Montezuma Formation of Costa Rica

Conference · Tue Jan 01 00:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6199058

McKee, W H; Sen Gupta, B K

The Montezuma Formation of the Nicoya Peninsula is one of the better known Neogene stratigraphic units of the Pacific side of Costa Rica. Past workers have reported its age to be Miocene-Pliocene or Miocene-Quaternary, and its environment of deposition to be inner shelf. The planktonic foraminiferal record of the unit in the type locality, however, places it firmly in the Lower Pliocene (Globorotalia margaritae zones). Furthermore, benthic such as Bolivina interjuncta var. bicostata, Epistominella exigua, and E. pacifica indicate that the sedimentation occurred at depths no shallower than the outermost shelf. No drastic faunal turnovers are observed within the formation; a cluster analysis of various Neogene samples from the Nicoya Peninsula and other Pacific areas of Costa Rica demonstrate an overall uniformity of the Montezuma fauna. The frequency trends of certain species, particularly of Epistominella exigua, however, suggest a transgression, the assemblage in the upper part of the section definitely representing upper bathyal depths. Judging by the present elevation of Montezuma outcrops, this part of Costa Rica has been uplifted at least 300 meters in the past 5 m.y.

• Research Organization: Louisiana State Univ., Baton Rouge (USA)
• OSTI ID: 6199058
• Report Number(s): CONF-8510489-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
COSTA RICA
SEDIMENTARY ROCKS
GEOLOGIC HISTORY
PALEONTOLOGY
FORAMINIFERA
FOSSILS
GEOLOGIC FORMATIONS
STRATIGRAPHY
TERTIARY PERIOD
ANIMALS
CENOZOIC ERA
CENTRAL AMERICA
DEVELOPING COUNTRIES
GEOLOGIC AGES
GEOLOGY
INVERTEBRATES
LATIN AMERICA
MICROORGANISMS
PROTOZOA
ROCKS
SARCODINA
580100* - Geology & Hydrology- (-1989)