Sandstone concretions. The concretions consist of sandstone which differs from th...

Wilcox Group - stratigraphy. The Wilcox Group is an i

Wilcox Group - stratigraphy. The Wilcox Group is an important geologic group in the Gulf of Mexico Basin and surrounding onshore areas from Mexico and Texas to Louisiana and Alabama.The group ranges in age from Paleocene to Eocene and is in Texas subdivided into the Calvert Bluff, Simsboro and Hooper Formations, and in Alabama into the Nanafalia and Hatchetigbee Formations.Navajo Sandstone HFO Concretions 62 Host Rock 62 External Structure 65 Internal Structure 67 Mineralogy and Crystallography 67 Size Distribution Comparison 70 Strengths and Weaknesses of Utah Analog 72 Conclusions 72 References 76 2. JOINT-CONTROLLED FLUID FLOW PATTERNS IN JURASSIC NAVAJO SANDSTONE: ANALOG IMPLICATIONS FOR MARS HEMATITE 83Iron-rich carbonates and the oxidized remains of former carbonates (iron-oxide concretions) underlie bleached Navajo Sandstone over large portions of southern Utah. Iron in the carbonates came from hematite rims on sand grains in the upper Navajo that were dissolved when small quantities of methane accumulated beneath the sealing Carmel Formation. As a second buoyant gas (CO2 derived from ...The sandstone formed from sand and other sediment deposited along the edge of a Cretaceous sea about 100 million years ago. Over time, circulating water deposited a limy cement between the sand grains in some parts of the formation, creating harder bodies of rock, called concretions , within the softer sandstone layer.Naming and rank. F.B. Meek and F.V. Hayden first used Dakota in 1862 to name the distinctive red sandstone exposures along the Missouri River near Dakota City, Nebraska.But, with this name, they applied the term "group", which at that time had the meaning of formation rank, as presently used. Dakota Formation is the unit's primary name and rank in the Great Plains.Princeton University Art Museum. International Image Interoperability Framework logo; Open ...Compelling similarities between concretions on Earth and "blueberries" on Mars are used to suggest the blueberries are concretions that formed from a history of watery diagenesis. In the terrestrial examples, groundwater flow produces varia-tions in sandstone color and iron oxide concretions in the Jurassic Navajo Sandstone of Utah.concretions (“blueberries”) form in Meridiani Planum, Mars. The analogous Navajo Sandstone concretions show similar characteristics of in situ self-organized spacing, spheroidal geometries, internal structures, conjoined forms, and precursor HFO phases that dehydrate to goethite or hematite. These characteristicsconcretions (“blueberries”) form in Meridiani Planum, Mars. The analogous Navajo Sandstone concretions show similar characteristics of in situ self-organized spacing, spheroidal geometries, internal structures, conjoined forms, and precursor HFO phases that dehydrate to goethite or hematite. These characteristicsThis is a wholesale flat of 38 flower-shaped, red sandstone concretions from the Sahara Desert in Morocco. They range from 1.5 to 3" across and you will receive the exact lot pictured. The flower-like pattern has been caused by surface erosion in the desert. At the wholesale price, each piece is approximately $2.A perfectly spherical natural Calcite concretion within an egg-shaped Calcite concretion on the beach at Laig Bay, Isle of Eigg. The Valtos Sandstone ...ney-like sandstone concretions, up to 10 mhigh,whichhavebeeninterpreted as part of a shallow subsurface plumb-ing network of Eocene methane seeps (De Boever et al., 2009b). MethodsAnhui Conch Cement News: This is the News-site for the company Anhui Conch Cement on Markets Insider Indices Commodities Currencies StocksThe concretions of the Bearreraig Sandstone Formation: geometry and geochemistry PER ARNE BJØRKUM Statoil, PO Box 300, 4001 Stavanger, Norway OLAV W ALDER HAUGThe Jurassic Navajo Sandstone of southern Utah in southwestern USA commonly hosts concretions cemented by iron oxides (Potter 2011, Loope 2012).Concretions are compact, often rounded, accumulations of mineral matter that form inside sedimentary rocks such as shale and sandstone or in soil.Some concretions, which form at shallow burial depths in fine-grained sediment, predate major compaction and, by resisting compaction, help to preserve lamination and delicate fossils that would otherwise be flattened beyond recognition. ... calcite cement typically accounts for only a few percent of the total sandstone volume (1-3%); locally ...The spherical iron concretions in the Navajo sandstone are composed of thick, iron-oxide-cemented rinds and lightly cemented, iron-poor, friable sandstone cores (Loope et al. 