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81-447: For a sediment to be considered to be a coquina, the particles composing it should average 2 mm (0.079 in) or greater in size. Coquina can vary in hardness from poorly to moderately cemented . Incompletely consolidated and poorly cemented coquinas are considered grainstones in the Dunham classification system for carbonate sedimentary rocks. A well-cemented coquina is classified as

162-465: A biosparite (fossiliferous limestone) according to the Folk classification of sedimentary rocks . Coquinas accumulate in high-energy marine and lacustrine environments where currents and waves result in the vigorous winnowing, abrasion, fracturing, and sorting of the shells that compose them. As a result, they typically exhibit well-developed bedding or cross-bedding , close packing, and good orientation of

243-595: A rift basin . The rift stage of the basin evolution combined with the arid Aptian climate of the southern latitudes resulted in the deposition of evaporites in the Late Aptian , approximately 112 million years ago. The phase of rifting was followed by a thermal sag phase and drift stage in the widening of the South Atlantic Ocean . This process led to the deposition of a more than 20 kilometres (66,000 ft) thick succession of clastic and carbonate sediments. One of

324-437: A 30 t/m reduction in apparent preconsolidation pressure. Coop and Airey (2003) show that for carbonate soils, cementation develops immediately after deposition and allows the soil to maintain a loose structure. Non-recognition of cementation has resulted in construction disputes. For example, a land on a major Project is marked as glacier on contract drawings. It was so hard that it had to be detonated. The contractor claimed that

405-624: A building stone in Florida for over 400 years, coquina forms the walls of the Castillo in St. Augustine. The stone made a very good material for building forts, particularly those built during the period of heavy cannon use. Because of coquina's softness, cannonballs would sink into, rather than shatter or puncture the walls. The first Saint Augustine lighthouse , built by the Spanish, was also made of coquina. Coquina

486-441: A calcium source (Chou et al. , 2010). Cementing has significant effects on the properties and stability of many soil materials. Cementation is not always easily identified and its effects cannot be easily determined quantitatively. It is known to contribute to clay tenderness and may be responsible for an apparent preconsolidation pressure. The filtration of iron compounds from a very sensitive clay from Labrador, Canada, resulted in

567-538: A clay matrix and their influence on geotechnical behavior is limited. The clay confinement maintains a large void ratio even at high effective stresses, allowing the interparticle forces to spring up. https://www.geolsoc.org.uk/ks3/gsl/education/resources/rockcycle/page3559.html Santos Basin The Santos Basin ( Portuguese : Bacia de Santos ) is an approximately 352,000 square kilometres (136,000 sq mi) large mostly offshore sedimentary basin . It

648-644: A common find all over the world, with the depositional requirements to form a coquina being a common thing in many marine facies . Adjacent to Shark Bay Road beginning 45 kilometres (28 mi) southeast of Denham is an approximately 110 kilometres (68 mi) long stretch of coastline composed of billions of tiny shells of the Shark Bay cockle ( Fragum erugatum ), averaging less than 14 millimetres (0.55 in) in length. The shell deposit, between 8 and 9 metres (26 and 30 ft) thick, has compacted and cemented in some areas into solid masses of limestone that formerly

729-466: A few meters thick, found 15 to 20 metres (49 to 66 ft) above present mean sea level. The ancient Maya built their city of Toniná in the highlands of what is now Chiapas in southern Mexico using native rocks to construct its masonry buildings, among them large coquina flagstones from which they made blocks and bricks for floors, walls, and stairways. Coquina has a very limited distribution in southeastern North Carolina . The best known outcrop

810-546: A marine platform setting. The age based on palynomorphs and calcareous nanofossils is Late Cretaceous (Santonian-Maastrichtian). Two new ostracod species were identified in the drilling cuttings of wells drilled into the Santonian-Campanian section, ?Afrocytheridea cretacea and Pelecocythere dinglei . Itamambuca Group is 4,200 metres (13,800 ft) thick and includes four formations, Ponta Aguda, Marambaia , Iguape and Sepetiba . The Ponta Aguda Formation

