Limestone sandstone shale. Imagine a sandy, tropical seashore extending across southe...

The main types of sedimentary rocks are clastic or chemical. Some

Common sedimentary rocks include sandstone, limestone, and shale. These rocks often start as sediments carried in rivers and deposited in lakes and oceans. When buried, the sediments lose water and become cemented to form rock. Tuffaceous sandstones contain volcanic ash. Clastic Sedimentary Rocks:ρ m = weighted average of grain (mineral) density (sandstone and shale = 2.65 g/cm 3, limestone = 2.71 g/cm 3) ρ w = weighted average of pore-water density (g/cm 3) φ = weighted average of rock porosity; d = depth (ft) To calculate weighted averages, use length::1000 ft or length::300 m increments. Geostatic gradientIt is the most common non-siliciclastic ( sandstone and shale are common siliciclastic rocks) sedimentary rock. Limestones are rocks that are composed of mostly calcium carbonate (minerals calcite or aragonite). Carbonate rocks where the dominant carbonate is dolomite (calcium magnesium carbonate) are named dolomite rock. o Cumulate dunite < troctolite layer < isotropic gabbro < layered gabbro. Espina Formation. o Late Cretaceous. o Unconformably underlies Panas Formation and Sumbiling Limestone. o Spilitic basalt with intercalated sandstone and chert. o Pelagic clastic rocks constitute the sedimentary carapace of Palawan Ophiolite.Chalk is a fine-grained limestone, usually formed by compacted microscopic animals called foraminifera. ... Concretions are compact, often rounded, accumulations of mineral matter that form inside sedimentary rocks such as shale and sandstone or in soil. Discover more.Sandstone sits atop a granite intrusion and pieces of the granite are contained within the limestone. Principle of Superposition. Undeformed sequence of sandstone on bottom, shale in the middle, and conglomerate on top. Principle of Lateral Continuity. Continuous layer of shale eventually thins out, grading into sandstone. Tracks. Deer footprints …a) the water is warm, fairly saline, and recharged by an affluent stream. b) pressurized groundwater rises from a deep, unsaturated aquifer. c) water rises above the top of the aquifer without any pumping. d) the well is horizontal and the water table is perched. c) water rises above the top of the aquifer without any pumping. Limestone, rock made of the calcium carbonate mineral known as calcite, can form in a variety of depositional environments, from hot spring deposits in lakes to coral reefs in the tropical oceans.Expert Answer. 1. As the rock is made up of powdery limestone, the rock is "Chalk". Sandstone is made up of quartz and feldspar. Shale is made up of quartz, feldspar and clay minerals. Chert is made up of microcrystalline quartz. So the answer is " Chal …. Knowns: This rock is a powdery limestone containing calcite from the shells of ...Terms in this set (32) Nonconformity. Conglomerate sits atop a granite intrusion. Principle of Original Horizontality. Rock layers have been tilted or folded, are not lying flat. Disconformity. Sandstone outcrop os submerged underwater, then overlain by shale. Angular Conformity. Marine shale sits atop folded strata. a) the water is warm, fairly saline, and recharged by an affluent stream. b) pressurized groundwater rises from a deep, unsaturated aquifer. c) water rises above the top of the aquifer without any pumping. d) the well is horizontal and the water table is perched. c) water rises above the top of the aquifer without any pumping.Feb 28, 2023 · Sandstone and carbonate have similar regression trendlines, however sandstone regression estimates higher UCS values for the corresponding ρ values. At a ρ of 2.8 g/cc, their regression trendline converges. The shale and plutonic rocks regressions have the highest gradients and are parallel to one another. 