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Potoco Formation

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Journal Article
Journal: GSA Bulletin
Published: 01 November 2001
GSA Bulletin (2001) 113 (11): 1387–1400.
...B.K. Horton; B.A. Hampton; G.L. Waanders Abstract Sedimentologic data and palynological ages from Paleogene clastic deposits of the northern and central Altiplano plateau suggest foreland basin development in the central Andes by mid-Paleocene time. The nonmarine Potoco Formation (3000–6500 m thick...
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First thumbnail for: Paleogene synorogenic sedimentation in the Altipla...
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 Figure 8. Photographs of Potoco Formation. (A) View of ∼450-m-thick section composed of interbedded sheets of laterally continuous,  resistant sandstone (∼1–3 m thick) and less resistant siltstone. Section 5. (B) View of ∼50-m-thick section of stacked, cross-stratified  sandstones. Foresets are best developed in lower resistant ledge at right. Section 6; person in center is ∼1.8 m tall. (C) Prominent, ∼2- m-thick sandstone overlying thin interbedded sandstone and siltstone. Tabular geometry and lack of basal erosional scour for thick  sandstone indicate limited or no channel incision. Section 5; person at lower right is ∼1.8 m tall. (D) View of ∼10-m-thick, coarsening-  and thickening-upward section of thinly interbedded siltstone and sandstone (left) overlain by thicker sandstone (right). Interval is  interpreted as progradation of a crevasse splay into a flood-plain environment. Section 5; hammer at lower right (arrow) is 30 cm long
Published: 01 November 2001
Figure 8. Photographs of Potoco Formation. (A) View of ∼450-m-thick section composed of interbedded sheets of laterally continuous, resistant sandstone (∼1–3 m thick) and less resistant siltstone. Section 5. (B) View of ∼50-m-thick section of stacked, cross-stratified sandstones. Foresets
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Published: 01 November 2001
TABLE 1. PALYNOLOGICAL AGE DATA FOR POTOCO FORMATION
Journal Article
Published: 01 September 2002
Journal of Sedimentary Research (2002) 72 (5): 711–726.
... (probable foredeep) was underway, as recorded by extensive east-directed fluvial systems of the 3-6.5-km-thick Potoco Formation. Potoco compositional data are compatible with sediment sources in the incipient Western Cordillera and regions farther west, including (1) a probable thrust-belt source terrane...
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First thumbnail for: Tertiary Provenance History of the Northern and Ce...
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 Figure 3. Chronostratigraphic diagram of the uppermost Cretaceous–Cenozoic rocks in  the northern and central Altiplano, including symbols denoting available age control.  Rocks underlying and overlying the Potoco Formation have been dated by previous studies  (see text). New palynological age data for the Potoco Formation (see text) are based on  the plotted age ranges of several key species (from Regali et al., 1974a, 1974b). Shading  represents the palynological age restrictions for the majority of the Potoco Formation.  Time scale from Cande and Kent (1992)
Published: 01 November 2001
Figure 3. Chronostratigraphic diagram of the uppermost Cretaceous–Cenozoic rocks in the northern and central Altiplano, including symbols denoting available age control. Rocks underlying and overlying the Potoco Formation have been dated by previous studies (see text). New palynological age data
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 Figure 7. Photographs of lowermost Potoco and Santa Lucia Formations. (A) View of ∼50-m-thick section (foreground) of interbedded  siltstone, fine-grained sandstone, and thin calcareous paleosols in the lower-middle Santa Lucia Formation. Most resistant ledges are  formed by ∼10-cm-thick calcareous paleosols. Section 2; arrow points to seated person. (B) View of ∼200-m-thick section composed of  upper Santa Lucia sandstone (narrow ridge at left), lowermost Potoco paleosol interval (slope-forming unit), and lower Potoco resistant  sandstone (wide ridge at right). Section 1; arrow points to person standing at approximate top of paleosol interval. (C) Interval of ∼2.5  m of stacked nodular paleosols developed in fine-grained sandstone and siltstone of basal Potoco Formation. Section 2; 30-cm-long  hammer is parallel to bedding. (D) Paleosol in basal Potoco Formation exhibiting upper horizon of mottled, bioturbated, fine-grained  sandstone containing root casts and lower horizon (below hammer) of calcareous nodules and discontinuous calcite-filled fractures within  a fine-grained sandstone matrix. Section 3; hammer is parallel to bedding
Published: 01 November 2001
Figure 7. Photographs of lowermost Potoco and Santa Lucia Formations. (A) View of ∼50-m-thick section (foreground) of interbedded siltstone, fine-grained sandstone, and thin calcareous paleosols in the lower-middle Santa Lucia Formation. Most resistant ledges are formed by ∼10-cm-thick calcareous
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 Figure 4. Measured stratigraphic sections of Paleogene deposits in the northern  and central Altiplano (locations shown in Fig. 2), including facies types, formation names, stratigraphic correlations, paleocurrent data, published K-Ar dates, and locations of palynological samples. Rose diagrams depict east-directed paleocurrents in the Potoco Formation and west-directed paleocurrents  in the Santa Lucia Formation. Lithostratigraphic correlations for lower intervals are made on the basis of distinctive, carbonate-bearing strata of the El Molino Formation and gypsum beds of the Chuquichambi member of the Potoco Formation. Correlations for the upper interval are based on the stratigraphically  lowest occurrence of volcanic tuffs
