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76-600: The Windimurra Igneous Complex is part of the c. 2813 Ma Meeline Suite of mafic-ultramafic layered intrusions of the central Murchison Domain, Yilgarn Craton of Western Australia. It is a conical body, approximately 7 km thick, primarily composed of layered gabbroic rocks, which intrude into c. 2820 Ma Norie Group rocks of the Murchison Supergroup. The intrusion is approximately 85 x 37 km (2500 km) in extent. Windimurra contains in excess of 13,000m of intact igneous stratigraphy formed of cumulate layering by

152-535: A characteristic fabric . All three types may melt again, and when this happens, new magma is formed, from which an igneous rock may once again solidify. Organic matter, such as coal, bitumen, oil, and natural gas, is linked mainly to organic-rich sedimentary rocks. To study all three types of rock, geologists evaluate the minerals of which they are composed and their other physical properties, such as texture and fabric . Geologists also study unlithified materials (referred to as superficial deposits ) that lie above

228-399: A hiatus because deposition was on hold for a period of time. A physical gap may represent both a period of non-deposition and a period of erosion. A geologic fault may cause the appearance of a hiatus. Magnetostratigraphy is a chronostratigraphic technique used to date sedimentary and volcanic sequences. The method works by collecting oriented samples at measured intervals throughout

304-485: A petrographic microscope , where the minerals can be identified through their different properties in plane-polarized and cross-polarized light, including their birefringence , pleochroism , twinning , and interference properties with a conoscopic lens . In the electron microprobe, individual locations are analyzed for their exact chemical compositions and variation in composition within individual crystals. Stable and radioactive isotope studies provide insight into

380-434: A definite homogeneous chemical composition and an ordered atomic arrangement. Each mineral has distinct physical properties, and there are many tests to determine each of them. Minerals are often identified through these tests. The specimens can be tested for: A rock is any naturally occurring solid mass or aggregate of minerals or mineraloids . Most research in geology is associated with the study of rocks, as they provide

456-450: A geological region, and then to every region, and by extension to provide an entire geologic record of the Earth. A gap or missing strata in the geological record of an area is called a stratigraphic hiatus. This may be the result of a halt in the deposition of sediment. Alternatively, the gap may be due to removal by erosion, in which case it may be called a stratigraphic vacuity. It is called

532-623: A length of less than a meter. Rocks at the depth to be ductilely stretched are often also metamorphosed. These stretched rocks can also pinch into lenses, known as boudins , after the French word for "sausage" because of their visual similarity. Where rock units slide past one another, strike-slip faults develop in shallow regions, and become shear zones at deeper depths where the rocks deform ductilely. The addition of new rock units, both depositionally and intrusively, often occurs during deformation. Faulting and other deformational processes result in

608-402: A lithostratigraphy or lithologic stratigraphy of the rock unit. Key concepts in stratigraphy involve understanding how certain geometric relationships between rock layers arise and what these geometries imply about their original depositional environment. The basic concept in stratigraphy, called the law of superposition , states: in an undeformed stratigraphic sequence, the oldest strata occur at

684-400: A means to provide information about geological history and the timing of geological events. The principle of uniformitarianism states that the geological processes observed in operation that modify the Earth's crust at present have worked in much the same way over geological time. A fundamental principle of geology advanced by the 18th-century Scottish physician and geologist James Hutton

760-608: A number of fields, laboratory, and numerical modeling methods to decipher Earth history and to understand the processes that occur on and inside the Earth. In typical geological investigations, geologists use primary information related to petrology (the study of rocks), stratigraphy (the study of sedimentary layers), and structural geology (the study of positions of rock units and their deformation). In many cases, geologists also study modern soils, rivers , landscapes , and glaciers ; investigate past and current life and biogeochemical pathways, and use geophysical methods to investigate

