Citation:

reports-gpi.1993.64

Name: Annotated record of the detailed examination of Mn deposits from the 1993 R/V Sonne SO-84 expedition in the Atlantic Ocean
Published: 1993
License: https://creativecommons.org/licenses/by/3.0/

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Published: 1993 (exact date unknown) • DOI registered: 2017-06-06

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Abstract:

The SO-84 cruise from Las Palmas to Cape Town studied the underwater volcanism associated with the St Helena hotspot. Wide-spaced grid mapping of a region south and west of St Helena island identified three previously unknown hotspot volcanoes (which we named Josephine 16°27'S-9°W, Jade 16°13'S-7°46'W and Benjamin 16°12'S-8°31'W) and several older, probably near-ridge-generated seamounts. The newly discovered hotspot seamounts, and the previously-known seamounts of Bagration, Bonaparte and Kutuzov were mapped and sampled. Onboard geochemical studies confirm that they all show trace-element (Rb, Nb, Y, Zr, Sr) enriched, hotspot magma-type compositions. Morphological studies and the state of the samples collected from the seamounts (all have at least 1 mm-thick Mn crusts) suggest that none of the volcanoes is presently active, and that the St Helena hotspot is probably extinct at the present time. Josephine appears to be the youngest volcano, and one dredge here yielded fossil hydrothermal material (Fe-hydroxides). To test the hypothesis that the extinction of the hotspot is due to its magmas being channelled to the Mid-Atlantic Ridge, several dredges were taken on the ridge opposite St Helena. Furthermore, in the proposed influence zone of the St Helena plume head, Grattan seamount (9°44'S-12°48'W) was also sampled to examine whether its composition has been affected by the St Helena plume. During the transit from Las Palmas to St Helena, several sediment cores were taken in 3000 m water depth close to the ridge axis for palaeoclimatological work.

Source:

Grant, John Bruce; Moore, Carla J; Alameddin, George; Chen, Kuiying; Barton, Mark (1992): The NOAA and MMS Marine Minerals Geochemical Database. National Geophysical Data Center, NOAA, https://doi.org/10.7289/V52Z13FT

Further details:

Warnken, Robin R; Virden, William T; Moore, Carla J (1992): The NOAA and MMS Marine Minerals Bibliography. National Geophysical Data Center, NOAA, https://doi.org/10.7289/V53X84KN

Project(s):

Institute for Geosciences, Christian Albrechts University, Kiel (GIK/IfG)

NOAA and MMS Marine Minerals Geochemical Database (NOAA-MMS)

Coverage:

Median Latitude: -14.641999 * Median Longitude: -10.178781 * South-bound Latitude: -17.152667 * West-bound Longitude: -25.149167 * North-bound Latitude: 0.601000 * East-bound Longitude: -5.659000

Date/Time Start: 1993-01-11T00:00:00 * Date/Time End: 1993-02-12T00:00:00

Minimum DEPTH, sediment/rock: 0 m * Maximum DEPTH, sediment/rock: 0 m

Event(s):

GIK17835-1 (1DS) * Latitude: 0.601000 * Longitude: -25.149167 * Date/Time: 1993-01-11T00:00:00 * Elevation: -4900.0 m * Location: North Atlantic Ocean * Campaign: (ST. HELENA HOTSPOT) * Basis: * Method/Device: Dredge (DRG) * Comment: Proben 1+2+Beutel mit Reststücke

GIK17841-1 (7DS) * Latitude: -8.214167 * Longitude: -9.331500 * Date/Time: 1993-01-16T00:00:00 * Elevation: -2126.0 m * Location: South Atlantic Ocean * Campaign: (ST. HELENA HOTSPOT) * Basis: * Method/Device: Dredge (DRG) * Comment: Basalt u. Koralle

GIK17846-1 (12DS) * Latitude: -9.664667 * Longitude: -12.873333 * Date/Time: 1993-01-18T00:00:00 * Elevation: -2430.0 m * Location: South Atlantic Ocean * Campaign: (ST. HELENA HOTSPOT) * Basis: * Method/Device: Dredge (DRG) * Comment: Pillowframente, 2 Proben für Analyse genommen

Comment:

From 1983 until 1989 NOAA-NCEI compiled the NOAA-MMS Marine Minerals Geochemical Database from journal articles, technical reports and unpublished sources from other institutions. At the time it was the most extended data compilation on ferromanganese deposits world wide. Initially published in a proprietary format incompatible with present day standards it was jointly decided by AWI and NOAA to transcribe this legacy data into PANGAEA. This transfer is augmented by a careful checking of the original sources when available and the encoding of ancillary information (sample description, method of analysis...) not present in the NOAA-MMS database.

Parameter(s):

#	Name	Short Name	Unit	Method/Device	Comment
1	Event label	Event
2	Identification	ID
3	DEPTH, sediment/rock	Depth sed	m		Geocode
4	Position	Position		Visual description
5	Deposit type	Deposit type
6	Quantity of deposit	Quantity
7	Size	Size
8	Substrate type	Substrate
9	Comment	Comment			Substrate
10	Sediment type	Sediment
11	Comment	Comment			Sediment
12	Description	Description

License:

Creative Commons Attribution 3.0 Unported (CC-BY-3.0)

Size:

725 data points

Data

Download dataset as tab-delimited text — use the following character encoding:

1 Event	2 ID	4 Position	5 Deposit type	6 Quantity	7 Size	8 Substrate	9 Comment (Substrate)	10 Sediment	11 Comment (Sediment)	12 Description
GIK17835-1	SO84-1DS-1-M	Surface	Mn crust	1	1.0 cm thick	Rock; gabbro	Fresh gabbros	Ooze	Foraminifera nannofossil ooze	1.0 cm Mn crust.
GIK17841-1	SO84-7DS-1-M	Surface	Mn crust	1	0.2 cm thick	Rock; basalt	Small piece of vesicular, fine-grained basalt	Hard ground		0.2 cm Mn-crust.
GIK17846-1	SO84-12DS-1-M	Surface	Mn crust	1		Rock; basalt	Basalt pillow, vesicular	Hard ground		Mn crust.
GIK17846-1	SO84-12DS-2-M	Surface	Mn crust	1	0.2 cm thick	Rock; basalt	Slightly hydrothermally altered pillow basalt	Hard ground		0.2 cm Fe-Mn oxide crust.
GIK17847-1	SO84-13DS-6-M	Surface	Mn crust	1	0.2 cm thick	Rock; basalt	Slightly hydrothermally altered pillow basalt	Ooze	Metal rich foraminifera nannofossil ooze	0.2 cm Fe-Mn oxide crust.
GIK17848-1	SO84-14DS-5-M	Surface	Mn crust	1		Rock; basalt	Aphyric, vesicular basalt with glass rim	Ooze	Metal rich foraminifera nannofossil ooze	Fe-Mn oxide crust
GIK17848-1	SO84-14DS-6-M	Surface	Mn crust	1		Rock; basalt	Vesicular basalt	Ooze	Metal rich foraminifera nannofossil ooze	Fe-Mn oxide crust on exposed surface.
GIK17854-1	SO84-20DS-3-M	Surface	Mn crust	1		Rock; volvanics	Some pieces of volcanic glass	Ooze	Foraminifera nannofossil ooze	Mn crust
GIK17855-1	SO84-21DS-1-M	Surface	Fe-Mn rch layer	1		Rock; basalt	Hydrothermally altered pillow basalt containing phenocrysts and yellowish (sulphur?) bands within the basalt Brown (Fe oxyhydroxide) layers	Hard ground		Hydrothermally altered pillow basalt containing phenocrysts and with brown (Fe oxyhydroxide) and yellowish (sulphur?) bands within the basalt
GIK17856-1	SO84-22DS-1-M	Surface	Mn crust	1	0.1 cm	Rock; basalt	Hydrothermally altered lava containing abundant phenocrysts	Ooze	Foraminifera nannofossil ooze	Thin (0.1 cm) black granular Mn crust on the surface
GIK17857-1	SO84-23DS-1-M	Surface	Fe-Mn staining	1	1.0 cm thick	Rock; basalt	Hydrothermally altered basalt with some phenocrysts	Ooze	Foraminifera nannofossil ooze	Fe staining on upper surface overlain by 1.0 cm of black granular Mn crust.
GIK17857-1	SO84-23DS 2-M	Surface	Mn crust	1	0.2 cm thick	Rock; basalt	Pillow basalt with 0.5 cm band of brownish Fe material	Ooze	Foraminifera nannofossil ooze	Overlain by 0.2 cm thick granular Mn crust on the upper surface
GIK17858-1	SO84-24DS-1-M	Surface	Mn coating	1	<0.1 cm	Rock; basalt	Dense aphyritic basalt	Hard ground		Thin (<0.1 cm) coating of granular Mn material
GIK17858-1	SO84-24DS-3-M	Surface	Mn coating	1		Rock; basalt	Large pillow piece, vesicular, glass rim	Hard ground		Mn coating
