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Bald Hill Claystone
Bald Hill Claystone is a sedimentary rock found in the Sydney Basin in eastern Australia. It is part of the Clifton sub-group of the Narrabeen Group of sedimentary rocks. It was formed by weathering of the Gerringong Volcanics in the early Triassic. Named after Bald Hill, in the northern Illawarra, where it is 15 metres thick. The claystone is easily noticed at Long Reef, where it is 18 metres thick. Mineralogy The Bald Hill Claystone is a redbed containing laterite. Primarily a red shale or fine to medium grained sandstone. Kaolinite is found in proportions of 50% to over 75%. Iron rich haematite is also present. Felspar and quartz may be present. This mineralogy indicates that Bald Hill Claystone is unlikely to swell. Typically this rock type is a chocolate brown to red brown colour, with bands of silty grey, or sandy greenish grey. Fossils Fossils of lycopod tree roots may be seen in this strata. Gymnosperm spore pollen from ''Protohaploxypinus samoilovichii'' has also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bald Hill Claystone - Long Reef NSW Australia
Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarring is not usually present. Hair loss in some people causes psychological distress. Common types include male- or female-pattern hair loss, alopecia areata, and a thinning of hair known as telogen effluvium. The cause of male-pattern hair loss is a combination of genetics and male hormones; the cause of female pattern hair loss is unclear; the cause of alopecia areata is autoimmune; and the cause of telogen effluvium is typically a physically or psychologically stressful event. Telogen effluvium is very common following pregnancy. Less common causes of hair loss without inflammation or scarring include the pulling out of hair, certain medications including chemotherapy, HIV/AIDS, hypothyroidism, and malnutrition including iron deficienc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Felspar
Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) feldspars and the ''alkali'' (potassium-sodium) feldspars. Feldspars make up about 60% of the Earth's crust, and 41% of the Earth's continental crust by weight. Feldspars crystalize from magma as both intrusive and extrusive igneous rocks and are also present in many types of metamorphic rock. Rock formed almost entirely of calcic plagioclase feldspar is known as anorthosite. Feldspars are also found in many types of sedimentary rocks. Compositions The feldspar group of minerals consists of tectosilicates, silicate minerals in which silicon ions are linked by shared oxygen ions to form a three-dimensional network. Compositions of major elements in common feldspars can be expressed in terms of three endmembers: * potassium feldspar (K-spar) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic Australia
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of arch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Formations Of Australia
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology, and so is treated as one major aspect of integrated 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. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists broadly study the properties and processes of Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulgo Sandstone
Bulgo Sandstone is a sedimentary rock occurring in the Sydney Basin in eastern Australia. This stratum is up to 100 metres thick, formed in the early Triassic. A component of the Narrabeen Group of sedimentary rocks. It consists of layers of fine to medium-grained quartz-lithic sandstone, with lenticular shale interbeds. Often seen as a grey-green colour when exposed, the Bulgo sandstone contains a high level of particles of volcanic rocks, and is dissimilar to other Sydney sandstones, such as Hawkesbury sandstone and Newport Formation. The rock breaks down to create a relatively fertile clayey soil. These soils contribute to the rainforest growth in the northern Illawarra. Bulgo sandstone may be seen at the "figure eight" rock pool at Royal National Park and at Long Reef in the northern Beaches in Sydney. A fossil of the giant salamander (Bulgosuchus gargantua) was found at Long Reef. See also * Sydney Basin * Bald Hill Claystone * Garie Formation * Narrabeen group Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garie Formation
The Garie Formation is a narrow band of sedimentary rocks occurring in the Sydney Basin in eastern Australia. This stratum is up to 8 metres thick, situated below the sandstones of the Newport Formation (NSW), Newport Formation. Formed in the mid-Triassic, it is part of the Narrabeen Group of sedimentary rocks. Garie formation consists of layers of clay pellet sandstone, dark Lithic fragment (geology), lithic particles, spotted volcanic deposits and chocolate coloured claystone bands. See also * Sydney Basin * Bald Hill Claystone * Bulgo Sandstone * Narrabeen group References Geologic formations of Australia Triassic Australia Sandstone formations Shale formations Geology of New South Wales {{Australia-geology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narrabeen Group
