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Core Data from the Deep Sea Drilling Project


Leg : 60    Top/Bottom Interval(mm): 1180/1200  Describer: Meijer, A.
Hole: 461A  Top of Core Depth(m)   :     0.00   Rock Type: IGNEOUS
Core:   1   Sample Midpoint(m)     :     2.69   Sect/Pc #:  2/

ROCK = FELDSPATHIC GABBRO;
       Texture: GRANOBLASTIC
       TEX UNCERTAIN,SLIGHT INDICATION OF FOLIATION*

Groundmass - PLAGIOCLASE               (   40%)
             Size(mm):    0.5-1.0
             APPROX COMP AN60,FRESH;

             CLINOPYROXENE             (   40%)
             Size(mm):    0.3-1.0
             FRESH,WITH EXSOLUTION LAMELLAE OF OPX;

             ORTHOPYROXENE             (   20%)
             Size(mm):    0.3-1.0
             FRESH,WITH CPX EXSOLUTION LAMELLAE*

Alteration - CLAY MINERALS
             SEVERAL FRACTURES RUNNING THROUGH SLIDE BEARING
             CLAYS(?) BUT OTHERWISE SECONDARY MINS ARE ABSENT*




Leg : 60    Top/Bottom Interval(mm):  340/ 370  Describer: Meijer, A.
Hole: 461A  Top of Core Depth(m)   :     0.00   Rock Type: UNIDENTIFIED
Core:   1   Sample Midpoint(m)     :     3.36   Sect/Pc #:  3/

ROCK = POLYMICT BRECCIA
       SECTION CONSISTS OF TWO CLASTS,ONE LARGE OPX-CPX
       PLAG GABBRO(2.0X2.5CM) + ONE BASALTIC(1.0X0.5CM) +
       FINE-GRAINED GRANULATED GABBROIC MATERIAL AS A
       MATRIX,GABBROIC CLAST HAS CUMULATE TEX AND COMP
       OF PLAG(45%) + CPX(30%) + OPX(10%) + ONE LARGE
       QUARTZ VEIN(0.5CM WIDE),BASALTIC CLAST CONSISTS OF
       FRESH PLAG(30%) + INTERSTITIAL GLASS(27%) +
       VESICLES(30%) + CPX(10%) + MAGN(3%),BRECCIA MATRIX
       INCLUDES ZEOLITES + AMPHS + PYXS + ANTIGORITE +
       GABBROIC FRAGS + VERY FINE GRAINED COMMINUTED
       MATERIAL*

Alteration - TALC
             Replacing: OPX

             CHLORITE
             Replacing: OPX

             CLAY MINERALS
             Replacing: CPX

             QUARTZ




Leg : 60    Top/Bottom Interval(mm):  470/ 480  Describer: Sharaskin, A.
Hole: 461A  Top of Core Depth(m)   :     0.00   Rock Type: IGNEOUS
Core:   1   Sample Midpoint(m)     :     3.48   Sect/Pc #:  3/

ROCK = METABASALT;
       Texture: PSEUDOSPHERULITIC-PSEUDOHYALOPILITIC;
       Where sampled: COBBLE IN SEDIMENTS*

Phenocrysts- PLAGIOCLASE               (   TR%)
             Size(mm):    TO 0.15  Morphology: LATHS
             ONLY SINGLE GRAIN IN THE SLIDE;

             CLINOPYROXENE             (   TR%)
             Size(mm):    TO 0.17  Morphology: SKELETAL
             APPROX COMP AUGITE,TWO GRAINS IN THE SLIDE*

Groundmass - GLASS
             TOTALLY ALTERED,ORIGINALLY VESICULAR+SPHERULITIC+
             HYALOPILITIC*

Alteration - CLAY MINERALS             (   97%)
             Location: THROUGHOUT

             QUARTZ                    (    3%)
             Location: VESICLES AND
             Location: MICROXLN

             ZEOLITE                   (    3%)
             Location: VEINS
             VEINS UP TO 0.5MM THICK;

             EPIDOTE                   (   <1%)
             Location: MESOSTASIS
             TINY GRAINS IN MICROXLN*

Vesicles   -
             Size(mm): 0.01-0.5
             Percent:     3
             Location: THROUGHOUT
             Filling: QUARTZ
             Shape: IRREGULAR




Leg : 60    Top/Bottom Interval(mm):  740/ 750  Describer: Meijer, A.
Hole: 461A  Top of Core Depth(m)   :     0.00   Rock Type: IGNEOUS
Core:   1   Sample Midpoint(m)     :     3.75   Sect/Pc #:  3/

ROCK = APHYRIC BASALT;
       Texture: INTERSERTAL*

Phenocrysts- PLAGIOCLASE               (   TR%)
             Size(mm):     TO 0.5  Morphology: SUBHEDRAL
             APPROX COMP AN70-80,UNALTERED;

             CLINOPYROXENE             (   TR%)
             Size(mm):    0.2-0.5  Morphology: EUHEDRAL
             APPROX COMP UNCERTAIN,FRESH LOOKING*

Groundmass - PLAGIOCLASE               (   20%)
             Size(mm):    0.1-1.0  Morphology: BLOCKY-ACICULAR
             APPROX COMP AN65;

             CLINOPYROXENE             (   15%)
             Size(mm):    0.1-0.3  Morphology: ACICULAR-SKELETAL

             MAGNETITE                 (    2%)
             Size(mm):  0.01-0.13  Morphology: SUBHEDRAL

Alteration - CLAY MINERALS             (   53%)
             Location: MESOSTASIS,
             Location: VESICLES

Vesicles   -
             Size(mm): 0.05-0.5
             Percent:    10
             Location: THROUGHOUT
             Filling: CLAY.MINS
             Shape: IRREGULAR




Leg : 60    Top/Bottom Interval(mm):  850/ 860  Describer: Meijer, A.
Hole: 461A  Top of Core Depth(m)   :     0.00   Rock Type: IGNEOUS
Core:   1   Sample Midpoint(m)     :     3.86   Sect/Pc #:  3/

ROCK = FELDSPATHIC GABBRO
       PART OF BRECCIA;
       Texture: CUMULATE*

Groundmass - PLAGIOCLASE               (   70%)
             Size(mm):    0.1-1.0
             APPROX COMP AN55,GENERALLY IN ADCUMULUS GROWTH
             TEXTURE,GENERALLY NOT ZONED,UNALTERED;

             CLINOPYROXENE             (   25%)
             Size(mm):    0.1-1.0
             GENERALLY INTERSTITIAL,MOSTLY ALTERED TO URALITE;

             QUARTZ                    (    3%)
             Size(mm):    0.1-0.5
             IN DISCRETE GRAINS AND IN VEINS WITH CHLORITE;

             OTHER                     (    2%)
             INCLUDES SMALL AMOUNT OF POLYMICT IGNEOUS BRECCIA
             MATERIAL ADHERED TO ONE SIDE OF FRAGMENT;

             ORTHOPYROXENE
             MAY HAVE BEEN PRESENT BEFORE URALITE ALTERATION*

Alteration - URALITE
             Replacing: CPX

             URALITE
             Replacing: OPX

             CHLORITE
             Location: IN VEINS

             QUARTZ                    (    3%)
             Location: VEINS




Leg : 60    Top/Bottom Interval(mm): 1210/1230  Describer: Meijer, A.
Hole: 461A  Top of Core Depth(m)   :     0.00   Rock Type: METAMORPHIC
Core:   1   Sample Midpoint(m)     :     4.22   Sect/Pc #:  3/

ROCK = META-MICRODIABASE;
       Texture: DIABASIC*

Groundmass - AMPHIBOLE                 (   50%)
             Size(mm):    0.1-0.5  Morphology: ANHEDRAL,FIBROUS
             ACTINOLITE(?),REPLACING PYX;

             PLAGIOCLASE               (   30%)
             Morphology: TABULAR-BLOCKY
             APPROX COMP AN50,PARTLY REPLACED BY CLAYS;

             QUARTZ                    (   15%)
             Size(mm):    0.1-0.5
             SOMETIMES IN MICROGRAPHIC INTERGROWTHS WITH
             FELDSPARS;

             MAGNETITE                 (    5%)
             Size(mm):   0.05-0.3  Morphology: SKELETAL-SUBHEDRAL
             USUALLY ASSOCIATED WITH SPHENE AND AMPH*

Alteration - SPHENE                    (   TR%)

             AMPHIBOLE
             Replacing: PYX

             CLAY MINERALS
             Replacing: PLAG




Leg : 60    Top/Bottom Interval(mm):  100/ 110  Describer: Sharaskin, A.
Hole: 461A  Top of Core Depth(m)   :     0.00   Rock Type: METAMORPHIC
Core:   1   Sample Midpoint(m)     :     6.00   Sect/Pc #: CC/

ROCK = METABASALT;
       Texture: PSEUDOHYALOPILITIC-PSEUDOSPHERULITIC;
       Where sampled: COBBLE IN SEDIMENTS*

Groundmass - MICROCRYST GROUNDMASS     (   70%)
             TOTALLY ALTERED TO CLAYS;

             PLAGIOCLASE               (   25%)
             Size(mm):     TO 0.2

             MAGNETITE                 (    5%)
             Size(mm):  0.01-0.03

             CLINOPYROXENE             (   <1%)
             Size(mm):     TO 0.1  Morphology: RELICTS
             RELICTS OF CRYSTALLITES*

Alteration - CLAY MINERALS             (   97%)
             Location: VESICLES,      Replacing: EVERYTHING
             Location: MESOSTASIS

             CHLORITE                  (    3%)
             Replacing: CPX
             PSEUDOMORPHS AFTER CPX GRAINS*

Vesicles   -
             Size(mm): 0.03-0.5
             Percent:     7
             Location: THROUGHOUT
             Filling: CLAY.MIN
             Shape: ROUND
             SOME VERY LARGE IRREGULAR VESICLES ARE PRESENT*




Leg : 60    Top/Bottom Interval(mm):  320/ 340  Describer: Meijer, A.
Hole: 461A  Top of Core Depth(m)   :     6.00   Rock Type: METAMORPHIC
Core:   2   Sample Midpoint(m)     :     6.33   Sect/Pc #:  1/

ROCK = METABASALT
       MICRODIABASE IS ALTERATE ROCK TYPE;
       Texture: SUBOPHITIC
       COARSE-GRAINED BASALT OR FINE-GRAINED MICRODIABASE*

Groundmass - PLAGIOCLASE               (   30%)
             Size(mm):    0.1-0.6  Morphology: TABULAR-BLOCKY
             APPROX COMP AN55,PARTLY ALTERED;

             AMPHIBOLE                 (   30%)
             Size(mm):    0.1-0.7  Morphology: ANHEDRAL
             GENERALLY FIBROUS,REPLACING CPX(?);

             MICROCRYST GROUNDMASS     (   20%)
             INTERGROWTH OF QUARTZ + FELDSPAR,HIGHLY ALTERED;

             QUARTZ                    (   10%)
             Size(mm):    0.1-0.5
             OFTEN FRACTURED,OCCUR THROUGHOUT ROCK;

             MAGNETITE                 (    8%)
             Size(mm):   0.05-0.3
             ASSOCIATED WITH AMPHIBOLE*

Alteration - EPIDOTE                   (    2%)
             Location: SCATTERED

             AMPHIBOLE
             Replacing: CPX




Leg : 60    Top/Bottom Interval(mm):  340/ 350  Describer: Sharaskin, A.
Hole: 461A  Top of Core Depth(m)   :     6.00   Rock Type: METAMORPHIC
Core:   2   Sample Midpoint(m)     :     6.35   Sect/Pc #:  1/

ROCK = METABASALT
       AMPHIBOLITE;
       Texture: POIKILOBLASTIC*

Groundmass - PLAGIOCLASE               (   60%)
             POIKILOBLASTS OF PLAG(ANDESINE)FORMS GRANOBLASTIC
             AGGREGATES TOGETHER WITH QUARTZ AND INCLUDES MAGN
             GRAINS AND AMPH NEEDLES AND PLAG LATHS,FOLIATION
             IS VERY WEAK,SOME EPIDOTE IS ALSO PRESENT;

             HORNBLENDE                (   25%)

             QUARTZ                    (    7%)

             MAGNETITE                 (    7%)

Alteration - EPIDOTE

             AMPHIBOLE




Leg : 60    Top/Bottom Interval(mm):  850/ 860  Describer: Meijer, A.
Hole: 461A  Top of Core Depth(m)   :     6.00   Rock Type: IGNEOUS
Core:   2   Sample Midpoint(m)     :     6.86   Sect/Pc #:  1/

ROCK = SIDEROMELANE;
       Texture: HOLOHYALINE*

Groundmass - GLASS                     (   98%)
             MOSTLY DEVITRIFIED(STILL ISOTROPIC) AND PARTLY
             ALTERED TO CLAYS IN VESICLES AND ALONG VEINS,
             FRESH;

             PLAGIOCLASE               (    1%)
             Size(mm):   0.01-0.2  Morphology: ACICULAR
             APPROX COMP UNCERTAIN*

Alteration - CLAY MINERALS
             Location: VESICLES,      Replacing: GLASS
             Location: ALONG VEINS




Leg : 60    Top/Bottom Interval(mm):  950/ 960  Describer: Sharaskin, A.
Hole: 461A  Top of Core Depth(m)   :     6.00   Rock Type: METAMORPHIC
Core:   2   Sample Midpoint(m)     :     6.96   Sect/Pc #:  1/

ROCK = METABASALT;
       Texture: PSEUDOSUBOPHITIC;
       Where sampled: COBBLE IN DRILLING BRECCIA*

Phenocrysts- PLAGIOCLASE               (   TR%)
             Size(mm):     TO 0.2  Morphology: EUHEDRAL
             APPROX COMP AN70,GLOMEROCRYSTS;

             CLINOPYROXENE             (   TR%)
             Size(mm):     TO 0.2  Morphology: EUHEDRAL
             APPROX COMP AUGITE,SOMETIMES GLOMEROCRYSTS*

Groundmass - MICROCRYST GROUNDMASS     (   67%)
             INCLUDES PYX MICROLITES;

