. Meanwhile, granite with tiny crystals cooled rapidly when exposed to air or water at the Earth’s surface.
Granite will contain 20-60% quartz, 19-65% feldspar, and 5-15% mica. The color of the granite depends on the amount of each of these minerals.
- Quartz = Milky White
- Feldspar = Off-White
- Potassium feldspar = Salmon Pink
- Biotite = Black or Dark Brown
- Muscovite = Metallic Gold or Yellow
- Amphibole = Black or Dark Green
After reading the information above and observing the object in front of you, please answer these required logging tasks:
- Estimate the monument's weight (hint: depth X width X height).
- Look at the granite; what three main minerals do you see?
- What size are the biotite crystals? (For example, the size of a penny, a pencil eraser, or a grain of rice. Be creative in your description).
- Is the igneous rock EXTRUSIVE or INTRUSIVE? Why?
- Take a selfie or a photo with your GPS unit with the Abraham Roberts Homesite in the background.
Confirm your findings by answering these questions and sending
Your answers via the message center.
** Please do not post your answers in your log! **
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Sources:
Bonewitz, R. 2012. Rocks and Minerals. 2nd edition. DK Publishing
Geology In. 2024. What is Granite, And How Is It Formed? https://www.geologyin.com/2015/11/what-is-granite-and-how-is-it-formed.html
Geology Science. 2023. Granite. https://geologyscience.com/rocks/granite/?amp
Permission:
Lesley Briones, Commissioner Harris County Precinct 4, granted permission for this Earthcache.