2010). At present, there are two explanations for the origin of spherical iron concretions. Chan et al. (2000, 2004, 2006, 2007) and Beitler et al.Abstract The iron oxide concretions of Shankargarh (Allahabad), India belongs to Dhandraul Sandstone of Vindhyan Supergroup. Petrography of concretions shows abundant quartz grains embedded within the iron oxide cementation. XRD analysis of the concretion shows diagnostic peaks for quartz, hematite, and goethite. The A-CN-K and A-CNK-FM ternary diagrams drawn for concretion and host ...The hardy sandstone structures, the largest of which have been found to top three feet in length, are only located in sediments dating to the time of the impact. And curiously there's a pattern ...Moeraki Boulders "World famous in New Zealand: Moeraki Boulders (photos)".Stuff (Fairfax). 29 July 2018. Biek, B., 2002, Concretions and Nodules in North Dakota North Dakota Geological Survey, Bismarck, North Dakota. Hokianga Tourism Association, nd, Koutu boulders Pictures of cannonball concretions similar in size and origin to Moeraki Boulders. Irna, 2006, All that nature can never do, part ...c Bored sandstone concretion isolated in pelagic marl. 848 Facies (2013) 59:843-861. 123. Author's personal copy. Sandstone petrography and geochemi stry of cements. Concretions and host ...Unit is calcareous and contains fossil wood fragments, volcanic ash beds, and limestone concretions. Yegua Formation, Claiborne Group; Mostly clay and lesser amounts of sandstone. Some beds are lignitic and bentonitic; some fossil wood. Sandstone is partly glauconitic and ferruginous.Sandstone contains distinct physical and chemical properties that include a hard, compact and dense composition along with texture consisting of fine granules, while chemical properties include a composition primarily of silica, along with ...20-million-year-old sandstone layers mixed with com-pressed volcanic ash; Nye mudstone, up to 20 million years old; and on south coast stretches of beach, Coledo ... concretions is often carbonized or fossilized wood that was once carried downstream from the Cascade Moun-tains. Crabs are one type of arthropod found inside con-Sandstone: Concretions: Volcanic ranges; domes, dikes, or sills: Dacite: Created by: frishanini Popular Geography sets. Northeast Capitals "50 States / Capitals" Semester 1 Vocabulary. Southeast States and Capitals. Primary Economic Activities. Midwest States and Capitals ...A cycle of host sand deposition, early diagenetic concretion formation and concretion reworking is documented: (1) Well-sorted shoreface sandstone deposited. (2) Spherical to ovoid, non-ferroan calcite-cemented concretions formed below flooding surfaces at shallow-burial depths during early eodiagenesis.These are actually sandstone concretions, but to the unknowing eye they can be quite the surreal sight. Victoria Beach — Laguna Beach, California. Aydin Palabiyikoglu / Getty Images Like a film set on Game of Thrones, the defining feature of Victoria Beach is a 60-foot medieval-style tower that looks out over the Pacific. In reality, …The abundant concretions found in the Navajo Sandstone consist of sandstone cemented together by hematite (Fe 2 O 3), and goethite (FeOOH). The iron forming these concretions came from the breakdown of iron-bearing silicate minerals by weathering to form iron oxide coatings on other grains. During later diagenesis of the Navajo Sandstone while ...Sandstone and rind concretions fall parallel to the A-CN line, away from the CN apex of the A-CN-K diagram (Fig. 6). This is expected for feldspar dominated weathering. On the other hand, there is a distinct iron enrichment trend as expected for the rind concretion in the A-CNK-FM plot (after Nesbitt and Wilson, 1992, Fig. 6, Table 2 a).Concrete is a versatile and durable material that is used in many construction projects. It is important to know the average price of concrete per yard before beginning a project. There are several factors that can affect the price of concr...Syn- and post-lithification cemented fractures are abundant in concretions formed during shallow burial of Hauterivian turbidites in the Outer Moray Firth. Early fractures are irregular, bifurcating, and contain entrained sand grains. They are confined to the concretion bodies, but commonly splay into narrower fracture swarms at the margins.Calcite‐cemented concretions can reduce reservoir quality and form important low‐permeability baffles for fluid flow in sandstone hydrocarbon carrier beds/reservoirs.Iron-rich carbonates and the oxidized remains of former carbonates (iron-oxide concretions) underlie bleached Navajo Sandstone over large portions of southern Utah. Iron in the carbonates came from hematite rims on sand