836-404: A process of fractional crystallization . Individual rock types can be grouped into a troctolite phase or series, a gabbro phase or series and a gabbro norite phase or series. Anorthosite cumulates are preserved in the roof sections, most of which are sheared and faulted off. A marginal granophyre complex exists in the roof and wall rocks, formed by advective heat transfer causing melting of

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912-553: A relative scale until the development of radiometric dating , which was based on an absolute time framework, leading to the development of chronostratigraphy. One important development is the Vail curve , which attempts to define a global historical sea-level curve according to inferences from worldwide stratigraphic patterns. Stratigraphy is also commonly used to delineate the nature and extent of hydrocarbon -bearing reservoir rocks, seals, and traps of petroleum geology . Chronostratigraphy

988-453: A resource in excess of 120 Mt grading 5% V 2 O 5 . The vanadium mineralisation is approximately 500 m thick and contains a basal 2m thick magnetite zone (containing >70% magnetite) and podiform, lenticular magnetite horizons above it, which is of principal economic interest. In addition a few oxide-rich layers in the upper zone of the intrusion are ilmenite rich, although these appear not to be economic. The Windimurra Vanadium operation

1064-436: A section. The samples are analyzed to determine their detrital remanent magnetism (DRM), that is, the polarity of Earth's magnetic field at the time a stratum was deposited. For sedimentary rocks this is possible because, as they fall through the water column, very fine-grained magnetic minerals (< 17  μm ) behave like tiny compasses , orienting themselves with Earth's magnetic field . Upon burial, that orientation

1140-451: A sedimentary rock. Sedimentary rocks are mainly divided into four categories: sandstone, shale, carbonate, and evaporite. This group of classifications focuses partly on the size of sedimentary particles (sandstone and shale), and partly on mineralogy and formation processes (carbonation and evaporation). Igneous and sedimentary rocks can then be turned into metamorphic rocks by heat and pressure that change its mineral content, resulting in

1216-493: A single environment and do not necessarily occur in a single order. The Hawaiian Islands , for example, consist almost entirely of layered basaltic lava flows. The sedimentary sequences of the mid-continental United States and the Grand Canyon in the southwestern United States contain almost-undeformed stacks of sedimentary rocks that have remained in place since Cambrian time. Other areas are much more geologically complex. In

1292-400: A variety of applications. Dating of lava and volcanic ash layers found within a stratigraphic sequence can provide absolute age data for sedimentary rock units that do not contain radioactive isotopes and calibrate relative dating techniques. These methods can also be used to determine ages of pluton emplacement. Thermochemical techniques can be used to determine temperature profiles within

1368-419: Is a weathered and disseminated Magnetite orebody, with base of weathering down to approximately 40-45m below surface. The economic key to Windimurra, is the ability to produce a low cost, reasonable quality Magnetite Concentrate to feed the site large Rotary Kiln. Stratigraphy Stratigraphy is a branch of geology concerned with the study of rock layers ( strata ) and layering (stratification). It

1444-422: Is accomplished in two primary ways: through faulting and folding . In the shallow crust, where brittle deformation can occur, thrust faults form, which causes the deeper rock to move on top of the shallower rock. Because deeper rock is often older, as noted by the principle of superposition , this can result in older rocks moving on top of younger ones. Movement along faults can result in folding, either because

1520-460: Is an intimate coupling between the movement of the plates on the surface and the convection of the mantle (that is, the heat transfer caused by the slow movement of ductile mantle rock). Thus, oceanic parts of plates and the adjoining mantle convection currents always move in the same direction – because the oceanic lithosphere is actually the rigid upper thermal boundary layer of the convecting mantle. This coupling between rigid plates moving on

1596-433: Is horizontal). The principle of superposition states that a sedimentary rock layer in a tectonically undisturbed sequence is younger than the one beneath it and older than the one above it. Logically a younger layer cannot slip beneath a layer previously deposited. This principle allows sedimentary layers to be viewed as a form of the vertical timeline, a partial or complete record of the time elapsed from deposition of

