USGS Coastal and Marine Geology Program

Coastal & Marine Geology Program

Field Activity Details for field activity 1989-003-FA

Other ID: none

Status: Completed

Organization(s): USGS, Woods Hole Coastal and Marine Science Center

Funding Program(s):

Principal Investigator(s): Kim D. Klitgord

Affiliate Investigator(s): Leonid V. Dmitriev - Vernadsky Institute of Geochemistry

Information Specialist(s):

Data Type(s): Sonar: Multibeam, Electro-Magnetic: Magnetics, Electro-Magnetic: Gravity, Sampling: Biology, Sampling: Geology

Scientific Purpose/Goals: The overall objective of the 12th cruise leg 1 of the R/V PETROV was to initiate an integrated geological sampling and geophysical surveying program of the Mid-Atlantic Ridge between the Atlantis Fracture Zone and the Hayes Fracture Zone, from 30 degrees N to 34 degrees N. The sampling and survey program was designed to address specific scientific objectives related to understanding the geological, geochemical, and geodynamic processes that help to control the generation and subsequent deformation of oceanic lithosphere. These scientific objectives are summarized as follows: 1) Establishing the morphotectonic framework of the axial Mid-Atlantic Ridge by: a. identifying and mapping the large-offset and the "zero-offset transform/fracture zones and the variability in their fault systems; b. identifying and mapping the axial bathymetric high, rift-valley graben, and flanking fault blocks including the segmentation characteristics of the ridge; and c. identifying and mapping magnetic lineations that provide age-isochron information and other magnetic signatures that reflect magmatic processes at the ridge. 2) Establishing the magmatic contribution to oceanic crustal generation by: a. determining the geochemical variations along the ridge axis in young oceanic crust; b. examining the relationships between these variations and ridge segmentation; and c. examining of small-scale variations at large-offset, small-offset, and zero-offset transform zones. 3) Investigating the deformation of oceanic crust within transform/fracture zones by: establishing the metamorphic character of mafic and ultramafic rocks, including microfabric, fluid-inclusion, and geochemical evidence.


Start Date: 1989-02-02

Start Port/Location: Rotterdam, Netherlands

End Date: 1989-02-28

End Port/Location: Bridgetown, Barbados

Equipment Used: Multibeam swath bathymetry, Marine magnetometer, Gravity meter (wh), Seismic reflection, Dredge

Information to be Derived:

Summary of Activity and Data Gathered:

Staff: Kim D. Klitgord

Affiliate Staff:
Dr. Leonid Dmitriev - Soviet co-chief scientist (Vernadsky Institute of Geochemistry
Russia); Dr. John F. Casey - petrologist (University of Houston
USA); Mr. Kevin Johnston - petrologist (MIT-WHOI joint program
Woods Hole
USA); Prof. Vladimar Tulin - gravity specialist (Institute of Physics of the Earth
Russia); Dr. Sergei Silantiev - metamorphic petrologist (Vernadsky Institute of Geochemistry
Russia); Sergei Zahpunny - Expedition secretary
facilitator (Vernadsky Institute of Geochemistry
Russia); Ruben Magakyan - petrologist - chief of dredge operations (Vernadsky Institute of Geochemistry
Russia); Mikhail Reisner - computer expert (Vernadsky Institute of Geochemistry
Russia); Matalia Kononkova - petrologist and watch stander (Institute of Geology
Russia); Dr. Vladimar V. Mayorshin - magnetic specialist (Institute of Terrestrial Maganetism - Troizk
Russia); Mikhail Zakharov - multibeam bathymetry specialist (Institute of Geology
Russia); Vadim Golod - seismic specialist (Institute of Geology
Russia); Boris Bazylev - ultramafic petrologist
dredge operations team (Vernadsky Institute of Geochemistry
Russia); Lyudmila Polosina - thin-section lab operations (Vernadsky Institute of Geochemistry
Russia); Olga Tsameryan - petrologist
multibeam bathymetry watch (Vernadsky Institute of Geochemistry

Project = Mid-Atlantic Ridge Crest Processes, Mid-Atlantic Ridge Crest Processes


Atlantis Fracture Zone, Hayes Fracture Zone, Mid-Atlantic Ridge axis, North Atlantic;

North: 35 South: 30 West: -45 East: -30


photo of Akademik Boris Petrov
Akademik Boris Petrov


Klitgord, K.D., Dmitriev, Leonid V., Casey, John F., Silantiev, Sergei, and Johnson, Kevin, 1993, U.S.-Soviet collaborative geological and geophysical survey of the Mid-Atlantic Ridge near 31 degrees N, the Petrov Fracture Zone: 23, download PDF.


Data Acquired

Survey EquipmentSurvey InfoData Type(s)Data Collected
Multibeam swath bathymetry --- Multibeam
Marine magnetometer --- Magnetics
Gravity meter (wh) --- Gravity
Seismic reflection --- 1989-003-FA-SE-001 ( microfilm of RUSSIAN COOP-KLITGORD)
Dredge --- Biology