Noreán Formation

The Noreán Formation (Spanish: Formación Noreán, J1-2n,[2][3] J1n)[4] is a geological formation of the Eastern Ranges of the Colombian Andes, the Serranía de San Lucas and as basement underlying the southernmost Lower and northern Middle Magdalena Valleys. The formation consists of volcanic and pyroclastic lavas that range from andesites to rhyolites. Vitric, lithic and crystal tuffs and andesitic dikes and hypabyssal bodies are also present in the formation.

Noreán Formation
Stratigraphic range: Sinemurian-Toarcian
194.6–174.8 Ma
Outcrop of the Effusive Rhyolitic Unit (Jner) south of Pailitas, Cesar[1]
TypeGeological formation
Sub-unitsSee text
UnderliesTablazo & La Luna Formations
OverliesBocas, Morrocoyal & Sudán Formations
Norosí Batholith, San Lucas & Bucaramanga Gneiss
Thickness2,062 m (6,765 ft)
Lithology
PrimaryAndesitic-rhyolitic lavas & pyroclastics
OtherIgnimbrites, thin sandstones
Location
Coordinates8°00′00″N 74°00′00″W
RegionBolívar, Cesar & Santander
Country Colombia
ExtentSerranía de San Lucas & Eastern Ranges, Andes
VIM & VMM (subsurface)
Type section
Named forCaserío Noreán
Named byClavijo
LocationAguachica
Year defined1995
Coordinates8°22′54″N 73°36′38″W
RegionCesar
Country Colombia

Paleogeography of Northern South America
200 Ma, by Ron Blakey

The more than 2,000 metres (6,600 ft) thick formation was deposited in a continental arc magmatic setting in an Early Jurassic graben that presently forms the basement of the Middle Magdalena Valley (VMM). A positive anomaly of Pb suggests a subduction-related genesis dominated by explosive volcanism.

Etymology

The Noreán Formation was first defined as the "Unidad Volcanoclástica de Noreán" ("Volcanoclastic Unit of Noreán") in 1995 and in the same year elevated to a formal formation by Clavijo in 1995 as part of the geologic mapping for Plancha 65 Tamalameque and named after the caserío Noreán, 1 kilometre (0.62 mi) north of Aguachica, Cesar.[5] The type locality of the Noreán Formation is along the road between Buturama and Bombeadero in Aguachica.[6]

Description

The Noreán Formation is found in the northern part of the Eastern Ranges of the Colombian Andes, stretching from the Cesar Department in the north, towards the Serranía de San Lucas in Bolívar to the Santander Massif in Santander in the south. The formation forms the economic basement in the southern Lower Magdalena Valley (VIM) and the northern Middle Magdalena Valley (VMM). The formation is interpreted as characteristic of an important explosive volcanic phase, the materials of which were deposited in a graben setting of the Middle Magdalena Valley. The Early Jurassic basin was covered by a shallow sea and in part drained by rivers and lakes. The basin at time of deposition was bordered by a volcanic arc, characterized by basaltic to calc-alkaline magmas.[7] The formation also comprises less than 1 metre (3.3 ft) thin very fine to fine sandstone beds constituting quartz (90 to 60 %), feldspars (10 to 40 %) and lithic fragments (1-2 %).[8]

The volcanic and pyroclastic rocks of the Noreán Formation are composed of lavas that range from andesitic to rhyolitic, together with vitric, lithic and crystal tuffs. Mainly andesitic dikes and hypabyssal bodies are also present. Geochemically, the volcanic and pyroclastic rocks exhibit chemical similarities, belong to the calc-alkaline series and have negative anomalies of Nb, P and Ti and a positive anomaly of Pb, suggesting a subduction-related genesis.[9]

U-Pb zircon geochronology resulted in ages of 192.4 ± 2.2 Ma in a basaltic andesite, 184.9 ± 2.0 Ma in an andesitic lava and 175.9 ± 1.1 Ma in a rhyolitic lava, indicating the occurrence of volcanic events in this section of the Noreán Formation from the Lower to the earliest Middle Jurassic. Zircon inheritance suggests that the volcanic arc was emplaced in a Meso- to Neoproterozoic basement. The Noreán Formation represents continental arc magmatism,[9] which occurred during a phase of extensional tectonics along the continental margin of northwestern South America from approximately 195 to 168 Ma.[10]

Stratigraphy

To the northwest of the Santander Massif, the formation overlies the Bocas Formation and is unconformably overlain by the Tablazo Formation.[6] In some locations in this area, the formation is found in faulted contact with the Bucaramanga Gneiss, La Virgen Formation and the Tablazo and La Luna Formations. In the Serranía de San Lucas, the Noreán Formation conformably overlies the Morrocoyal Formation and in this area is overlain by the Tablazo Formation and the Arenal Conglomeratic Unit. Across the San Lucas mountains, the formation is in faulted and discordant contact with the Norosí Batholith, the San Lucas Gneiss and the Sudán Formation.[7]