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1672-616: Is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources , understanding natural hazards , remediating environmental problems, and providing insights into past climate change . Geology is a major academic discipline , and it is central to geological engineering and plays an important role in geotechnical engineering . The majority of geological data comes from research on solid Earth materials. Meteorites and other extraterrestrial natural materials are also studied by geological methods. Minerals are naturally occurring elements and compounds with

1748-570: Is integrated with Earth system science and planetary science . Geology describes the structure of the Earth on and beneath its surface and the processes that have shaped that structure. Geologists study the mineralogical composition of rocks in order to get insight into their history of formation. Geology determines the relative ages of rocks found at a given location; geochemistry (a branch of geology) determines their absolute ages . By combining various petrological, crystallographic, and paleontological tools, geologists are able to chronicle

1824-411: Is preserved. For volcanic rocks, magnetic minerals, which form in the melt, orient themselves with the ambient magnetic field, and are fixed in place upon crystallization of the lava. Oriented paleomagnetic core samples are collected in the field; mudstones , siltstones , and very fine-grained sandstones are the preferred lithologies because the magnetic grains are finer and more likely to orient with

1900-478: Is primarily accomplished through normal faulting and through the ductile stretching and thinning. Normal faults drop rock units that are higher below those that are lower. This typically results in younger units ending up below older units. Stretching of units can result in their thinning. In fact, at one location within the Maria Fold and Thrust Belt , the entire sedimentary sequence of the Grand Canyon appears over

1976-436: Is primarily used in the study of sedimentary and layered volcanic rocks . Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age). Catholic priest Nicholas Steno established the theoretical basis for stratigraphy when he introduced the law of superposition , the principle of original horizontality and

2052-568: Is that "the present is the key to the past." In Hutton's words: "the past history of our globe must be explained by what can be seen to be happening now." The principle of intrusive relationships concerns crosscutting intrusions. In geology, when an igneous intrusion cuts across a formation of sedimentary rock , it can be determined that the igneous intrusion is younger than the sedimentary rock. Different types of intrusions include stocks, laccoliths , batholiths , sills and dikes . The principle of cross-cutting relationships pertains to

2128-413: Is the branch of stratigraphy that places an absolute age, rather than a relative age on rock strata . The branch is concerned with deriving geochronological data for rock units, both directly and inferentially, so that a sequence of time-relative events that created the rocks formation can be derived. The ultimate aim of chronostratigraphy is to place dates on the sequence of deposition of all rocks within

2204-523: Is used for geologically young materials containing organic carbon . The geology of an area changes through time as rock units are deposited and inserted, and deformational processes alter their shapes and locations. Rock units are first emplaced either by deposition onto the surface or intrusion into the overlying rock . Deposition can occur when sediments settle onto the surface of the Earth and later lithify into sedimentary rock, or when as volcanic material such as volcanic ash or lava flows blanket

2280-500: The bedrock . This study is often known as Quaternary geology , after the Quaternary period of geologic history, which is the most recent period of geologic time. Magma is the original unlithified source of all igneous rocks . The active flow of molten rock is closely studied in volcanology , and igneous petrology aims to determine the history of igneous rocks from their original molten source to their final crystallization. In

2356-512: The geochemical evolution of rock units. Petrologists can also use fluid inclusion data and perform high temperature and pressure physical experiments to understand the temperatures and pressures at which different mineral phases appear, and how they change through igneous and metamorphic processes. This research can be extrapolated to the field to understand metamorphic processes and the conditions of crystallization of igneous rocks. This work can also help to explain processes that occur within

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2432-402: The mantle below (separated within itself by seismic discontinuities at 410 and 660 kilometers), and the outer core and inner core below that. More recently, seismologists have been able to create detailed images of wave speeds inside the earth in the same way a doctor images a body in a CT scan . These images have led to a much more detailed view of the interior of the Earth, and have replaced

2508-547: The natural remanent magnetization (NRM) to reveal the DRM. Following statistical analysis, the results are used to generate a local magnetostratigraphic column that can then be compared against the Global Magnetic Polarity Time Scale. This technique is used to date sequences that generally lack fossils or interbedded igneous rocks. The continuous nature of the sampling means that it is also a powerful technique for

2584-415: The principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment. The first practical large-scale application of stratigraphy was by William Smith in the 1790s and early 19th century. Known as the "Father of English geology", Smith recognized the significance of strata or rock layering and the importance of fossil markers for correlating strata; he created

2660-440: The 1960s, it was discovered that the Earth's lithosphere , which includes the crust and rigid uppermost portion of the upper mantle , is separated into tectonic plates that move across the plastically deforming, solid, upper mantle, which is called the asthenosphere . This theory is supported by several types of observations, including seafloor spreading and the global distribution of mountain terrain and seismicity. There

2736-424: The Earth, such as subduction and magma chamber evolution. Structural geologists use microscopic analysis of oriented thin sections of geological samples to observe the fabric within the rocks, which gives information about strain within the crystalline structure of the rocks. They also plot and combine measurements of geological structures to better understand the orientations of faults and folds to reconstruct

2812-478: The Grand Canyon in the southwestern United States being a very visible example, the lower rock units were metamorphosed and deformed, and then deformation ended and the upper, undeformed units were deposited. Although any amount of rock emplacement and rock deformation can occur, and they can occur any number of times, these concepts provide a guide to understanding the geological history of an area. Geologists use

2888-645: The Pre-Feasibility study on Windimurra. In 1998 the Bankable feasibility study was completed. At the time, the Mine was designed to produce 16 million pounds per annum of high Quality Vanadium Pentoxide Flake (V2O5). this was equivalent to approximately 10% of the world's vanadium production at the time (1999). The first salable product was produced as V2O5 Flake in January 2000. Then through suppressed vanadium market pricing

2964-588: The ambient field during deposition. If the ancient magnetic field were oriented similar to today's field ( North Magnetic Pole near the North Rotational Pole ), the strata would retain a normal polarity. If the data indicate that the North Magnetic Pole were near the South Rotational Pole , the strata would exhibit reversed polarity. Results of the individual samples are analyzed by removing

3040-407: The base of the sequence. Chemostratigraphy studies the changes in the relative proportions of trace elements and isotopes within and between lithologic units. Carbon and oxygen isotope ratios vary with time, and researchers can use those to map subtle changes that occurred in the paleoenvironment. This has led to the specialized field of isotopic stratigraphy. Cyclostratigraphy documents

3116-537: The beginning of the 20th century, advancement in geological science was facilitated by the ability to obtain accurate absolute dates to geological events using radioactive isotopes and other methods. This changed the understanding of geological time. Previously, geologists could only use fossils and stratigraphic correlation to date sections of rock relative to one another. With isotopic dates, it became possible to assign absolute ages to rock units, and these absolute dates could be applied to fossil sequences in which there

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3192-506: The country rocks. The Windimurra Intrusion has been of great interest to mineral exploration companies for decades, as it is one of the thickest and largest ultramafic intrusions in the world, though it has been fragmented and mostly removed by shearing unlike the Bushveld Igneous Complex of South Africa . Exploration has focused on finding basal nickel sulfide and chromitite deposits, although that has proved fruitless as

3268-515: The creation of topographic gradients, causing material on the rock unit that is increasing in elevation to be eroded by hillslopes and channels. These sediments are deposited on the rock unit that is going down. Continual motion along the fault maintains the topographic gradient in spite of the movement of sediment and continues to create accommodation space for the material to deposit. Deformational events are often also associated with volcanism and igneous activity. Volcanic ashes and lavas accumulate on

3344-437: The crust, the uplift of mountain ranges, and paleo-topography. Fractionation of the lanthanide series elements is used to compute ages since rocks were removed from the mantle. Other methods are used for more recent events. Optically stimulated luminescence and cosmogenic radionuclide dating are used to date surfaces and/or erosion rates. Dendrochronology can also be used for the dating of landscapes. Radiocarbon dating