Published: 01 November 2001
depict east-directed paleocurrents in the Potoco Formation and west-directed paleocurrents in the Santa Lucia Formation. Lithostratigraphic correlations for lower intervals are made on the basis of distinctive, carbonate-bearing strata of the El Molino Formation and gypsum beds of the Chuquichambi
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Generalized stratigraphic sections of Paleocene-lower Miocene deposits from the northern, central, and southern study regions (locations are shown in Fig. 1). Depicted features include thickness (km), basic lithology, paleocurrent data, and locations of sandstone point-count samples. Stratigraphic correlations are based on (1) distinctive lithostratigraphic elements such as the top of the El Molino Formation (0 m level, Sections 1-4, 9), the top of the Santa Lucia Formation (Sections 1-4, 9), the basal gypsum member of the Potoco Formation (Sections 5, 7, 8A), and basal conglomerate of the Coniri Formation (Sections 7, 8A, 8B), (2) palynological ages from the Potoco Formation, and (3) published 25-23 Ma K-Ar ages for the stratigraphically lowest tuffs in overlying volcaniclastic deposits. See Horton et al. (2001) for facies analyses and stratigraphic nomenclature.
Published: 01 September 2002
. Stratigraphic correlations are based on (1) distinctive lithostratigraphic elements such as the top of the El Molino Formation (0 m level, Sections 1-4, 9), the top of the Santa Lucia Formation (Sections 1-4, 9), the basal gypsum member of the Potoco Formation (Sections 5, 7, 8A), and basal conglomerate
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Simplified Cenozoic stratigraphic framework for the northern and central Altiplano. Ages are based on palynological assemblages, magnetostratigraphy, and isotopic ages of tuffs (see text). Ruled area indicates zone of limited sediment accumulation and extensive paleosol development in the lowermost Potoco Formation (after Horton et al. 2001). Dashed lines depict approximate boundaries between partially age-equivalent strata (upper Potoco, Coniri, and Neogene-Quaternary volcaniclastic units).
Published: 01 September 2002
in the lowermost Potoco Formation (after Horton et al. 2001 ). Dashed lines depict approximate boundaries between partially age-equivalent strata (upper Potoco, Coniri, and Neogene-Quaternary volcaniclastic units).
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Schematic reconstructions of Altiplano basin development. The top row shows map-view reconstructions based on provenance data (the map outline corresponds approximately to the map in Fig. 1). The bottom row shows interpretive, unrestored regional cross sections based on provenance, structural, and thermochronological data (see text for discussion). A) Mid-Paleocene deposition of a thin succession of east-derived Santa Lucia Formation in eastern Altiplano and Eastern Cordillera concurrent with contractional deformation and foredeep development in the Precordillera. At this time, depositional systems derived from a probable thrust belt to the west did not reach the Altiplano. B) Late Eocene-Oligocene deposition across Altiplano of the thick Potoco Formation derived from a thrust belt and volcanic arc to the west (Western Cordillera and Precordillera). Question marks and dashed thrust faults convey uncertainty in initial age of shortening-related uplift in Eastern Cordillera. C) Late Oligocene- Miocene deposition of uppermost Potoco and Coniri formations derived primarily from a west-vergent backthrust belt in the Eastern Cordillera. Coeval west-derived volcaniclastic units are limited to the westernmost Altiplano and signify erosion of a volcanic arc to the west (Western Cordillera). Neogene deposition in the Altiplano is synchronous with shortening in the east-vergent Andean thrust belt (central Eastern Cordillera to Subandean Zone) and foreland-basin development in the Chaco Plain.
Published: 01 September 2002
, depositional systems derived from a probable thrust belt to the west did not reach the Altiplano. B) Late Eocene-Oligocene deposition across Altiplano of the thick Potoco Formation derived from a thrust belt and volcanic arc to the west (Western Cordillera and Precordillera). Question marks and dashed thrust
Journal Article
Journal: GSA Bulletin
Published: 01 June 1997
GSA Bulletin (1997) 109 (6): 709–727.
... Ma. This unconformity separates the Upper Puca and Corocoro supersequences in Bolivia, and is thus coeval with the Zuni-Tejas sequence boundary of North America. The thick overlying Potoco and Camargo formations represent a late Paleocene–Oligocene foreland fill. The onset of shortening along...
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Map-view summary of sandstone point-count data and paleocurrent data for the Potoco and Coniri formations. The map outline corresponds approximately to the map in Fig. 1. In the Q-F-L ternary diagrams, irregular filled areas represent the approximate range of compositions for sandstone samples from the indicated stratigraphic section (Figs. 5, 6, 8, 9). Note the substantial compositional difference between west-derived and east-derived deposits. Arrows represent mean paleocurrent directions for entire measured sections or indicated stratigraphic intervals. Dotted lines define Paleocene-lower Miocene outcrop belts, and dashed lines indicate the present margins of the Altiplano (from Fig. 1).