891-629: A process continuing towards the north later in the Cretaceous. The deposition of the lowermost 600 metres (2,000 ft) of salt in the Aptian would have taken approximately 20,000 to 30,000 years. With the continental break-up of the Santos and Campos Basins from the opposite Namibia and Kwanza Basins , oceanic circulation returned during the post-rift stage. The drift phase since the Late Cretaceous produced

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972-740: A sequence of rift basins bordering the present-day South Atlantic. The Pelotas-Namibia spreading commenced in the Hauterivian , around 133 million years ago and reached the Santos Basin to the north in the Barremian . Seafloor spreading continued northwards to the Campos Basin in the Early Albian , at approximately 112 Ma. Five tectonic stages have been identified in the Brazilian basins: The sag phase in

1053-438: A thick sequence of clastic and carbonate deposits. Differential thermal regimes and sediment loading of these units produced halokinesis ; salt movement in the subsurface . The resulting salt diapirs , listric and thrust faults and various salt-related structures produced several stratigraphic and combined stratigraphic-structural traps for hydrocarbon accumulation in the Brazilian and southwest African offshore. During

1134-558: A transitional continental and shallow marine environment. The age of this formation has been estimated to be Late Barremian to Aptian. It is correlative with the Macabu Formation in the Campos Basin, as both are typified by laminated microbialites and stromatolites. These limestones are one of the sub-salt reservoirs in the Santos Basin. The Ariri Formation is in the type oil well 581 metres (1,906 ft) thick and may be up to 4,000 metres (13,000 ft) thick in other areas of

1215-490: Is 1,103 metres (3,619 ft) thick and consists of bioclastic calcarenites and calcirudites, containing bryozoa , echinoids , corals , foraminifera, fragmented shells, and algae remains. They are interbedded with grey-greenish clays, siltstones, marls and variegated grey fine-to-medium grained conglomerates. These facies are interbedded with and change laterally to the Marambaia Formation . The depositional environment

1296-661: Is 4,200 metres (13,800 ft) thick and includes four formations, from old to young the Camboriú , Piçarras, Itapema and Barra Velha Formations. The group is equivalent to the Lagoa Feia Group of the Campos Basin. The Camboriú Formation is 40 metres (130 ft) thick and includes the basaltic rocks with a basin–wide distribution. The basalts are dark green to dark grey, holocrystalline, medium grained, with an ophiolitic texture. The main components are plagioclase and augite , usually fresh, non-altered. The Piçarras Formation

1377-498: Is 517 metres (1,696 ft) thick and consists of dark grey shales, silts and light grey marls, ochre-brown calcisilts and subordinated sandstones. These facies change laterally into the coarse clastics of the Florianópolis Formation. Facies analysis indicates a marine environment ranging from sub-littoral (inner neritic) and more rarely to pelagic (outer bathyal) conditions. The age based on planktonic foraminifera and pollen

1458-527: Is 952 metres (3,123 ft) thick and includes a succession of clastics between the coarse facies of the Santos Formation in the west and the fine-grained clastics of the Itajai-Açu Formation in the east. The formation is characterized by dark grey to greenish and brown shales, dark grey siltstones, fine-very fine sandstones and light ochre calcisilts. The depositional environment is thought to be of

1539-452: Is 990 metres (3,250 ft) thick and consists of clastic and carbonate rocks. The formation includes reddish polymictic conglomerates , with clasts of basalt and quartz in a clay-sandy matrix. It also includes white, reddish lacustrine coquinas (shelly limestones) and sandstones, siltstones and shales of stevensite composition. Its age, based on the ostracod assemblages, is Hauterivian to Aptian. The conglomerates and sandstones of

1620-416: Is Early Albian. The Frade Group is 4,000 metres (13,000 ft) thick and includes three formations: Santos , Itajaí-Açu and Juréia . They predominantly comprise turbidites . The Santos Formation is 1,275 metres (4,183 ft) thick and consists of reddish lithic conglomerates and sandstones, interbedded with grey shales and reddish clays. These facies are interbedded and change laterally into