10 thg 1, 2022 ... Meanwhile, unconventional oil and gas resources are also rich in the Ordos Basin, including coalbed methane, shale gas, and tight sandstone gas, ...The known useful mineral resources in Elk County include oil, gas, limestone, shale and clay, sandstone, and gravel. Ground water, another important mineral resource, is discussed in Part 3 of this report. Natural gas has been produced in the county since 1901 and oil since 1902 (Jewett, 1954, p. 202). Both hydrocarbons still are important ...In most ledges the beds are considerably broken into an irregular coarse breccia, which in places carries much calcite in veins and geodes. The second and third members consist of alternations of limestone, sandstone, and sandy shale in beds ranging in thickness from 1 to 20 ft and presenting much local variation in character and succession.In the study area, the Bahram Formation is between 351 (Hutk) and 386 m (Sardar) thick, and generally includes limestone, sandstone, dolomite and shale units (Fig. 4). The rocks contain skeletal grains of various groups, including debris fossil and brachiopods which are very common together with coral, bryozoans, echinoderm, fish …Sandstone that contains feldspar, which weathers more quickly than quartz, is useful for analyzing the local geologic history. Greywacke is a term with conflicting definitions . Greywacke may refer to sandstone with a muddy matrix, or sandstone with many lithic fragments (small rock pieces). Figure \(\PageIndex{1}\): The Rochester Shale, New York.Limestone: Sandstone: Shale: Table courtesy of King (2003). Activity 3: Rock Cycle Model. The rock cycle model is two dimensional and shows a cross-section through the earth’s crust. Vertically, it represents a depth of two to five miles. Horizontally, it could represent distances ranging from a few miles to several hundred miles.The Kinkaid Limestone is about 160 ft thick and is divided into three informal members: a basal skeletal limestone member with numerous gastropods and the brachiopod Spirifer increbescens; a middle member of calcareous, fine-grained sandstone and silty shale overlain by skeletal and dolomitic limestone and succeeded by red and green shale; and ...8 thg 10, 2007 ... Download this Sandstone Limestone Shale Rock Layers Geology photo now. And search more of iStock's library of royalty-free stock images that ...In a sedimentary sequence, alternating sandstone, shale, and limestone generally indicates a marine environment. Almost all limestone is deposited in the ocean. The sandstones and shale would contain fossils of marine organisms. The shales would almost certainly have no mudcracks. off the continental shelf (Figs. 5-33, 5-34)o Massive sandstone, shale, conglomerate. o Equivalent to Pulute Formation. Sagasa Melange. o Possible Oligocene. o Probably formed through tectonism. o Chaotic mixture of turbidite, pillow basalt, chert, quartzite. o Outcropping in the Ulugan Bay area. Balabac Formation. o Late Oligocene – Miocene.Limestone: Sandstone: Shale: Table courtesy of King (2003). Activity 3: Rock Cycle Model. The rock cycle model is two dimensional and shows a cross-section through the earth’s crust. Vertically, it represents a depth of two to five miles.Geology: The formation is predominantly shale with small amounts of siltstone, silty to conglomeratic sandstone, limestone, and glossy black chert. The shale is mostly gray-black, but thin layers of olive-gray silty shale or siltstone are interbedded with the darker shales in some sequences. A comparative study of butterfly communities in 15 urban/suburban remnants of tropical semideciduous forest in Campinas (São Paulo state, SE Brazil; 24°S, 47°W), with areas from 1.0 to 252 ha and widely varying histories and environments, shows that the most significant factors, besides area and sampling time, distinguishing the sites and influencing their diversity (80-702 species) and ...This shift of the shoreline is reflected in the Tapeats Sandstone beach facies, Bright Angle Shale near-offshore mud facies, and Muav Limestone far-offshore facies. Marine organisms had plenty of time to evolve and adapt to their slowly changing environment; these changes are reflected in the biological facies, which show older life forms in ...given by Barrell (1914) as: shale, 8.2 percent; sandstone, 14.8 per­ cent; limestone, 5.3 percent; and all sedimentary rocks, 8.5 percent. Additional data since the publication of Barrell's summary indicate that the average value of 8.2 percent for the porosity of shale may be low. Athy's graph (1930) for Pennsylvanian and Permian shalesThe exposed Paleocene and Eocene rocks are composed of chalk, limestone, sandstone, shale, and silt-clay facies. The Upper Mesozoic and Lower Tertiary strata of the Farafra area are subdivided according to Figure 4a (Hermina, 1990) and comprise a Campanian to Middle Eocene transgressive-regressive open-marine sequence. From …Limestone changes facies eastward into sandstone, the Elbow Ridge Sandstone Member - Medium-bedded, medium- to coarse-grained, calcarous sandstone; thickness 10 to 18 feet.; and the Keyser Limestone - Dark gray, thin- to thick-bedded, fine- to