Deep Sea Drilling Project, Leg 77, southeastern Gulf of Mexico

Online Access: Get full text
doi: 10.1130/0016-7606(1984)95<226:DSDPLS>2.0.CO;2
Author(s): Schlager, Wolfgang; Buffler, Richard T.; Angstadt, David; Bowdler, Jay L.; Cotillon, Pierre H.; Dallmeyer, R. David; Halley, Robert B.; Kinoshita, Hajimu; Magoon, Leslie B.; McNulty, Charles L.; Patton, James W.; Pisciotto, Kenneth A.; Premoli-Silva, Isabella; Suarez, Otmara Avello; Testarmata, Margaret M.; Tyson, Richard V.; Watkins, David K.
Author Affiliation(s): Primary:
Univ. Miami, Miami, FL, United States
Other:
Univ. Tex., United States
Union Oil Co. Calif., United States
Univ. Claude Bernard, France
Univ. Ga., United States
U. S. Geol. Surv., United States
Chiba Univ., Japan
Marathon Oil Co., United States
Sohio Pet. Co., United States
Univ. Milano, Italy
Oceanol. Inst., Cuba
The Open Univ., United Kingdom
Fla. State Univ., United States
Volume Title: Geological Society of America Bulletin
Source: Geological Society of America Bulletin, 95(2), p.226-236. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0016-7606 CODEN: BUGMAF
Note: In English. 34 refs.; illus. incl. sketch map
Summary: Holes 535 and 540 were drilled in a basinal terrane for maximum penetration of the Cretaceous-Tertiary sequence. Rhythmic alternations of light bioturbated and dark laminated carbonaceous limestone represent the Early Cretaceous. Late Cretaceous rocks are almost totally missing. Holes 536, 537, and 538A were drilled on high-standing fault blocks. Hole 537 recovered phyllite that records 40/39Ar plateau ages of about 500 m.y. In Hole 538A, basement consists of mylonitic gneiss and amphibolite, intruded by diabase dikes. 40Ar/39Ar dates of the regional metamorphic rocks suggest a 500-m.y. age; dike intrusions between 190 and 160 m.y. ago. Among the most significant results are: (1) recovery of "transitional" crust with early Paleozoic (Pan-African) metamorphic rocks, (2) recovery of Early Cretaceous deep-water limestones with immature petroleum source beds, (3) recovery of mid-Cretaceous platform talus resembling the reservoirs in the Poza Rica and some of the Reforma fields, and (4) discovery of a Late Cretaceous hiatus of 30 m.y. that corresponds to the "mid-Cretaceous unconformity" recognized widely on seismic records in the Gulf of Mexico. Modified journal abstract.
Year of Publication: 1984
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 07 Marine Geology and Oceanography; Absolute age; Ar/Ar; Atlantic Ocean; Basement; Block structures; Cambrian; Carbonate rocks; Cenozoic; Cores; Cretaceous; Crust; DSDP Site 535; DSDP Site 536; DSDP Site 537; DSDP Site 538; DSDP Site 540; Deep Sea Drilling Project; Faults; Geophysical methods; Geophysical surveys; Gulf of Mexico; IPOD; Jurassic; Leg 77; Limestone; Mesozoic; Metamorphic rocks; North Atlantic; Ocean basins; Ocean floors; Oceanography; Paleozoic; Sedimentary rocks; Seismic methods; Stratigraphy; Surveys; Systems; Tectonophysics; Unconformities
Coordinates: N231500 N240000 W0840000 W0853000
Record ID: 1984029734
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute.