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77-442: Ngualla is a Proterozoic carbonatite estimated to be about 1,000 million years old and is a plug-like intrusive carbonatite with a diameter of approximately 3 km, made up of various successive carbonatite phases. Ngualla is intrusive into Precambrian gneisses , quartzites and rhyolite - dacite volcanics . It is a carbonatite- fenite complex of oval outline with a longer axis orientated approximately north-south. Over

154-483: A pitch trace on a musical scale . Beyond the letters themselves, there are a variety of secondary symbols which aid in transcription. Diacritic marks can be combined with the letters to add tone and phonetic detail such as secondary articulation . There are also special symbols for prosodic features such as stress and intonation. There are two principal types of brackets used to set off (delimit) IPA transcriptions: Less common conventions include: All three of

231-532: A conflicting use to delimit prosodic transcription within the Voice Quality Symbols , which are an extension of IPA used in extIPA, but are not otherwise used in IPA proper. Other delimiters sometimes seen are pipes and double pipes taken from Americanist phonetic notation . However, these conflict with the pipes used in basic IPA prosodic transcription. Other delimiters are double slashes, –

308-589: A few billion years in age. It is believed that 43% of modern continental crust was formed in the Proterozoic, 39% formed in the Archean, and only 18% in the Phanerozoic . Studies by Condie (2000) and Rino et al. (2004) harvp error: no target: CITEREFRinoKomiyaWindleyet_al2004 ( help ) suggest that crust production happened episodically. By isotopically calculating the ages of Proterozoic granitoids it

385-481: A few plausible models that explain tectonics of the early Earth prior to the formation of Columbia, but the current most plausible hypothesis is that prior to Columbia, there were only a few independent cratons scattered around the Earth (not necessarily a supercontinent, like Rodinia or Columbia). The Proterozoic can be roughly divided into seven biostratigraphic zones which correspond to informal time periods. The first

462-580: A group of French and English language teachers, led by the French linguist Paul Passy , formed what would be known from 1897 onwards as the International Phonetic Association (in French, l'Association phonétique internationale ). The idea of the alphabet had been suggested to Passy by Otto Jespersen . It was developed by Passy along with other members of the association, principally Daniel Jones . The original IPA alphabet

539-452: A mix of IPA with Americanist phonetic notation or Sinological phonetic notation or otherwise use nonstandard symbols for various reasons. Authors who employ such nonstandard use are encouraged to include a chart or other explanation of their choices, which is good practice in general, as linguists differ in their understanding of the exact meaning of IPA symbols and common conventions change over time. Many British dictionaries, including

616-435: A north-south trending central ridge and an area of the north-western side of the complex carbonatite outcrops are found, surrounded by red soil. This is in turn surrounded by a ring of low-hills that are predominantly covered by fenite. The fenite zone is up to 1 km wide with a breccia zone adjacent to the carbonatite. The carbonatite is broadly of three types: Dolomitic and ankeritic veins are widespread throughout

693-526: A period of increasing crustal recycling, suggesting subduction . Evidence for this increased subduction activity comes from the abundance of old granites originating mostly after 2.6  Ga . The occurrence of eclogite (a type of metamorphic rock created by high pressure, > 1 GPa), is explained using a model that incorporates subduction. The lack of eclogites that date to the Archean Eon suggests that conditions at that time did not favor

770-695: A row left out to save space. In the table below, a slightly different arrangement is made: All pulmonic consonants are included in the pulmonic-consonant table, and the vibrants and laterals are separated out so that the rows reflect the common lenition pathway of stop → fricative → approximant , as well as the fact that several letters pull double duty as both fricative and approximant; affricates may then be created by joining stops and fricatives from adjacent cells. Shaded cells represent articulations that are judged to be impossible or not distinctive. Vowel letters are also grouped in pairs—of unrounded and rounded vowel sounds—with these pairs also arranged from front on

847-452: A variety of foreign languages. They are also taught by vocal coaches to perfect diction and improve tone quality and tuning. Opera librettos are authoritatively transcribed in IPA, such as Nico Castel 's volumes and Timothy Cheek's book Singing in Czech . Opera singers' ability to read IPA was used by the site Visual Thesaurus , which employed several opera singers "to make recordings for

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924-493: Is an alphabetic system of phonetic notation based primarily on the Latin script . It was devised by the International Phonetic Association in the late 19th century as a standard written representation for the sounds of speech . The IPA is used by lexicographers , foreign language students and teachers, linguists , speech–language pathologists , singers, actors, constructed language creators, and translators . The IPA

1001-421: Is designed for transcribing sounds (phones), not phonemes , though it is used for phonemic transcription as well. A few letters that did not indicate specific sounds have been retired (⟨ ˇ ⟩, once used for the "compound" tone of Swedish and Norwegian, and ⟨ ƞ ⟩, once used for the moraic nasal of Japanese), though one remains: ⟨ ɧ ⟩, used for the sj-sound of Swedish. When

1078-483: Is designed to represent those qualities of speech that are part of lexical (and, to a limited extent, prosodic ) sounds in oral language : phones , intonation and the separation of syllables . To represent additional qualities of speech—such as tooth gnashing , lisping , and sounds made with a cleft palate —an extended set of symbols may be used. Segments are transcribed by one or more IPA symbols of two basic types: letters and diacritics . For example,

1155-495: Is elected by the membership – for further discussion and a formal vote. Many users of the alphabet, including the leadership of the Association itself, deviate from its standardized usage. The Journal of the IPA finds it acceptable to mix IPA and extIPA symbols in consonant charts in their articles. (For instance, including the extIPA letter ⟨ 𝼆 ⟩ , rather than ⟨ ʎ̝̊ ⟩, in an illustration of

1232-528: Is not always accessible to sight-impaired readers who rely on screen reader technology. Double angle brackets may occasionally be useful to distinguish original orthography from transliteration, or the idiosyncratic spelling of a manuscript from the normalized orthography of the language. Pipes are sometimes used instead of double angle brackets to denote the distinct allographs of a grapheme that are known as glyphs . For example, print | g | and script | ɡ | are two glyph variants of

1309-427: Is the official chart as posted at the website of the IPA. The letters chosen for the IPA are meant to harmonize with the Latin alphabet . For this reason, most letters are either Latin or Greek , or modifications thereof. Some letters are neither: for example, the letter denoting the glottal stop , ⟨ ʔ ⟩, originally had the form of a question mark with the dot removed. A few letters, such as that of

1386-645: Is the third of the four geologic eons of Earth's history , spanning the time interval from 2500 to 538.8   Mya , the longest eon of the Earth's geologic time scale . It is preceded by the Archean and followed by the Phanerozoic , and is the most recent part of the Precambrian "supereon". The Proterozoic is subdivided into three geologic eras (from oldest to youngest): the Paleoproterozoic , Mesoproterozoic and Neoproterozoic . It covers

1463-466: The Handbook recommended against their use, as cursive IPA is "harder for most people to decipher". A braille representation of the IPA for blind or visually impaired professionals and students has also been developed. The International Phonetic Alphabet is occasionally modified by the Association. After each modification, the Association provides an updated simplified presentation of the alphabet in

1540-460: The Hebrew alphabet for transcription of foreign words. Bilingual dictionaries that translate from foreign languages into Russian usually employ the IPA, but monolingual Russian dictionaries occasionally use pronunciation respelling for foreign words. The IPA is more common in bilingual dictionaries, but there are exceptions here too. Mass-market bilingual Czech dictionaries, for instance, tend to use

1617-570: The IPA extensions . In the IPA itself, however, only lower-case letters are used. The 1949 edition of the IPA handbook indicated that an asterisk ⟨*⟩ might be prefixed to indicate that a word was a proper name, but this convention was not included in the 1999 Handbook , which notes the contrary use of the asterisk as a placeholder for a sound or feature that does not have a symbol. The IPA has widespread use among classical singers during preparation as they are frequently required to sing in

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1694-792: The Oxford English Dictionary and some learner's dictionaries such as the Oxford Advanced Learner's Dictionary and the Cambridge Advanced Learner's Dictionary , now use the International Phonetic Alphabet to represent the pronunciation of words. However, most American (and some British) volumes use one of a variety of pronunciation respelling systems, intended to be more comfortable for readers of English and to be more acceptable across dialects, without

1771-562: The voiced pharyngeal fricative , ⟨ ʕ ⟩, were inspired by other writing systems (in this case, the Arabic letter ⟨ ﻉ ⟩, ʿayn , via the reversed apostrophe). Some letter forms derive from existing letters: The International Phonetic Alphabet is based on the Latin script , and uses as few non-Latin letters as possible. The Association created the IPA so that the sound values of most letters would correspond to "international usage" (approximately Classical Latin ). Hence,

1848-542: The 150,000 words and phrases in VT's lexical database ... for their vocal stamina, attention to the details of enunciation, and most of all, knowledge of IPA". The International Phonetic Association organizes the letters of the IPA into three categories: pulmonic consonants, non-pulmonic consonants, and vowels. Pulmonic consonant letters are arranged singly or in pairs of voiceless ( tenuis ) and voiced sounds, with these then grouped in columns from front (labial) sounds on

1925-662: The Ediacaran, proving that multicellular life had already become widespread tens of millions of years before the Cambrian Explosion in what is known as the Avalon Explosion . Nonetheless, the upper boundary of the Proterozoic has remained fixed at the base of the Cambrian , which is currently placed at 538.8 Ma. International Phonetic Alphabet The International Phonetic Alphabet ( IPA )

2002-733: The Greek alphabet, though their sound values may differ from Greek. For most Greek letters, subtly different glyph shapes have been devised for the IPA, specifically ⟨ ɑ ⟩, ⟨ ꞵ ⟩, ⟨ ɣ ⟩, ⟨ ɛ ⟩, ⟨ ɸ ⟩, ⟨ ꭓ ⟩ and ⟨ ʋ ⟩, which are encoded in Unicode separately from their parent Greek letters. One, however – ⟨ θ ⟩ – has only its Greek form, while for ⟨ ꞵ ~ β ⟩ and ⟨ ꭓ ~ χ ⟩, both Greek and Latin forms are in common use. The tone letters are not derived from an alphabet, but from

2079-467: The IPA Handbook , the letters ⟨ c ⟩ and ⟨ ɟ ⟩ are used for /t͡ʃ/ and /d͡ʒ/ . Among the symbols of the IPA, 107 letters represent consonants and vowels , 31 diacritics are used to modify these, and 17 additional signs indicate suprasegmental qualities such as length , tone , stress , and intonation . These are organized into a chart; the chart displayed here

2156-579: The IPA have consisted largely of renaming symbols and categories and in modifying typefaces . Extensions to the International Phonetic Alphabet for speech pathology (extIPA) were created in 1990 and were officially adopted by the International Clinical Phonetics and Linguistics Association in 1994. They were substantially revised in 2015. The general principle of the IPA is to provide one letter for each distinctive sound ( speech segment ). This means that: The alphabet

2233-412: The IPA is used for broad phonetic or for phonemic transcription, the letter–sound correspondence can be rather loose. The IPA has recommended that more 'familiar' letters be used when that would not cause ambiguity. For example, ⟨ e ⟩ and ⟨ o ⟩ for [ɛ] and [ɔ] , ⟨ t ⟩ for [t̪] or [ʈ] , ⟨ f ⟩ for [ɸ] , etc. Indeed, in the illustration of Hindi in