coarse-grained calcarenite; contains nodular limestone, dolomitic limestone, and calcarous shale; …Common sedimentary rocks include sandstone, limestone, and shale. These rocks often start as sediments carried in rivers and deposited in lakes and oceans. When buried, the sediments lose water and become cemented to form rock. Tuffaceous sandstones contain volcanic ash. Clastic Sedimentary Rocks: Limestone is a sedimentary rock composed of calcium carbonate typically derived from the remains of fossil animal shells. ... Siltstone is much less common than sandstone or shale. This type of …Coal-measure gas refers to a set of coalbed methane, coal-measure shale gas (includes shale gas and certain coal-derived gas, abbreviated as shale gas), and tight sandstone gas that are linked ...The basic pattern recognition of sandstone/chert (density higher porosity than neutron), dolomite (neutron higher than density porosity) and limestone ( density and neutron porosities are similar) is valid for SHALE-FREE zones. Shales will have both a higher gamma-ray value and a neutron porosity greater than a density porosity. Sandstone, shale and limestone layers. Kingsbarnes to St Andrews Geology Trail. Done. Dave Haynes and plantmandrew faved this. Loading comments... Add comment.bedded sandstone and shale 672 Interbedded shale and silty limestone (shale dominant) 680 Interbedded limestone and calcareous shale 681 Till or diamicton (1st option) 682 Till or diamicton (2nd option) 683 Till or diamicton (3rd option) 684 Loess (1st option) 685 Loess (2nd option) 686 Loess (3rd option) 673 Interbedded shale and limestone ... Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al 2 Si 2 O 5 4) and tiny fragments (silt-sized particles) of other minerals, …Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al 2 Si 2 O 5 4) and tiny fragments (silt-sized particles) of other minerals, …Helderburg Group: mostly cherty limestone, with some sandstone and shale. Contains several named stratigraphic units, including the Keyser Formation, which is partly Silurian and includes the Clifton Forge Sandstone and Big Mountain Shale Members. Stonehenge Limestone (Ordovician) at surface, covers 0.1 % of this area. Gray, thin-bedded to …ρ m = weighted average of grain (mineral) density (sandstone and shale = 2.65 g/cm 3, limestone = 2.71 g/cm 3) ρ w = weighted average of pore-water density (g/cm 3) φ = weighted average of rock porosity; d = depth (ft) To calculate weighted averages, use length::1000 ft or length::300 m increments. Geostatic gradient... sandstone. 2- siltstone. 3- claystone. 4- shale. 5- limestone. 6- dolomite. By: Rawezh H. Anwar Pet. Geoscientist to be Specialized in reservoir engineering ...Over the past 6 million years, the Colorado River has carved through almost 2 billion years of the earth’s geologic history at the Grand Canyon. Layers of limestone, sandstone, shale, granite, and schist make up the Grand Canyon’s rock sequences. These layers continue to be worn away through water and wind erosio, creating the cliffs and ...It is common to find limestone and sandstone lying near shale. Shale usually occurs on the leaves. Roughly 55% of all sedimentary rocks are shale. Some shales are probably high in calcium due to the fossils they contain. Shale with high alumina content is used in cement production.shale and bitumen are all unconventional oil re-sources. Confusing heterogeneous denominations arise because of similar key characteristics presented by these resources. The general oil classification is related to the crude oil's ease of flow and conse-quently it denotes specific technical characteristics ofLaser drilling technique was employed by using 12 kW Trumph Laser Cell 1005. CO 2 laser in continuous mode was used and smaller diameter holes were obtained. The specifications of the laser machine are as indicated in Table 1.The rock minerals such as limestone, sandstone and shale were used in the experimental studies and trepanning drilling technique was used for drilling holes in samples.Conneaut Group, undivided (Upper Devonian) at surface, covers 4 % of this area. In west: Ellicott and Dexterville Formations-shale, siltstone. In east: Germania Formation-shale, sandstone; Whitesville Formation-shale, sandstone; Hinsdale Sandstone; Wellsville Formation-shale, sandstone; Cuba Sandstone.Expert Answer. 