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64-749: Santos Basin 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

128-627: A depth of about 3 kilometres (9,800 ft), and the reservoirs are marine turbidite deposits transgressing over the Albian limestone shelf. The stratigraphy starts with basalt flows dated at 120 Ma, overlain by the Lagoa Feia Group , consisting of the organic-rich lacustrine "green shales" followed by lacustrine limestones and continental sandstones and conglomerates , transitioning into marine sediments with evaporites, limestones, and limestone altered dolomites . The shallow marine limestones of

192-543: 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

256-768: A new 65 million barrel discovery was made by Petrobras near the Barracuda oil field. Tropical savanna climate Tropical savanna climate or tropical wet and dry climate is a tropical climate sub-type that corresponds to the Köppen climate classification categories Aw (for a dry "winter") and As (for a dry "summer"). The driest month has less than 60 mm (2.4 in) of precipitation and also less than 100 − ( Total Annual Precipitation (mm) 25 ) {\textstyle 100-\left({\frac {\text{Total Annual Precipitation (mm)}}{25}}\right)} mm of precipitation. This latter fact

320-627: 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

384-774: 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: Oil reservoirs include formations deposited during

448-418: 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

512-437: 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

576-556: 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

640-464: A tropical monsoon climate or have more pronounced dry season(s). It is impossible for a tropical savanna climate to have more than 2,500 mm (98 in) as such would result in a negative value in that equation. In tropical savanna climates, the dry season can become severe, and often drought conditions prevail during the course of the year. Tropical savanna climates often feature tree-studded grasslands due to its dryness, rather than thick jungle. It

704-455: A water depth of 124 metres (407 ft). The largest fields, listed by their year of discovery year, include Linguado (1978), Carapeba (1982), Vermelho (1982), Marimba (1984), Albacora (1984), Marlim (1985), Albacora-Leste (1986), Marlim Sul (1987), Marlim Leste (1987), Barracuda (1989), Caratinga (1989), Espadarte (1994), Roncador (1996), Jubarte (2002), Cachalote (2002), and Badejo (2008). The largest Marlim field

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768-490: 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

832-498: 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

896-527: 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

960-451: 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

1024-414: 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

1088-606: 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

1152-571: Is also prevalent in sections of northern Australia , the Pacific Islands, in extreme southern North America in south Florida , and some islands in the Caribbean . Most places that have this climate are found at the outer margins of the tropical zone , but occasionally an inner-tropical location (e.g., San Marcos , Antioquia , Colombia ) also qualifies. Similarly, the Caribbean coast, eastward from

1216-445: Is in a direct contrast to a tropical monsoon climate , whose driest month sees less than 60 mm (2.4 in) of precipitation but has more than 100 − ( Total Annual Precipitation (mm) 25 ) {\textstyle 100-\left({\frac {\text{Total Annual Precipitation (mm)}}{25}}\right)} of precipitation. In essence, a tropical savanna climate tends to either see less overall rainfall than

1280-432: Is located in the northeast of the basin, 110 kilometres (68 mi) offshore in water depths ranging from 650 to 1,050 metres (2,130 to 3,440 ft). By 2003, 41 oil and gas fields were discovered, which ranging at distances from 50 to 140 kilometres (31 to 87 mi) from the coast and at water depths varying from 80 to 2,400 metres (260 to 7,870 ft). Of these fields, 37 are being developed by Petrobras . By 2003,

1344-403: Is the case East Africa (Mombasa, Kenya, Somalia), Sri Lanka ( Trincomalee ) and coastal regions of Northeastern Brazil (from São Luís through Natal to Maceió ), for instance. The difference between "summer" and "winter" in such tropical locations is usually so slight that a distinction between an As and Aw climate is trivial. In most places that have tropical wet and dry climates, however,

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1408-556: Is this widespread occurrence of tall, coarse grass (called savanna) which has led to Aw and As climates often being referred to as the tropical savanna. However, there is some doubt whether tropical grasslands are climatically induced. Additionally, pure savannas, without trees, are the exception rather than the rule. There are generally four types of tropical savanna climates: Tropical savanna climates are most commonly found in Africa , Asia , Central America , and South America . The climate