2310-682: The IPA only for sounds not found in Czech . IPA letters have been incorporated into the alphabets of various languages, notably via the Africa Alphabet in many sub-Saharan languages such as Hausa , Fula , Akan , Gbe languages , Manding languages , Lingala , etc. Capital case variants have been created for use in these languages. For example, Kabiyè of northern Togo has Ɖ ɖ , Ŋ ŋ , Ɣ ɣ , Ɔ ɔ , Ɛ ɛ , Ʋ ʋ . These, and others, are supported by Unicode , but appear in Latin ranges other than

2387-537: The IPA remained nearly static until the Kiel Convention in 1989, which substantially revamped the alphabet. A smaller revision took place in 1993 with the resurrection of letters for mid central vowels and the retirement of letters for voiceless implosives . The alphabet was last revised in May 2005 with the addition of a letter for a labiodental flap . Apart from the addition and removal of symbols, changes to

Ngualla - Misplaced Pages Continue

2464-532: The IPA.) Of more than 160 IPA symbols, relatively few will be used to transcribe speech in any one language, with various levels of precision. A precise phonetic transcription, in which sounds are specified in detail, is known as a narrow transcription . A coarser transcription with less detail is called a broad transcription. Both are relative terms, and both are generally enclosed in square brackets. Broad phonetic transcriptions may restrict themselves to easily heard details, or only to details that are relevant to

2541-499: The International Phonetic Association. As of the most recent change in 2005, there are 107 segmental letters, an indefinitely large number of suprasegmental letters, 44 diacritics (not counting composites), and four extra-lexical prosodic marks in the IPA. These are illustrated in the current IPA chart , posted below in this article and on the International Phonetic Association's website. In 1886,

2618-737: The Neoproterozoic Era at the end of the Proterozoic Eon, possibly climaxing with the hypothesized Snowball Earth of the Sturtian and Marinoan glaciations. One of the most important events of the Proterozoic was the accumulation of oxygen in the Earth's atmosphere. Though oxygen is believed to have been released by photosynthesis as far back as the Archean Eon, it could not build up to any significant degree until mineral sinks of unoxidized sulfur and iron had been exhausted. Until roughly 2.3 billion years ago, oxygen

2695-592: The Palaeoproterozoic or Mesoproterozoic, according to molecular data. Classically, the boundary between the Proterozoic and the Phanerozoic eons was set at the base of the Cambrian Period when the first fossils of animals, including trilobites and archeocyathids , as well as the animal-like Caveasphaera , appeared. In the second half of the 20th century, a number of fossil forms have been found in Proterozoic rocks, particularly in ones from

2772-424: The above are provided by the IPA Handbook . The following are not, but may be seen in IPA transcription or in associated material (especially angle brackets): Also commonly seen are the braces of set theory , especially when enclosing the set of phonemes that constitute the morphophoneme, e.g. {t d} or {t|d} or {/t/, /d/} for a conflated /t/ and /d/ . Braces have

2849-617: The alphabet or the chart is to propose the change in the Journal of the IPA . (See, for example, December 2008 on an open central unrounded vowel and August 2011 on central approximants.) Reactions to the proposal may be published in the same or subsequent issues of the Journal (as in August 2009 on the open central vowel). A formal proposal is then put to the Council of the IPA – which

2926-486: The breakup of the supercontinent Columbia and prior to the assemblage of the supercontinent Gondwana (~500 Ma). The defining orogenic event associated with the formation of Gondwana was the collision of Africa, South America, Antarctica and Australia forming the Pan-African orogeny . Columbia was dominant in the early-mid Proterozoic and not much is known about continental assemblages before then. There are

3003-524: The complex as are calcite-quartz veins with minor galena , baryte and chalcopyrite . The name 'Ngualla' comes from the Swahili word for 'bald head', which reflects the appearance of a large piece of the mostly bare land in which there is no habitation, agriculture and very little wild life. The carbonatite has important resources of rare earth elements and is currently managed by ASX -listed Peak Resources. It gained widespread attention in 2010 after it

3080-458: The conceptual counterparts of spoken sounds, are usually enclosed in slashes (/ /) and tend to use simpler letters with few diacritics. The choice of IPA letters may reflect theoretical claims of how speakers conceptualize sounds as phonemes or they may be merely a convenience for typesetting. Phonemic approximations between slashes do not have absolute sound values. For instance, in English, either