1. As the rock is made up of powdery limestone, the rock is "Chalk". Sandstone is made up of quartz and feldspar. Shale is made up of quartz, feldspar and clay minerals. Chert is made up of microcrystalline quartz. So the answer is " Chal …. Knowns: This rock is a powdery limestone containing calcite from the shells of ... Dalwood Group and lower Shoalhaven Group: calcareous sandstone, conglomerate, shale, limestone, lava flows and tuff. Greta Coal Measures: sandstone, shale, conglomerate, coal seams; Maitland and Shoalhaven Groups: siltstone, sandstone, shale, conglomerate (with abundant volcanics - the Gerringong Volcanics on the south coast; and glacial ...A. limestone, shale 1, basalt dike 3, sandstone 2 , limestone 4, fault B. limestone, shale 1, sandstone 2, limestone 4, fault , dike 3 A Which order shows the correct order from oldest to youngest layers?Limestone, sandstone, shale, shaley sandstone. 5 8. 390. N Y. Limestone, sandstone, shale, shaley sandstone. 4 1. 391. N Y. Limestone, sandstone, igneous ...Aug 22, 2023 · It is common to find limestone and sandstone lying near shale. Shale usually occurs on the leaves. Roughly 55% of all sedimentary rocks are shale. Some shales are probably high in calcium due to the fossils they contain. Shale with high alumina content is used in cement production. Examples include: breccia, conglomerate, sandstone, siltstone, and shale. Chemical sedimentary rocks form when dissolved materials preciptate from solution. Examples include: chert, some dolomites, flint, iron ore, limestones, and rock salt. Organic sedimentary rocks form from the accumulation of plant or animal debris.A sedimentary marine facies diagram showing the lateral position of limestone, shale, and sandstone. Spatial Scale Geologist interpret these geological changes in sea level on a variety of scales to help interpret the whole large-scale changes that have been observed throughout geologic history.Shale forms from muddy deposits that settle out in slow moving water, such as in deltas or along continental shelves. Sandstone forms from sandy deposits and limestone forms from deeper deposits. Shale is a mudrock—a classification of rocks that are composed mainly of silt-sized or clay-sized particles (both microscopic). This shift of the shoreline is reflected in the Tapeats Sandstone beach facies, Bright Angle Shale near-offshore mud facies, and Muav Limestone far-offshore facies. Marine organisms had plenty of time to evolve and adapt to their slowly changing environment; these changes are reflected in the biological facies, which show older life forms in ...10 thg 1, 2022 ... Meanwhile, unconventional oil and gas resources are also rich in the Ordos Basin, including coalbed methane, shale gas, and tight sandstone gas, ...Sandstone and minor shale: A coarse-grained clastic sedimentary rock composed of grains of sand (primarily quartz) in a matrix of silt or clay. Sandstone is commonly interbedded with shale. Shale and limestone: Interbedded shale and limestone. More than 50 percent of the shale layers.Jul 2, 2013 · Limestone, rock made of the calcium carbonate mineral known as calcite, can form in a variety of depositional environments, from hot spring deposits in lakes to coral reefs in the tropical oceans. 10 thg 1, 2022 ... Meanwhile, unconventional oil and gas resources are also rich in the Ordos Basin, including coalbed methane, shale gas, and tight sandstone gas, ...Unlike limestone, sandstone is formed from rocks and minerals from the continental crust, rather than from minerals in the water of the ocean. One of the sandstones at Mammoth Cave, named the Big Clifty Sandstone, formed about 320 million years ago, when sand was deposited over top of Mammoth Cave’s shale and limestone beds by a …At a given location, the changes from one rock type to another indicate the moving positions of the shoreline. During an ice age these cycles can repeat hundreds of times, and gave rise to the great coal swamps of the Carboniferous. These formed in coastal swamps, but above and below will be offshore sandstone, shale, and limestone.There are many formations and PSI that PDC bits work well in such as shale, sandstone, limestone, sand, and clay. The benefit to PDC bits is they also can work well in both soft and hard formations. Whereas, most rock bits are only designed for rock and the rate of penetration dramatically drops when in softer formations.Sandstone outcrop is submerged underwater, then overlain by shale: disconformity Conglomerate sits atop a granite intrusion: nonconformity Marine shale sits atop folded strata: angular unconformity Unreformed sequence of sandstone on bottom, shale in