3420-484: The estimation of sediment-accumulation rates. Geology Geology (from Ancient Greek γῆ ( gê )  'earth' and λoγία ( -logía )  'study of, discourse') is a branch of natural science concerned with the Earth and other astronomical objects , the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences , including hydrology . It

3496-570: The fault is a normal fault or a thrust fault . The principle of inclusions and components states that, with sedimentary rocks, if inclusions (or clasts ) are found in a formation, then the inclusions must be older than the formation that contains them. For example, in sedimentary rocks, it is common for gravel from an older formation to be ripped up and included in a newer layer. A similar situation with igneous rocks occurs when xenoliths are found. These foreign bodies are picked up as magma or lava flows, and are incorporated, later to cool in

3572-403: The faults are not planar or because rock layers are dragged along, forming drag folds as slip occurs along the fault. Deeper in the Earth, rocks behave plastically and fold instead of faulting. These folds can either be those where the material in the center of the fold buckles upwards, creating " antiforms ", or where it buckles downwards, creating " synforms ". If the tops of the rock units within

3648-523: The first geologic map of England. Other influential applications of stratigraphy in the early 19th century were by Georges Cuvier and Alexandre Brongniart , who studied the geology of the region around Paris. Variation in rock units, most obviously displayed as visible layering, is due to physical contrasts in rock type ( lithology ). This variation can occur vertically as layering (bedding), or laterally, and reflects changes in environments of deposition (known as facies change). These variations provide

3724-483: The folds remain pointing upwards, they are called anticlines and synclines , respectively. If some of the units in the fold are facing downward, the structure is called an overturned anticline or syncline, and if all of the rock units are overturned or the correct up-direction is unknown, they are simply called by the most general terms, antiforms, and synforms. Even higher pressures and temperatures during horizontal shortening can cause both folding and metamorphism of

3800-404: The formation of faults and the age of the sequences through which they cut. Faults are younger than the rocks they cut; accordingly, if a fault is found that penetrates some formations but not those on top of it, then the formations that were cut are older than the fault, and the ones that are not cut must be younger than the fault. Finding the key bed in these situations may help determine whether

3876-579: The geological history of the Earth as a whole. One aspect is to demonstrate the age of the Earth . Geology provides evidence for plate tectonics , the evolutionary history of life , and the Earth's past climates . Geologists broadly study the properties and processes of Earth and other terrestrial planets. Geologists use a wide variety of methods to understand the Earth's structure and evolution, including fieldwork , rock description , geophysical techniques , chemical analysis , physical experiments , and numerical modelling . In practical terms, geology

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3952-423: The internal composition and structure of the Earth. Seismologists can use the arrival times of seismic waves to image the interior of the Earth. Early advances in this field showed the existence of a liquid outer core (where shear waves were not able to propagate) and a dense solid inner core . These advances led to the development of a layered model of the Earth, with a lithosphere (including crust) on top,

4028-459: The later end of the scale, it is marked by the present day (in the Holocene epoch ). The following five timelines show the geologic time scale to scale. The first shows the entire time from the formation of the Earth to the present, but this gives little space for the most recent eon. The second timeline shows an expanded view of the most recent eon. In a similar way, the most recent era is expanded in

4104-451: The lower zone is not exposed. However, exploration for vanadium deposits related to oxide cumulate layers higher up in the intrusion has proved successful, with a positive bankable fesability study completed in 1998 followed by the construction and opening of a major vanadium operation in 1999. The Shepherd's Discordant Zone is host to a laterally extensive vanadiferous magnetite and ilmenite adcumulate and mesocumulate deposit, forming

4180-454: The lowest layer to deposition of the highest bed. The principle of faunal succession is based on the appearance of fossils in sedimentary rocks. As organisms exist during the same period throughout the world, their presence or (sometimes) absence provides a relative age of the formations where they appear. Based on principles that William Smith laid out almost a hundred years before the publication of Charles Darwin 's theory of evolution ,