Published: 01 September 2002
Figure 11 Map-view summary of sandstone point-count data and paleocurrent data for the Potoco and Coniri formations. The map outline corresponds approximately to the map in Fig. 1 . In the Q-F-L ternary diagrams, irregular filled areas represent the approximate range of compositions
Journal Article
Published: 07 December 2021
Journal of the Geological Society (2022) 179 (3): jgs2021-003.
... Ar/ 39 Ar ages that document the depositional chronology and sediment sources of the Paleogene Potoco Formation and Neogene Totora Formation exposed in the eastern limb of the Corque Syncline ( Fig. 2 ). Our results indicate that c. 7.4 km of strata were deposited between 36.7 and 18.7 Ma. Flexural...
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First thumbnail for: Basin evolution in response to flat-slab subductio...
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Journal Article
Journal: GSA Bulletin
Published: 01 January 2003
GSA Bulletin (2003) 115 (1): 58–77.
... for extremely slow deposition of these units (discussed subsequently). Sempere et al. (1997) summarized biostratigraphic evidence from units in northern Argentina that are lithostratigraphically similar to the Impora and Camargo (Potoco) Formations and suggest Paleocene–early Eocene ages. In the Camargo...
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First thumbnail for: Early to middle Tertiary foreland basin developmen...
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Journal Article
Journal: GSA Bulletin
Published: 01 September 2010
GSA Bulletin (2010) 122 (9-10): 1443–1462.
... Formation) and east-derived, distal-fluvial siltstone and sandstone (Santa Lucia Formation); (2) a 3000–6500-m-thick middle succession of upper Eocene to Oligocene west-derived fluvial sandstone (Potoco Formation); (3) a 1000–4000-m-thick upper succession of poorly dated, partially Potoco-age–equivalent...
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First thumbnail for: Oligocene–Miocene basin evolution in the northern ...
Second thumbnail for: Oligocene–Miocene basin evolution in the northern ...
Third thumbnail for: Oligocene–Miocene basin evolution in the northern ...
Journal Article
Published: 26 April 2021
Petroleum Geoscience (2021) 27 (3): petgeo2020-099.
... of the Supplementary material ), and the sedimentation rates. Limestones (Potoco Formation), 80 m thick, overlie these sands and are the first transgressive deposits above the BAU. The overlying unit is marked by a sharp increase in the GR log. A thick interval of calcareous mudstone with a high organic content...
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First thumbnail for: Evaluating the segmented post-rift stratigraphic a...
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Journal Article
Journal: Economic Geology
Published: 01 May 2002
Economic Geology (2002) 97 (3): 573–592.
... ( Richter et al., 1991 ). Potassium-argon ages of 8.0 ± 0.1 Ma and 8.5 ± 0.3 Ma have been reported on biotite from dacite samples ( Ludington et al., 1992 ). The igneous rocks were emplaced into continental red beds (sandstone, shale, and conglomerate) of the early Eocene to early Oligocene Potoco Formation...
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First thumbnail for: Sources of Lead in the San Cristobal, Pulacayo, an...
Second thumbnail for: Sources of Lead in the San Cristobal, Pulacayo, an...
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Journal Article
Journal: Economic Geology
Published: 01 December 2002
Economic Geology (2002) 97 (8): 1701–1740.
... Atacama basin east of the Domeyko fault, which was then experiencing sinistral-transpressive displacement. Moreover, on a regional scale, Horton et al. (2001) identify a westerly, i.e., Chilean, source for the thick succession of clastic sedimentary rocks making up the Potoco Formation on the present...
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First thumbnail for: Anatomy, Evolution, and Metallogenic Significance ...
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Journal Article
Journal: Lithosphere
Publisher: GSW
Published: 01 April 2015
Lithosphere (2015) 7 (2): 117–137.
... Altiplano, the Eocene–Oligocene San Jerónimo (Puno) Group commonly exceeds 5 km ( Newell, 1949 ; Palacios et al., 1993 ). For the central Altiplano, a 6-km-thick succession is composed of the upper Eocene–lowermost Miocene Potoco Formation or lower Corocoro Group ( Ahlfeld and Branisa, 1960 ; Evernden et...
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First thumbnail for: Punctuated shortening and subsidence in the Altipl...
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Series: Geological Society, London, Special Publications
Published: 01 January 2016
DOI: 10.1144/SP431.10
EISBN: 9781862399631
... Potoco Formation; uA/A, upper Aptian–Albian marker; Cen, top Cenomanian sediments; Tur, top Turonian sediments; NA, the New Amsterdam Formation; O, the Oligocene Pomeroon Formation. SDR, seawards-dipping reflector wedge. The Lower Jurassic–Lower Cretaceous strata have been found on the Guyana...