the middle, and conglomerate on top: principle of superposition Rock layers have been tilted or folded, are not lying flat: angular unconformity ...30 thg 1, 2018 ... ... sandstones of Old Red Sandstone facies occur toward the base. ... The upper part of the Lower Limestone Shale consists of greenish grey shale ...Terms in this set (32) Nonconformity. Conglomerate sits atop a granite intrusion. Principle of Original Horizontality. Rock layers have been tilted or folded, are not lying flat. Disconformity. Sandstone outcrop os submerged underwater, then overlain by shale. Angular Conformity. Marine shale sits atop folded strata. limestone, sandstone, shale and coal beds. limestone sandstone. shale coal beds. life. etching depicting some of the . most significant pl ants of . the carboniferous.Antalo Limestone is the thickest Jurassic formation in the basin, which mainly comprises limestone with subordinate marl, shale and sandstone units, and …Age: Middle Ordovician Period Distribution: West-central Arkansas, Ouachita Mountains; southeastern Oklahoma Geology: The formation consists of black and green shale in alternating layers with hard, gray sandstone and some bluish-gray limestone. Although the shale may locally make up 50 to 75 percent of the sequence, the sandstones appear …Solutions for shale, sandstone, limestone, permafrost, saline and alkali land.A feldspar-rich sandstone is called a(n) _____ . arkose litharenite quartz arenite shale. A sandstone with abundant rock fragments and clay minerals is a(n) _____ . arkose litharenite quartz arenite shale. Which of the following rocks is deposited only by non-biological, chemical precipitation ? halite limestone chert arenite coal(RTTNews) - Peoples Bancorp Inc. (PEBO) and Limestone Bancorp, Inc. (LMST) has signed a Merger Agreement, pursuant to which Peoples will acquire, ... (RTTNews) - Peoples Bancorp Inc. (PEBO) and Limestone Bancorp, Inc. (LMST) has signed a Me...At a given location, the changes from one rock type to another indicate the moving positions of the shoreline. During an ice age these cycles can repeat hundreds of times, and gave rise to the great coal swamps of the Carboniferous. These formed in coastal swamps, but above and below will be offshore sandstone, shale, and limestone.Common clast types include granite, limestone, sandstone, shale, and volcanic rocks. Poor Sorting: Conglomerates often exhibit poor sorting, meaning that the clasts vary in size and may not be well-sorted by size or type. This is due to the variable energy levels of the transporting agents. ... Sandstone is a notably popular building …At a given location, the changes from one rock type to another indicate the moving positions of the shoreline. During an ice age these cycles can repeat hundreds of times, and gave rise to the great coal swamps of the Carboniferous. These formed in coastal swamps, but above and below will be offshore sandstone, shale, and limestone.Aug 22, 2023 · It is common to find limestone and sandstone lying near shale. Shale usually occurs on the leaves. Roughly 55% of all sedimentary rocks are shale. Some shales are probably high in calcium due to the fossils they contain. Shale with high alumina content is used in cement production. There are many formations and PSI that PDC bits work well in such as shale, sandstone, limestone, sand, and clay. The benefit to PDC bits is they also can work well in both soft and hard formations. Whereas, most rock bits are only designed for rock and the rate of penetration dramatically drops when in softer formations.The oil and natural gas migrated out of the shale and upwards through the sediment mass because of their low density. The oil and gas were often trapped within the pore spaces of an overlying rock unit such as a sandstone (see illustration). These types of oil and gas deposits are known as "conventional reservoirs" because the fluids can easily flow through the pores of the rock and into the ...Portland (hydraulic) cement itself comes from naturally occurring minerals that include limestone, sandstone, shale, iron, clay, and fly ash. Manufacturers pour these raw materials into cylindrical concrete kilns and heat them …Question: Use the video below to answer each question. Knowns This rock is composed entirely of reef building organisms Cuestion. What is the name of this rock? Rock Names: Chert, Chalk, Coralline Limestone, Sandstone, Shale, Breccia, Conglomerate, Coquina Chalk Coralline Limestone Oolitic Limestone ChertView the full