3157-496: The consonant letters ⟨ b ⟩, ⟨ d ⟩, ⟨ f ⟩, ⟨ ɡ ⟩, ⟨ h ⟩, ⟨ k ⟩, ⟨ l ⟩, ⟨ m ⟩, ⟨ n ⟩, ⟨ p ⟩, ⟨ s ⟩, ⟨ t ⟩, ⟨ v ⟩, ⟨ w ⟩, and ⟨ z ⟩ have more or less their word-initial values in English ( g as in gill , h as in hill , though p t k are unaspirated as in spill, still, skill ); and

Ngualla - Misplaced Pages Continue

3234-522: The deciphering of Precambrian Supereon tectonics. It is known that tectonic processes of the Proterozoic Eon resemble greatly the evidence of tectonic activity, such as orogenic belts or ophiolite complexes, we see today. Hence, most geologists would conclude that the Earth was active at that time. It is also commonly accepted that during the Precambrian, the Earth went through several supercontinent breakup and rebuilding cycles ( Wilson cycle ). In

3311-731: The discussion at hand, and may differ little if at all from phonemic transcriptions, but they make no theoretical claim that all the distinctions transcribed are necessarily meaningful in the language. For example, the English word little may be transcribed broadly as [ˈlɪtəl] , approximately describing many pronunciations. A narrower transcription may focus on individual or dialectical details: [ˈɫɪɾɫ] in General American , [ˈlɪʔo] in Cockney , or [ˈɫɪːɫ] in Southern US English . Phonemic transcriptions, which express

3388-608: The end of words. the alternations /f/  – /v/ in plural formation in one class of nouns, as in knife /naɪf/  – knives /naɪvz/ , which can be represented morphophonemically as {naɪV } – {naɪV+z }. The morphophoneme {V } stands for the phoneme set {/f/, /v/ }. [ˈf\faɪnəlz ˈhɛld ɪn (.) ⸨knock on door⸩ bɑɹsə{ 𝑝 ˈloʊnə and ˈmədɹɪd 𝑝 }] — f-finals held in Barcelona and Madrid. IPA letters have cursive forms designed for use in manuscripts and when taking field notes, but

3465-426: The eon continued the massive continental accretion that had begun late in the Archean Eon. The Proterozoic Eon also featured the first definitive supercontinent cycles and wholly modern mountain building activity ( orogeny ). There is evidence that the first known glaciations occurred during the Proterozoic. The first began shortly after the beginning of the Proterozoic Eon, and evidence of at least four during

3542-757: The evolution of eukaryotes via symbiogenesis ; several global glaciations , which produced the 300 million years-long Huronian glaciation (during the Siderian and Rhyacian periods of the Paleoproterozoic) and the hypothesized Snowball Earth (during the Cryogenian period in the late Neoproterozoic); and the Ediacaran period (635–538.8  Ma ), which is characterized by the evolution of abundant soft-bodied multicellular organisms such as sponges , algae , cnidarians , bilaterians and

3619-678: The first half of the Ediacaran from 0.63–0.55 Ga, and the Belomorian, spanning from 0.55–0.542 Ga. The emergence of advanced single-celled eukaryotes began after the Oxygen Catastrophe . This may have been due to an increase in the oxidized nitrates that eukaryotes use, as opposed to cyanobacteria . It was also during the Proterozoic that the first symbiotic relationships between mitochondria (found in nearly all eukaryotes) and chloroplasts (found in plants and some protists only) and their hosts evolved. By

3696-403: The form of a chart. (See History of the IPA .) Not all aspects of the alphabet can be accommodated in a chart of the size published by the IPA. The alveolo-palatal and epiglottal consonants, for example, are not included in the consonant chart for reasons of space rather than of theory (two additional columns would be required, one between the retroflex and palatal columns and the other between