The formation is offset by the megaregional Bucaramanga-Santa Marta Fault.[3][1]

Subdivision

On the western flanks of the Eastern Cordillera, the formation is subdivided into six units and in the Serranía de San Lucas into four (1, 3, 5 and 6 of the six named below), from young to old:

  1. Hypobyssal Andesitic Unit (Jnha) - 12 metres (39 ft)[11]
  2. Effusive Rhyolitic Unit (Jner) - 150 metres (490 ft)[12]
  3. Dacitic Effusive Unit (Jned) - 350 metres (1,150 ft)[13]
  4. Pyroclastic and Effusive Dacitic Unit (Jnpd) - 450 metres (1,480 ft)[14]
  5. Effusive Spherulitic Unit (Jnee) - 300 metres (980 ft)[15]
  6. Pyroclastic-epiclastic Unit (Jnpe) - 800 metres (2,600 ft)[16]

Age
Geologic map of the northern VMM and Santander Massif with the Noreán Formation in light purple. U-Pb dating sites with associated ages are indicated.

The age of the Noreán Formation has been established using potassium-argon (K-Ar), rubidium-strontium (Rb-Sr), and uranium-lead dating (U-Pb). The first method gave an age range of 194 ± 6 Ma, the Rb-Sr dating method provided a range of 161 ± 27 Ma and U-Pb dating of zircons resulted in ages of 201.6 ± 3.6 and 196.1 ± 4.4.[7] Refined dating of the formation performed in 2019 by Correa Martínez et al. concluded an age range between 192.4 ± 2.2 and 175.9 ± 1.1 Ma, spanning most of the Early Jurassic, from Sinemurian to Toarcian.[17] The Noreán Formation was intruded by the San Lucas Granitoid in the Middle Jurassic, dated at 166.9 ± 6 Ma.[18] A 2020 thermochronological study concluded that the Jurassic volcanic rocks covering the Santander Massif were exhumed during the latest Cretaceous to early Paleocene.[19]

Outcrops

The northernmost outcrop of the Noreán Formation is found in Chimichagua, Cesar.[2] In Cesar, outcrops occur south of the village of Saloa and around the town of Pailitas,[3] east of Tamalameque and Pelaya and west of La Gloria,[1] in the western part of Morales, Bolívar, north and east of Aguachica where its type locality is situated,[20] in the Serranía de San Lucas, where the urban center of Santa Rosa del Sur rests on top of the formation,[21] in the west of San Pablo, Bolívar,[22] and in the western part of Cantagallo, Bolívar.[23]

Regional correlations

In the Santander Massif, the Noreán Formation has been correlated to the Jordán Formation, while in the Serranía de San Lucas the formation correlates with and is partly overlying the Morrocoyal Formation. In the Sierra Nevada de Santa Marta of northern Colombia, the Noreán Formation is considered equivalent with the Guatapurí Formation, the Corual and Los Indios Formations and the ignimbrite complexes of Caja de Ahorros, La Paila and La Piña. In the Serranía del Perijá to the east of the extent of the formation, the Noreán Formation correlates with La Quinta Formation. In the La Guajira peninsula, the formation is time-equivalent with the Rancho Grande Formation while to the south of its area in the Upper Magdalena Valley the Noreán Formation is correlated with the Saldaña Formation.[7] The Lower Jurassic is missing in the Llanos Basin to the southeast of the extent of the Eastern Cordillera.[24]