1701-662: Is a mostly offshore sedimentary basin across the Tropic of Capricorn , bordering from north to south the Brazilian states of Rio de Janeiro , Sáo Paulo , Paraná and Santa Catarina . The basin covers an area of approximately 352,000 square kilometres (136,000 sq mi), and is bounded in the north by the Cabo Frio High , separating the basin from the Campos Basin and the Florianópolis High and Fracture Zone , separating

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1782-433: Is called cementation and is a part of the rock cycle. Cementation involves ions carried in groundwater chemically precipitating to form new crystalline material between sedimentary grains. The new pore-filling minerals form "bridges" between original sediment grains, thereby binding them together. In this way, sand becomes sandstone , and gravel becomes conglomerate or breccia . Cementation occurs as part of

1863-586: Is continuous in the groundwater zone, so much so that the term "zone of cementation" is sometimes used interchangeably. Cementation occurs in fissures or other openings of existing rocks and is a dynamic process more or less in equilibrium with a dissolution or dissolving process. Cement found on the sea floor is commonly aragonite and can take different textural forms. These textural forms include pendant cement, meniscus cement, isopachous cement, needle cement, botryoidal cement, blocky cement, syntaxial rim cement, and coarse mosaic cement. The environment in which each of

1944-657: Is located in New Hanover County , near Fort Fisher , along the southern tip of North Carolina's coast. It is one of the few naturally occurring outcrops in the coastal plain region of North Carolina, described as “a low-relief plain underlain by beds of shallow-marine, estuarine, shoreline, and fluvial sediments" in The Geology of the Carolinas . These sediments were deposited during numerous episodes of sea level rise and fall over hundreds of thousands of years. The coastlines of

2025-715: Is located in the south Atlantic Ocean , some 300 kilometres (190 mi) southeast of Santos , Brazil . The basin is one of the Brazilian basins to have resulted from the break-up of Gondwana since the Early Cretaceous , where a sequence of rift basins formed on both sides of the South Atlantic; the Pelotas, Santos, Campos and Espírito Santo Basins in Brazil, and the Namibia, Kwanza and Congo Basins in southwestern Africa. Santos Basin

2106-758: Is separated from the Campos Basin to the north by the Cabo Frio High and the Pelotas Basin in the south by the Florianópolis High and the northwestern boundary onshore is formed by the Serra Do Mar coastal range. The basin is known for its thick layers of salt that have formed structures in the subsurface due to halokinesis . The basin started forming in the Early Cretaceous on top of the Congo Craton as

2187-497: Is thought to be a marine carbonate platform, influenced by the arrival of alluvial clastics in the most proximal areas. Biostratigraphic data from planktonic foraminifera, calcareous nanofossils and palynomorphs indicate a Tertiary age. The Marambaia Formation is 261 metres (856 ft) thick and consists of grey shales and light grey marls interbedded with fine-grained turbiditic sandstones. This formation in places can be found cropping out at sea bottom. The depositional environment

2268-515: Is thought to be coastal. The stratigraphy following the classifications by Vieira 2007, Kiang Chang 2008 and Contreras 2011 is: 4D Basin analysis of the Santos Basin has revealed insights about the interplay among the elements and processes of the petroleum system to assess source rock potential (vertical and horizontal distribution), thermal evolution of the source rocks, transformation ratio , hydrocarbon generation and charge, timing of migration, oil origin, quality, and volume of petroleum in

2349-459: Is thought to be talus and open marine basin. Biostratigraphic data indicate a Tertiary age. The Sepetiba Formation is the uppermost formation in the Santos Basin. It has a variable thickness due to the proximal erosion of the uppermost part. The formation consists of whitish grey fine to coarse grained carbonitic sands. They are feldspar -rich, glauconitic coquinas consisting of bivalve fragments and foraminifera. The depositional environment

2430-432: Is up to 2,200 metres (7,200 ft) thick and consists of conglomerates, coarse to fine-grained sandstones interbedded with siltstones and shales. The dominant facies are coarse to fine-grained quartzitic sandstones. They range from reddish to grey, usually with calcite cements. Intercalated are reddish to light grey claystones and siltstones. They represent a fluvial to shallow marine environment. The Iguape Formation