3773-419: The formation of high grade metamorphism and therefore did not achieve the same levels of subduction as was occurring in the Proterozoic Eon. As a result of remelting of basaltic oceanic crust due to subduction, the cores of the first continents grew large enough to withstand the crustal recycling processes. The long-term tectonic stability of those cratons is why we find continental crust ranging up to

3850-412: The grapheme ⟨ g ⟩ of Latin script. Some examples of contrasting brackets in the literature: In some English accents, the phoneme /l/ , which is usually spelled as ⟨l⟩ or ⟨ll⟩ , is articulated as two distinct allophones: the clear [l] occurs before vowels and the consonant /j/ , whereas the dark [ɫ] / [lˠ] occurs before consonants, except /j/ , and at

3927-438: The implication of a preferred pronunciation that the IPA might convey. For example, the respelling systems in many American dictionaries (such as Merriam-Webster ) use ⟨y⟩ for IPA [ j] and ⟨sh⟩ for IPA [ ʃ ] , reflecting the usual spelling of those sounds in English. (In IPA, [y] represents the sound of the French ⟨u⟩ , as in tu , and [sh] represents

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4004-665: The late Palaeoproterozoic, eukaryotic organisms had become moderately biodiverse. The blossoming of eukaryotes such as acritarchs did not preclude the expansion of cyanobacteria – in fact, stromatolites reached their greatest abundance and diversity during the Proterozoic, peaking roughly 1.2 billion years ago. The earliest fossils possessing features typical of fungi date to the Paleoproterozoic Era, some 2.4 billion years ago; these multicellular benthic organisms had filamentous structures capable of anastomosis . The Viridiplantae evolved sometime in

4081-625: The late Proterozoic (most recent), the dominant supercontinent was Rodinia (~1000–750 Ma). It consisted of a series of continents attached to a central craton that forms the core of the North American Continent called Laurentia . An example of an orogeny (mountain building processes) associated with the construction of Rodinia is the Grenville orogeny located in Eastern North America. Rodinia formed after

4158-454: The left to back (glottal) sounds on the right. In official publications by the IPA, two columns are omitted to save space, with the letters listed among "other symbols" even though theoretically they belong in the main chart. They are arranged in rows from full closure (occlusives: stops and nasals) at top, to brief closure (vibrants: trills and taps), to partial closure (fricatives), and finally minimal closure (approximants) at bottom, again with

4235-428: The left to back on the right, and from maximal closure at top to minimal closure at bottom. No vowel letters are omitted from the chart, though in the past some of the mid central vowels were listed among the "other symbols". A pulmonic consonant is a consonant made by obstructing the glottis (the space between the vocal folds) or oral cavity (the mouth) and either simultaneously or subsequently letting out air from

4312-408: The lungs. Pulmonic consonants make up the majority of consonants in the IPA, as well as in human language. All consonants in English fall into this category. The pulmonic consonant table, which includes most consonants, is arranged in rows that designate manner of articulation , meaning how the consonant is produced, and columns that designate place of articulation , meaning where in the vocal tract

4389-441: The mineral resource at Ngualla is contained within the southern rare earth zone and most of the highest grade component occurs near surface within the weathered zone. The south west alluvial zone is located the south west of Ngualla with rare earth mineralisation occurring from the surface within unconsolidated ferruginous] gravels to depths up to 30 meters. These alluvials are the result of erosion, transportation and deposition from

4466-469: The pharyngeal and glottal columns), and the lateral flap would require an additional row for that single consonant, so they are listed instead under the catchall block of "other symbols". The indefinitely large number of tone letters would make a full accounting impractical even on a larger page, and only a few examples are shown, and even the tone diacritics are not complete; the reversed tone letters are not illustrated at all. The procedure for modifying

4543-427: The same notation as for morphophonology, – exclamation marks, and pipes. For example, ⟨ cot ⟩ would be used for the orthography of the English word cot , as opposed to its pronunciation /ˈkɒt/ . Italics are usual when words are written as themselves (as with cot in the previous sentence) rather than to specifically note their orthography. However, italics are sometimes ambiguous, and italic markup

