Santa Teresa Formation
Stratigraphic range: Late Oligocene (Deseadan) ~
Type	Geological formation
Underlies	alluvium
Overlies	San Juan de Río Seco Formation
Thickness	Type section: 118 m (387 ft) Maximum: 150 m (490 ft)
Lithology
Primary	Claystone
Other	Siltstone, calcareous sandstone
Location
Coordinates	4°50′55″N 74°37′14″W / 4.84861°N 74.62056°W / 4.84861; -74.62056
Country	Colombia
Extent	Western Eastern Ranges, Andes Southern Middle Magdalena Valley
Type section
Named for	Vereda Santa Teresa
Named by	De Porta
Location	San Juan de Rioseco
Year defined	1966
Coordinates	4°50′55″N 74°37′14″W / 4.84861°N 74.62056°W / 4.84861; -74.62056
Region	Cundinamarca
Country	Colombia
Thickness at type section	118 m (387 ft)
Paleogeography of Northern South America 35 Ma, by Ron Blakey

The Santa Teresa Formation (Spanish: Formación Santa Teresa, Tist, Pgst) is a geological formation of the western Eastern Ranges of the Colombian Andes, west of the Bituima Fault, and the southern Middle Magdalena Valley. The formation spreads across the western part of Cundinamarca and the northern portion of Tolima. The formation consists of grey claystones intercalated by orange quartz siltstones and sandstones of small to conglomeratic grain size. The thickness at its type section has been measured to be 118 metres (387 ft) and a maximum thickness of 150 metres (490 ft) suggested.

In the formation, dated on the basis of its fossil content to the Late Oligocene, many leaf imprints and mollusks were found, suggesting a lacustrine to deltaic depositional environment with periodical marine incursions.

Etymology

The formation was defined by De Porta in 1966 and named after the vereda Santa Teresa, San Juan de Rioseco.^[1]

Description

Type locality of the Santa Teresa Formation in Cundinamarca

The Santa Teresa Formation is the youngest unit outcropping in the Jerusalén-Guaduas synclinal, western Eastern Ranges, covering the San Juan de Río Seco Formation. The formation was formerly called La Cira Formation. In the Balú quebrada, the formation shows a thickness of 118 metres (387 ft), while the maximum thickness could reach 150 metres (490 ft).^[1]

The lower boundary of the formation is marked by the first occurrence of grey claystones, covering the light brown claystones of the San Juan de Río Seco Formation. The formation comprises grey claystones intercalated by orange quartz siltstones and sandstones of small to conglomeratic grain size. The roundness of the sandstone grains has been characterized as angular to subangular by Lamus Ochoa et al. in 2013.^[2] The claystones occur in thick layers with wavy lamination.^[1]

In these thick packages of claystones, the formation has provided fossil leaves in various forms and sizes, and to a lesser extent the remains of mollusks; gastropods and bivalves. The basal contacts of these beds are straight to transitional and most of the time are coarsening upward towards quartz arenites where the gastropods dominate. These facies sequences have a thickness of about 2 metres (6.6 ft). Locally, bioturbation, siderite nodules and coal beds occur in the formation. The sandstones occur in very thin to very thick beds, characterized by plain parallel lamination, in lenses and very locally in flasers. The cement of the arenites is calcareous.^[1] The grain composition of the lithic fraction comprises zircon,^[3] epidote, zoisite, clinozoisite and pyroxenes, which at the top of the formation amounts to 86 percent.^[4]

Paleontology

The Santa Teresa Formation has provided fossil mollusks, described by De Porta and Solé De Porta in 1962 and De Porta Anodontites laciranus, Diplodon oponcintonis, Diplodon waringi,^[8] and Corbula sp., among other mollusks described by De Porta in 1966.^[1]