2511-416: Is up to 6,100 metres (20,000 ft) thick and includes three formations, Florianópolis , Guarujá and Itanhaém . The Florianópolis Formation is 343 metres (1,125 ft) thick in the type oil well, and consists of reddish, fine to coarse-grained sandstones with a clay matrix, reddish micaceous shales and siltstones. These clastic units are thought to represent alluvial environments distributed along

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2592-713: The Atlantic Coastal Ridge , a Pleistocene barrier island chain that extends from Duval County to Dade County . Other coquina deposits are found in the state, but only in limited areas. The Anastasia Formation is naturally exposed in a number of places along the east coast including Washington Oaks Gardens State Park , Gilbert's Bar House of Refuge , Hutchinson Island in Martin County and Blowing Rocks Preserve , owned by The Nature Conservancy , in Martin County. Still occasionally quarried or mined , and used as

2673-641: The Baja California peninsula, including submerged "reefs". So-called coquina "reefs" occur at Punta Borrascosa, San Felipe and Coloraditos on the northeast coast of Baja California. These have been uranium-thorium dated to the Pleistocene epoch, with an age estimated at 130,000 ybp . Semi-continuous coquina outcrops have been found 13 kilometres (8.1 mi) east of Puerto Peñasco , in the shallow subtidal zone or partly submerged under intertidal sands. Other Pleistocene outcrops occur along both coastlines of

2754-533: The Neoproterozoic mobile belts composed of less resistant metamorphic rocks . The Precambrian basement of the Santos Basin is exposed as the Araçuaí Belt along the Brazilian coast, most notably in the inselbergs of Rio de Janeiro, of which Sugarloaf Mountain is the most iconic. The ancient rocks consist of a Neoproterozoic to Cambrian high-grade metamorphic core of granites and gneisses , formed during

2835-534: The Tidewater region of North Carolina change constantly in response to wind and wave action, sedimentary deposition, tidal movements, and changes in sea level. Although the inner coastal plain is considered to be more stable, the coastal plain was inundated by repeated marine transgressions due to fluctuating sea levels during the late Pliocene and early Pleistocene. Historical records and extant buildings, foundations, basements, and retaining walls indicate that coquina

2916-514: The diagenesis or lithification of sediments. Cementation occurs primarily below the water table regardless of sedimentary grain sizes present. Large volumes of pore water must pass through sediment pores for new mineral cements to crystallize and so millions of years are generally required to complete the cementation process. Common mineral cements include calcite , quartz , and silica phases like cristobalite , iron oxides , and clay minerals ; other mineral cements also occur. Cementation

2997-538: The 1930s, large-scale mining of coquina for use in highway construction began at Fort Fisher in North Carolina. Large pieces of coquina of unusual shape are sometimes used as landscape decoration. Because coquina often includes a component of phosphate , it is sometimes mined for use as fertilizer . Cementation (geology) A brief, easy-to-understand description of cementation is that minerals bond grains of sediment together by growing around them. This process

3078-788: The Barremian and Aptian sag phase of the continental crust subsidence. Coquina deposits in Florida occur mostly along the eastern coast of the peninsula. This coquina is named the Anastasia Formation after Anastasia Island , where the Spanish quarried the rock to construct the Castillo de San Marcos , the fortress they built to defend St. Augustine . The Anastasia Formation stretches from just north of St. Augustine in St. Johns County to southern Palm Beach County . The formation and associated sand form part of

3159-574: The Cape Fear". Sprunt compared Sedgeley Abbey in dimensions and appearance to the two-story, cellared, Governor Dudley mansion that still stands in Wilmington . Like many southern plantations, Sedgeley Abbey was abandoned after the Civil War . The vacant house was demolished in the 1870s and the coquina rubble was burned and spread on the fields as fertilizer. A cellar eight feet deep carved into solid coquina

3240-458: The Itajai-Açu and Juréia Formations. The sedimentary environment is thought to be transitional continental to marginal marine, ranging from alluvial to braided rivers and deltas. Biostratigraphic data indicate a Late Cretaceous age (Cenomanian-Maastrichtian). The Itajaí-Açu Formation is 1,545 metres (5,069 ft) thick and comprises a thick interval of dark grey clayey rocks, interbedded with

