CHAPTER 1

PALEOMAGNETISM AND THE OCEAN DRILLING PROGRAM

INTRODUCTION

ODP is an international partnership of scientists and governments which have joined together to explore the structure and history of the Earth beneath the ocean basins. The central purpose of ODP is to provide core samples and downhole measurements from beneath the oceans' floors and the facilities to study those samples. The United States, the Federal Republic of Germany, France, the Canada/Australia Consortium for the Ocean Drilling Program, Japan, the United Kingdom, the European Science Foundation Consortium for the Ocean Drilling Program (including Belgium, Denmark, Finland, Iceland, Italy, Greece, The Netherlands, Norway, Spain, Sweden, Switzerland, and Turkey), and the Academy of Sciences (Russia) (inactive) are working together to organize the scientific study of the sediments and rocks that fill and underlie the ocean basins. The data generated will lead to a better understanding of the processes of plate tectonics, of the Earth's crustal structure and composition, of conditions in ancient oceans, and of changes in climate through time, and in turn to a fuller comprehension of the evolution of our planet (Fig. 1.1).

Shipboard paleomagnetists provide the first paleomagnetic analysis of sediments and rocks recovered by ODP. This information is used by shipboard and shore-based scientists as the basis for further sampling and study, and for forming the first general conclusions about the geologic history of the drilling site. The shipboard paleomagnetists have a tremendous responsibility to the scientific community to provide accurate and reliable data. Hence, the paleomagnetics laboratory on board the JOIDES Resolution contains state-of-the-art equipment to perform detailed paleomagnetic and rock-magnetic measurements.

This handbook is divided into six chapters and eight appendixes. Chapter 1 discusses the research objectives of paleomagnetic measurements. Chapter 2 addresses the duties and responsibilities of the shipboard paleomagnetists, as well as shipboard procedures, from the first arrival of a core on deck through the writing of shipboard reports. Chapter 3 examines the paleomagnetics laboratory and analytical equipment on board the JOIDES Resolution.Chapter 4 considers software for data collection, data analysis, and graphics. Chapter 5 introduces the resources of the Deep Sea Drilling Project (DSDP) and ODP databases available both on board ship and on shore. Chapter 6 examines problems encountered on past cruises and their solutions.

The appendixes contain examples of sample-request forms, and lists of paleomagnetic reference books and equipment manuals available aboard the ship. Information about DSDP/ODP paleomagnetic databases is also appended.

RESEARCH OBJECTIVES

Paleomagnetic objectives for the Ocean Drilling Program are identified in "Paleomagnetic Objectives for the Ocean Drilling Program," a report of a JOI/USSAC workshop held at the University of California, Davis, in 1986 (Verosub et al., 1986). A copy of this report can be obtained from Joint Oceanographic Institutions, Inc. (JOI):

Joint Oceanographic Institutions, Inc. 1755 Massachusetts Avenue NW Suite 800 Washington, D.C. 20036-2102 U.S.A.

According to this report, paleomagnetic objectives can be divided into four general areas:

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