10. SITE 191
The Shipboard Scientific Party1

SITE DATA
Date Occupied: 25-28 Aug 71.
Position:
191: 56°56.70'N;168°10.72'E
191 A: 100 ft., 090°T from 191.
19IB: 200 ft., 090°T from 191.
Water Depth:
191: 3854 meters
191 A: 3860 meters
19IB: 3860 meters.
Penetration:
191: 919 meters
191 A: 50 meters
191B: 9 meters
Number of Holes: Three.
Number of Cores:
191: 16
191A: 4
191B: 1
Total Core Recovered:
191: 44 meters
191 A: 21.5 meters
191B: 8.5 meters.
Acoustic Basement:
Depth: 900 meters
Nature: Basalt
Velocity: 4.5-5.0 km/sec.
Age of Oldest Sediment: Upper Miocene.
Basement: Basalt, middle Oligocene
SUMMARY
Site 191 is located at a water depth near 3800 meters on
the east-central side of the Kamchatka Basin. A 900-meter
sediment and sedimentary rock sequence consists of 520
meters of upper Pleistocene to upper Pliocene diatomaceous silty clay, diatom ooze, silty sand, and sandy silt, and
380 meters of underlying Pliocene (?) to upper Miocene (?)
indurated silty clay and diatomaceous silty clay containing
1
David W. Scholl, U.S. Geological Survey, Menlo Park, California; Joe S. Creager, University of Washington, Seattle, Washington; Robert E. Boyce, Scripps Institution of Oceanography, La
Jolla, California; Ronald J. Echols, University of Washington,
Seattle, Washington; Timothy J. Fullam, Standard Oil Company ofCalifornia, La Habra, California; John A. Grow, Massachusetts
Institute of Technology, Cambridge, Massachusetts; Itaru Koizumi,
Osaka University, Osaka, Japan; Homa J. Lee, Naval Civil Engineering Laboratory, Port Hueneme, California; Hsin Yi Ling, Universityof Washington, Seattle, Washington; Richard J. Stewart, Universityof Washington, Seattle, Washington; Peter R. Supko, Scripps
Institution of Oceanography, La Jolla, California; Thomas R.
Worsley, University of Washington, Seattle, Washington.

beds of indurated lithic wacke. These overlie a tholeiitic or
low-K (0.24% K 2 O) basalt, cored to 19 meters, (1.4 m
recovered), containing textural variation that suggests it is asubmarine flow (see Stewart et al., this volume). The upper
520 meters has recognizable variations in the abundance ofsand, degree of induration, and occurrence of limestone
beds. Volcanic ash is present in the upper 240 meters(middle and upper Pleistocene). Reworked extinct Miocene
species of diatoms and silicoflageHates, and sublittoral andfreshwater diatoms are found to a depth of 520 meters
throughout the Pleistocene section and into upper Pliocene
beds as well. Shallow-water foraminiferal assemblages are
typically associated with the sand layers.
The upper 300 meters of sandy and silty deposits coredin Kamchatka Basin are rather "classically" a turbidite
sequence. Size-graded layers are present as well as reworked
fossils and displaced freshwater and shallow-water species,
size-graded units were not detected below 300 meters,
but silty clay containing displaced fresh- and shallow-water
diatoms occur to 520 meters, close to the base of theturbidite sequence indicated on seismic reflection records.
The coarser upper 300 meters includes all but the lower
part of the lower Pleistocene, whereas the finer grained
distal turbidites between 300 and 520 meters include bedsof late Pliocene age. Nearly identical relationships were
found at Site 190 in the adjacent Aleutian Basin (see Scholl
and Creager, this volume).
In Kamchatka Basin, the turbidites are much coarser
grained and far less diatomaceous than those in theadjoining but much larger -Aleutian Basin. Similarly, in
Kamchatka Basin, Pliocene and late Miocene (?) mudstone
beds containing lithic wackes underlie the turbidite
sequence, whereas in the Aleutian Basin the sequence isunderlain by silty biogenic pelagic deposits. The coarser andfar more terrigenous nature of the Neogene deposits ofKamchatka Basin reflect its small size and nearness tohigh-gradient drainages.
The geologic implication of the basalt beneath late
Miocene deposits in Kamchatka Basin is difficult to assess.
Because seismic records (Ludwig et al., 1971a) reveal thatthe mafic layer is regional in extent, has a gentle but
undulating relief, and appears to be buried depositionally.
However, during its emplacement, probably in middle
Oligocene time, it may have engulfed older Tertiary
deposits filling the basin (see Scholl and Creager, andStewart et al).
BACKGROUND AND OBJECTIVES
Description
Shirshov Ridge, a submerged north-south trending
mountain range, projects southward from Cape Olyutorskiy, eastern Siberia, and divides the deep-water region of413

SITE 191

the Bering Sea into Kamchatka Basin (to the west) and themuch larger Aleutian Basin (Figure 1). Site 191 is located ata water depth near 3800 meters on the east-central side of
the abyssal floor of Kamchatka Basin.
A thick turbidite sequence underlies the gently southward sloping floor of the basin. At Site 191, this sequenceis 350 to 400 meters thick and overlies an equally thicksection of weakly reflecting strata, presumably a pelagic
unit. The lower pelagic section is gently arched over a
bedrock knoll encountered acoustically at about 1.0 sec
below bottom. Throughout Kamchatka Basin a rather
rough acoustic basement appears on seismic reflection
records; the knoll at Site 191, part of this basement relief,appears to be depositionally draped by the pelagic
sequence.
Objectives

Nearly everywhere in the Aleutian Basin, except near
Shirshov Ridge, the sedimentary section is 2 km or more in
thickness. In contrast, the sedimentary sequence in
Kamchatka Basin is only 1 to 1.5 km thick, and accordingly, can be sampled to bedrock. The principal purpose indrilling Site 191 was to sample and thereby determine thesedimentary history of the basin and the age and composition of the rough acoustic basement underlying it.
Other objectives included a study of the preserved
textural and structural properties of the turbidite sequence,and especially the mineralogical composition relative tothat of the turbidites cored at Site 190, located in the
Aleutian Basin to the east. The terrigenous debris of theturbidites of these basins was contributed by different
source areas; central and eastern Alaska for the Aleutian
Basin and eastern Kamchatka for the Kamchatka Basin. A

54°

Figure 1. Base map showing the location of Site 191,
Kamchatka Basin.

414

comparison of the sedimentary deposits cored at Sites 190
and 191 should be helpful in interpreting sedimentarycharacteristics typical of two modern marginal oceanic
basins, one flanked by high mountain ranges (Kamchatka
Basin) and the other having received debris from a majorriver (the Yukon, for the Aleutian Basin).
OPERATIONS
Pre- and Post-drilling Survey

Site 191 is located in the east-central Kamchatka Basinjust west of Shirshov Ridge, along the track of thereference profile obtained by D. W. Scholl, 1970 (Figure2). The site was approached with a ship's heading of
328°T, about 75° more northerly than the heading used in
obtaining the reference profile. The air-gun profile (Figure3) obtained during the approach revealed the same undulating basement structure as the reference profiles permitting the dropping of the beacon on the fly at 1020 hrs
25 Aug 71. The beacon failed to operate and after 45
minutes a second beacon was dropped. The finallyaccepted position is: 56°56.70'N; 168°10.72'E. No postdrilling survey was deemed necessary. However, a sonobuoy record was taken over the site (Figure 4); the record
taken during departure from Site 191 is included as Figure
5. A map showing the approach and departure tracks plus
the site location is shown in Figure 6.

10 km

wmmmmiFigure 2. Reference seismic reflection profile, Site 191,
collected by D. W. Scholl, 24 Aug 70.

SITE 191

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Figure 3. Glomar Challenger air-gun profile obtained upon approach to Site 191.
Drilling Program

Site 191 was occupied from 1020 hrs 25 Aug 71(beacon away) until 0650 hrs 28 Aug 71 with alternating
coring and washing from the sea floor to a subbottom
depth of 919 meters. At about 900 meters drilling became
extremely difficult (slow). A core taken at 905 meters
showed the material to be basalt which is correlated withthe deepest reflection horizon. One additional core wascollected and the hole was abandoned.
Using recently acquired hydrographic data, the sonic
depth of 2055 fms was corrected to 3833 meters, giving awater depth of 3839 meters and a drill-floor depth of 3849
meters. This compares with 3864 meters below drill floor
based upon "feel" of the drill string by the driller and somesediment recovery in the first coring attempt. The 3864

415

SITE 191

Sonobuoy I

meters below drill floor, or 3854 meters below sea level, isthe accepted depth for this site.
The first three cores to a depth of 29 meters contained atotal of 3.4 meters of sediment. In each case the sock was
destroyed or inverted permitting most of the sediment towash from the core barrel. No other drilling difficulties
were encountered in drilling the upper 520 meters of sandand mud. Between 143 and 520 meters drilling wasalternately fast and slow, with pump being used. This
probably biases the cores collected by washing away thesands and preferentially retaining the muds. Mudstones
from 520 to 900 meters required longer drilling times but
were not otherwise difficult to drill and core.
By 0650 hrs the drill string had been pulled above the
mud line. The ship was moved 100 feet due east (090°T)
and Hole 191A was occupied from 0650 hrs to 1515 hrs 28
Aug 1971, with continuous coring to a total subbottom
depth of 50 meters. This hole was cored in an attempt torecover the near-bottom sediment which we were not able
to collect at Hole 191. Sock difficulties, this time using
both cloth and plastic socks, again allowed the first 14
meters of below bottom sediment to escape collection. A
depth of 3870 meters below drill floor, or 3860 meters
below sea level, determined by driller's "feel" is the accepted
depth for this hole.
At 1515 hrs the drill string was again lifted above the
mud line and the ship was moved to a position 200 feetdue east (090°T) from Hole 191. Hole 19IB was occupied
from 1515 hrs to 2230 hrs on 28 Aug 71. One 9-meter core
was attempted with a recovery of 8.5 meters. The same
depths were accepted for this hole as for Hole 191 A. A
coring summary is given in Table 1.
LITHOSTRATIGRAPHY

AN ODE TO GRAY CLAY
byRichard J. Stewart, Ph.D.
Semi-lithified and burrowed
dark greenish clay
diatom-bearing silty clay,
with lenses and laminae ofgreenish black to olive graydiatom-bearing silty clay.

Figure 4. Sonobuoy record, Site 191.

416

At Site 191 a 900-meter sedimentary section overlies
basalt. Based on the abundance of sand, the degree of
induration, and the occurrence of limestone beds, thesection can be subdivided into two units (see Table 2).
Unit A (0-520 m) is diatom-bearing silty clay and diatom
ooze, with abundant size-graded layers of silty sand andsandy silt above 290 meters. Volcanic ash is present
between 0 and 240 meters. An ice-rafted(?) erratic pebble
occurs at 452 meters.
Unit B (520-900 m) is indurated silty clay and diatombearing silty clay with beds of lithic sandstone. The upper
portion, from 520 to 529 meters, contains a limestone bed
and an ice-rafted(?) pebble.
The nature of the basalt-sediment contact at 900 meters
is unknown. Textural variations in the basalt suggest it is asubmarine lava flow.

SITE 191

DSDP 191

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Figure 5. Glomar Challenger air-gun profile obtained upon departure from Site 191.
Unit A - 0 to 520 meters
In the first 300 meters size-graded beds of olive blacksandy silt and silty sand are commonly intercalated in darkgray diatomaceous and diatom-rich silty clay and olive graysilt-rich clayey diatom ooze. The sand layers are up to 1.0
meter thick, are usually size-graded, and have sharp bottom
contacts in contrast to the often indistinct tops. Typicalcompositions are 45% feldspar, 35% lithic fragments, 5%quartz, and 10% pyroxene, with lesser quantities of
epidote, amphibole, biotite, chlorite, garnet, and zircon.
Pods and lenses of dark greenish gray carbonate-bearing
clay are abundant in Core 4 (78 to 87 m). A crystal ash bed
occurs at 179 meters (Core 6). An ice-rafted(?) pebble
occurs in the catcher of Core 1 (0 to 1 m).
The first semilithified sediments occur in Core 7(227-236 m) and coincide with the occurrence of frequent

mottles and lenses of olive gray calcite silty clay. The darkgray silty clay is extensively burrowed.
Two beds of olive gray to grayish olive limestone occur
at 236 meters (Core 7) and 281 meters (Core 8). An olive
gray ash layer composed of light-colored glass occurs at 235
meters (Core 7).
Between 300 and 520 meters, distinct size-graded sandor silty sand layers were not recovered. The basic lithology
is semilithified and burrowed, dark greenish gray diatombearing silty clay, with lenses and laminae of greenish black
to olive gray diatom-bearing silty clay. An ice-rafted(?)
volcanic pebble occurs at 460 meters (Core 11; see
Figure 7).
Unit B - 520-900 meters
At 520 meters the drilling rate dropped sharply, coinciding with a sharp increase in lithification, decrease in diatom

417

SITE 191
168°05'EI

168°15'E

168°10'E

56°58'NI

SITE 191 - 56°56.7'N x 168°10.7'E

1018L - Beacon Away

100L/25 Aug. 71
c/c 317°56°55'N

0948L
c/c 325C

56°52'N

Figure 6. Approach and departure tracks, Glomar Challenger, Site 191.
content, and the presence of limestone beds and carbonatecemented sandstone. Sediments in the interval 520 to 900
meters are dominantly dark gray to dark greenish gray silty
clays with beds of light gray to dark gray and olive black
lithic sandstone. In contrast to the sands recovered at otherLeg 19 sites, most of the sand layers recovered at Site 191
are not calcite-cemented, but instead have a firm clay
matrix and are poorly sorted lithic wackes or textural
graywackes. Size-grading is not evident in most beds, as
poor recovery and fracturing during drilling destroyed most
top and bottom contacts. However, one ungraded sand withboth sharp top and bottom contacts occurs at 628 meters(Core 13; see Figure 8). Limestone and calcite-cemented
sandstone occur at 527 meters (Core 12).
Greenish black silt-bearing, clay- and silt-rich diatom
ooze occurs at 520 to 523 meters (Core 12). An ice
rafted(?) pebble was recovered from 523 meters (Core 12).
BasaltBasalt totaling 1.4 meters was recovered in two cores(191-15CC and 191-16) and the drilling rate record
indicates that it was probably first reached at about 900
meters. Unfortunately, the critical contact zone was notcored. The recovered material is variolitic pyroxeneplagioclase high-alumina tholeiite basalt grading downward
to subdiabasic basalt in one apparently continuous unit. A
K-Ar date of 30 m.y. was obtained on Plagioclase microlite
fractions of the basalt (see Stewart et al., this volume, Table

4183), corroborating the inference from textural evidence andgeophysical records that the basalt is extrusive andprobably regional in extent. Detailed petrography is given
in appendix to this chapter while chemistry, mineralogy
and regional significance of the basalt are discussed in
Stewart et al. (loc cit).
Holes 191A and 191B
Hole A at Site 191 penetrated to a depth of 50 meters.
The recovered sediment is identical to the upper part ofUnit A. The section is dominantly dark gray diatom-bearing
silty clay and dark gray to dark greenish gray diatom ooze,
with frequent intercalations of olive black silty sand andsandy silt. Ash beds occur at approximately 20 meters(light-colored glass), 21 meters (dark-colored glass), 23
meters (light-colored glass), and 48 meters (light-coloredglass). An ice-rafted(?) pebble was recovered from the corecatcher of Core 3 (32 to 41 m).
Hole B penetrated to a depth of 9.0 meters. The
recovered sediment consists of olive gray silt andclay-bearing to silt- and clay-rich diatom ooze, withinterbedded olive black silty sand.
PHYSICAL PROPERTIES

Bulk density, water content, natural gamma radiation,
acoustic velocity, vane shear strength, and residual negative
pore water pressure were measured on the samples obtained

SITE 191
TABLE 1
Coring Summary - Hole 191
Cored Interval
Core

TABLE 2
Recovered

(m)

(m)

(m)

(%)

0-1

0.05

5.0

1-10

1
9

3.3

36.7

20-29

9

CC

0.0

78-87

9

9.5

105.6

134-143

9

9.5

105.6

Hole 191
1
2

Depth Below
Sea Floor(m)
Unit Cores
A

1-6

0-200

7,8

200-300

9-11

300-52012-15

520-900

Basalt 15CC,
16900-919

Wash
3

Wash
4

Wash
5

Wash
6

171-180

9

2.2

24.4

Wash
7
Wash

227-236

9

1.8

20.0

8

274-283

9

2.6

28.9

Wash
9
Wash

321-330

9

1.5

16.7

10

384-393

9

3.1

34.4

452-461

9

2.0

22.2

520-527

7

2.5

35.7

620-629

9

3.0

33.3

723-732

9

1.7

18.9

905-910910-919

5

9

CC
1.4

15.6

130

44.15

34.0

9
9
9
9

9.0
4.5
CC
8.0

100.0
50.0

36

21.5

59.7

9

8.5

94.4

B

Lithology

Age

Diatom silty clay,
diatom ooze, andsilty sandSemi-indurated
diatom-bearing
silty clay andsandy silt
Semi-indurated
diatom-bearing
silty clay
Indurated silty
clay and lithic
wacke
Pyroxeneplagioclase
basaltUpper and middle
Pleistocene
Middle and lower
Pleistocene

Lower Pleistocene
and Pliocene
Pliocene? andupper Miocene?
Upper Miocene?

Wash
11

Wash
12

Wash
13

Wash
14

Wash
15
16

0.0

Hole 191A
1
2
3
4

14-23
23-32
32-41
41-50

0.0

88.9

Hole 19 IB
10-9

at Site 191. Bulk density was measured in the usual three
ways. Two unsplit segments of core were obtained andsealed for shore consolidation testing (Lee, this volume).
GRAPE densities are shown on the core summary sheets.
Mean GRAPE densities are shown on the site summary
sheet along with shore laboratory densities, water displacement densities, and measured acoustic velocities.
A problem with gas expansion-induced disturbance wasonce again encountered at Site 191. The zone from about
20 to 140 meters was affected most severely, and thephysical properties measured on samples from this range are
relatively unreliable.
Bulk Density
The GRAPE density was measured to a sediment depthof 450 meters, below which the sediment no longer filled

Figure 7. An ice-rafter (?) pebble in silty clay. (191-11-1,
144-150 cm).
the core liner. The density for the remainder of thesediment was measured by the water displacement method.
The GRAPE densities, as shown on the core summary
sheets, once again required modification to compensate forgas expansion-induced disturbance. The dashed lines shown
represent envelopes which enclose the peak density values
in the most severely disturbed sections. In the less disturbed
portions, sand and ash layers appear as dense sections while
the silty clay zones appear as medium-dense sections. Verylittle detail is apparent in the badly disturbed sections. The

419

SITE 191

Below this point, the density and acoustic velocity increase
gradually and consistently to 2.0 g/cm3 and 2.2 km/sec,
respectively, at 730 meters. The only sharp deviations fromthis trend occur in the vicinity of high-velocity sandstonesin the zone, 500 to 700 meters. A marked change inphysical properties occurs at the bottom of the hole wherebasalt with a density of 2.7 g/cm3 and an acoustic velocityof 4.7 km/sec occurs.
PALEONTOLOGY

Sediments from this site contain poor microfossil assemblages; calcareous nannofossils are essentially absent; Radiolaria and silicoflagellates are low in number of specimens aswell as species; foraminifera, both planktonic and benthic,
are usually sparse to absent; and even diatoms, which havebeen the dominant fossil element in the Bering Sea andNortheast Pacific deposits, are diminished in number.
Reworked microfossils are found throughout the Pleistocene intervals. They are either extinct Miocene species or
sublittoral and fresh-water diatoms. Inner sublittoral andouter sublittoral plus bathyal foraminiferal groups are
frequently associated with deep-sea sand at this site.
The thick Pleistocene section is apparently the productof turbidity currents, as inferred from the seismic record.
The presence of fresh-water diatoms plus sublittoral
diatoms and foraminifera combined with low radiolarianand silicoflagellate populations supports this contention.
Foraminifera
HOP

Summary

At Site 191 the vertical distribution of foraminifera
generally follows the pattern established at previous sites in
the Bering Sea. That is, fluctuating abundances of planktonic and calcareous benthic populations in the Quaternary,a barren Pliocene (but perhaps not the total Pliocene at thissite), and sparse arenaceous populations in the Miocene.
Displaced tests are much more common than at previous
sites. Displaced species may be divided into a sublittoral
group and an outer sublittoral and bathyal group (Table 3).
The sublittoral group, dominated by Eliphidium clavatum,
is very similar to that occurring in sediments deposited
during late Wisconsin time on what is now the outer shelfof the Bering Sea (Knebel et al., in press). The outersublittoral and bathyal group is very similar to thatreported by Smith {In Hopkins et al., 1969) in lower
Pleistocene rocks dredged from the Pribilof Canyon on thecontinental slope of the Bering Sea. During times of low sea
level, the inner shelf species group would have inhabited thepresent outer shelf, while the outer shelf bathal species
group probably was confined beyond the shelf break. The
two groups are subequally represented in sediments of Site
191 and, in some samples, outnumber the indigenous groupof species. In Core 1, core catcher, near-surface sediments
appear to have been sampled; these lack displaced tests.
Sparse middle Pleistocene benthic faunas also lack displaced
tests, but the sampling density is too low to attach
significance to this. Greater frequency of displaced tests at
this site is associated with a greater proportion of deep-sea
sands than at previous sites. The sand content in individual
samples having displaced tests may not be particularly high,but some sand is always present.

The basic silty clay material at Site 191 is relatively
uniform and dense throughout the upper 520 meters.

The typical upper Miocene arenaceous fauna was notfound in the core catcher sample of Core 12, but it has

Figure 8. Sandstone with sharp top and bottom contacts
and angular shale pebble (rip-up?) at base. (191-13-2,
108-116 cm).
most interesting GRAPE record is that for Hole 19IB, Core
1. The increase in the clay density over the length of thiscore is well shown and allows for a relatively reliablecalculation of the sediment compressibility (Lee, thisvolume).
The general density trends for this site are shown by theaverage values plotted on the site summary sheet. The firstcore is seen as a zone of rapidly increasing density as
discussed above. The section which follows, to a depth of
140 meters, is characterized by considerable data scatter
resulting from ash and sand layers and gas expansioninduced disturbance. From 140 to 520 meters, the density
is virtually constant and equal to about 1.75 g/cm3. The
density then increases gradually to 2.0 g/cm3 at 730
meters. The basalt at the bottom of the hole has a densityof 2.65 to 2.75 g/cm3.
Acoustic Velocity
The acoustic velocity remains around 1.5 km/sec for the
first 250 meters. It then begins to increase gradually,reaching a value of 2.2 km/sec at 730 meters. The basalt at
the bottom of the hole has an acoustic velocity of 4.5 to
5.0 km/sec. Sandstone layers between 500 and 700meters
have velocities of about 2.5 km/sec.

420

SITE 191

:oup

TABLE 3
Number of Displaced Foraminifera of the Sublittoral Group and the Outer Sublittoral-Upper Bathyal Group
Compared to the Number of Probable Indigeneous Foraminifera of the Bathyal-Abyssal Group

O
13

CΛ

•15

CU

u

soo

w

11
40
9

5

1
1

1
1
1

5

2

2
14
42
15

2
5

1

3
1
19
3

1

1
"3
K

•2
S

2
5

Total Bathyal-Abys lGro

/OSC

1
1

1
2

3

S

•S

"o

1

I
1
9
7
2

Total

Cu

Total

Protelphidium o

"£

1
1

1

K

Cassidulina noru

Buliminella elegt

Bucella frigida

E. subarcticum

E. frigidum

E. bartletti

Elphidium clava

Sublittoral Group

1
2
1A
2A
4
5
6
7
8
9
10

'Si

Epistominella cf

o

2

1
10
23
32
87
143
180
236
283
330
393

c

^=>

Angulogerina an<uSamples (all CC)<o

Depth in Hole (m)Age5Outer Sublittoral-U er Ba

^3

a

6
10
28
10

1
2

19
6
164
63
28
2
4
6
12
3

t>

E 3
been found in center bit cuttings from between 732 and905 meters, and also in the core catcher of Core 14.
Calcareous Nannoflora
Nannofossils are rare in the Pleistocene and are notage-diagnostic. They are absent below the Pleistocene. Theirabsence at many levels may be a result of their exclusionfrom low-temperature surface waters.
Radiolaria and Silicoflagellates
Except for the upper Pleistocene section, sediments weregenerally poor in radiolarians and silicoflagellates. Species
diversity and population density are very low, and fromCore 12 to the bottom of the hole, sediments are barren ofthese siliceous microfossils.
Radiolarians (Table 10, Chapter 28) identified in Cores 1
and 2 of Holes 191 and 191A, and Core 1 of 191B, were
those found in the surface sediment of previous Bering Sea
sites. From Core 191-3 downward, species diversity
decreases and only a few long-ranging forms were found.
Silicoflagellates from the site are rather poor (Table 10,
Chapter 27), being similar to Site 189 in this regard.
However, reworked forms were noted; they are: Mesocena
circulus var. apiculata (late Miocene) in Cores 191A-1 and
191B-1, and Ehriopsis antiqua (spineless form) (early
Pliocene-Miocene) in 191B-1. A similar observation wasmade on diatoms, suggesting that reworking at this site ismore apparent than at previous sites in the Pleistocene
section. The high sedimentation, rate may account for the
low frequency of microfossils recovered from this site.

Diatoms
Diatoms recovered from samples at Site 191 are moderate to well preserved, and their stratigraphic sequence isshown in Table 9, Chapter 30.
Samples in the lowest part of the sequence are barren of
diatoms, except a sample (191-14-2, 4-5 cm) whichcontains poorly preserved Coscinodiscus marginatus (common) and Thalassiosira zablinae (few), suggesting a possible
late Pliocene age.

CORRELATION BETWEEN REFLECTION PROFILEAND STRATIGRAPHIC COLUMN
The ship tracks followed by the Glomar Challenger toand from Site 191 are shown in Figure 9, and thecorresponding reflection profiles with magnetics are shownin Figures 10 and 11. The upper sediment (0.6 sec) in
Kamchatka Basin is generally flat lying except near the
periphery of the basin and shows strong internal
stratification. Below 0.6 sec the sediment appears
transparent and only locally do deeper reflections orbasement appear on the Challenger's profile. Records byother vessels in this area have found a continuous but
irregular basement between 1.0 and 1.5 sec. The
magnetometer data generally show small anomalies overKamchatka Basin except for the 350 gamma anomaly justsouth of Site 191 (Figure 11). The magnetic anomalies over
the Shirshov and Komandorsky ridges are also relatively
small for volcanic features.

421

SITE 191

760
164°

168C

Figure 9. Ship's track o/Glomar Challenger to and from Site 191, shown with respect to bathymetry.

A sonobuoy profile taken by the Challenger while on
Site 191 is shown in Figure 12 along with the stratigraphic
column and physical properties. The sonobuoy profileshows the same stratified sequence for the upper 0.65 sec
and the underlying transparent layer, but it also shows aclear terminal reflector at 1.0 sec. The upper sequence iscomposed of Unit A, Plio-Pleistocene turbidites, while thetransparent Unit B is upper Miocene mudstone and sandstone. The 1.0-sec reflection is from the surface of a basalt

422

basement reached at 900 meters. Unfortunately, theimportant sediment-basalt contact was not cored.
Interval velocities for Unit A range from 1.5 to 1.7
km/sec according to the shipboard laboratory data, while
the travel-time estimates are 1.6 km/sec (520 m by 0.65
sec). Unit B has very heterogeneous shipboard laboratory
values, ranging from 1.6 to 2.6 km/sec, in spite of its apparent homogeneity, suggested by the profiler record. The
time-travel estimate for velocity of Unit B is 2.2 km/sec.

SITES 190 to 191

Figure 10. Seismic reflection profile obtained by Glomar Challenger approaching Site 191, with corresponding magnetics.

toSITE 191

Figure 11. Seismic reflection profile obtained by Glomar Challenger departing Site 191, with corresponding magnetics.

REFERENCES
Hopkins, D. M., Scholl, D. W., Addicott, W. O., Pierce,
R. L., Smith, P. B., Wolfe, J. A., Gershanovich, D.,
Kotenov, B., Lohman, K. E., Lipps, J.H. and Obradovich, J., 1969. Cretaceous, Tertiary, and Early Pleistocene rocks from the continental margin of the Bering
Sea. Bull. Geol. Soc. Am. 80, 1471.

424

Knebel, J. H., Creager, J. S. and Echols, R. J., in press.
Holocene sedimentary framework, east-central Bering
Sea continental shelf. In Arctic Sedimentation Symposium Volume, Y. Herman (Ed.). Elsevier Press.
Ludwig, W. J., Marauchi, J., Den, N., Ewing, M., Hotta, H.,
Houtz, R. E., Yoshii, T., Asanuma, T., Hagiwara, K.,
Sato, T. and Ando, S., 1971. Structure of Bowers Ridge,
Bering Sea. J. Geophys. Res. 76 (26), 6350.

SITE 191

LU LU
i—I >~
LU
IS)

CJ3

<C

DENSITY

VELOCITY

^J-U?

Φ

CO O

O

< * 00,_! i— ,_! C\J ,— CVJ çyj C\J

•I

T U

I

I >

WITH
SAND
AND
SILT

I'
LU

o
00

SAND
AND
SILT,
SEMI-

o
I—1

_1

SAND
STONE

INDURATED
SILTY
CLAY
AND
LITHICWACKE

BASALT

2.7

4.8i

i

Figure 12. Correlation ofsonobuoy profile with stratigraphic column and physical properties, Site 191.

425

SITE 191

Basalt was recovered in two cores (191-15CC and191-16) and the drilling rate record indicates that basalt
was probably first reached at about 900 meters.
Unfortunately, the critical contact zone was not cored. The
recovered material is variolitic pyroxene-plagioclase highalumina tholeiitic basalt (See Stewart et al., this volume)
grading downward to subdiabasic basalt in one apparently
continuous unit. No glassy material was recovered at any
interval.
A thin section of the topmost variolitic material (191-15
CC) contains acicular needles and laths of labradorite up to
1.5 mm long set in a matrix of plumose sheafs of intimatelyintergrown Plagioclase and pyroxene needles (Figure 13).
The larger feldspar needles often have splayed ends andcores of pyroxene needles, usually parallel to the plagioclase 010 direction, with length to width ratios of 10 or
20:1. The intergrown Plagioclase microlites typically follow
the bends and twists of the pyroxene sheafs and tufts,
arranged roughly parallel with the pyroxene needles,
alternating with them as integral parts of the variolites.
There are essentially no glassy patches free of variolites or
crystals, but some patches of green nontronite may be theirremains. Where variolites are relatively free of the plagioclase microlites, sometimes a fine cross-hatched pattern canbe seen where two pyroxene sheafs have intergrown.
Opaques are ubiquitous, very tiny, and rather uniformly
scattered, except rarely where they are concentrated
between variolites. These may be secondary. A few labradorite microphenocrysts and a few 0.5 mm or smaller
vesicles, well outlined by surrounding pyroxene sheafs, arescattered through the section.
Further down the core (191-16), the variolitic habit
involves larger crystals. Labradorite laths with splayed ends,
not quite so acicular, commonly form spoke-like radialclusters, and the cross-hatched pyroxene variolites develop
a distinctive herringbone-type texture. The pyroxene sheafs
are more distinct, Plagioclase microlites tending to develop
around rather than inside the variolites.
Toward the base of the 1.4 meters of basalt recovered,
the texture is subdiabasic (Figure 14), with light brownpyroxenes forming fairly well-defined grains with impressive herringbone texture. Opaques again are widespread,particularly along grain boundaries. The feldspars only
rarely develop splayed ends or radial clusters. A curious
feature of the lower parts of the core, however, is spheres
up to 2 mm in diameter of herringbone-type pyroxenes,
usually with some glass generally altered to green nontronite, plated or armored tangentially by small Plagioclase
laths. Several of these can be seen in some sections. If, as
seems the case, the crystallizing basalt was on the pyroxeneplagioclase cotectic, the spheres may have been incipient
pyroxene phenocrysts that settled from the top part of themelt with a surrounding droplet of melt; the addition ofthis mafic mass surrounded by its glassy membrane may
have forced the invaded liquid to attempt to restore
equilibrium by clustering the invader with Plagioclase.

Figure 13. Variolitic texture in basalt. Crossed nicols. Scalebar is 0.5 mm. (191-15-CC).

Figure 14. Subdiabasic texture in basalt. Crossed nicols.
Scale bar is 0.5 mm. (191-16-1,128 cm).

APPENDIXPETROGRAPHY OF BASALT, SITE 191

James H. Natland, Department of the
Scripps Institution of Oceanography,
University of California, San Diego, La Jolla, California
Richard J. Stewart, Department of Geological Sciences,
University of Washington, Seattle, Washington

426

SITE 191

Other glomerophenocrysts (Figure 15), predominantly offeldspar, occur sporadically in the subdiabasic material.
Phenocrystal Plagioclase compositions are An7Q-75(carlsbad-albite twins); microlites range from An7Q-60

Figure 15. Glomeroporphorytic clot. Plane light. Scale bar
is 0.5 mm. (191-16-1,128 cm).

Microprobe data (Stewart et al., this volume) on pyroxenes
show them to be augites.
The rock is fairly well altered. Patches of bright green
nontronite fill rare vesicles and form irregular patches
replacing interstitial material. Sometimes the vesicles arefestooned with tiny hemispheres of dark brown-red ironoxides or hydroxides along their rims; the remainder isfilled in radially by the green clay fibers. Sometimes a clear,isotropic mineral of low relief (zeolite?) forms the cores ofthese green spherulites. Some of the plagioclases show
incipient sericitization. The degree of alteration decreases
downward with the least altered rocks being the subdiabasic
bottom of Core 16. In places the rock is fractured, thecracks filled with dark red-brown iron oxides and spongelike green nontronite. These cracks are similar to those in
the basalts of Site 192. There, iron oxide fillings in cracks
seem related to a layer of ferruginous clays above thevolcanics. Perhaps a similar layer of ferruginous sedimentexists at Site 191, but was not cored.
Because the sediment-basalt contact was not recovered,
it is difficult to determine a mode of emplacement for thebasalt. The thickness of the section, and the gradational
textural changes suggest the margin of a dike or sill. The
variolitic texture is probably the result of rapid freezing ofa basaltic liquid and is most commonly reported from thequenched margins of submarine basalt flows, but has beenreported from sills. A radiometric age of 30 m.y. on thebasalt much older than the late Miocene or early Pliocene
sediments overlying it, virtually certifies an extrusion
origin, as further suggested by the regional extent of thebasement acoustic reflector and apparent depositional
relations of overlying sediments to it (see Stewart et al., thisvolume).

427

SITE 191

to00

DENSITY(gm/cc)Mean GRAPE Density, +Shore Laboratory Density, x
Water Displacement Density,
LITHOLOGIC DESCRIPTION

.0

2.0

DENSITY(gm/cc)Mean GRAPE Density, +Shore Laboratory Density, x
Water Displacement Density, A

COMPRESSIONALWAVE
VELOCITY(km/sec)
LITHOLOGIC DESCRIPTION<**UNIT B(see sheet 2)

UNIT A
DIATOMACEOUS
SILTY CLAY, darkgray and CLAYEY
DIATOM OOZE, olive
gray

SANDY SILT and
SILTY SAND, o l i v e
black, size graded,intercalated w i t h i n
the upper 300 m.

Volcanic ash
present above
240 m.

z

f i r s t semi l i t h i f i e dsediments.0

2.0

3.0 1.5

COMPRESSIONALWAVE
VELOCITY(km/sec)
2.0

SITE 191

DENSITY(gm/cc)Mean GRAPE Density, +Shore Laboratory Density, x
Water Displacement Density, A

DEPTH
LITHOLOGIC DESCRIPTION

.0

2.0

3.1

DENSITY(gm/cc)Mean GRAPE Density, +Shore Laboratory Density, x
Water Displacement Density, *COMPRESSIONALVELOCITY(km/sec)

DEPTH

M

LITHOLOGIC DESCRIPTIONUNIT A(see sheet 1)

UNIT ßMUDSTONE,dark gray to darkgreenish gray, with
important beds of
UNIT B(see sheet 2)

to

LITHIC SANDSTONE,
gray and olive black

COMPRESSIONALWAVE
VELOCITY(km/sec)52.0

SITE 191

A
R

G
M

1 1 1

Q_
OH
LU
α_
D.

atus

inae

CENE

o

N
§
=
<Λ
en
R
r— +*
S
o o PF
BF<u «=*

R M
R M
R M
F
F

Core
CatcherQ

Q"<U(S) DiIΛExplanatory notes in Chapter 1

430

LITHOLOGY

ii
111

Q.

O.SAM

D

CO

DRMAT

CO

Cored Interval:0-l
σ1ETERS<cCore 1ECTIOI

SIL
o
Lu

CO
LU
CH
O_

CO

CO
i—

ND.

Hole
FOSSILCHARACTER

ZONE

AGE

Site 191

LITHOLOGIC DESCRIPTION

i—

CLAY BEARING SILTY DIATOM OOZE
erratic
core catcher onlySITE 191
Site 191

Hole
FOSSILCHARACTER

Core 2

Cored Interval: 1-10

LITHOLOGY

LITHOLOGIC DESCRIPTIONSILT RICH CLAYEY DIATOM OOZE
moderate olive brown (5Y 4/4)
locally contains more silt and less clay

0.5H
1.0—1

VOID
CARBONATE and CLAY RICH DIATOM OOZE, olive gray (5Y 4/2)
DIATOMACEOUS SILTY CLAY, dark gray (5Y 4/1)
contains pods of overlying unit

-100

PYRITE and DIATOM BEARING SILT RICH CLAY
dark gray (5Y 4/1)

-130
SANDY SILT - SILTY SAND, olive black (5Y 2/1)
size graded-67-90
CLAYEY SILT, olive gray (5Y 3/2) to dark olive gray (5Y 3/1)
Slide 3-90: 55% silt, 45% clay
-148
Core
Catcher

SILTY CLAY, olive gray (5Y 3/2)
Slide 3-148: 40% silt, 60% clay

Slide 2-7
55% diatoms
25% clay
15% carbonate
5% silt

Slide 2-10
40% diatoms
45% clay
15% silt
TR forams

Slide 2-100
5% diatoms
10% s i l t
80% clay

Slide 3-67
TR diatoms
TR foram fragments
40% lithic frags, and altered grainsincl. chert
45% feldspar
10% pyroxene
1% chlorite

3% pyrite

2% fine carbonate
TR forams
Explanatory notes in Chapter 1

432Core Catcher
D A G
N _ _
R R P
S F M
PF F
BF

SITE 191
WET-BULK DENSITY, gm/cc
1

2

POROSITY,%
100
0

SECTION3

I • i • ' l ' ' ' ' i " • • ' i i ' i

CM
-0

I

Grain
Density

|2o
ε

M

-25

2-

-50

1

3-

4-75

r ._

6-

-100

7-

-125

8-

9-150

191-2-1 191-2-2 191-2-3

433

SITE 191

D
N
R
S

F

M

R

P

Core
Catcher

Explanatory notes in Chapter 1

434

Cored Interval:20-29

LITHOLOGY

LITHO.SAMPLE |

PRES.

*

ABUND.

ZONE*FOSSILAGE

FOSSILCHARACTER

METERS

Core 3

DEFORMATION |HoleSECTION

Site 191-

LITHOLOGIC DESCRIPTION

CLAY RICH SILTY SAND
Slide:
40% sand, 40% silt, 20% clay
40% feldspar
30% lithic fragments
20% clay
5% chert
3% pyroxene
2% other

UPPER PLEISTOCENE(D) Denticula seminae

SITE 191
Site 191

Hole

Core 4

Cored I n t e r v a l : 78-87

FOSSILCHARACTER

LITHOLOGY

LITHOLOGIC DESCRIPTION

VOID
0.5—

1.0-

-110

-78

Basic lithology
PYRITE BEARING SILT RICH CLAYEY DIATOM OOZE
olive gray (5Y 4/1 - 4/2)

-148
with thin (up to 10 cm) interbeds of:1) CLAYEY SILT and SILT, very dark gray (5Y 3/1)
to olive black (5Y 2/1)--------Jand 2) CARBONATE BEARING DIATOMACEOUS CLAY
dark greenish gray (5GY 4/1)

Slide 1-110 (basic lith.)
55% diatoms
15% silt (feldspar etc.)
30% clay
3% pyrite

VOID

Slide 2-78 (lith #1)
65% feldspar
10% lithics and altered grains
10% diatoms
5% glass
5% pyroxene
3% pyrite
2% chlorite

Slide 2-148 (lith #2)
40% diatoms
50% clay
5% silt
5% carbonate
Core
Catcher
Explanatory notes in Chapter 1

436Core CatcherD
c G
PF F M
BF F_
N
R ' R M

SITE 191

WET-BULK DENSITY, gm/cc
1
2
3

SECTIONCM
i i | i i i i I

POROSITY,*
100
0

Grain
Density-a 2 o

ro
M
o-i

1-

•i

r-25

2-

-50

3-

f

4-75

-100

-125

-150

191-4-1 191-4-2 191-4-3 191-4-4 191-4-5 191-4-6

437

SITE 191
Site 191

Hole

Core 5

Cored I n t e r v a l : 134-143

FOSSILCHARACTER

LITHOLOGIC DESCRIPTION

LITHOLOGY

I

0.5-

-60
-76

1.0-

pods of olive gray (5Y 4/1) CLAY RICH SILT
80% silt, 20% clay
SILTY CLAY
medium dark gray (N4)

»
-83

VOID

I
I

-75
-89

pods of olive black (5Y 2/1) SILT RICH CLAY
10% silt, 90% clay

SILT RICH CLAY, medium dark gray (N4)
25% silt, 75% clayto
SILTY CLAY
to

-50

I
-84
-105

CLAYEY SILT, dark gray (N3)
70% silt, 30% clay
SILT, olive black (5Y 2/1)
lab grain size determ. sect. 4, 117 cm:
6% sand
38% silt
56% clay

pods of FELDSPAR SILT, grayish olive (10Y 4/2 - 3/2)
extremely well sorted

Slide 6-75
25% diatoms
15% silt
60% clay-57-75

SILT and DIATOM RICH CLAY
very dark gray (5Y 3/1)
with thin interbeds of: SANDY SILTCore
Catcher
Explanatory notes in Chapter 1

438Core Catcher:

D
PF _
BF R
N - R R Ms

SITE 191

WET-BULK DENSITY, gm/cc
1
2
3

SECTIONCM

1 i i i i i i i i

POROSITY,*
100

ro

Grain
Density
. ε

3 at

t .)

u

M

• W•l
-25

2-

-50
3-

J

4-75

5-

-100

-125
8-1

1-150

191-5-1 191-5-2 191-5-3 191-5-4 191-5-5 191-5-6

439

SITE 191
Site 191

Hole

Core 6

Cored I n t e r v a l : 171-180

FOSSILCHARACTER

LITHOLOGY

LITHOLOGIC DESCRIPTIONVOID

Basic lithology
PYRITE and DIATOM BEARING SILTY CLAY
dark gray (5Y 4/1)

0.5—

1.0

-90

5 - 1 0 % diatoms
35 - 40% silt
50 - 55% clay
2 - 5% pyri te

SILTY SAND, black, graded

Slide 2-74 (ash layer) Core Catcher:
glass
D C M
35% feldspar
10% lithic frags.
5% pyroxene
R R M

SAND, black
CRYSTAL ASH

S R M
PF A G
BF R

-140
Core
Catcherlab s a n d / s i l t / c l a y percents for graded u n i t , sect. 1-2

sect. 1 112 cm
143 cmsect. 2
3 cm
16 cm
31 cm
Explanatory notes in Chapter 1

440

62
67
73
75
83

26
23
17
16
11

12
10
10
9
6

SITE 191
WET-BULK DENSITY, gm/cc
1

2

SECTION

3

CM
POROSITY,*
100
0

ro

Grain
Density
2
I3
"

1-

-25

2-

-50

3-

4-75

5-

-100
6-

7-

-125

8-

9-1

1-150

191-6-1 191-6-2

441

SITE 191
Site 191

Hole

Core 7

Cored Interval: 227-236

FOSSILCHARACTER
LITHOLOGIC DESCRIPTION

1

o
<-π

LITHOLOGYo

VOID
Semi-lithified-135
SILTY CLAY, olive black (5Y 2/1)
with interbeds, lenses and mottles of TERRIG. SILT RICH
CARBONATE MUD 90% CaC0 3
VITRIC ASH, olive gray (5Y 4/1)

Core
Catcher-105

DIATOM BEARING SILTY CLAY, olive black (5Y 2/1)

-138

SILT, olive gray (5Y 4/1), graded
DIATOM BEARING LIMESTONE
olive gray to light olive gray (5Y 4/1-6/1)
mottles and lenses

Core Catcher
D F G
Z
Qi

442

* LOWER PLEISTOCENE* (D) Actinocyclus oculatus

BF

1 Qi

Explanatory notes in Chapter 1

XR 2-100
Slide 2-105 70% amorph
5% diatoms
7% quartz
25% feldspar 5% plag.
TR pyroxene 13% mica
TR chlorite 3% chlor.
70% clay
2% mont.

Qi OO

Slide 1-135
20% feldspar
3% pyroxene
2% opaque
75% clayF
R

M
MSITE 191

WET-BULK DENSITY, gm/cc
1

2

SECTION3
CM

11 i i i I i i i i i i > i i i i i i 11

POROSITY,*

rθ

Grain
Density
-32 o
M
ü-i

-25

2-

-50
3ca

4-75

•<

C£S
O

O
Q_

5-

O

-100
D~•

7-

-125

8-

9-1
1—150

191-7-1 191-7-2

443

SITE 191
Site 191

Hole

Core 8

Cored Interval: 274-283

FOSSILCHARACTER

LITHOLOGY

LITHOLOGIC DESCRIPTION

VOID
0.5-

LIMESTONE, grayish olive (10Y 4/2) (layer about 4 cm thick)

1.0-120
-138
-148

-90

Core
Catcher

SILTY CLAY, dark gray (N3), semi-lithified, burrowed
40% silt, 60% clay
DIATOM BEARING, CLAY RICH SILT, olive gray (5Y 3/2)
5% diatoms, 75% silt, 20% clay

SAND, olive black (5Y 2/1)
DIATOM RICH SILTY CLAY
gray (N3-4)
with thin laminae of olive
black (5Y 2/1) SAND

Slide 2-90
20% diatoms
35% silt
45% clay
Explanatory notes in Chapter 1

444Core Catcher
N _ R R M
S R M
PF
BF

R
R

SITE 191

WET-BULK DENSITY, gm/cc
1
POROSITY,%
100
0

SECTION

CM
-0

Grain
Density
M
0-1

1-

-25

2-

-50

3-

4-75

5-

-100

6-

7-

-125

8-

-150

191-8-1 191-8-2

445

SITE 191
Cored I n t e r v a l : 321-330

LITHOLOGY

LITHO.SAMPLE |PRES.

ABUND.

FOSSILZONE

AGE
LOWER PLEISTOCENEMETERS

Core 9FOSSILCHARACTER

DEFORMATION |HoleSECTION

Site 191

LITHOLOGIC DESCRIPTION

-12
0.5-

1

*

SILTY CLAY
dark olive gray (5Y 3/1)
thin, irregular lenses and bands
containing carbonate, lightolive gray (5Y 5/1)

-75
1.0-

Core
Catcher

XR 1-60
71% amorph.
7% quartz
5% plag.
H % mica
2% chlor.
3% mont.
TR amphib.

Slide 1-75
35% silt
65% claySemi-lithified* ( D ) Actinocyclus ocuiatus
Site 191

Hole

Core 10

Cored Interval: 384-393

FOSSILCHARACTER

LITHOLOGIC DESCRIPTION

LITHOLOGY

0.5VOID

Semi-indurated, burrowed-70

DIATOM BEARING SILTY CLAY
dark greenish gray (5GY 4/1)
mottled: greenish black (5GY 2/1)
to olive gray (5Y 4/1)

Slide 2-70
5 - 10% diatoms
35% silt
60% clayCore
Catcher
Explanatory notes in Chapter 1

446Core Catcher
D C GNR S PF R
BF R

Core Catcher:
D A G
N
R

- R M
S R M
PF C M
BF R

SITE 191

WET-BULK DENSITY, gm/cc
1
2
3
Grain
Density

POROSITY,*
100
0|

SECTION
CM
-0

M
On

1 1

1-

-25

2-

-50
3-

WET-BULK DENSITY, gm/cc
1
2
3
POROSITY,*
100
0

Grain
Density

-75

•32 o

M

2-

\
3-

\
>

-125

4-

-150

191-9-1 191-10-1 191-10-2 191-10-3

447

SITE 191
Core 11LITHO.SAMPLE

1

Semi-lithifiedI
1
1
1 -130

1.0_.».
R
S

R M

2

Core 12

DIATOM BEARING SILTY CLAY
dark greenish gray (5GY 3/1)
section less silty than section 1

1
1
5 - 1 0 % diatoms
20 - 30% silt
65 - 75% clay

Core
CatcherHolerounded porphyritic volcanic pebble-75

1

Site 191

LITHOLOGIC DESCRIPTIONVOID

I1 1 1 1 1 1 1 1 1 1 11 1

(S) Ammodochium rectangulare(D) Thalassiosira zabelinae

LITHOLOGYLOo

UPPER PLIOCENE

Cored I n t e r v a l : 452-461
DEFORMATION |PRES.

ABUND.

FOSSILAGE

ZONE

FOSSILCHARACTER

METERSHoleSECTION

Site 191

XR 2-110
65% amorph.
10% quartz
6% plag.
13% mica
3% chlor.
3% mont.
1% amphib.

Core Catcher:
D A G
N
R R M
S R M

Cored I n t e r v a l : 520-527

FOSSILCHARACTER
LITHOLOGY

LITHOLOGIC DESCRIPTION

0.5Semi-lithified, burrowed
1.0-120o.^z

SILT and CLAY RICH DIATOM OOZE
greenish black (5Y 3/1)
65 - 70% diatoms
10 - 20% silt
10 - 25% clay
XR 2-30
erratic pebble

-78

-125

lithic fragment SAND

70% amorph.
8% quartz
5% plag.
12% mica
3% chlor.
3% mont.

Core Catcher:
D R M

N R S PF BF --graded, lithic SAND; lower part in CC (?) calcite cemented
Core
Catcher

Explanatory notes in Chapter 1

448

core catcher sample also contains:
SAND and SILT BEARING LIMESTONE
and CARBONATE and SILT BEARING CLAY
with scattered solution corroded diatoms

SITE 191
WET-BULK DENSITY, gm/cc
1

2

POROSITY,*
100
0

SECTION

3

CM

ro

Grain
Density

1-

-25

2-

-50

3-

4-75

5-

-100

6-

7-

-125

8-

9_J
1—150

191-11-1 191-11-2 191-12-1 191-12-2

449

SITE 191-

LITHO.SAMPLE

LITHOLOGY

DEFORMATION

Cored Interval: 620-629

METERS

Core 13
SECTIONPRES.

ABUND.

Hole
FOSSILCHARACTERFOSSIL

ZONE

AGE

Site 191-15

LITHOLOGIC DESCRIPTIONSILTY SAND

0.5-

Semi-lithified

1-75
SILT RICH CLAY
yery dark gray (5Y 3/1) todark gray (5Y 4/1)

1 1 11 1 1 1 11 1 1 1 1 1

1.0-

2

horizontal, lensy bedding
burrowed
scattered forams
.113
T15

L.Lv .j

VOID

Q-

1

1
1

1

Core
Catcher
Explanatory notes in Chapter 1

LITHO.SAMPLE

1

DEFORMATION

LITHOLOGY

2450

Slide 1-75
10% feldspar, etc.
3% opaque
85% clay

Cored Interval: 723-732

METERS

Core 14ocn
11 1 1 1 1 1 1 1 11 11

PRES.

Qi

D
R
S

ABUND.

FOSSIL

ZONE

1

AGE

1

00

Hole
FOSSILCHARACTER

111 1 1 11 1 1 1 1 1 1

1Qi

Site 191

SAND layers

c ore
Cat cher

SECTION

Qi

Id Z

M

XR 2-60
71% amorph.
7% quartz
4% plag.
8% mica
2% chlor.
4% mont.
3% clinop.
1% pyrite_---_-_-50' " ' '. :•:-no

LITHOLOGIC DESCRIPTION

Basic lithology
SILTY CLAY, dark greenish gray (5GY 2/1)
burrowed; thin sand laminae
70% clay, 30% silt

SILTY SAND, olive black (5Y 2/1)
60% feldspar, some altered
25% lithics and opaques
5% pyroxene

5% chert
TR chlorite

Core Catcher:
D R M

J "
£ "
BF R

SITE 191

WET-BULK DENSITY, gm/cc
I
2
3

SECTIONCM

I1 i i i I i i i i i ' > ' ' i < ' > " i

POROSITY,%
100
0

ro

Grain
Density
-32 «
3

H

h50

hioo

h i 258H

1—150

191-13-1 191-13-2 191-14-1 191-14-2

451

SITE 191
Cored Interval: 905-910

LITHOLOGY

LITHO.SAMPLE |PRES.

ABUND.

FOSSILZONE

AGEMETERS

Core 15

FOSSILCHARACTER

DEFORMATION |HoleSECTION

Site 191

LITHOLOGIC DESCRIPTION

core catcher sample onlyCore
CatcherCore Catcher:
D - -BASALT
dark gray (N3)LITHOLOGYino

I I I l | 1 l 1 1 | i I \ 1

1CoreCatcher
Explanatory notes in Chapter 1

452

Cored Interval: 910-919

LITHO.SAMPLE |PRES.

ABUND.

FOSSILZONE

AGE

FOSSILCHARACTER

METERS

Core 16

DEFORMATION |HoleSECTION

Site 191JS

LITHOLOGIC DESCRIPTION

VOID

, y <

^

V

•* >

i.

j.

BASALT
dark gray (N3)Core C a t c her:

D

- -

N
R
S

- - - -" "- -

SITE 191
WET-BULK DENSITY, gm/cc
1

2

I i i i i i • ' ' • i ' ' ' ' i

POROSITY,*
100
0

SECTION3CM-0• ' »i

Grain
Density
32 o

-3

°

i

3 &

ù-

1-

-25

2-

-50
3-

-75

5-

-100
6-

7-

-125

f•

8-

9-1
•150

^

191-16-1

453

SITE 191
Site 191

Hole A

Core 1

Cored I n t e r v a l : 1 4 - 2 3

FOSSILCHARACTER

LITHOLOGY

LITHOLOGIC DESCRIPTION

Alternating:
SILT RICH DIATOMACEOUS CLAY, dark gray (5Y 4/1)
and

0.5—

1.0-

-no
-130

SILT and CLAY RICH DIATOM OOZE, olive gray (5Y 4/2)
Slide 1-110
Slide 1-130
60% diatoms
35% diatoms
15% silt
15% silt
25% clay
50% clay-65

SILTY SAND

-130

SILTY SANDSILTY SAND

-75

GLASS BEARING SILTY SAND
55% feldspar
20% lithic fragments
10% glass
10% clay
5% pyroxene
2% chlorite

I

-140
-23

-75

I

SAND BEARING SILTY CLAY
very dark gray (5Y 3/1)
Slide 2-130
25% silt (incl. minor sand)
75% clay

SILTY CLAY
olive gray (5Y 4/1)
with disturbed streaks and pods of:

-105
-VOID

1) FELDSPATHIC SANDY SILT, olive black (5Y 2/1)
70% feldspar, 20% glass, 10% pyroxene2) VITRIC ASH
light olive gray (5Y 5/2) andolive black (5Y 2/1)
3) SILT RICH CLAY, dark greenish gray (5GY 4/1)
20% silt, 80% clay

-30
-75

I
soupy section
-75

Core
Catcher
Explanatory notes in Chapter 1

454

DIATOM BEARING SILTY CLAY
very dark gray (5Y 3/1)
Slide 6-75
10% diatoms
45% silt
45% clay

Core Catcher:D
PF C M
BF C
F
R

M
M

SITE 191

WET-BULK DENSITY, gm/cc
1
2
3
11 i i i i i i i < i i > > > i i

POROSITY,*
100
0

SECTION

CM

i 11

ro

Grain
Density

1* o

13 t

oA
1-

-25

2-

-50
3-

-75

5-

-100

6-

7-

-125

8-

9-1
L-150

191A-1-1 191A-1-2 191A-1-3 191A-1-4 191A-1-5 191A-1-6

455

SITE 191
Site 191

Hole A

Core 2

Cored I n t e r v a l : 23-32

FOSSILCHARACTER

LITHOLOGY

LITHOLOGIC DESCRIPTION-44

0.5- -::-::-*:
1.0—

-130

Alternating:
DIATOMACEOUS SILTY CLAYandGLASS BEARING FELDSPATHIC SANDY SILTvery dark gray (5Y 3/1)

-40
-60

-123

SILT BEARING, CLAY RICH DIATOM OOZE
dark greenish gray (5GY 4/1)
SILT BEARING VITRIC ASH, light olive gray (5Y 5/2)

SILTY CLAY and CLAYEY SILT
olive gray (5Y 3/2)
pods of SILT BEARING CLAY, dark greenish gray (5G 4/1)

-33
-60

ASH (?) olive black (5Y 2/1)

Core
Catcher

Slide 1-44 and 2-40 (sandy silt)
50 - 55% feldspar
30% altered grains; lithics
5 - 10% glass
3 - 5% pyroxene
2 - 5% diatoms
2% chlorite

Core Catcher

D
N

_ _

R

F M
F M

s
PF C M
BF C

456

Slide 3-60 (basic lith)
30% silt
70% claylab grain size 3-90
9% sand
73% silt
18% clayCore
Catcherm

LITHO.SAMPLE |METERSLITHOLOGY

Explanatory notes in Chapter 1

Slide 2-60 (basic lith)
75% diatoms
10% silt
15% clay (incl. minor carbonate)

Cored Interval: 32-41

DEFORMATION |Core 3

SECTIONPRES.

ABUND.

Hole A
FOSSILCHARACTERFOSSIL

ZONE

AGE

Site 191

Slide 1-130 (basic lith)
30% diatoms
20% silt
50% clay

LITHOLOGIC DESCRIPTION

CC only
VOLCANIC PEBBLE

SITE 191

WET-BULK DENSITY, gm/cc
1
2
3
j i i i i | i i i i I ' ' ' ' M 'SECTION
CM

I

ro

Grain
Density

POROSITY,*
100
0

-32 o
I

I

M
O-i

1-

-25

2-

-50
3-

4-75

-100
6-

7-

-125

8-

9-1
L-150

191A-2-1 191A-2-2 191A-2-3

457

SITE 191
Site 191

458

Hole A

Core 4

Cored Interval: 41-50

SITE 191

WET-BULK DENSITY, gm/cc
1
2
3

SECTION

I' ' ' ' I ' ' ' ' i ' ' ' ' i ' ' ' ' i

CM

Grain
Densityro

POROSITY,*
100
0

i

I

I2
i

i

i

M

T 1

1-

-25

2-

-50
3-

-75

5-

-100

6-

7-

-125

8-

1-150

191A-4-1 191A-4-2 191A-4-3 191A-4-4 191A-4-5 191A-4-6

459

SITE 191
Site 191

Hole BFOSSILCHARACTER

Core 1

Cored Interval: 0-9

LITHOLOGY

LITHOLOGIC DESCRIPTION

VOID
0.5—

1.0-118
124

SILT and CLAY BEARING DIATOM OOZE
olive gray (5Y 4/2) and grayish olive (10Y 4/2)
to olive brown (5Y 3/4)
composition range:
80 - 90% diatoms
3 - 10% silt
5 - 10% clay
locally contains TR carbonate

65

=70
74

SAND, olive black (5Y 2/1) (1-2 cm thick)^150

CLAY and DIATOM RICH SILT, dusky yellowish brown (10YR 2/2)
20% diatoms
70% silt
10% clay
TR forams

K75

^75

SILT and CLAY RICH DIATOM OOZEtoSILT RICH CLAYEY DIATOM OOZE
dark gray (5Y 4/1)
Slide 3-75
Slide 4-75
50% diatoms
70% diatoms
15% silt
10% silt
35% clay
20% clay
TR nannos and forams

-140

-65

-120

Interbedded:
SILT RICH CLAY, olive gray (5Y 4/1)
and
SANDY SILT or SILTY SAND, olive black (5Y 2/1)

Slide 5-65
15% silt
85% clay

Slide 5-120
30% sand70% silt

Core Catcher
D

N
R
S
-145
Core
Catcher

Explanatory notes in Chapter 1

460

R
R

M
M

SITE 191

WET-BULK DENSITY, gm/cc
1
2
3
11

i i i I i i i i i i i > • i i

POROSITY,%
100
0

i

SECTION

CM

11

ro

Grain
Density
M
O-i

1-

-25

2-

-50

3-

4-75

5-

-100

6-

7-

-125

8-

9-1
I—150

191B-1-1 191B-1-2 191B-1-3 191B-1-4 191B-1-5 191B-1-6

461