Regional correlations

Stratigraphy of the Llanos Basin and surrounding provinces

Ma	Age	Paleomap	Regional events	Catatumbo	Cordillera	proximal Llanos	distal Llanos	Putumayo	VSM	Environments	Maximum thickness	Petroleum geology	Notes
0.01	Holocene		Holocene volcanism Seismic activity	alluvium								Overburden
1	Pleistocene		Pleistocene volcanism Andean orogeny 3 Glaciations	Guayabo	Soatá Sabana	Necesidad	Guayabo	Gigante Neiva		Alluvial to fluvial (Guayabo)	550 m (1,800 ft) (Guayabo)		[9][10][11][12]
2.6	Pliocene		Pliocene volcanism Andean orogeny 3 GABI		Subachoque
5.3	Messinian		Andean orogeny 3 Foreland		Marichuela			Caimán	Honda				[11][13]
13.5	Langhian		Regional flooding	León	hiatus	Caja	León			Lacustrine (León)	400 m (1,300 ft) (León)	Seal	[12][14]
16.2	Burdigalian		Miocene inundations Andean orogeny 2	C1		Carbonera C1		Ospina		Proximal fluvio-deltaic (C1)	850 m (2,790 ft) (Carbonera)	Reservoir	[13][12]
17.3				C2		Carbonera C2				Distal lacustrine-deltaic (C2)		Seal
19				C3		Carbonera C3				Proximal fluvio-deltaic (C3)		Reservoir
21	Early Miocene		Pebas wetlands	C4		Carbonera C4			Barzalosa	Distal fluvio-deltaic (C4)		Seal
23	Late Oligocene		Andean orogeny 1 Foredeep	C5		Carbonera C5		Orito		Proximal fluvio-deltaic (C5)		Reservoir	[10][13]
25				C6		Carbonera C6				Distal fluvio-lacustrine (C6)		Seal
28	Early Oligocene			C7		C7		Pepino	Gualanday	Proximal deltaic-marine (C7)		Reservoir	[10][13][15]
32	Oligo-Eocene			C8	Usme	C8	onlap			Marine-deltaic (C8)		Seal Source	[15]
35	Late Eocene			Mirador		Mirador				Coastal (Mirador)	240 m (790 ft) (Mirador)	Reservoir	[12][16]
40	Middle Eocene				Regadera				hiatus
45
50	Early Eocene			Socha		Los Cuervos				Deltaic (Los Cuervos)	260 m (850 ft) (Los Cuervos)	Seal Source	[12][16]
55	Late Paleocene		PETM 2000 ppm CO2	Los Cuervos	Bogotá				Gualanday
60	Early Paleocene		SALMA	Barco	Guaduas	Barco		Rumiyaco		Fluvial (Barco)	225 m (738 ft) (Barco)	Reservoir	[9][10][13][12][17]
65	Maastrichtian		KT extinction	Catatumbo	Guadalupe				Monserrate	Deltaic-fluvial (Guadalupe)	750 m (2,460 ft) (Guadalupe)	Reservoir	[9][12]
72	Campanian		End of rifting	Colón-Mito Juan									[12][18]
83	Santonian							Villeta/Güagüaquí
86	Coniacian
89	Turonian		Cenomanian-Turonian anoxic event	La Luna	Chipaque	Gachetá	hiatus			Restricted marine (all)	500 m (1,600 ft) (Gachetá)	Source	[9][12][19]
93	Cenomanian		Rift 2
100	Albian				Une	Une		Caballos		Deltaic (Une)	500 m (1,600 ft) (Une)	Reservoir	[13][19]
113	Aptian			Capacho	Fómeque			Motema	Yaví	Open marine (Fómeque)	800 m (2,600 ft) (Fómeque)	Source (Fóm)	[10][12][20]
125	Barremian		High biodiversity	Aguardiente	Paja					Shallow to open marine (Paja)	940 m (3,080 ft) (Paja)	Reservoir	[9]
129	Hauterivian		Rift 1	Tibú- Mercedes	Las Juntas	hiatus				Deltaic (Las Juntas)	910 m (2,990 ft) (Las Juntas)	Reservoir (LJun)	[9]
133	Valanginian			Río Negro	Cáqueza Macanal Rosablanca					Restricted marine (Macanal)	2,935 m (9,629 ft) (Macanal)	Source (Mac)	[10][21]
140	Berriasian			Girón
145	Tithonian		Break-up of Pangea	Jordán	Arcabuco	Buenavista Batá		Saldaña		Alluvial, fluvial (Buenavista)	110 m (360 ft) (Buenavista)	"Jurassic"	[13][22]
150	Early-Mid Jurassic		Passive margin 2	La Quinta	Montebel Noreán	hiatus				Coastal tuff (La Quinta)	100 m (330 ft) (La Quinta)		[23]
201	Late Triassic			Mucuchachi				Payandé					[13]
235	Early Triassic		Pangea		hiatus							"Paleozoic"
250	Permian
300	Late Carboniferous		Famatinian orogeny						Cerro Neiva ()				[24]
340	Early Carboniferous		Fossil fish Romer's gap		Cuche (355-385)	Farallones ()				Deltaic, estuarine (Cuche)	900 m (3,000 ft) (Cuche)
360	Late Devonian		Passive margin 1	Río Cachirí (360-419)					Ambicá ()	Alluvial-fluvial-reef (Farallones)	2,400 m (7,900 ft) (Farallones)		[21][25][26][27][28]
390	Early Devonian		High biodiversity	Floresta (387-400) El Tíbet						Shallow marine (Floresta)	600 m (2,000 ft) (Floresta)
410	Late Silurian		Silurian mystery
425	Early Silurian			hiatus
440	Late Ordovician		Rich fauna in Bolivia	San Pedro (450-490)		Duda ()
470	Early Ordovician		First fossils		Busbanzá (>470±22) Chuscales Otengá	Guape ()		Río Nevado ()	Hígado () Agua Blanca Venado (470-475)				[29][30][31]
488	Late Cambrian		Regional intrusions	Chicamocha (490-515)	Quetame ()	Ariarí ()		SJ del Guaviare (490-590)	San Isidro ()				[32][33]
515	Early Cambrian		Cambrian explosion										[31][34]
542	Ediacaran		Break-up of Rodinia		pre-Quetame		post-Parguaza		El Barro ()	Yellow: allochthonous basement (Chibcha Terrane) Green: autochthonous basement (Río Negro-Juruena Province)		Basement	[35][36]
600	Neoproterozoic		Cariri Velhos orogeny	Bucaramanga (600-1400)				pre-Guaviare					[32]
800			Snowball Earth										[37]
1000	Mesoproterozoic		Sunsás orogeny			Ariarí (1000)			La Urraca (1030-1100)				[38][39][40][41]
1300			Rondônia-Juruá orogeny			pre-Ariarí	Parguaza (1300-1400)		Garzón (1180-1550)				[42]
1400				pre-Bucaramanga									[43]
1600	Paleoproterozoic						Maimachi (1500-1700)		pre-Garzón				[44]
1800			Tapajós orogeny				Mitú (1800)						[42][44]
1950			Transamazonic orogeny				pre-Mitú						[42]
2200			Columbia
2530	Archean		Carajas-Imataca orogeny										[42]
3100			Kenorland
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

• Geology of the Eastern Hills
• Geology of the Ocetá Páramo
• Geology of the Altiplano Cundiboyacense

Notes and references