answer. Transcribed image text: Use the video below to answer each question. Knowns: This rock is composed almost entirely of shell fragments. Question: What is the name of this rock? Rock Names, Chert, Chalk, Coralline Limestone, Sandstone, Shale, Breccia, Conglomerate, Coquina Breccia Coralline Limestone Conglomerate Coquina.Limestone is almost always marine (ocean water) in origin and is usually associated with other near shore rocks types. In a typical marine scenario, to the shore side of a reef is the silica mud of a lagoon and closer to shore is the sand of a beach. The silica mud will form a shale while the beach sand will form a sandstone.Limestone, sandstone, shale, shaley sandstone. 5 8. 390. N Y. Limestone, sandstone, shale, shaley sandstone. 4 1. 391. N Y. Limestone, sandstone, igneous ...phyllite, sandstone, schist, shale: R3 ; Medium: strong: 25 -50 1 - 2 : Cannot be scraped or : ... Crystalline Limestone to 2) (12 not equal to 3) Sparitic Limestones ...Sandstone, shale and limestone layers. Kingsbarnes to St Andrews Geology Trail. Done. Dave Haynes and plantmandrew faved this. Loading comments... Add comment.The basic cyclothem is initiated by Lowstand terrestrial deposits of gray shales and sandstones with local developments of coals, succeeded by a Transgressive systems tract limestone. Black shales occur in the Highstand condensed section and interpreted to reflect deposition in the deepest water under reducing conditions which preserve organic matter …Geology: The St. Peter Sandstone is generally a massive bedded, medium- to fine-grained, well- rounded, friable, white sandstone. A few minor beds of shale, limestone, and/or dolostones have been noted in places. The cement is commonly calcite often with single crystals incorporating hundreds to thousands of sand grains.Helderberg Group (Devonian) at surface, covers 0.5 % of this area. Mostly cherty limestone, with some sandstone and shale. Contains several named stratigraphic units, including the Keyser Formation, which is partly Silurian and includes the Clifton Forge Sandstone and Big Mountain Shale Members.Oil Shale Extraction - Oil shale extraction is more complicated than crude oil extraction; it includes the extra steps of retorting and refining. Read about oil shale extraction. Advertisement The process of extracting liquid crude oil from...Interbedded sandstone, shale, and limestone usually characterized by ledgy outcrops. Orange to reddish sandstone forms cliffs near Sedona. This unit includes Supai Group and Hermit Shale in northern Arizona and Naco Group in southern Arizona. It was deposited in coastal-plain to shallow-marine settings during time of variable and changing sea ...Marine shale has high content of shale gas. Tzortzis and Tsertos (2002) [3] measure the concentration of uranium, thorium and potassium in cyprus and found that uranium, thorium and potassium is present in chalk, gypsum, marl, calcareous sandstone, limestone, beech deposits and red clay soil. This means that radioactive source is associated in ...limestone: pavement and shale:Shale Sedimentary Rock. Gray rock fromed in deep sections of the ocean from clay. Shale is a very common rock worldwide that can be split into layers. An information ...Porous and layered sedimentary rocks like limestone, sandstone, shale, and conglomerate, and breccia can explode when heated. Extrusive igneous rocks (pumice, basalt, rhyolite, andesite, dacite) and foliated metamorphic rocks (slate) can explode if they contain water inside. River rocks can also explode.We would like to show you a description here but the site won’t allow us.. limestone, sandstone, shale and coal beds. limestone sandstone. shaJan 22, 2020 · Sandstone. 2.2–2.8. Shale. 2.4–2.8. Slate. 2.7–2.8. As Limestone Sandstone Sandstone Sandstone Mudstone Limestone Limestone Ironstone Sandstone 18.00 ± 0.62 (20) 19.17 ± 0.21 (23) 23.10 ± 0.48 (19) 24.21 ± 0.83 (8) 35.17 ± 3.17 (4) 36.28 ± 1.24 (24) 38.76 ± 2.69 (23) 44.28 ± 4.48 (5) 65.66 ± 0.83 (11) 41.45 ± 3.52 (4) 77.59 ± 1.59 (5) 80.83 ± 2.21 (10) 90.48 ± 3.86 (4) 50.07 ± 3.79 (4 ... Jul 19, 2023 · Sandstone is a sedimentary rock formed from sand-siz Limestone: Sandstone: Shale: Table courtesy of King (2003). Activity 3: Rock Cycle Model. The rock cycle model is two dimensional and shows a cross-section through the earth’s crust. Vertically, it represents a depth of two to five miles. If these layers are buried deeply enough to be lithified...

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