Cintura Formation

The Cintura Formation is a geologic formation in the northeastern Sonora of Arizona and Mexico.^[1] It preserves fossils dating back to the Cretaceous period.

Cintura Formation
Stratigraphic range: Albian–Cenomanian PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of	Bisbee Group
Sub-units	Marquechi, San Marcos and San Juan Member
Thickness	1,146 meters[1]
Location
Region	Arizona and Sonora
Country	United States, Mexico
Type section
Named by	Ransome
Year defined	1904

Description

The Cintura Formation is divided into 3 stratigraphic members which represent deltaic depositional elements: the basal Marquechi Member, medial San Marcos Member and the uppermost San Juan Member.^[1] The delta is thought to have prograded southward and have an immediate source to its north based on paleocurrents and provenance data.^[1]

Fossil content

Dinoflagellates
Genus	Species	Presence	Material	Notes	Images
Oligosphaeridium	O. sp.	Base of the Marquechi Member.[2]	Dinoflagellate cysts.[2]

Plants
Genus	Species	Presence	Material	Notes	Images
cf. Acanthotriletes	cf. A. varispinosus	Base of the Marquechi Member.[2]	Spores.[2]
Alisporites	A. sp.	Base of the Marquechi Member.[2]	Pollen grains.[2]
Araliaephyllum	A. silvapinedae	Near the town of Cabullona, Sonora, Mexico.[3]	A trilobed leaf.[3]	A laurale.
Baculatisporites	B. sp.	Base of the Marquechi Member.[2]	Spores.[2]
Cicatricosisporites	C. hallei	Base of the Marquechi Member.[2]	Spores.[2]	A schizaeacean fern.
	C. sp.	Base of the Marquechi Member.[2]	Spores.[2]	A schizaeacean fern.
Classopollis	C. spp.	Base of the Marquechi Member.[2]	Pollen grains.[2]	A cheirolepidiaceaen conifer.
Clavatipollenites	C. tenellis	Base of the Marquechi Member.[2]	Pollen grains.[2]
Cycadopites	C. sp.	Base of the Marquechi Member.[2]	Pollen grains.[2]
Deltoidospora	D. sp.	Base of the Marquechi Member.[2]	Spores.[2]
Ephedripites	E. sp.	Base of the Marquechi Member.[2]	Pollen grains.[2]
Exesipollenites	E. tumulus	Base of the Marquechi Member.[2]	Pollen grains.[2]
Inaperturopollenites	I. sp.	Base of the Marquechi Member.[2]	Pollen grains.[2]	A conifer.
Isoetites	I. sp.	San Juan Member.[2]	Leaves.[2]	An isoetalean.
Leptolepidites	L. sp. 1	Base of the Marquechi Member.[2]	Spores.[2]	A fern.
	L. sp. 2	Base of the Marquechi Member.[2]	Spores.[2]	A fern.
	L. sp. 3	Base of the Marquechi Member.[2]	Spores.[2]	A fern.
Osmundacites	O. wellmanii	Base of the Marquechi Member.[2]	Spores.[2]
Ovoidites	O. parvus	Base of the Marquechi Member.[2]	Spores.[2]	An aquatic zygnematale.
Patellasporites	P. sp.	Base of the Marquechi Member.[2]	Spores.[2]
Perinopollenites	P. sp.	Base of the Marquechi Member.[2]	Pollen grains.[2]
Peromonolites	P. allensis	Base of the Marquechi Member.[2]	Spores.[2]	A fern.
Pityosporites	P. sp.	Base of the Marquechi Member.[2]	Pollen grains.[2]
Plicatella	P. potomacensis	Base of the Marquechi Member.[2]	Spores.[2]
Raistrickia	R. sp.	Base of the Marquechi Member.[2]	Spores.[2]
Retimonocopites	R. sp. 1	Base of the Marquechi Member.[2]	Pollen grains.[2]
	R. sp. 2	Base of the Marquechi Member.[2]	Pollen grains.[2]
Spheripollenites	S. sp.	Base of the Marquechi Member.[2]	Pollen grains.[2]
Taxodiaceaepollenites	T. hiatus	Base of the Marquechi Member.[2]	Pollen grains.[2]
Todisporites	T. minor	Base of the Marquechi Member.[2]	Spores.[2]
Triporoletes	T. sp. cf. T. radiatus	Base of the Marquechi Member.[2]	Spores.[2]	A bryopsid.
Tucanopollis	T. sp.	Base of the Marquechi Member.[2]	Pollen grains.[2]
Undulatisporites	U. undulapolus	Base of the Marquechi Member.[2]	Spores.[2]
	U. sp.	Base of the Marquechi Member.[2]	Spores.[2]

See also

• Earth sciences portal
• Arizona portal
• Paleontology portal

• List of fossiliferous stratigraphic units in Arizona
• Paleontology in Arizona