4256-493: The mantle and show the crystallographic structures expected in the inner core of the Earth. The geological time scale encompasses the history of the Earth. It is bracketed at the earliest by the dates of the first Solar System material at 4.567 Ga (or 4.567 billion years ago) and the formation of the Earth at 4.54 Ga (4.54 billion years), which is the beginning of the Hadean eon  – a division of geological time. At

4332-405: The matrix. As a result, xenoliths are older than the rock that contains them. The principle of original horizontality states that the deposition of sediments occurs as essentially horizontal beds. Observation of modern marine and non-marine sediments in a wide variety of environments supports this generalization (although cross-bedding is inclined, the overall orientation of cross-bedded units

4408-478: The often cyclic changes in the relative proportions of minerals (particularly carbonates ), grain size, thickness of sediment layers ( varves ) and fossil diversity with time, related to seasonal or longer term changes in palaeoclimates . Biostratigraphy or paleontologic stratigraphy is based on fossil evidence in the rock layers. Strata from widespread locations containing the same fossil fauna and flora are said to be correlatable in time. Biologic stratigraphy

4484-449: The operation was making a loss, through which PMA could not maintain their ownership. This resulted in PMA's ownership diluting to net 15% royalty or a minimum of $ 500,000 per year which ever was the higher. In 2023 and after prolonged low vanadium pricing Xstrata made the decision to place Windimurra into care and maintenance. This was followed by the controversial decision to permanently close

4560-413: The primary record of the majority of the geological history of the Earth. There are three major types of rock: igneous , sedimentary , and metamorphic . The rock cycle illustrates the relationships among them (see diagram). When a rock solidifies or crystallizes from melt ( magma or lava ), it is an igneous rock . This rock can be weathered and eroded , then redeposited and lithified into

4636-569: The principles of succession developed independently of evolutionary thought. The principle becomes quite complex, however, given the uncertainties of fossilization, localization of fossil types due to lateral changes in habitat ( facies change in sedimentary strata), and that not all fossils formed globally at the same time. Geologists also use methods to determine the absolute age of rock samples and geological events. These dates are useful on their own and may also be used in conjunction with relative dating methods or to calibrate relative methods. At

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4712-522: The project to Xstrata AG, and Glencore retained the rights to 100% of the product off take. While PMA was the junior company, PMA had retained the technical expertise to progress the project, so remained the Managing partner of the joint venture. After PMA attempted the first feasibility study in 1991, the project was not deemed economical at the time. Meanwhile its competing project in South Africa (Rhovan)

4788-428: The rocks. This metamorphism causes changes in the mineral composition of the rocks; creates a foliation , or planar surface, that is related to mineral growth under stress. This can remove signs of the original textures of the rocks, such as bedding in sedimentary rocks, flow features of lavas , and crystal patterns in crystalline rocks . Extension causes the rock units as a whole to become longer and thinner. This

4864-433: The simplified layered model with a much more dynamic model. Mineralogists have been able to use the pressure and temperature data from the seismic and modeling studies alongside knowledge of the elemental composition of the Earth to reproduce these conditions in experimental settings and measure changes within the crystal structure. These studies explain the chemical changes associated with the major seismic discontinuities in

4940-502: The site remove the processing plant and commence site rehabilitation in 2004. Since then, various attempts have been made to redevelop the Windimurra Vanadium mine, unfortunately these attempts were not fruitful. This can be explained through poorly conceived wholesale changes made to the processing plant, along with a misconception to focus the mine on the deeper fresh Magnetite zones which result in high strip ratios. The deposit

5016-524: The southwestern United States, sedimentary, volcanic, and intrusive rocks have been metamorphosed, faulted, foliated, and folded. Even older rocks, such as the Acasta gneiss of the Slave craton in northwestern Canada , the oldest known rock in the world have been metamorphosed to the point where their origin is indiscernible without laboratory analysis. In addition, these processes can occur in stages. In many places,

5092-550: The subsurface. Sub-specialities of geology may distinguish endogenous and exogenous geology. Geological field work varies depending on the task at hand. Typical fieldwork could consist of: In addition to identifying rocks in the field ( lithology ), petrologists identify rock samples in the laboratory. Two of the primary methods for identifying rocks in the laboratory are through optical microscopy and by using an electron microprobe . In an optical mineralogy analysis, petrologists analyze thin sections of rock samples using

5168-407: The surface of the Earth and the convecting mantle is called plate tectonics . The development of plate tectonics has provided a physical basis for many observations of the solid Earth . Long linear regions of geological features are explained as plate boundaries: Plate tectonics has provided a mechanism for Alfred Wegener 's theory of continental drift , in which the continents move across

5244-488: The surface of the Earth over geological time. They also provided a driving force for crustal deformation, and a new setting for the observations of structural geology. The power of the theory of plate tectonics lies in its ability to combine all of these observations into a single theory of how the lithosphere moves over the convecting mantle. Advances in seismology , computer modeling , and mineralogy and crystallography at high temperatures and pressures give insights into

5320-474: The surface, and igneous intrusions enter from below. Dikes , long, planar igneous intrusions, enter along cracks, and therefore often form in large numbers in areas that are being actively deformed. This can result in the emplacement of dike swarms , such as those that are observable across the Canadian shield, or rings of dikes around the lava tube of a volcano. All of these processes do not necessarily occur in

5396-742: The surface. Igneous intrusions such as batholiths , laccoliths , dikes , and sills , push upwards into the overlying rock, and crystallize as they intrude. After the initial sequence of rocks has been deposited, the rock units can be deformed and/or metamorphosed . Deformation typically occurs as a result of horizontal shortening, horizontal extension , or side-to-side ( strike-slip ) motion. These structural regimes broadly relate to convergent boundaries , divergent boundaries , and transform boundaries, respectively, between tectonic plates. When rock units are placed under horizontal compression , they shorten and become thicker. Because rock units, other than muds, do not significantly change in volume , this

5472-407: The third timeline, the most recent period is expanded in the fourth timeline, and the most recent epoch is expanded in the fifth timeline. Horizontal scale is Millions of years (above timelines) / Thousands of years (below timeline) Epochs: Methods for relative dating were developed when geology first emerged as a natural science . Geologists still use the following principles today as

5548-419: Was based on William Smith's principle of faunal succession , which predated, and was one of the first and most powerful lines of evidence for, biological evolution . It provides strong evidence for the formation ( speciation ) and extinction of species . The geologic time scale was developed during the 19th century, based on the evidence of biologic stratigraphy and faunal succession. This timescale remained

5624-467: Was commissioned in 1991, as a magnetic concentrate producer. (Rhovan installed their kiln in 1994 and then in 1996 Glencore took over Rhovan, resulting in the technical team looking for a new project to develop) The original Rhovan Technical team that built and managed Rhovan under the leadership of Tony Simpson, reviewed the Windimurra project in early 1997, and later that year commenced with PMA to deliver

5700-615: Was datable material, converting the old relative ages into new absolute ages. For many geological applications, isotope ratios of radioactive elements are measured in minerals that give the amount of time that has passed since a rock passed through its particular closure temperature , the point at which different radiometric isotopes stop diffusing into and out of the crystal lattice . These are used in geochronologic and thermochronologic studies. Common methods include uranium–lead dating , potassium–argon dating , argon–argon dating and uranium–thorium dating . These methods are used for

5776-574: Was initially formed as the Vanadium Australia Pty Ltd Joint Venture between PMA (49%) and Glencore (51%), with Glencore providing the offtake agreement and in turn support funding for the project. PMA being the original developer retained 49% ownership and was appointed as the projects manager to oversee the detailed design, construction and commissioning of the Vanadium Processing plant. Glencore transferred its interest in

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