Limestone:
What is limestone?
Limestone is a sedimentary rock that is widely found in New Zealand. The rock is made up of more than 50% calcium carbonate (CaCO3) which is derived from the shells of tiny marine fossils. Limestone commonly forms in shallow marine water from a build-up of marine organism’s fossils. In the Waikato there are two major quarries where limestone is formed, one in Te Kuiti and another in Otorohanga which is near where the Waitomo Caves are based. In this report, I will be investigating and analysing the chemical processes involved with the formation of limestone caves, and the consequences these chemical processes pose on the environment.
Formation of limestone:
In New Zealand most limestones are made of shell fragments and lime muds which were originally deposited in the shallow marine waters. These fragments are loose sediment, which undergoes diagenesis to form a hard sediment rock of limestone. The loose sediment is buried beneath the ground, which applies a lot of pressure to the calcium carbonate sediment. This application of pressure is called pressure dissolution. Through this pressure the calcium carbonate actually starts to dissolve. It then seeps into the pores and reprecipitates as cement, which provides the solid characteristic of limestone.
Formation of limestone caves:
Limestone is formed when carbonic acid reacts with the limestone bedrock. However, we first must look at how this carbonic acid was formed: Co2 + H2O H2CO3 . The word for this equation is Carbon dioxide + Water Carbonic Acid. This reaction occurs when the evaporated water combines with the carbon dioxide in the atmosphere to produce carbonic acid. Include soil Co2
The carbonic acid lea...
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...in the cave’s atmosphere. The air we breathe contains carbon dioxide, therefor the Waitomo Cave’s decision to limit the amount of visitors to certain caves each day, is a great way to reduce the impact on the equilibrium. (http://books.google.co.nz/books?id=IBESYmQcb0sC&pg=PA119&lpg=PA119&dq=chemical+equilibrium+in+caves&source=bl&ots=XQ9_hSQ5GP&sig=0i8oZ2ZIAyqHOSKd9R2wr3yo7_I&hl=en&sa=X&ei=gLB4U53tMbKp7AbSwIGQBA&ved=0CCcQ6AEwAA#v=onepage&q=chemical%20equilibrium%20in%20caves&f=false)
Another impact on caves is the extensive road works and agriculture to produce an urban lifestyle. Water is huge part in the formation process of caves and mineral crystallites. Through toxic chemicals produced from urbanization, this water is contaminated and poses a threat to the continuity of the caves.
(http://www2.nature.nps.gov/views/KCs/CaveKarst/HTML/ET_Threats.htm)
The shelf-edge includes carbonate-to-clastic facies transition and tectonic uplift and erosion of the carbonates followed by deposition of the clastics. The Saint Peter Sandstone is a well-sorted, almost pure quartz arenite deposited during a major mid-Ordovician low stand. Clastics spread across an exposed carbonate platform by transportation. This is shown by the well-rounded, frosted texture of the quartz grains.
When standing on top of the butte, the rock that makes up a majority of the area is quartzite. Quartzite is a metamorphic rock that forms when existing rock is exposed to extreme amounts of heat and pressure (4). The quartzite that is found on Kamiak Butte was formed sometime around 1.47 to 1.4 billion years ago during the Paleozoic period of the Precambrian era. Many of the metamorphic rocks have been fractured and decayed due to physical and chemical weathering, but because quartzite consists of one of the strongest minerals quartz...
This sedimentary rock has hardened over the many years with sand shells, small pebbles, grains of sand and rocks of various sizes. In comparison to our 4.5 billion year old Earth, these sand shells might as well be brand new, when in reality they could be up to 1,000 years old. If the sandstone were to be replaced with calcite it would completely change the subclass of rock, it would then be chemical & organic limestone. The variation in sand stone is due to different rates of deposition and change in patterns of the sediment movement (Mc Knight, p. 384). These tightly compacted varying stones and shells will be weathered away by wind and waves over time and could eventually be reduced to a rock the size of your hand.
Over the last century, [it is evident that] the current levels are beginning to impact organisms that make their shells out of the minerals aragonite and calcite…” (Bralower) “Coral reef[s] are highly vulnerable to ocean acidific...
Many different organisms, including mollusks, sponges, and worms, help shape reefs, but hard corals and various algae are the major architects. In effect, the corals build limestone, because their skeletons are made of Calcium Carbonate. The skeletons deposited by these corals and other organisms accumulate, along with sand and other debris, to form the backbone of the reef. Over tens of thousands of years, chemical and mechanical changes turn the reef into true rock (Alstyne and Paul, 1988).
Coral reefs are limestone ridges built by tiny, coral animals called coral polyps. These reefs form when a single, free-swimming coral larva attaches itself to a rock or another f...
...y comes from the Balcones Escarpment. Larger crushed rock from this area is used as a base layer for roads and buildings, to protect them from the shifting soils. Very pure limestone is procesed into lime, wich is then used in a wide variety of agricultural, industrial, and construction activities. Other rocks crushed for building materials include basalt, used for railroad track beds, and marble, used for fancy terrazzo floors.
The corals use these products to make proteins, fats, and carbohydrates, and produce calcium carbonate. The calcium carbonate is what the coral uses to make its hard skeleton. The coral reefs of the world are of vast importance because they host 25% of all marine life on the planet.
There are several theories about how the Cambrian Explosion started. There were major changes in marine environments and chemistry from the late Precambrian into the Cambrian, and these also may have impacted the rise of mineralized skeletons among previously soft-bodied organisms. One theory as to what happened is that oxygen in the atmosphere, with the contribution of photosy...
Minerals are found worldwide and have countless uses. The mineral gypsum, is just one of the thousands named. Gypsum has always been a critical mineral in the building of innumerable ancient constructions, and is still being used in today’s construction. (The History of Gypsum, 1985) It is speculated that the first use of it was in ancient Greece, where is was called “gypsos”, or “selenite”, but, gypsum’s first recorded usability was in Ancient Egypt, where it was used in the building of the Pyramids. They used the material called “Alabaster” (which is a form of gypsum), but later in the 18th century, they realized that gypsum in its natural and raw state, was much too wet, so they altered it to create the building material called “Plaster
Rate of Reaction Between Calcium Carbonate and Hydrochloric Acid Plan: In my experiment I will measure the rate of reaction between calcium carbonate and hydrochloric acid. The rate of the reaction is the speed that the reaction takes place so by measuring the rate I will measure the amount of time the reaction takes. Hydrochloric acid is a strong acid that is found in digestive juices in the stomach, it is also used for cleaning metals before they are coated. Calcium carbonate has a few forms including chalk and limestone the main use of these two materials is in the making of concrete, which is used for many things such as buildings. When you put calcium carbonate and hydrochloric acid together they react to form calcium chloride, carbon dioxide and water.
This carbon dioxide influx is threatening marine life. Coral reefs serve as crucial habitat for 25% of marine species. The increased acidity of the water is causing a decrease in coral skeletal growth. If current carbon dioxide emission trends continue, net coral reefs may begin to dissolve by the end of the century (Harrould-Kolieb and Herr 380). In addition to increasing ocean acidity, the hydrogen ions released by carbonic acid also react with carbonate ions. Low t...
The two aqueous solutions were mixed separately in order to ensure their complete homogeneous transition. Once each solution is completely dissolved, the aqueous solutions of Ca(NO3)2 and Na2(C2O4) are mixed together to form the precipitate, which produces the Calcium oxalate stone sample. The calcium phosphate stone is synthesized in a corresponding manner. 12.9 grams of Ca(NO3) is mixed with 75mL of DI water to form the first aqueous solution.
Igneous rocks are formed from the ejection of earth’s volcanoes. Deep down inside earth’s mantle there lies hot magma. Magma is molten rock that is kept below the surface. This mixture is usually made up of four parts: a hot liquid substance which is called the melt; minerals that have been crystallized by the melt; solid rocks that have made themselves tangled in the melt because of loose materials, and finally gases that have become liquid. Magma is created by an increase in temperatures, pressure change, and a alter in composition. When this magma is ejected from earth’s crust it earns a new name called lava. The lava hardens and becomes an Igneous rock.
mineral equilibria of metamorphic carbonate ejecta (2). Fluid inclusions ([CO.sub.2] and [H.sub.2]O-[CO.sub.2]) in clinopyroxenes from cumulate and nodules indicate a trapping pressure of 1.0 to 2.5 kbar at about 1200 [degrees]C, suggesting that these minerals crystallized at depths of 4 to 10 km (3). The differentiated magma fraction was about 30% of the total magma in the reservoir, and a volume of about 2 to 3 [km.sup.3] was