3321-618: The Itapema Formation is Barremian to Aptian. The Barra Velha Formation is approximately 300 to 350 metres (980 to 1,150 ft) thick. In the proximal sections, the formation comprises limestones of stromatolites and laminated microbialites. In the distal sections, it is composed of shales. Interbedded with the laminated microbialites there are limestones with packstone and grainstone textures made up of algal clasts and bioclasts (fragmented ostracods). The carbonates frequently are partly or completely dolomitized. These facies represent

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3402-620: The Late Barremian to Early Aptian, and the younger rift/sag microbial limestones deposited during the Aptian, just before the establishment of the major evaporitic sag basin between South America and Africa." There are abundant beds of coquina in the Outer High of the Santos Basin , similar to those from the neighboring Campos. Pre-salt stratigraphy of the Santos Basin shows lacustrine sediments composed of coarse pelecypod (bivalve) coquina during

3483-563: The Pampo and Linguado Fields in 1978. The coquinas of the Morro do Chaves Formation were formed by non-marine bivalves and ostracods . The shells of the bivalves, which lived in shallow oxygenated water, were transported and deposited as washout over stream fans and beaches by storms and long-shore drift . The palynological record of coquinas of the Sergipe-Alagoas Basin has been analyzed and

3564-518: The Santos Basin from the Pelotas Basin . Along the Brazilian coast, the basin is bounded by the Serra do Mar and stretches from Cabo Frio in the northeast to Florianópolis in the southwest. The city of Rio de Janeiro is located at the coastal edge of the Santos Basin in the northern portion, Santos , Guarujá and the islands of Ilhabela in the central area and Itajaí and Balneário Camboriú in

3645-470: The Santos Basin started in the 1970s. Between 1970 and 1987, 59 dry wells were drilled, with one discovery in Santonian turbidites in 1979, Merluza Field. From 1988 to 1998, 45 wells were drilled in the basin providing small discoveries, with the 30 million barrels (4.8 million cubic metres) of oil equivalent Tubarão Field discovered in 1988. Eighty-one wells were drilled from 1999 to 2005, leading to

3726-456: The Santos Basin was characterised by thermal subsidence and generated restricted depocentres with relatively uniform water depths, ranging from 600 to 950 metres (1,970 to 3,120 ft). The Late Aptian climate was arid with high evaporation rates which triggered hypersaline conditions in these marginal sag basins. This resulted in the accumulation of thick layers of evaporites along the Brazilian and southwestern African continental margins,

3807-470: The alluvial clastics of the Florianópolis Formation. The Guarujá name is restricted to the lowest limestone intercalation, previously named Lower Guarujá by Ojeda and Ahranha in Pereira and Feijó (1994). The microfacies indicate a tidal flat to shallow lagoon and open carbonate platform depositional environment. The age based on planktonic foraminifera and pollen is Early Albian. The Itanhaém Formation

3888-438: The basin. It is predominantly composed of evaporites . The formation is characterized by thick intervals of white halite , associated with white anhydrite , ochre greyish calcilutites, shales and marls . The sedimentary environment probably was restricted marine including mudflat sabkhas , evolving under an arid climate. The ostracod assemblages of this formation indicate a neo-Algoas age (local time scale). The Camburi Group

3969-477: The bottom of grains where water droplets are held. Hardgrounds are hard crusts of carbonate material that form on the bottom of the ocean floor, below the lowest tide level. Isopachous (which means equal thickness) cement forms in subaqueous conditions where the grains are completely surrounded by water (Boggs, 2006). Carbonate cements can also be formed by biological organisms such as Sporosarcina pasteurii , which binds sand together given organic compounds and

4050-408: The cements is found depends on the pore space available. Cements that are found in phreatic zones include: isopachous, blocky, and syntaxial rim cements. As for calcite cementation, which occurs in meteoric realms (freshwater sources), the cement is produced by the dissolution of less stable aragonite and high-Mg calcite. (Boggs, 2011) Classifying rocks while using the Folk classification depends on

4131-466: The clastics of the Santos and Juréia Formations. Within this formation, the Ilhabela Member includes the turbiditic sandstones occurring along the section. The sedimentary environment is thought to be marine talus to open basin. Biostratigraphic data from palynomorphs, calcareous nannofossils and planktonic foraminifera indicate a Late Cretaceous age (Cenomanian-Maastrichtian). The Juréia Formation

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4212-531: The coast of northeastern Brazil hold coquina reservoirs of oil. The coquinas are generally heterogeneous in their porosity and permeability, but like other lacustrine carbonates, they are uncommonly reservoirs. Corbett et al. (2015) in their discussion of the reservoirs say the finding of the Badejo Field ( Campos Basin ) in 1975 was the first hydrocarbon discovery in the coquinas of the Lagoa Feia, followed by that of

4293-683: The collision of Gondwana in the Pan-African - Brasiliano orogeny . Basalts similar to the Paraná and Etendeka traps , exposed to the west in the Paraná Basin , have been found underlying the Santos Basin. The Tristan da Cunha hotspot , known as the Tristan hotspot , is considered the driver behind the formation of these flood basalts . During the Early Cretaceous , the former continent Gondwana , as southern part of Pangea , starting to break-up, resulting in

4374-514: The discovery of the Lula Field by Petrobras and partners in 2006 opened petroleum exploration in the Barremian/ Aptian pre-salt play in the offshore Santos and Campos basins, and consequently deeper coquina reservoirs have become important targets. He says the two main reservoir targets recognized for the pre-salt within the study areas are: "late rift coquinas, lacustrine facies deposited at

4455-659: The discovery of the Mexilhão Field. Exploration boomed between 2006 and 2012, with 166 wells and the giant Tupi field (8 BBOE), discovered at the Tupi prospect in 2006. In 2013, the Sagitário Field was discovered in the sub-salt carbonates at a water depth of 1,871 metres (6,138 ft) and a true vertical depth of 6,150 metres (20,180 ft). In 2014, the pre-salt reservoirs of the Santos Basin produced more than 250 thousand barrels per day (40 × 10 ^  m /d). Thanks to

4536-560: The eastern half area is in the main oil window , whereas the western half is in the late oil/wet gas generation window. In terms of transformation ratio, the Barremian and Aptian source rock systems in the area reached 70% to 80% today where the main depocentres are. The charge and accumulation simulation model for the pre-salt province suggests a potential reserve in the Cluster area of Santos Basin much larger than that reported, getting numbers to 60 billion barrels of oil reserves. Exploration in

4617-458: The formation are representative of an alluvial environment. The coquinas represent a shallow lacustrine environment . Similar to the Atafona Formation of the Campos Basin, the sandstones, stevensite-bearing siltstones and shales represent an alkaline lacustrine environment affected by volcanic activity. The shales represent deeper lacustrine waters in more distal areas. The alternation of

4698-483: The formation consists of dark organic matter rich shales. In the well 1-RSJ-625, the formation includes 110 metres (360 ft) of radioactive shales interbedded with carbonates. These facies are thought to represent a lacustrine environment. The organic matter-rich shales are one of the main source rocks of the Santos Basin. This formation is correlative with the Coqueiros Formation in the Campos Basin. The age of

4779-399: The largest Brazilian sedimentary basins, it is the site of several recently (2007 and later) discovered giant oil and gas fields , including the first large pre-salt discovery Tupi (8 billion barrels), Júpiter (1.6 billion barrels and 17 tcf of gas), and Libra , with an estimated 8 to 12 billion barrels of recoverable oil. Main source rocks are the lacustrine shales and carbonates of

4860-457: The main reservoirs. In a basin modeling study performed in 2008 and 2009, a detailed facies model from the pre-salt section was built based on well data and conceptual models from seismic interpretation associated with previous knowledge of the tectono-sedimentary sequences of the Santos Basin. The predicted vitrinite map , integrated with all data, indicates that the Coquinas source rock in most of

