U.s. Geological survey core drilling on the atlantic shelf

Area of Science:

• Marine Geology
• Geophysics
• Geotechnical Engineering

Background:

• The U.S. Atlantic continental shelf is a critical area for resource exploration and infrastructure development.
• Previous geological understanding of the shelf's shallow subsurface was limited, hindering comprehensive assessments.

Purpose of the Study:

• To conduct a broad scientific shallow drilling program on the U.S. Atlantic continental shelf.
• To delineate subsurface stratigraphy, identify hydrocarbon potential, analyze pore fluid characteristics, and assess sediment engineering properties.

Main Methods:

• Shallow drilling operations were conducted across the U.S. Atlantic continental shelf.
• Analysis included age dating of rock strata, detection of hydrocarbon gases, pore fluid salinity measurements, and evaluation of sediment engineering properties from core samples.

Main Results:

• Delineated rocks ranging from Pleistocene to Late Cretaceous, including Miocene phosphorites and Eocene carbonates.
• Identified light hydrocarbon gases with mature petroleum affinity at two sites off Maryland and New Jersey.
• Observed fresh to brackish pore waters, with increased salinity suggesting evaporitic strata in specific areas; sediment cores exhibited variable engineering properties.

Conclusions:

• The drilling program provided a foundational understanding of the U.S. Atlantic shelf's shallow geology and resource potential.
• Findings highlight the presence of hydrocarbons and inform geotechnical assessments for offshore engineering projects.
• Geochemical and geotechnical data are crucial for future exploration and safe infrastructure development in the region.