A Magnetic Petrology Database forLithospheric Magnetic Anomaly Interpretations Status of Development

Katherine Nazarova Raytheon ITSS NASA/GSFC

--------------------------------------------------------------- IUGG Sapporo July 11, 2003

Overview

A Magnetic Petrology Database (MPDB) is now being compiled at Geodynamics Branch NASA/Goddard Space Flight Center. The purpose of this database is to provide the geomagnetic community with a comprehensive and user-friendly method of accessing magnetic petrology data via Internet for more realistic interpretation of satellite magnetic anomalies. Magnetic Petrology Data had been acquired from the NASA/Goddard Space Flight Center (code 691 and 921), United Institute of Physics of the Earth (Russia) and Institute of Geophysics (Ukraine) and from the other worldwide sources. This data was accumulated over several decades and now consists of many thousands of records of data in our archives. The MPDB is focused on lower crustal and upper mantle rocks and include data on mantle xenoliths, serpentinized ultramafic rocks, granulites, iron quartzites and rocks from Archean-Proterozoic metamorphic sequences from all around the world. A substantial amount of data is coming from the area of unique Kursk Magnetic Anomaly and Kola Deep Borehole (which recovered 12 km of continental crust).          

Magnetic Petrology Data Locations

A MPDB does not exist and is needed especially after recent launching at near Earth orbit Oersted, Champ and SAC-C satellites which will provide magnetic maps with better spatial and amplitude resolution. Apparently there will be an increasing demand for more realistic intrerpretations of these anomalies and increased demand in crustal magnetic petrology data which will be accessible via Internet.

The origin of the major satellite magnetic anomalies(except Kursk and Kiruna magnetic anomalies) identified by satellite magnetic data is still unclear and magnetic petrology data provides realistic constraints for magnetic models.

MPDB will contain magnetic data on lower crustal and upper mantle rocks all around the world.

MPDB will be part of the system of existing geomagnetic and paleomagnetic databases widely used by Earth scientists all over the world.

Why do We Need Magnetic Petrology Database (MPDB)?

                                                         

Database ManagementDatabase Management

Interaction between MySQL Server, PHP module and WEB Browser

MySQL server PHP module SQL language (to search database)PHP and PERL languages (to communicate with WEB Server) PHP which stands for “Hypertext Preprocessor” is an HTML embedded scripting language.

Schema of Magnetic Petrology Database

Clickable Map for Magnetic Petrology Data Locations

StatisticsRocks Tectonic # of samples

Structure

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Data submitted and included into database

Iron Quartzites(BIF) Ukrainian Shield 10000

Sedimentary and BIF Ukrainian Shield 303

Krivoy Rog BoreHole

Sedimentary volcanic Baltic Shield 400

Serpentinites, gabbro Kola Deep BoreHole

Continental Serpentinites worldwide 210

Oceanic Serpentinites worldwide 460

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Data expected to be included into database until October 2003

Xenoliths Iceland 2000

Granulites Urals Mountains 900

Archean Proterozoic worldwide

Sequences 480

MySQL relational database management system was utilized to create relational searchable Magnetic Petrology Database(MPDB) accessible via Internet. A prototype MPDB can be found on the Geodynamics Branch web server of NASA/Goddard Space Flight Center at http://core2.gsfc.nasa.gov/terr_mag/php/MPDB/frames.html

PHP module was utilized to present MPDB on WEB and make it accessible for Geomagnetic Community.

Submission forms have been developed. To submit new data use Data Entry Forms in Excel format at http://core2.gsfc.nasa.gov/terr_mag/doc.html

Datasets on Deep BoreHoles (703 samples), Band Iron Formations (10000 samples) and Serpentinized ultramafic rocks ( 670 samples) have been compiled in EXCEL and TEXT formats and included into database.

Queries structure has been developed and MPDB can be searched by different criteria at: http://core2.gsfc.nasa.gov/research/terr_mag/php/MPDB/third.html

Status of Development

Further Development

Additional PHP and MySQL scripts will be developed to putall available data in searchable format and query database by different criteria.

New magnetic data coming from different sources and Institutions are needed to be refined, calibrated and converted into SI units.

Clickable maps are going to be compiled.

Lithospheric Magnetic Models (CMP3e, MF1,MF2) and datasets are going to be included into MPDB.

A working database version is expected by October 2003.

Database Applications :

Study of Kola Deep and Krivoy Rog BoreHoles

Study of Kuril-Kamchatka Trench

Study of Icelandic Ferrobasalts

Magnetic properties of rocks from Kola superdeep borehole and Krivoy Rog deep borehole have been compared. Extremely high values of remanent magnetization (NRM), magnetic susceptibility (K) and Konigsberger ratio (Qn) are found at approximately the same depths of about 2000 m for both boreholes. Highly magnetic serpentinized peridotites and sedimentary rocks affected by sulfide mineralization were recovered at the Kola borehole for a depth interval of 1540-1940 m. The Krivoy Rog borehole recovered highly magnetic iron quartzites of Band Iron Formations at depths of 1853-2040 m. There is no obvious reason why high magnetizations should occur in two boreholes with different lithologies at the same depth. Magnetic surveys and surface sampling in the nearby Krivoy Rog and Kursk Magnetic Anomaly areas have revealed iron quartzites with high magnetization, similar to values given here. AF demagnetization tests suggest that hard and stable NRM component which is caused by hematite occurred in iron quartzites in different forms and grain sizes ranges. Hematite deposits recently discovered on Mars in western equatorial areas of Aram Chaos crater and Sinus Meridiani layered topography formation could be of hydrothermal origin and may be formed similar to hematite precipitated in band iron formation on Earth

MPDB – a Research-Oriented DatabaseMagnetic Study of Rocks from two Deep BoreHoles

Kola and Krivoy Rog BoreHoles Location

Rockmag Data versus depth for Kola and Krivoy Rog BoreHoles

Location of hematite deposits in the areas of Aram Chaos and Sinus Meridiani on Mars by TES data (Christensen et al., 2000)

CM3e-K Lithospheric Magnetic Model (Sabaka et al., 2003)