In geology, a sediment is defined as an assemblage of particles, loose or indurated materials that form on the Earth’s surface (Selley 2000, 41). The study of sediment includes its provenance and the processes that result in their deposition of the weathered and eroded products of its older material. The purpose of sedimentology is to provide a deeper understanding about the Earth’s history.
In a sediment, maturity is described as the degree of how much a sediment changed due to weathering, transport and reworked toward its ultimate end product, quartz sand (Nichols 2009, 26). Sediment maturity can be measured in terms of its texture and composition.
Texture in a sedimentary rock refers to its grain sizes, grain shapes, sorting and rounding.
Textural maturity is defined by the sorting and its roundness of sediment whereas composition maturity is a reflection to its quartz content. The maturity of a sediment or a sedimentary rock can be represented as shown in Figure 1.
There are four types of textural maturity; immature, submature, mature and supermature.
Texturally immature sediments are those which comprise of mostly matrix and contains little amount of grains in the rock. The grains are usually poorly sorted and are angular (Tucker 2001, 20). A rock which composed of mud, silt and sand sized materials such as the greywacke is considered to be texturally immature. An indication of a texturally immature sediment is that the distance of its transport may be short.
A sediment is considered to be submature when sorting is moderate to poor. Submature grains are usually smaller and appears to be slightly more rounded than immature sediments.
Texturally mature sediments are those where there is little matrix and have a range of moderate to good sorting and subrounded to rounded grains. Mature grains usually often more rounded and have higher sphericity compare to immature and submature grains.
Texturally supermature sediments are those with no matrix, have very good sorting and consists of well-rounded grains. As quartz is hard and lacks cleavage, it is commonly the ultimate survivor and is durable to changes in a turbulent environment (Skinner, Porter and Park 2004, 178). A rock which consists of well-rounded quartz grains of a restricted grain size would be very mature.
The determination of the textural maturity of a sediment is independent to its composition as it is influenced largely to its depositional processes, although it can be altered by diagenetic processes (Tucker 2001, 11).
Depending on the type of path that was created, it would largely influence the rate and distance to which the sediment was transported.
Sedimentary rock from the older Silurian Period is further from the river banks (Geological map of Victoria, 1973). Mudstone, inter-bedded shale and greywacke depositions indicate the Maribyrnong River may have previously taken a different shape, and younger sediments have replaced the older sediments in more recent geological periods.
...ts were labelled with the upper case letters which represented the material types and a numeric letter. The artifacts were placed in different boxes. The artifact analysis was then conducted and the characteristics such as tool type and material type of each artifact were recorded on the artifact catalog forms. The material samples of lithic tools, faunal remains, and ceramics remains were compare with existing artifacts to identify their material type. The Vernier scale was used for the measurements of each lithic tools.
The coastal belt of the Franciscan Complex is composed of the youngest and least deformed units and makes up the western quarter of all Franciscan rocks. The rocks of the coastal belt are composed of arkosic sandstones, andesitic graywackes, and quartzofeldspathic graywackes interbedded with radiolarian chert (turbidite deposits) (Blake and Jones, 1981). These sedimentary rocks suggest a depositional environment of deep-sea fan systems with both oceanic and continental provenance. Parts of the belt show evidence of later metamorphism, principally due to subduction. Low-grade blueschist mineral facies are indicated by the presence of minerals such as laumonite and prehnite-pumpellyite (Blake and Jones, 1981). All rock units show evidence of thrust (imbricate) faulting due to the compressional forces of subduction. Ages of the coastal belt run from as little as 40 Ma (Eocene) to as old as 100 Ma (middle Cretaceous).
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.
More recently than Zeck’s work, Cesare et al. (1997), only divided the xenoliths into two main types: garnet-biotite-sillimanite and spinel-cordierite xenoliths. The quartz-cordierite rocks, distinguished by Zeck (1970), were interpreted as the products of interaction between garnet-biotite-sillimanite xenoliths and blebs of mafic magma and are not recognised. The xenoliths were observed to contain widespread occurrences of rhyolitic glass as...