Stratigraphy of the Llanos Basin and surrounding provinces
MaAgePaleomapRegional eventsCatatumboCordilleraproximal Llanosdistal LlanosPutumayoVSMEnvironmentsMaximum thicknessPetroleum geologyNotes
0.01Holocene
Holocene volcanism
Seismic activity		alluviumOverburden
1Pleistocene
Pleistocene volcanism
Andean orogeny 3
Glaciations		GuayaboSoatá
Sabana		NecesidadGuayaboGigante
Neiva		Alluvial to fluvial (Guayabo)550 m (1,800 ft)
(Guayabo)		[25][26][27][28]
2.6Pliocene
Pliocene volcanism
Andean orogeny 3
GABI		Subachoque
5.3MessinianAndean orogeny 3
Foreland		MarichuelaCaimánHonda[27][29]
13.5LanghianRegional floodingLeónhiatusCajaLeónLacustrine (León)400 m (1,300 ft)
(León)		Seal[28][30]
16.2BurdigalianMiocene inundations
Andean orogeny 2		C1Carbonera C1OspinaProximal fluvio-deltaic (C1)850 m (2,790 ft)
(Carbonera)		Reservoir[29][28]
17.3C2Carbonera C2Distal lacustrine-deltaic (C2)Seal
19C3Carbonera C3Proximal fluvio-deltaic (C3)Reservoir
21Early MiocenePebas wetlandsC4Carbonera C4BarzalosaDistal fluvio-deltaic (C4)Seal
23Late Oligocene
Andean orogeny 1
Foredeep		C5Carbonera C5OritoProximal fluvio-deltaic (C5)Reservoir[26][29]
25C6Carbonera C6Distal fluvio-lacustrine (C6)Seal
28Early OligoceneC7C7PepinoGualandayProximal deltaic-marine (C7)Reservoir[26][29][31]
32Oligo-EoceneC8UsmeC8onlapMarine-deltaic (C8)Seal
Source		[31]
35Late Eocene
MiradorMiradorCoastal (Mirador)240 m (790 ft)
(Mirador)		Reservoir[28][32]
40Middle EoceneRegaderahiatus
45
50Early Eocene
SochaLos CuervosDeltaic (Los Cuervos)260 m (850 ft)
(Los Cuervos)		Seal
Source		[28][32]
55Late PaleocenePETM
2000 ppm CO2		Los CuervosBogotáGualanday
60Early PaleoceneSALMABarcoGuaduasBarcoRumiyacoFluvial (Barco)225 m (738 ft)
(Barco)		Reservoir[25][26][29][28][33]
65Maastrichtian
KT extinctionCatatumboGuadalupeMonserrateDeltaic-fluvial (Guadalupe)750 m (2,460 ft)
(Guadalupe)		Reservoir[25][28]
72CampanianEnd of riftingColón-Mito Juan[28][34]
83SantonianVilleta/Güagüaquí
86Coniacian
89TuronianCenomanian-Turonian anoxic eventLa LunaChipaqueGachetáhiatusRestricted marine (all)500 m (1,600 ft)
(Gachetá)		Source[25][28][35]
93Cenomanian
Rift 2
100AlbianUneUneCaballosDeltaic (Une)500 m (1,600 ft)
(Une)		Reservoir[29][35]
113Aptian
CapachoFómequeMotemaYavíOpen marine (Fómeque)800 m (2,600 ft)
(Fómeque)		Source (Fóm)[26][28][36]
125BarremianHigh biodiversityAguardientePajaShallow to open marine (Paja)940 m (3,080 ft)
(Paja)		Reservoir[25]
129Hauterivian
Rift 1Tibú-
Mercedes		Las JuntashiatusDeltaic (Las Juntas)910 m (2,990 ft)
(Las Juntas)		Reservoir (LJun)[25]
133ValanginianRío NegroCáqueza
Macanal
Rosablanca		Restricted marine (Macanal)2,935 m (9,629 ft)
(Macanal)		Source (Mac)[26][37]
140BerriasianGirón
145TithonianBreak-up of PangeaJordánArcabucoBuenavista
Batá
SaldañaAlluvial, fluvial (Buenavista)110 m (360 ft)
(Buenavista)		"Jurassic"[29][38]
150Early-Mid Jurassic
Passive margin 2La Quinta
Montebel

