Evolution of the Blake Plateau basin from rift basin to carbonate platform to present eroded continental borderland

Conference · Tue May 01 04:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:7061423

Dillon, W P; Poag, C W; Klitgord, K O ^[1]; Battuello, P A ^[2]; Trehu, A M

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1. Geological Survey, Woods Hole, MA (USA)
2. Univ. of New Mexico, Albuquerque, NM (USA)

Multichannel seismic profiles, well and submersible diver samples, and GLORIA long-range sonar data disclose the evolution of the Blake Plateau Basin (BPB) off the southeastern US. The BPB contains strata more than 16 km thick and is roughly 350 km wide. At the postrift unconformity, the northern and western sides of the basin are relatively steep, whereas the southern and eastern sides slope more gently. The entire region probably was a shallow-water carbonate platform during most of the Late Jurassic and Early Cretaceous; the depocenters of the BPB slowly migrated westward during this period, probably due to thermal or magmatic variations in the lithosphere. Although subsidence slowed during the Late Cretaceous, carbonate deposition failed to maintain the surface near sea level, and chalks and marls blanketed the sinking platform. During the Cenozoic, the Gulf Stream scoured the top of the present plateau and restricted clastic deposition to the westernmost part of the BPB region where a narrow shelf is formed. Southerly deep water thermohaline currents have eroded the old continental slope/reef front into a steep escarpment except for an area having relict canyons. Deep-water erosional retreat of platform deposits forms steep, smooth or stepped cliffs east of the northern and central BPB; but to the south, erosional cliff retreat occurs by collapse of huge (<10 km) blocks, probably initiated by faults that bound the south side of the BPB. These faults may be reactivated due to differential loading caused by growth of the Bahama platform.

• OSTI ID: 7061423
• Report Number(s): CONF-900605--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 74:5
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ATLANTIC OCEAN
CARBONATE ROCKS
CRETACEOUS PERIOD
GEOLOGIC AGES
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
JURASSIC PERIOD
MEASURING INSTRUMENTS
MESOZOIC ERA
RANGE FINDERS
RIFT ZONES
ROCKS
SEAS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
SONAR
SURFACE WATERS