"Sedimentary Rocks." Backyard Nature with Jim Conrad. N.p., 18 May 2015. Web. 25 Oct. 2015.
Huang, Ter-chien. The Sediments and Sedimentary Processes of the Eastern Mississippi Cone, Gulf of Mexico. Tallahassee: Florida State University, Sedimentological Research Laboratory, 1969. Print.
The "skeleton" structures of the rocks of reservoir are affected by the depositional surrounding and numerous earth processes after deposition.
"Step 1. Characterizations of the Watershed." Forest Service: 17 pars. Viewed 7 Nov. 2002. <http://www.fs.fed.us/r2/psicc/spl/south_platte_web/step_1.htm>.
Maturity is commonly used word, but when asked what the word means many people simply shrug their shoulders. Maturity isn’t a word that has a clear definition. Being based primarily on one’s connotation, it doesn’t mean the same thing to everyone. Personally I picked this word up through context. However, upon doing a careful study of where this word originates and other’s connotation’s, I feel I’ve achieved a relatively good understanding. Webster claims the word to mean “based on slow careful consideration,” but I feel there is much more to this word than that.
It is composed of two elements; oxygen and sulfur. This mineral can either be white in colour, gray, brown, orange, green, red, pink, yellow, beige, or it can be colourless, and the streak that it leaves is white. Based on the Moh’s Hardness scale, Gypsum falls somewhere around the 2 margin. Its lustre is close to that of glass (in properties and in appearance), and is considered vitreous. The cleavage—where it breaks along its line of weakness—is 1,1 – micaceous ; 2,2 and its fracture is uneven. Gypsum is slightly flexible, has low hardness, where it can be scratched by a fingernail, and is sectile (can be cut with a knife). Gypsum is a sedimentary rock, meaning it was formed by cementation at the surface of the Earth near bodies of water; it causes the mineral (gypsum) to settle within the
Thousands of years ago when sea levels dropped over years at the Southern end of Muriwai, the sedimentary rock and sandstone was exposed to the air. Rock from volcanic activity mixed with the sedimentary rock; this is called Breccia -- a mixture of all rock. An example of this is at Maori Bay.
There are two types of Igneous rocks. The first is intrusive, which is when the magma slowly cools beneath the earths surface. Because the magma is cooling slowly it allows the rocks end result to form crystal- like pigments. Examples of intrusive igneous rocks are Diorite, Gabbro, Granite, Pegmatite, and Periodotite. All of these rocks are course and grainy. The other type is an extrusive Igneous rock. This lava erupts onto the surface of the earth and cools rapidly also forming crystals, the lava cools so fast that at times it allows the rocks to form as clear-like glass. Examples of these rocks are Andesite, Basalt, Obsidian, Pumice, Rhyolite, Scoria,
Igneous rock is formed when molten rock (magma) cools and solidifies, with or without crystallization. Igneous rock is then further classified into intrusive and extrusive; this phenomenon will affect the grain texture of the rocks. Intrusive igneous rock is rock that formed below the Earth surface whereas extrusive igneous rock is erupted onto the surface, hence this leads to the formation of coarse-grained and fine-grained rocks respectively. Sedimentary rock is formed from several ways; (i) the deposition of the weathered remains of the other rocks, (ii) the deposition of the results of biogenic activity, and (iii) the precipitation of solution. As for metamorphic rock, it is the formation of new rock from the transformation of an existing rock through metamorphism, i.e. the process in which the rock is subjected high heat and pressure. In comparison between the three types of rocks; igneous, sedimentary and metamorphic rocks, sedimentary rocks have a lower material strength than igneous and metamorphic rocks. This is due to the texture of the rock itself. In another words, the grains of sedimentary rocks are usually clastic which means that the