Showing posts with label rocks. Show all posts
Showing posts with label rocks. Show all posts

Tuesday, May 25, 2021

The Geological Impact of Hemp Agriculture

               
                               Image Source: pixabay.com

Looking out over a field of crops, it can be hard to determine exactly what is growing if you don’t have prior experience. It could be a variety of different types of wheat, legumes, corn, or so on. It may come as somewhat of a surprise given decades of federal regulations, but the crop growing out in the field you’re gazing upon could also be hemp.

Hemp products have made a surprising entry into a marketplace they were once forbidden from. Loosening of federal regulations surrounding marijuana plants — particularly those parts and varieties that are not known for altering your mental state — has led to a boom in the market. Hemp has long been known as a highly versatile and useful material and could come to replace many of the alternatives in the market because it is cheaper and of similar quality.

Most surprising though are the potential positive impacts hemp growing could provide for the local ecology. Particularly geological features such as soils. The conversion in American agriculture back to hemp growth could play a profound role in preserving and building the health of soils across the country.  

Hemp Resurgence

Due to its association with marijuana, hemp has earned a bad rap in the past half-century. However, hemp played a significant historical role in the founding and building of the United States. The crop arrived in the U.S. with the first settlers in Jamestown, who used it to make all sorts of essential items including rope, sails, and clothing. Hemp was so important that farmers in the colonies were required by law to grow it as a part of their overall agricultural production.

 Hemp has long been known as a vastly useful product. In the early 1900s, the U.S. Department of Agriculture published findings that hemp produced 4 times more paper per acre than trees and in the 1930s, Popular Mechanics determined hemp could be used in the production of over 25,000 different products. However, none of this stopped hemp from being listed alongside marijuana as a Schedule I drug in 1970.

Only in the past decade have regulations restricting the production of hemp been loosened to allow farmers to grow the plant. Only with the 2018 Farm Bill legislation did hemp become fully legal to grow in the U.S. Economists estimate that the industrial hemp market will reach nearly $36 billion by 2026 — a huge explosion in value and production.

Building Soils

Though the resurgence of the hemp market is interesting, there are many less visible benefits than the money. For instance, hemp can be a powerful means of conserving and building valuable agricultural soils. Soils are complicated and can take decades to form but they are quite easy to destroy, especially in arid or heavily utilized areas. 

 Hemp can be a wonderful rotational crop because, even though it is an annual, it puts down deep roots. Deep roots hold soils in place, preventing erosion, and break up soils which can allow for the planting of more sensitive crops in the following years. Beyond that, hemp produces an incredible amount of biomass, which can be turned back into the soil and used to increase nutrient value for the next round of plants.

Believe it or not, hemp can also be used to remediate damaged soils. The plant can typically grow in contaminated soils without any negative impacts. It can also be used as a means of reducing herbicide and pesticide usage because it is naturally resistant to most pests. This means that not only can damaged areas be put back into production over time, but fewer chemicals are leached into waterways, which would not only improve natural habitat but could increase the quality of drinking water.

Many Uses

As previously mentioned, hemp has all sorts of potential uses and stands to compete with or replace many materials that are currently used. Building construction is just one of many examples. Geological and materials considerations are significant in building projects, and hemp is entering the markets in more ways than one.

One of the most interesting ways hemp can be used in construction is through what is known as hempcrete. The material is only about 15% as dense as concrete and could float on water, yet it supports vertical loads such as wood stud framing well. Such material was used long before concrete and may even extend the life of wood structures because it allows the wood to ‘breathe’ a bit more.

Hemp also makes a great insulation material without many of the harmful side effects that some previous supermaterials such as asbestos have. While asbestos is extremely heat resistant, it causes myriad health problems. Hemp is also resistant to both heat and mold, which can protect a house or building even longer, and it heals health problems instead of causing them.

***

Hemp has had a long, significant history as an agricultural commodity in the United States. The redaction of laws that prevent growing the product has led to a boom in the market and thousands of updated ideas on how to use it in all sorts of industries. Aside from the great economic benefits, hemp has the potential to play a significant environmental role in building and rehabilitating the soils that all of us depend upon. 

Indiana Lee is a  journalist from the Pacific Northwest with a passion for covering workplace issues, environmental protection, social justice, and more. When she is not writing you can find her deep in the mountains with her two dogs. Follow her work on Contently, or reach her at indianaleewrites@gmail.com

Friday, March 24, 2017

30+ Thin Section Photos That Will Develop Your Interest in Petrography

 “thin section” of rock is a sample that is mounted to a microscope slide and cut so thin that you can see light through it. The process of creating a thin section is a blend of artistry, technology and science.  
The art of preparing thin sections has been critical to understanding the core samples that scientists are observing. Thin section samples allow scientists to observe minerals in rocks, their crystal structure and texture at a microscopic level.

Want to revise how do geologists study rock? Follow this link to see our blog on "Studying Rock".

In this blog, we're taking you into the journey of thin section photos that were captured and given by students and young professionals from Finland, Ireland, Denmark, Czech Republic and Plymouth (UK). 


Again our purpose is to encourage students and professionals' research by promoting "learning and scope" of Geology through our blogs. Help us to help others in learning and understanding geology. See this link that how you can contribute to Learning Geology.


Note: We are using following thin section photos by having permission from their owners. If 
you like to use these photos, leave us a message or email us here.

1. A beautiful heart shaped hornblende in XPL (cross polarized light) view.It is a thin section of basalt with some secondary mineralization in the vesicles. Plagioclase is present in the form of black and white matrix and large phenocryst (with some zoning). Alignment of plagioclase grains is indicative of the "flow" of magma.

Photo Credits: Astaley

2. Thin Section of a Biotite and Muscovite, XPL view 

Photo Courtesy: Laura

3. Thin Section of a Plagioclase (orthoclase) and Pyroxene, XPL 

Photo Courtesy: Laura


4. Eclogite in Thin Section, XPL

Photo Courtesy: Laura

 5. Cummulate Rock with Pyroxene and plagioclase, XPL

Photo Courtesy: Laura

6. Blueschist, XPL

Photo Courtesy: Laura

7. Agglomerate in a Thin Section, XPL view

  
     Agglomerates are pyroclastic igneous rocks that consist almost wholly of angular or rounded lava fragments of varying size and shape. Fragments are usually poorly sorted in a tuffaceous matrix, or appear in lithified volcanic ash. (Britannica.com)

Photo Courtesy: Laura
8. Thin Section of a Pigeonite and Olivine, XPL

Photo Courtesy: Laura

9. Olivine phenocryst in Basaltic Lapilli, XPL

Photo Courtesy: Laura

10. Thin Section of a Gabbro, XPL

Showing minerals; Pyroxene and Olivine, plagioclase and others. Learn more about Gabbro here.


Photo Courtesy: Laura

 11. Another beautiful thin section of a Gabbro, XPL

Photo Courtesy: Laura
12. Thin Section of a Greenschist, XPL

Photo Courtesy: Laura

13. Thin Section showing intrusion of rocks from magma chamber into country rocks, XPL

Photo Courtesy: Jack Lewis Donnelly


14. Thin Section of a Sillimanite - a mineral found in rocks formed by the metamorphism of a mudstone. (XPL view)

Photo Courtesy: Jack Lewis Donnelly
15. Microgeode in ultrabasic vulcanite (
a rare copper telluride mineral), 30 µm thin section, PPL and XPL 

Photo Courtesy: Petr Hyks

Photo Courtesy: Petr Hyks
                                                              See original photo here

16. Muscovite & biotite (30 µm thin section, PPL and XPL)


Photo Courtesy: Petr Hyks


Photo Courtesy: Petr Hyks
Same photo in XPL view. See original photo here

17. Quartz and epidote (30 µm thin section, PPL and XPL)

Photo Courtesy: Petr Hyks

Photo Courtesy: Petr Hyks
                                                        See original here.

18. Olivine (30 µm thin section, PPL and XPL)

Photo Courtesy: Petr Hyks
See this photo here on Petr Hyks' website

19. Zircons in biotite (30 µm thin section, PPL views, showing extinction)
                                                                                         
                                                                                  
                          Photo Courtesy: Petr Hyks
                              See this photo here on Petr's website






20. Zircon in biotite (30 µm thin section, XPL)

Photo Courtesy: Petr Hyks
See this photo here on Petr's website

21. Kyanite surrounded by muscovite (30 µm thin section, PPL and XPL)

Photo Courtesy: Petr Hyks
See these photos on Petr's page here and here

22. Zircon crystal in chloritized biotite (30 µm thin section, PPL and XPL)



     
Photo Courtesy: Petr Hyks
See these photos on Petr's page  here and here
Petr Hyks is 21 year old geology student from Masaryk University in Brno (Czech Republic). He has uploaded 5000+ photos about geology, astronomy and meteorology on his Flickr page. Follow this link to visit his website. Thank you Petr for contributing to Learning Geology and helping others to learn geology through your thin section photos. 🙂 Now following 10 thin section photos are from a geology student of University of Helsinki, Finland.

23. Thin Section of Olivine Diabase in XPL and PPL view.

Photo Courtesy: GeoAmethyst

24. Thin Section of Basalt in XPL view
        Having minerals: Olivine (in center) plagioclase, pyroxene and other accessory minerals
Photo Courtesy: GeoAmethyst

25. Thin Section of a Trachyte, XPL view

    Trachyte is an igneous volcanic rock with aphanitic to porphyritic texture. It is volcanic equivalent of Syenite. Major or essential minerals are alkali feldspar with less amount of plagioclase, quartz or feldspathiod. 

Photo Courtesy: GeoAmethyst


26. Thin Section of a Harzburgite, XPL view
      Harzburgite is an ultramafic igneous rock. It chiefly contains plagioclase (under 10%) , olivine, orthopyroxene (enstatite), clinopyroxene (diopside) and biotite. There could be a small amount of talc, carbonate, tremolite, cummingtonite, chlorite, serpentine and titanite.
Photo Courtesy: GeoAmethyst

27.  Another thin section of Harzburgite, XPL view

Photo Courtesy: GeoAmethyst

28.  Thin Section of Pyroxenite (an ultramafic igneous rock), XPL view

Photo Courtesy: GeoAmethyst

29. Thin Section of Trachyte showing Sandine mineral in center, XPL view

Photo Courtesy: GeoAmethyst
 
30.  Thin Section of Andesite, XPL view
       It is an extrusive igneous, of intermediate composition, with aphanitic to porphyritic texture.              Here this thin section is showing chiefly hornblende and plagioclase.
Photo Courtesy: GeoAmethyst

31. Thin Section of Alkali Basalt (silica undersaturated) in XPL view.

Photo Courtesy: GeoAmethyst


32. Thin Section showing small clinopyroxene grains within orthopyroxene

Photo Courtesy: GeoAmethyst

Like this article? Leave a comment down or send us your valuable suggestion or feedback here  to help us in improving this article.
Useful Websites: 

1. Polarized light Microscopy (Image Gallery)
2. How to make a thin section
3. Petrographic thin section preparation
4. Guide to Thin Section Microscopy
5. Index of Minerals in Thin Section
6.
Optical Petrography website by an Italian Geologist

7. Carbonate Thin Section Images and 
Exercises

Sunday, January 8, 2017

Siccar Point - the world's most important geological site and the birthplace of modern geology


Siccar Point is world-famous as the most important unconformity described by James Hutton (1726-1797) in support of his world-changing ideas on the origin and age of the Earth.

James Hutton unconformity with annotations - Siccar Point 



In 1788, James Hutton first discovered Siccar Point, and understood its significance. It is by far the most spectacular of several unconformities that he discovered in Scotland, and very important in helping Hutton to explain his ideas about the processes of the Earth.At Siccar Point, gently sloping strata of 370-million-year-old Famennian Late Devonian Old Red Sandstone and a basal layer of conglomerate overlie near vertical layers of 435-million-year-old lower Silurian Llandovery Epoch greywacke, with an interval of around 65 million years.
Standing on the angular unconformity at Siccar Point (click to enlarge). Photo: Chris Rowan, 2009
As above, with annotations. Photo: Chris Rowan, 2009





Hutton used Siccar Point to demonstrate the cycle of deposition, folding, erosion and further deposition that the unconformity represents. He understood the implication of unconformities in the evidence that they provided for the enormity of geological time and the antiquity of planet Earth, in contrast to the biblical teaching of the creation of the Earth. 

   
How the unconformity at Siccar Point formed.



At this range, it is easy to spot that the contact between the two units is sharp, but it is not completely flat. Furthermore, the lowest part of the overlying Old Red Sandstone contains fragments of rock that are considerably larger than sand; some are at least as large as your fist, and many of the fragments in this basal conglomerate are bits of the underlying Silurian greywacke. These are all signs that the greywackes were exposed at the surface, being eroded, for a considerable period of time before the Old Red Sandstone was laid down on top of them.
The irregular topography and basal conglomerate show that this is an erosional contact. Photo: Chris Rowan, 2009

The Siccar Point which is a rocky promontory in the county of Berwickshire on the east coast of Scotland.

Thursday, January 5, 2017

Igneous Origin of Diamonds

Diamonds are a rare occurrence on the surface of the planet because it takes extremely hot and high pressure conditions to create them. Physical and chemical conditions where diamonds form only exist in the mantle, nearly 70 miles down or more. In that environment in the upper mantle, diamonds may be a common mineral! It takes incredible events, nothing that has ever been witnessed in historic times, to bring diamonds to the surface.
Kimberlite-Diamond-mantle-rock

Diamond deposits around the world (that have any economic significance) are associated with volcanic features called 
diatremes.  A diatreme is a long, vertical pipe formed when gas-filled magma forces its way through the crust to explosively erupt at the surface. Kimberlite a special kind of intrusive igneous rock associated with some diatremes that sometimes contain diamonds, typical coarse grained an bluish in color.    

Diamond-bearing kimberlite pipes are diatremes that originate in the mantle.
   
Diamonds are xenoliths carried up from deep sources in the mantle, and often occur in association with other gem minerals including garnet, spinel and diopside. Most "economically significant" diamond deposits occur in ancient rocks (Precambrian age), but have been discovered on all continents. Because diamonds are so hard, they survive torturously-long histories, recycled through sedimentary and metamorphic environments without being destroyed. As a result they have been found almost everywhere as very rare, isolated discoveries. Diamonds of microscopic size have been discovered in meteorites and asteroid impact sites, and some metamorphic rocks. They are most extensively mined from kimberlite pipes or from alluvial gravels derived downstream from diamond source areas. It should be noted that most diamonds are not of gem quality, but those that are not are used for industrial purposes.

Credits to Phil Stoffer at geologycafe.com
Text and figures are used with permission.

Thursday, March 3, 2016

Studying Rock

Studying Rock 

Outcrop Observations 

The study of rocks begins by examining a rock in an outcrop. If the outcrop is big enough, such an examination will reveal relationships between the rock you’re interested in and the rocks around it, and will allow you to detect layering. Geologists carefully record observations about an outcrop, then break off a hand specimen, a fist-sized piece, that they can examine more closely with a hand lens (magnifying glass). Observation with a hand lens enables geologists to identify sand-sized or larger grains, and may enable them to describe the texture of the rock.

Thin-Section Study 

Studying rocks in thin section.

The Basis of Rock Classification

The Basis of Rock Classification 

Examples of three major rock groups.
Beginning in the 18th century, geologists struggled to develop a sensible way to classify rocks, for they realized, as did miners from centuries past, that not all rocks are the same. Classification schemes help us organize information and remember significant details about materials or objects, and they help us recognize similarities and differences among them. By the end of the 18th century, most geologists had accepted the genetic scheme for classifying rocks that we continue to use today. This scheme focuses on the origin (genesis) of rocks. Using this approach, geologists recognize three basic groups: (1) igneous rocks, which form by the freezing (solidification) of molten rock (figure above a); (2) sedimentary rocks, which form either by the cementing together of fragments (grains) broken off preexisting rocks or by the precipitation of mineral crystals out of water solutions at or near the Earth’s surface (figure above b); and (3) metamorphic rocks, which form when pre-existing rocks change character in response to a change in pressure and temperature conditions (figure above c). Metamorphic change occurs in the solid state, which means that it does not require melting. In the context of modern plate tectonics theory, different rock types form in different geologic settings (figure below).