4620-473: The sequence of consonants in gra ssh opper .) The IPA is also not universal among dictionaries in languages other than English. Monolingual dictionaries of languages with phonemic orthographies generally do not bother with indicating the pronunciation of most words, and tend to use respelling systems for words with unexpected pronunciations. Dictionaries produced in Israel use the IPA rarely and sometimes use

4697-554: The sessile Ediacaran biota (some of which had evolved sexual reproduction ) and provides the first obvious fossil evidence of life on Earth . The geologic record of the Proterozoic Eon is more complete than that for the preceding Archean Eon. In contrast to the deep-water deposits of the Archean, the Proterozoic features many strata that were laid down in extensive shallow epicontinental seas ; furthermore, many of those rocks are less metamorphosed than Archean rocks, and many are unaltered. Studies of these rocks have shown that

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4774-467: The sound of the English digraph ⟨ch⟩ may be transcribed in IPA with a single letter: [c] , or with multiple letters plus diacritics: [t̠̺͡ʃʰ] , depending on how precise one wishes to be. Slashes are used to signal phonemic transcription ; therefore, /tʃ/ is more abstract than either [t̠̺͡ʃʰ] or [c] and might refer to either, depending on the context and language. Occasionally, letters or diacritics are added, removed, or modified by

4851-482: The southern rare earth zone located in the centre of the carbonatite around Ngualla Hill, and the southwest alluvial zone. The southern rare earth zone is a 1 kilometre by 1 kilometre area in the low magnetic central core of the Ngualla carbonatite. Rare earth mineralisation occurs from the surface and is enriched in the weathered zone of the carbonatite, varying from a few metres to 140 metres vertical depth. The bulk of

4928-961: The southern rare earth zone. In December 2012, Peak Resources announced - as part of their planned beneficiation process of the Ngualla deposit - that results had shown an intimate association between iron oxide and rare earth minerals (hematite and bastnaesite). The gangue minerals of barite and silica generally do not contain rare earth inclusions and have discrete grain boundaries with bastnaesite, indicating that grinding will separate these minerals. Geological similarities have been drawn to fellow Australian miner Lynas 's world class Western Australian project Mount Weld . 7°42′31″S 32°50′22″E  /  7.7086222°S 32.83932176°E  / -7.7086222; 32.83932176 Proterozoic The Proterozoic ( IPA : / ˌ p r oʊ t ər ə ˈ z oʊ ɪ k , ˌ p r ɒ t -, - ər oʊ -, - t r ə -, - t r oʊ -/ PROH -tər-ə- ZOH -ik, PROT-, -⁠ər-oh-, -⁠trə-, -⁠troh- )

5005-538: The time from the appearance of free oxygen in Earth's atmosphere to just before the proliferation of complex life on the Earth during the Cambrian Explosion . The name Proterozoic combines two words of Greek origin: protero- meaning "former, earlier", and -zoic , meaning "of life". Well-identified events of this eon were the transition to an oxygenated atmosphere during the Paleoproterozoic;

5082-567: The time was virtually all obligate anaerobic . A second, later surge in oxygen concentrations is called the Neoproterozoic Oxygenation Event , occurred during the Middle and Late Neoproterozoic and drove the rapid evolution of multicellular life towards the end of the era. The Proterozoic Eon was a very tectonically active period in the Earth's history. The late Archean Eon to Early Proterozoic Eon corresponds to

5159-457: The vowel letters ⟨ a ⟩, ⟨ e ⟩, ⟨ i ⟩, ⟨ o ⟩, ⟨ u ⟩ correspond to the (long) sound values of Latin: [i] is like the vowel in mach i ne , [u] is as in r u le , etc. Other Latin letters, particularly ⟨ j ⟩, ⟨ r ⟩ and ⟨ y ⟩, differ from English, but have their IPA values in Latin or other European languages. This basic Latin inventory