The Narrabeen group of sedimentary rocks occurs in the Sydney Basin in eastern Australia. This series of rocks was formed in the Triassic Period. Geology It includes various rock types including lithic sandstone, quartz sandstone, siltstones, claystones, conglomerate (geology), conglomerate and shales, some of which have fossils of plants and fish. Partly in these rocks plants, fish and amphibious animals are petrified. The red and green shales of the Narrabeen Group are water-tight over the sandstone bodies and the shale of Bald Hill (Australia), Bald Hill, which forms the top layer of the Narrabeen Group, forms a regional water-barrier layer. Over the Narrabeen Group, the younger stratigraphic formation of Hawkesbury sandstones accumulated. Structure Above the Narrabeen group is the younger less fertile Hawkesbury sandstone. Below are Permian sedimentary rocks including measures of coal broadly known as the Illawarra Coal Measures. Whereabouts The Narrabeen group is most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ashfield Shale
Ashfield Shale is part of the Wianamatta group of sedimentary rocks in the Sydney Basin. It lies directly on contemporaneously eroded Hawkesbury sandstone or the Mittagong formation. These rock types were formed in the Triassic Period. It is named after the Sydney suburb of Ashfield. Some of the early research was performed at the old Ashfield Brickworks Quarry. This rock type is often associated with the Inner West and North Shore of the city. However, it has also been recorded at Penrith, Revesby, Bilpin and Mount Irvine. Description Ashfield Shale comprises black mudstones and grey shales with frequent sideritic clay ironstone bands. The thickness ranges between 45 and 64 metres. It is 20 metres thick at the Sydney Olympic Site. The chemistry of the rock is typical of shales, with high iron levels, and some iron sulphide and low calcium levels. The geology of the shale lenses within the Hawkesbury Sandstone is chemically similar to the Ashfield Shale. At Turra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawkesbury Sandstone
Sydney sandstone is the common name for Sydney Basin Hawkesbury Sandstone, one variety of which is historically known as Yellowblock, and also as "yellow gold" a sedimentary rock named after the Hawkesbury River north of Sydney, where this sandstone is particularly common. It forms the bedrock for much of the region of Sydney, Australia. Well known for its durable quality, it is the reason many Aboriginal rock carvings and drawings in the area still exist. As a highly favoured building material, especially preferred during the city's early years—from the late 1790s to the 1890s—its use, particularly in public buildings, gives the city its distinctive appearance. The stone is notable for its geological characteristics; its relationship to Sydney's vegetation and topography; the history of the quarries that worked it; and the quality of the buildings and sculptures constructed from it. This bedrock gives the city some of its "personality" by dint of its meteorological, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnosperm
The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers, cycads, ''Ginkgo'', and gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμνόσπερμος ( el, γυμνός, translit=gymnos, lit=naked, label=none and el, σπέρμα, translit=sperma, lit=seed, label=none), literally meaning 'naked seeds'. The name is based on the unenclosed condition of their seeds (called ovules in their unfertilized state). The non-encased condition of their seeds contrasts with the seeds and ovules of flowering plants (angiosperms), which are enclosed within an ovary. Gymnosperm seeds develop either on the surface of scales or leaves, which are often modified to form cones, or solitary as in yew, ''Torreya'', ''Ginkgo''. Gymnosperm lifecycles involve alternation of generations. They have a dominant diploid sporophyte phase and a reduced haploid gametophyte phase which is dependent on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lycopodiophyta
The lycophytes, when broadly circumscribed, are a vascular plant (tracheophyte) subgroup of the kingdom Plantae. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldest lineages of extant (living) vascular plants; the group contains extinct plants that have been dated from the Silurian (ca. 425 million years ago). Lycophytes were some of the dominating plant species of the Carboniferous period, and included tree-like species, although extant lycophytes are relatively small plants. The scientific names and the informal English names used for this group of plants are ambiguous. For example, "Lycopodiophyta" and the shorter "Lycophyta" as well as the informal "lycophyte" may be used to include the extinct zosterophylls or to exclude them. Description Lycophytes reproduce by spores and have alternation of generations in which (like other vascular plants) the sporophyte generation is dominant. Some lycophyte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. Quartz is the mineral defining the val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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