4941-488: The matrix, which is either sparry (prominently composed of cement) or micritic (prominently composed of mud). Beachrock is a type of carbonate beach sand that has been cemented together by a process called synsedimentary cementation. Beachrock may contain meniscus cements or pendant cements. As the water between the narrow spaces of grains drains from the beachrock, a small portion of it is held back by capillary forces, where meniscus cement will form. Pendant cements form on

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5022-743: The onshore stretch of the basin ranges from tropical savanna climate (Aw), tropical monsoon climate (Am) and tropical rainforest climate (Af) to a humid subtropical climate (Cfa). The onshore portion of the Santos Basin is in the Serra do Mar coastal forests ecoregion of the Atlantic Forest biome. On the islands of the Superagüi National Park in the Santos Basin, the endemic critically endangered Superagüi lion tamarin ( Leontopithecus caissara ) has its restricted habitat. The South Atlantic margin developed on Archean stable cratons consisting of hard and resistant rocks and partly on

5103-531: The phases of halokinesis, dated to the Albian to Paleocene , several areas of the now deep water distal part of the Santos Basin were exposed to subaerial conditions and suffered erosion. The distal parts of the basin were affected by E-W to NW-SE oriented shortening, sub-perpendicular to the Brazilian margin. The basement of the Santos Basin is composed of granites and gneisses of the Araçuarí Belt that formed at

5184-491: The porous coquina was protected by lime plaster. With the exception of a few residences that have been restored in St. Augustine, the coquina masonry of these structures is today exposed to the elements and is slowly deteriorating. Overlying the fossiliferous sands and sandy clays of the upper San Fernando River in northeastern Mexico is a bed of coquina limestone dating probably to the Cenozoic era. Coquina deposits also occur in

5265-620: The pre-salt Guaratiba Group and the marine shales of the post-salt Itajaí-Açu Formation. Reservoir rocks are formed by the pre-salt Guaratiba sandstones , limestones and microbialites , the Albian limestones of the Guarujá Formation and the Late Cretaceous to Paleogene turbiditic sandstones of the Itanhaém, Juréia, Itajaí-Açu, Florianópolis and Marambaia Formations. The mobile salt of the Ariri Formation forms regional seals , as well as

5346-528: The pre-salt production, compensating for the declining post-salt production, the total oil production of Brazil rose above 2,500 thousand barrels per day (400 × 10 ^  m /d) in April 2016. The Lapa Field, originally named Carioca, was taken in production in December 2016. In 2017, the Santos Basin accounted for 35% of Brazil's oil, with the Campos Basin at 55%. In the same year, 76 blocks were open for bidding in

5427-429: The sediments dated to the late Barremian age ; the results suggest a marine and/or brackish environment. Daniel Thompson (2013) asserts that the coquinas of the Morro do Chaves Formation include a wide range of marine mollusca characteristic of brackish environmental conditions, suggesting periodic marine ingression during the Early Cretaceous . According to a paper by Senira Kattah published in The Sedimentary Record ,

5508-414: The shales of the post-salt sedimentary infill. In 2014, the total production of only the sub-salt reservoirs accumulated to more than 250 thousand barrels per day (40 × 10 ^  m /d). In 2017, the Santos Basin accounted for 35% of Brazil's oil, with the northern neighbour Campos Basin at 55%. The Santos Basin is named after the coastal city of Santos in the state of São Paulo . The Santos Basin

5589-413: The shell fragments. The high-energy marine or lacustrine environments associated with coquinas include beaches, shallow submarine raised banks, swift tidal channels, and barrier bars. Coquina is composed mainly of the mineral calcite , often including some phosphate , in the form of seashells or coral . Coquinas dating from the Devonian period through to the much more recent Pleistocene epoch are

5670-419: The soil was cemented during excavation as it was formed due to the clay matrix as well as the gravel. The owner concluded that this was due to the weathering of the pebbles. Proper evaluation of the material before the award of the contract could have avoided the problem. Clay particles adhere to the surfaces of larger silt and sand particles, a process called clay bonding. Eventually, larger grains are embedded in

5751-441: The south in New Smyrna , a large storehouse and wharf were constructed of coquina at the 1770s Andrew Turnbull colony. Around 1816, John Addison constructed a kitchen house of coquina on his plantation on the Tomoka River . The material was also used in the construction of sugar mill buildings on sugar plantations in the 1820s and 1830s. Examples are the Bulow , Dunlawton and New Smyrna sugar mills. In these early structures,

5832-407: The south of the basin. Within the basin, several highs are located. The Outer High, in the distal part of the Santos Basin, is the most prominent and extensive intra-basinal high with an approximate area of 12,000 square kilometres (4,600 sq mi). The Outer High is likely a segmented series of rift fault-block shoulders which were uplifted and eroded during the Late Barremian. The climate of

5913-478: The stone is also at first much too soft to be used for building. In order to be used as a building material, the stone is left out to dry for approximately one to three years, which causes the stone to harden into a usable, but still comparatively soft, form. Coquina has also been used as a source of paving material. It is usually poorly cemented and easily breaks into component shell or coral fragments, which can be substituted for gravel or crushed harder rocks . In

5994-504: The two facies implies a series of alluvial progradation-retractions into the Cretaceous carbonate lakes. The low textural and compositional maturity of conglomerates and sandstones implies the basin was supplied from areas close to the basin margins. The Itapema Formation is several hundreds of metres thick and consists of calcirudites (limestones) and dark shales. The calcirudite limestones consist of fragmented bivalve shells, frequently dolomitized and silicified. In more distal sections,

6075-584: The upper Gulf of California . On the Vizcaino Peninsula of western Baja California, the informally named " Tivela stultorum " coquina is abundant in shells of the Pismo clam. Until analysis of the shells by U-series and amino-acids methods is concluded, this marine transgression is assigned an approximate age of 200,000 ybp. Outcrops in Bahía de San Hipolito and Bahía de Asunción are loosely consolidated, sandy beachrock

6156-709: The western Brazilian basin margin, along the Santos Hinge Line. These alluvial environments were gradational towards the east, with the shallow marine carbonates of the Guarujá Formation, and further to the open basin with the siltstones of the Itanhaém Formation. Biostratigraphical data and its relations with the Guarujá Formation point towards an Albian age. The Guarujá Formation is 832 metres (2,730 ft) thick and consists of oolitic calcarenites , which laterally grade to greyish ochre and brownish grey calcilutites and grey marls. These facies are interbedded with

6237-453: The western boundary of the Congo Craton. The erosion resistant metamorphic and magmatic rocks are exposed in the Serra do Mar , forming the edge of the Santos Basin along the Brazilian coast. The total stratigraphic thickness of the sediments in the Santos Basin has been estimated at 23,170 metres (76,020 ft) and has been described in detail by Clemente in 2013. The Guaratiba Group

6318-469: Was being mined in North Carolina by at least 1760, evidenced by the extant architectural ruins at the colonial-era Clear Springs Plantation near New Bern . Sedgeley Abbey , an 18th-century plantation house on the lower Cape Fear River was built of locally quarried coquina. The house that once stood on a vast tract of land directly across the river from Orton was described by local historian and author James Sprunt as "the grandest colonial residence of

6399-509: Was located during archaeological investigations on the site of the former plantation in 1978. In the past coquina was used for the construction of buildings in Denham, Western Australia , but quarrying is no longer permitted in the World Heritage Site . When first quarried, coquina is extremely soft. This softness makes it very easy to remove from the quarry and cut into shape. However,

6480-698: Was quarried and cut into blocks used in local construction. St Andrew's Anglican Church, the Old Pearler Restaurant, and parts of the Shark Bay Hotel in Shark Bay were built from coquina shell blocks. The church, built in 1954, has walls infilled with coquina shell blocks between a light steel frame and a shell facing, while the Old Pearler was built in 1974–1977 with buttressed coquina shell block walls. Recently discovered petroleum-bearing formations off

6561-510: Was used as building stone in St. Augustine as early as 1598 for construction of a powder house. This was the beginning of a building tradition that extended into the 1930s along Florida's Atlantic Coast. In the St. Augustine vicinity, the Castillo de San Marcos, Fort Matanzas , the old city gates, the Cathedral , Spanish and British Period residential structures, property line walls and tombs were constructed of coquina quarried on Anastasia Island. To

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