5236-463: The vowel of pick or the vowel of peak may be transcribed as /i/ , so that pick , peak would be transcribed as /ˈpik, ˈpiːk/ or as /ˈpɪk, ˈpik/ ; and neither is identical to the vowel of the French pique , which would also be transcribed /pik/ . By contrast, a narrow phonetic transcription of pick , peak , pique could be: [pʰɪk] , [pʰiːk] , [pikʲ] . IPA is popular for transcription by linguists. Some American linguists, however, use

5313-505: The weathered bedrock mineralisation in the southern rare earth zone. Mineralogical studies have shown that bastnasite and synchysite are the main rare earth minerals and occur within a baryte – iron oxide hydroxide lithology in the weathered zone and a carbonate rich lithology with baryte in fresh carbonatite. Alumina is negligible and there are no clay minerals . Uranium and thorium levels are very low at 17 ppm and 37 ppm average respectively within +1% REO mineralisation in

5390-612: Was based on the Romic alphabet , an English spelling reform created by Henry Sweet that in turn was based on the Palaeotype alphabet of Alexander John Ellis , but to make it usable for other languages the values of the symbols were allowed to vary from language to language. For example, the sound [ ʃ ] (the sh in shoe ) was originally represented with the letter ⟨c⟩ for English but with ⟨x⟩ for French and German; with German, ⟨c⟩

5467-444: Was determined that there were several episodes of rapid increase in continental crust production. The reason for these pulses is unknown, but they seemed to have decreased in magnitude after every period. Evidence of collision and rifting between continents raises the question as to what exactly were the movements of the Archean cratons composing Proterozoic continents. Paleomagnetic and geochronological dating mechanisms have allowed

5544-446: Was extended by adding small-capital and cursive forms, diacritics and rotation. The sound values of these letters are related to those of the original letters, and their derivation may be iconic. For example, letters with a rightward-facing hook at the bottom represent retroflex equivalents of the source letters, and small capital letters usually represent uvular equivalents of their source letters. There are also several letters from

5621-405: Was first reported to contain quantities of rare earths oxides. The area is also prospective for phosphate , tantalum and niobium which have also been found in commercial quantities, the area currently contains a JORC compliant resource of 1.6 million tonnes (using a 3% lower-cut grade) of rare earths. The Ngualla rare earth deposit can be divided into two geographic and geological areas,

5698-511: Was probably due to two factors: Exhaustion of the chemical sinks, and an increase in carbon sequestration , which sequestered organic compounds that would have otherwise been oxidized by the atmosphere. The first surge in atmospheric oxygen at the beginning of the Proterozoic is called the Great Oxygenation Event , or alternately the Oxygen Catastrophe – to reflect the mass extinction of almost all life on Earth, which at

5775-487: Was probably only 1% to 2% of its current level. The banded iron formations , which provide most of the world's iron ore , are one mark of that mineral sink process. Their accumulation ceased after 1.9 billion years ago, after the iron in the oceans had all been oxidized . Red beds , which are colored by hematite , indicate an increase in atmospheric oxygen 2 billion years ago. Such massive iron oxide formations are not found in older rocks. The oxygen buildup

5852-761: Was the Labradorian, lasting from 2.0–1.65  Ga . It was followed by the Anabarian, which lasted from 1.65–1.2 Ga and was itself followed by the Turukhanian from 1.2–1.03 Ga. The Turukhanian was succeeded by the Uchuromayan, lasting from 1.03–0.85 Ga, which was in turn succeeded by the Yuzhnouralian, lasting from 0.85–0.63 Ga. The final two zones were the Amadeusian, spanning

5929-402: Was used for the [ x ] sound of Bach . With a growing number of transcribed languages this proved impractical, and in 1888 the values of the letters were made uniform across languages. This would provide the base for all future revisions. Since its creation, the IPA has undergone a number of revisions. After relatively frequent revisions and expansions from the 1890s to the 1940s,

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