169 Prospectus

Site: DD1-4, Dead Dog hydrothermal area

Location: Middle Valley, Juan de Fuca Ridge, northeast Pacific Ocean

Priority: 1

Position: 48°26.517'N, 128°42.651'W

Water Depth: 2420 m

Sediment Thickness: 250 m

Total Penetration: ±50 mbsf

Seismic Coverage: Multichannel Line 89-14

Objectives: Sample the principal area of hydrothermal activity in Middle Valley to test the subsurface inflation model of hydrothermal mound growth.

Drilling Program: APC/XCB/MDCB on top, flank, and periphery of an actively venting hydrothermal mound.

Logging and Downhole Operations: None

Nature of Rock Anticipated: Semimassive sulfide and hydrothermally altered hemipelagic and turbiditic sediment.

To Site BH3-6

169 Table of Contents

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