grains in the upper Navajo that were dissolved when small quantities of methane accumulated beneath the sealing Carmel Formation. As a second buoyant gas (CO2 derived from ...In Minnesota, sandstone and other sedimentary rocks were deposited during the early Paleozoic Era, about 500 million years ago. At that time, Minnesota was near the equator, and shallow seas covered most of the state. Sediment eroded from upland areas was transported to the seashore, and the coarser-grained sediment eventually …Classification based on origin Uluru (Ayers Rock) is a large sandstone formation in Northern Territory, Australia.. Sedimentary rocks can be subdivided into four groups based on the processes responsible for their formation: clastic sedimentary rocks, biochemical (biogenic) sedimentary rocks, chemical sedimentary rocks, and a fourth category for "other" sedimentary rocks formed by impacts ...Numerous vertebrate and plant fossils have been found in ex-situ sandstone concretions near Isisford in central-west Queensland since the mid-1990s. These concretions are found in the Lower ...The sandstone concretions at Rock City are scattered across an area about the size of two football fields. (Image credit: Tim Sharp) Rock City is a park in north-central Kansas that features more...Carbonate concretions are common features of sedimentary rocks of all geological ages. They are most obvious in sandstones and mudstones as ovoid bodies of rock that protrude from natural outcrops: clearly harder or better cemented than their host rocks. Many people are excited by finding fossils in the centre of mudstone-hosted concretions ...Naming and rank. F.B. Meek and F.V. Hayden first used Dakota in 1862 to name the distinctive red sandstone exposures along the Missouri River near Dakota City, Nebraska.But, with this name, they applied the term "group", which at that time had the meaning of formation rank, as presently used. Dakota Formation is the unit's primary …Is Cool! The buried concretions trail is a short, one-mile long hiking trail that leads to a hillside with the unique geological concretions that are known to occur throughout the region. These large - some of them are six feet in diameter - circles look like the cross-section of a tree, but infact are thought to be the result of mineral ...The iron mobilization and recycling in the sandstone pore spaces have formed concretions with Fe 2O 3 (25-35% by volume). The sandstone volume required to produce a 6 mm diameter iron oxide concretion is 1807.83 mm3. The Fe laminae and random red colouration patterns in Dhandraul sandstone are consistent with the movement of iron-enriched CuidApr 3, 2020 · The size of the concretion may be related to the permeability of the rock in which it occurs: the more permeable the surrounding rock, the larger the concretion. Below we introduce the major types of concretions and similar rocks, as well as share images of concretions that were sent to us by the public and often initially mistaken for various ... The concretions are resistant to weathering compared to the host sandstone, which is fairly soft, so stick out from the cliff in a sometimes rather alarming manner as you walk below them. I’ve been visiting the concretions sporadically for around 30 years and some of the ones that I photographed in the cliffs in the 1980s are now lying loose ...Deux « gogottes » de Fontainebleau, concrétions naturelles de grès siliceux Two French Sandstone Concretions--"Gogottes" Oligocene 30 million years old Fontainebleau, France A gogotte is a millions-of-years old naturally shaped mineral rarity consisting of tiny quartz fragments held together by calcium carbonate. A mineralogical work of art ...Primary sandstone outcroppings containing concretions in great abundance may be seen in the small stream channels immediately east and south of the International Boundary Line marker at elevation 62.97 feet in the midst of the area. Here may be found large numbers of concretions, mostly of the spherical 'accretion' type, along with fewer ...२०१४ मे ५ ... taken 9 years ago, near to Cleadale, Eigg, Scotland. Sandstone with Concretions. Curious shapes have resulted from erosion of the Valtos ...Sandstone mineralogy is the best indicator of sedimentary provenance: the nature of a sedimentary rock source area, its composition, relief, and location. Sandstone textures and sedimentary structures also are reliable indexes of the transportational agents and depositional setting. ... Local cementation may result in concretions of calcite ...Iron oxide concretions form in porous sandstone by chemical reduction and solution of iron minerals, transport of Fe 2+ in solution, and precipitation of hydrous ferric oxide by oxidation. Concretions form quickly in 1000's of years by diffusion and advection, and K-feldspar consumption of H + initiates nucleation. The Jurassic Navajo Sandstone,Sandstone, light-gray (N7); weathers "whitish"; fine to medium grained (at base to calcareous at top); subrounded, cherty, noncalcareous at base to calcareous at top ~ 77.0 23.5 42. In part covered, clays tone, gray; contains ironstone concretions; and interbedded thin silty lenticular sandstone; fine­Spheroidal (cannon ball) calcite-cemented concretions, some of gigantic size, were studied from three Cretaceous shelf sandstone units: Ferron, Frontier, and Second Frontier. The concretions have diameters between 2 cm and 6 m; those larger than 40 cm in diameter in the Ferron and Frontier have septarian structure.Concretions are masses of mineral matter embedded within rock layers, including limestone, sandstone, and shale. They often take shape when minerals precipitating (settling) out of water collect around a nucleus, such as a pebble, leaf, shell, bone, or fossil. Contents show 1 How are iron concretions formed? 2 How long do concretions take to form?These concretions occur in four stratigraphic levels (C1–C4, Fig. 1 F) in porous and friable sandstone. The lowermost (C1) is the largest concretion (at least 25 m long, 4 m high and more than 3 m broad) and forms a …The sandstone concretions have been formed over thousands of years as the ground erodes around them, leaving behind huge spherical rocks that resemble the surface of Mars. See on Instagram. While the stunning red rocks are impressive to see any time of day, they really come alive at sunrise or sunset when the light catches the unique …Sedimentary > Clastic > Sandstone (Glauconitic) cross-bedded glauconitic sand; one or more thin beds of fossiliferous marly glauconitic sand and sandstone occur in the upper part. Near the base is a prominent bed of glauconitic calcareous sand containing abundant fossils and spheroidal to pillow-shaped sandstone concretions (Bashi Marl Member).Concretions and nodules, which may also be composed in part of the iron oxy-hydroxides such as limonite and goethite, come in a wide variety of shapes. Sometimes they are shiny on the surface, which might give the impression of a meteorite fusion crust. Note that while pure hematite is rich in iron, it does not attract a simple magnet. Tabular, jointed concretions in current-ripple-laminated sandstone at Little Creek Mountain. Overlying siltstone has been eroded away. A) Joints are bounded by sandstone that is heavily cemented ...Navajo Sandstone is mostly white with shades of yellow. Both pale orange and bleached white sandstone coloration in Grand Staircase - Escalante National Monument, Utah. Iron concretions in the Navajo Sandstone. Discrete, small, pea-sized "marbles" accumulated on a flat sandstone surface. Scale card = 6.5 inches (16.5 cm) long.The Navajo Sandstone concretions were likely precipitated at circumneutral pH (Beitler, 2003, Beitler, 2005, Busigny and Dauphas, 2007, Chan et al., 2000, Chan et al., 2004, Chan et al., 2005, Chan et al., 2007). The Mars spherules may also exhibit a higher degree of crystallinity due to greater iron abundance in the Burns formation sediments.Concretions are hard bodies that form in sediments before they become sedimentary rocks. Slow chemical changes, perhaps related to microbial activity, cause minerals to come out of the groundwater and seal the sediment together. Most often the cementing mineral is calcite, but the brown, iron-bearing carbonate mineral siderite is also common.Middle part is light-gray, yellow, red brown and dark-gray, sandy carbonaceous shale; commonly contains a zone of concretions near top. Lower part is sandstone similar to that in upper except there are zones of siderite concretions and, locally a basal zone of chert pebbles. Approx. max thickness 600 ft.Concretions form in the pore spaces between grains of sand in sandstones. They usually grow as an algal colony from a central point. They usually grow as an algal colony from a central point. As they fill the pores with calcite, the living outer part encases the dead core and forms a spherical feature.1. 1969. 38°55′00″N95°14′00″W / 38.916667°N 95.233333°W. Douglas. Private. An example of undisturbed wetland prairie. 2. Baldwin Woods. 1980.The range of colors of the Navajo Sandstone -red, brown, pink, salmon, gold, and even white—results from varying amounts and forms of iron oxide within the rock, and in the case of the white upper portion of the Navajo, the overall lack of iron. The processes behind the color variation are complex and took place in multiple phases over long ...The eolian Jurassic Navajo Sandstone spheroidal hydrous ferric oxide (HFO) concretions are divided into two size classes: macro-concretions of > 5 mm diameter and micro-concretions of < 5 mm diameter. Three internal structural end-members ofSandstone concretions are extensively bored by Lithophaga and have attached oysters, barnacles, and corals (Fig. 5A - C). Outsized angular sandstone clasts (2 - 4 m in diameter) are found in ...unit called the Navajo Sandstone features prominently in this landscape, and contains some of the largest and most abundant iron concretions found anywhere in the world. The Navajo Sandstone was named for the "Navajo country" of Arizona, Utah, and New Mexico. The red rock country on the Colorado Plateau where the Navajo Sandstone and other ...Known in Romania as "Trovants" the stones of Costesti, Romania are a type of sandstone concretion that secrete cement and can at times appear to grow as if alive. Consisting of a stone core with an outer shell of sand, after a heavy rain small forms are said to appear on the rocks leading them to be dubbed the "growing stones" by locals.Numerous vertebrate and plant fossils have been found in ex-situ sandstone concretions near Isisford in central-west Queensland since the mid-1990s. These concretions are found in the Lower ...Concretions in lower part of Ohio Shale. Either Worthington or Flint or Lewis Center, east of Olentangy River, Ohio. 1006.Ea.3: Concretions from Lower part of Ohio Shale; one is double. Worthington, Ohio, West od Olentangy River. ... Berea Sandstone, S. Amherst, Canyon Quarry, Ohio Quarries Co. Viw W. along long axis of "channel", sandstone ...Spheroidal (cannon ball) calcite-cemented concretions, some of gigantic size, were studied from three Cretaceous shelf sandstone units: Ferron, Frontier, and Second Frontier. The concretions have diameters between 2 cm and 6 m; those larger than 40 cm in diameter in the Ferron and Frontier have septarian structure.The effect of the pyrite concretions on the evolution of macroscale cracks in the sandstone was further investigated through numerical simulations with Particle Flow Code in 2D (PFC2D). The results revealed that pyrite concretions substantially influence the mechanical properties and macroscale and mesoscale failure characteristics of sandstone.Yellowish orange sandstone, sandy and silty carbonaceous shale, and coal. Alluvial plain. ... Dark gray shale with several zones of calcareous concretions, a basal zone of ferruginous concretions, and numerous thin bentonite beds. Marine. Thickness as much as 300 m (984 ft). Judith River Formation (Cretaceous) at surface, covers 5 % of this area.There's some debate around this, but it's thought that trovants are sandstone concretions with tough outer layers of sand, a bit like an M&M.ArtAncient, a gallery that deals in antiquities and, increasingly, elements of natural history, is offering a "gogotte," a sandstone concretion formed roughly 30 million years ago near ...No. 8 is a spiral with a different knob of sandstone on the lower right side. This is a finer grade of sandstone which formed as a concretion outside the area and then carried in and deposited before the others were formed. Nos. 9, 10, and 11 are the double spirals, one left and two right-hand twists. SANDSTONE CONCRETIONS. OF THE COLORADO DELTA.The Rilu Member is composed of diamictite, orthoquartzite, khaki shale, coal, carbonaceous shale, siltstone, sandstone, concretions with marine fossils. The Bomte Member is comprised of carbonaceous shale, grey shale, coal, shaly coal, sandstone occasionally with marine fossils (Roy Chowdhury 1978; Mahanta et al. 2017, 2019).spheroidal concretions and carbonate sandstone beds. Within the Grès de la Crèche, calcite cementation occurs as continuously cemented layers, as layers of strataboundCarbonate concretions have been recorded in many recent and ancient marine sediments around the world. The Middle Miocene marl of the Tenes area, situated in the northeast of the Lower Chelif ...Small, spherical ironstone concretions called Moqui marbles are seen forming in this close up a Navajo sandstone formation in Snow Canyon State Park, Utah, USA. The concretions are formed by the uneven weathering of elements within the sandstone.The concretion enveloping the burrow is always composed of sandstone, in some cases with the rare presence of pebbles. The loose, uncemented deposits surrounding the concretions seem to be macroscopically similar to the sandstone concretions: the primary difference is in their lack of siliceous cements.Finally, based on the petrographic study and the age determined by the fossil assemblage (Cretaceous), we have found a high similarity with "reworked marine sandstone concretions" described by ...In Minnesota, sandstone and other sedimentary rocks were deposited during the early Paleozoic Era, about 500 million years ago. At that time, Minnesota was near the equator, and shallow seas covered most of the state. Sediment eroded from upland areas was transported to the seashore, and the coarser-grained sediment eventually …In the present study, five different types of concretion were collected from mostly clay and coal interbedded sandstone beds, which are circular (1.5-4cm), elongate (0.5-1cm diameter; 4-6cm length ...Ironstone (sandstone with iron oxides) from the Mississippian Breathitt Formation, Mile Marker 166, I-64, Kentucky. Ironstone is a sedimentary rock, either deposited directly as a ferruginous sediment or created by chemical replacement, that contains a substantial proportion of an iron ore compound from which iron (Fe) can be smelted commercially.. Not to be confused with native or telluric ...A more detailed characterization of Navajo Sandstone spheroidal concretions and comparison to Mars spherules were given by Potter et al.. However, some characteristics of self‐organized spacing, size, sphericity, and trace elements of the Utah concretions can be used to infer chemical reaction fronts, mass transfer processes, and …About this book. Diagenesis affects all sediments after their deposition and includes a fundamental suite of physical, chemical and biological processes that control the texture, mineralogy and fluid-flow properties of sedimentary rocks. Understanding the processes and products of diagenesis is thus a critical component in the analysis of the ...sandstone concretion sample indicates a dominance of quartz in the clast population and calcite as the cementing mineral. The XRD pattern for the mudstone concretion sample shows an abundance of kaolinitic clay with quartz as detrital components and siderite as the cementing mineral. Figure 5. Photomicrograph of sandstone concretion.The Salton concretions, on the other hand, have but half the sand and twice the calcite required for such a constitution. There are four hypotheses which may account for this excess of calcite: 1. The concretion may have formed in a partially opened crevice; 2. Part of the calcite may be fragmental; 3.A concretion is a roughly spherical mass of sandstone embedded in less durable sandstone. Concretions form within layers of sand/sandstone that have already been deposited, usually before the rest of the sand has hardened into rock. Concretions form when a mineral precipitates and cements sediment around some sort of "nucleus", which is often ...The iron-oxide-rich concretions in the Jurassic Navajo Sandstone in southern Utah are unusual in two fundamental ways. First, they are cemented by iron oxide (Fe2O3, or Fe(OH)3); most other ...The stony spheres are concretions — sandstone balls cemented by a hard shell of iron oxide minerals. Often called moqui marbles, acres of the chocolate-colored rocks are scattered across Utah ...Abstract. Concretions are prevalent features in the generally lacustrine deposits of the Murray formation in Gale crater. In this work, we document the morphologic, textural, and chemical properties of these concretions throughout 300 m of Murray formation stratigraphy from Mars Science Laboratory observations between Sols …In most concretions there has been replacement of at least some of the pre-exiting sediment. Many concretions are saucer shaped to rounded. More recent siltstones form rings that are often formed by a twig eroding out and leaving a hole. Example of remnant concretion having eroded out of a sandstone depression. Example of a row of concretion .... Concretion. Concretions are masses of minIf the nodules or concretions are numerous, they can grow large Iron oxide concretions form in porous sandstone by chemical reduction and solution of iron minerals, transport of Fe 2+ in solution, and precipitation of hydrous ferric oxide by oxidation. Concretions form quickly in 1000's of years by diffusion and advection, and K-feldspar consumption of H + initiates nucleation. The Jurassic Navajo Sandstone,Jun 26, 2019 · The concretions are resistant to weathering compared to the host sandstone, which is fairly soft, so stick out from the cliff in a sometimes rather alarming manner as you walk below them. I’ve been visiting the concretions sporadically for around 30 years and some of the ones that I photographed in the cliffs in the 1980s are now lying loose ... The sandstone consists of more than 95 per The hardy sandstone structures, the largest of which have been found to top three feet in length, are only located in sediments dating to the time of the impact. And curiously there’s a pattern ... English: Concretion & quartz veins in sandsto...

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