1472-496: 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

1536-514: 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

1600-458: 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

1664-431: 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

1728-415: 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

1792-428: Is used in place of Aw if the dry season occurs during the time of higher sun and longer days. This is typically due to a rain shadow effect that cuts off ITCZ-triggered summer precipitation in a tropical area while winter precipitation remains sufficient to preclude a hot semi-arid climate ( BSh ) and temperatures in the summer months are warm enough to preclude a Mediterranean climate ( Csa/Csb ) classification. This

1856-512: The Aptian and pre-Aptian continental rift phase, of post-salt Albian - Cenomanian shallow-water marine carbonates and deepwater sandstones , and in turbidites of the open marine drift phase of Late Cretaceous and early Tertiary ages. The Namorado Field "location was selected based on seismic interpretation of a structural high at the top of the Macaé Formation (Albian limestones )" at

1920-514: 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

1984-671: The Congo Craton as 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

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2048-894: The Gulf of Urabá on the Colombia – Panamá border to the Orinoco river delta , on the Atlantic Ocean (ca. 4,000 km (2,485 mi)), have long dry periods (the extreme is the BSh climate (see below), characterized by very low, unreliable precipitation, present, for instance, in extensive areas in the Guajira , and Coro, western Venezuela, the northernmost peninsulas in South America, which receive <300 mm (11.8 in) total annual precipitation, practically all in two or three months). This condition extends to

2112-655: The Lesser Antilles and Greater Antilles forming the Circumcaribbean dry belt. The length and severity of the dry season diminishes inland (southward); at the latitude of the Amazon river—which flows eastward, just south of the equatorial line—the climate is Af. East from the Andes, between the arid Caribbean and the ever-wet Amazon, are the Orinoco river Llanos or savannas , from where this climate takes its name. Sometimes As

2176-533: 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

2240-422: 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

2304-457: 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

2368-617: 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

2432-743: The Macaé Formation follow, then the Namorado turbidite sandstones, and finally the Campos Formation , consisting of the turbidite sandstone Carapebus Member and the prograding slope and shelf Ubatuba Formation . The off-shore oil exploration in the Campos Basin began in 1968. The first exploratory well was drilled in 1971. The first field to be discovered was Garoupa in 1974, at a shallow water depth of 120 metres (390 ft), followed by Namorado in 1975 in 166 metres (545 ft) of water. The first oil production started in 1977 from Enchova Field , at

2496-517: 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

2560-469: 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

2624-456: 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,

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2688-667: The Santos Basin. Campos Basin The Campos Basin is one of 12 coastal sedimentary basins of Brazil . It spans both onshore and offshore parts of the South Atlantic with the onshore part located near Rio de Janeiro . The basin originated in Neocomian stage of the Cretaceous period 145–130 million years ago during the breakup of Gondwana . It has a total area of about 115,000 square kilometres (44,000 sq mi), with

2752-469: 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

2816-437: 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

2880-465: 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

2944-741: 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

3008-477: 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

3072-655: 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

3136-611: 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

3200-458: 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

3264-483: 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

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3328-399: 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

3392-457: 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

3456-404: The oil production from the basin had reached 1.21 million barrels per day. The production comes from a variety of reservoirs including siliciclastic turbidites , fractured basalts , coquinas , calcarenites (limestones). The total cumulative production from the Campos Basin by 2003 was 3.9 billion barrels of oil with remaining reserves of 8.5 billion barrels. In February 2010,

3520-790: The onshore portion small at only 500 square kilometres (190 sq mi). The basin is named after the Campos dos Goytacazes city. The Campos Basin is bound on the south by the Cabo Frio High , separating the basin from the Santos Basin and on the north by the Vitória High , forming the boundary with the Espírito Santo Basin . Campos Basin contains the Paraiba do Sul River delta. The South Atlantic margin developed on Archean stable cratons consisting of hard and resistant rocks and partly on

3584-742: 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

3648-481: 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

3712-620: 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

3776-523: 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

3840-411: 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

3904-463: 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

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3968-503: 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,

4032-708: 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

4096-539: 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 is 4,200 metres (13,800 ft) thick and includes four formations, from old to young

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