             PLAGIOCLASE               (   25%)
             Size(mm):     TO 0.3
             APPROX COMP UNCERTAIN;

             QUARTZ                    (    5%)
             Size(mm):   0.01-0.3
             SECONDARY,SEPARATE GRAINS AND AGGREGATES;

             MAGNETITE                 (    3%)
             Size(mm):   0.01-0.1

Alteration - CLAY MINERALS             (   90%)
             Location: MESOSTASIS

             QUARTZ                    (    5%)
             Location: MESOSTASIS,
             Location: VESICLES

             EPIDOTE                   (  1-3%)
             Location: MESOSTASIS

Vesicles   -
             Size(mm): 0.05-1.0
             Percent: 10-15
             Location: THROUGHOUT
             Filling: QUARTZ,MINOR
             Shape: SUBROUND-

             Filling: CLAY.MINS
             Shape: IRREGULAR




Leg : 60    Top/Bottom Interval(mm): 1050/1070  Describer: Meijer, A.
Hole: 461A  Top of Core Depth(m)   :     6.00   Rock Type: IGNEOUS
Core:   2   Sample Midpoint(m)     :     7.06   Sect/Pc #:  1/

ROCK = GABBRO;
       Texture: GRANOBLASTIC*

Groundmass - PLAGIOCLASE               (   45%)
             Morphology: EUHEDRAL-SUBHEDRAL
             APPROX COMP AN55 ZONED TO AN25 ON RIMS,INCIPIENTLY
             ALTERED TO SERICITE;

             AMPHIBOLE                 (   35%)
             Size(mm):    0.3-2.0  Morphology: ANHEDRAL
             ACTINOLITE-TREMOLITE FILLING INTERSTITIAL AREAS
             BETWEEN PLAG,OFTEN COMPLEXLY TWINNED,PROBABLY
             REPLACEMENT OF CPX;

             QUARTZ                    (    8%)
             Morphology: ANHEDRAL
             INTERSTITIAL,SOMETIMES IN MICROGRAPHIC
             INTERGROWTHS WITH FELDSPAR;

             MAGNETITE                 (    5%)
             Size(mm):     TO 1.0  Morphology: EQUANT
             GENERALLY LARGE(1.0MM)GRAINS;

             CHLORITE                  (    5%)
             Size(mm):       <0.5
             IN SMALL CLUMPS,PARTLY ALTERATION PRODUCT OF AMPH;

             CLINOPYROXENE             (    2%)
             REMNANTS MOSTLY REPLACED BY AMPH;

             EPIDOTE                   (   TR%)
             AS ALTERATION PRODUCT OF AMPH;

             SPHENE
             ASSOCIATED WITH LARGE MAGN GRAINS*

Alteration - AMPHIBOLE
             Replacing: CPX

             SERICITE
             Replacing: PLAG

             CHLORITE
             Replacing: AMPH

             EPIDOTE
             Replacing: AMPH




Leg : 60    Top/Bottom Interval(mm):  150/ 160  Describer: Meijer, A.
Hole: 461A  Top of Core Depth(m)   :     6.00   Rock Type: METAMORPHIC
Core:   2   Sample Midpoint(m)     :     7.59   Sect/Pc #: CC/

ROCK = EPIDOSITE
       OBSERVER STATES THIS IS A WEIRD SLIDE*

Groundmass - EPIDOTE
             NEARLY PURE EPIDOTE OR MINERAL OF SAME GROUP,IN A
             FINE GRAINED MASS,LESSER AMOUNT OF THE MINERAL
             WITH VERY LOW BIREFRINGENCE AND UNDULATORY
             EXTINCTION-POSSIBLY A ZEOLITE*

Alteration - EPIDOTE
             IDENTITY UNCERTAIN;

             ZEOLITE
             IDENTITY UNCERTAIN*




    

Introduction


Cite as: Deep Sea Drilling Project (1989): Archive of Core and Site/Hole Data and Photographs from the Deep Sea Drilling Project (DSDP). National Geophysical Data Center, NOAA. doi:10.7289/V54M92G2 [access date]

These Web pages are from the Core Data from the Deep Sea Drilling Project Legs 1-96 CD-ROM produced in 1989 and modified in 2000 by the U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Environmental Satellite, Data, and Information Service, National Geophysical Data Center (now part of the National Centers for Environmental Information), and collocated World Data Center for Marine Geology and Geophysics, Boulder (now part of the World Data Service for Geophysics). Data were compiled in cooperation with the U.S. Science Support Program, of the Joint Oceanographic Institutions, Inc. (now the Consortium for Ocean Leadership), and the U.S. National Science Foundation.

Please see NOAA's privacy and disclaimer information. Send questions or comments to mgg.info@noaa.gov.

Department of Commerce > NOAA > NESDIS > NCEI > doi:10.7289/V54M92G2