Noreán		hiatusCoastal tuff (La Quinta)100 m (330 ft)
(La Quinta)		[39]
201Late Triassic
MucuchachiPayandé[29]
235Early Triassic
Pangeahiatus"Paleozoic"
250Permian
300Late Carboniferous
Famatinian orogenyCerro Neiva
()		[40]
340Early CarboniferousFossil fish
Romer's gap		Cuche
(355-385)		Farallones
()		Deltaic, estuarine (Cuche)900 m (3,000 ft)
(Cuche)
360Late Devonian
Passive margin 1Río Cachirí
(360-419)		Ambicá
()		Alluvial-fluvial-reef (Farallones)2,400 m (7,900 ft)
(Farallones)		[37][41][42][43][44]
390Early Devonian
High biodiversityFloresta
(387-400)
El Tíbet		Shallow marine (Floresta)600 m (2,000 ft)
(Floresta)
410Late SilurianSilurian mystery
425Early Silurianhiatus
440Late Ordovician
Rich fauna in BoliviaSan Pedro
(450-490)		Duda
()
470Early OrdovicianFirst fossilsBusbanzá
(>470±22)
Chuscales
Otengá		Guape
()		Río Nevado
()		Hígado
()
Agua Blanca
Venado
(470-475)
[45][46][47]
488Late Cambrian
Regional intrusionsChicamocha
(490-515)		Quetame
()		Ariarí
()		SJ del Guaviare
(490-590)		San Isidro
()		[48][49]
515Early CambrianCambrian explosion[47][50]
542Ediacaran
Break-up of Rodiniapre-Quetamepost-ParguazaEl Barro
()		Yellow: allochthonous basement
(Chibcha Terrane)
Green: autochthonous basement
(Río Negro-Juruena Province)		Basement[51][52]
600Neoproterozoic
Cariri Velhos orogenyBucaramanga
(600-1400)		pre-Guaviare[48]
800
Snowball Earth[53]
1000Mesoproterozoic
Sunsás orogenyAriarí
(1000)		La Urraca
(1030-1100)		[54][55][56][57]
1300Rondônia-Juruá orogenypre-AriaríParguaza
(1300-1400)		Garzón
(1180-1550)		[58]
1400
pre-Bucaramanga[59]
1600PaleoproterozoicMaimachi
(1500-1700)		pre-Garzón[60]
1800
Tapajós orogenyMitú
(1800)		[58][60]
1950Transamazonic orogenypre-Mitú[58]
2200Columbia
2530Archean
Carajas-Imataca orogeny[58]
3100Kenorland
Sources
Legend
  • group
  • important formation
  • fossiliferous formation
  • minor formation
  • (age in Ma)
  • proximal Llanos (Medina)[note 1]
  • distal Llanos (Saltarin 1A well)[note 2]

See also

Notes
  1. based on Duarte et al. (2019)[61], García González et al. (2009),[62] and geological report of Villavicencio[63]
  2. based on Duarte et al. (2019)[61] and the hydrocarbon potential evaluation performed by the UIS and ANH in 2009[64]

References
  1. Plancha 65, 1994
  2. Plancha 47, 2001
  3. Plancha 55, 2006
  4. González Iregui et al., 2015, p.56
  5. Royero, 1996, p.10
  6. Correa Martínez et al., 2019, p.31
  7. Correa Martínez et al., 2019, p.32
  8. González Iregui et al., 2015, p.58
  9. Correa Martínez et al., 2019, p.29
  10. Rodríguez García et al., 2020, p.43
  11. Royero, 1996, p.16
  12. Royero, 1996, pp.15-16
  13. Royero, 1996, p.15
  14. Royero, 1996, pp.13-15
  15. Royero, 1996, p.12
  16. Royero, 1996, pp.11-12
  17. Correa Martínez et al., 2019, p.43
  18. Clavijo et al., 2008, p.52
  19. Amaya Ferreira et al., 2020, p.11
  20. Plancha 75, 1992
  21. Plancha 85, 2006
  22. Plancha 96, 2006
  23. Plancha 108, 2012
  24. Barrero et al., 2007, p.70
  25. García González et al., 2009, p.27
  26. García González et al., 2009, p.50
  27. García González et al., 2009, p.85
  28. Barrero et al., 2007, p.60
  29. Barrero et al., 2007, p.58
  30. Plancha 111, 2001, p.29
  31. Plancha 177, 2015, p.39
  32. Plancha 111, 2001, p.26
  33. Plancha 111, 2001, p.24
  34. Plancha 111, 2001, p.23
  35. Pulido & Gómez, 2001, p.32
  36. Pulido & Gómez, 2001, p.30
  37. Pulido & Gómez, 2001, pp.21-26
  38. Pulido & Gómez, 2001, p.28
  39. Correa Martínez et al., 2019, p.49
  40. Plancha 303, 2002, p.27
  41. Terraza et al., 2008, p.22
  42. Plancha 229, 2015, pp.46-55
  43. Plancha 303, 2002, p.26
  44. Moreno Sánchez et al., 2009, p.53
  45. Mantilla Figueroa et al., 2015, p.43
  46. Manosalva Sánchez et al., 2017, p.84
  47. Plancha 303, 2002, p.24
  48. Mantilla Figueroa et al., 2015, p.42
  49. Arango Mejía et al., 2012, p.25
  50. Plancha 350, 2011, p.49
  51. Pulido & Gómez, 2001, pp.17-21
  52. Plancha 111, 2001, p.13
  53. Plancha 303, 2002, p.23
  54. Plancha 348, 2015, p.38
  55. Planchas 367-414, 2003, p.35
  56. Toro Toro et al., 2014, p.22
  57. Plancha 303, 2002, p.21
  58. Bonilla et al., 2016, p.19
  59. Gómez Tapias et al., 2015, p.209
  60. Bonilla et al., 2016, p.22
  61. Duarte et al., 2019
  62. García González et al., 2009
  63. Pulido & Gómez, 2001
  64. García González et al., 2009, p.60

Bibliography

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