GIK17859-1	SO84-25DS-1-M	Surface	Mn coating	1		Rock; basalt	Fresh basalt with surface coating (up to 0.5 cm) of brown Fe oxyhydroxides	Ooze	Foraminifera nannofossil ooze	Overlain by granular Mn oxides
GIK17860-1	SO84-26DS-2-M	Surface	Mn coating	1	<0.1 cm	Rock; basalt	Dense, fractured slightly vesicular pillow basalt with 3.0 cm alteration rim	Ooze	Foraminifera nannofossil ooze	Thin (< 0.1 cm) Mn coating
GIK17861-1	SO84-27DS-1-M	Surface	Mn coating	1		Rock; basalt	Aphyric basalt, slightly vesicular, glass rim up to 1.0 cm	Ooze	Foraminifera nannofossil ooze	Mn coating
GIK17861-1	SO84-27DS-2-M	Surface	Mn coating	1		Rock; basalt	Aphyric basalt, slightly vesicular, glass rim up to 1.0 cm	Ooze	Foraminifera nannofossil ooze	Mn coating
GIK17861-1	SO84-27DS-3-M	Surface	Mn coating	1		Rock; basalt	Basalt, slightly vesicular, glass rim up to 1.0 cm	Ooze	Foraminifera nannofossil ooze	Mn coating
GIK17861-1	SO84-27DS-4-M	Surface	Mn coating	1		Rock; basalt	Basalt, slightly vesicular, glass rim up to 1.0 cm	Ooze	Foraminifera nannofossil ooze	Mn coating
GIK17861-1	SO84-27DS-5-M	Surface	Mn coating	1		Rock; basalt	Basalt, slightly vesicular, glass rim up to 1.0 cm	Ooze	Foraminifera nannofossil ooze	Mn coating
GIK17861-1	SO84-27DS-6-M	Surface	Mn coating	1		Rock; basalt	Basalt with thin (< 0.1 cm)	Ooze	Foraminifera nannofossil ooze	Mn coating
GIK17865-1	SO84-31DS-2-M	Surface	Mn coating	1		Rock; basalt	Basalt with thin (< 0.1 cm)	Ooze	Foraminifera nannofossil ooze rich in volcanic glass	Mn coating
GIK17869-1	SO84-35DS-1-M	Surface	Mn coating	1	Thin	Rock; basalt	Altered and tectonized fine grained, dense basalt, veins in centre	Ooze	Foraminifera nannofossil ooze	Thin Mn coating
GIK17869-1	SO84-35DS-2-M	Surface	Mn coating	1	Thin	Rock; basalt	Altered and tectonized fine grained, dense basalt, large veins in centre	Ooze	Foraminifera nannofossil ooze	Thin Mn coating
GIK17869-1	SO84-35DS-3-M	Surface	Mn coating	1	Thin	Rock; basalt	Altered and tectonized ? fine grained aphyric basalt	Ooze	Foraminifera nannofossil ooze	Thin Mn coating
GIK17869-1	SO84-35DS-4-M	Surface	Mn coating	1	<0.1 cm	Rock; basalt	Altered basalt	Ooze	Foraminifera nannofossil ooze	Thin (< 0.1 cm) Mn coating
GIK17869-1	SO84-35DS-5-M	Surface	Mn crust	1	0.1 cm	Rock; basalt	Altered basalt	Ooze	Foraminifera nannofossil ooze	Granular Mn crust (0.1 cm) in depressions
GIK17871-1	SO84-37DS-1-M	Surface	Mn coating	1		Rock; basalt	Altered, fine grained aphyric basalt, 3 cm alteration rim, relatively fresh core	Hard ground		Mn coating
GIK17871-1	SO84-37DS-4-M	Surface	Mn coating	1		Rock; basalt	Altered, dense fine grained aphyric lava with many plagioclase	Hard ground		Mn coating
GIK17871-1	SO84-37DS-5-M	Surface	Mn crust	1	0.1 cm	Rock; volvanics	Volcanic conglomerate containing large (35mm) angular fragments	Hard ground		Covered with granular Mn crust (0.1 cm) on the upper surface
GIK17876-1	SO84-42DS-1-M	Surface	Mn coating	1	<0.1 cm	Rock; basalt	Altered vesicular basalt	Hard ground		Occasional Mn coating (< 0.1 cm)
GIK17876-1	SO84-42DS-3-M	Surface	Mn coating	1		Rock; basalt	Altered, phyric lava with phenos of plag (up to 1.0 cm)	Hard ground		Mn coating
GIK17877-1	SO84-43DS-1-M	Surface	Mn crust	1	1.5-2.0 cm	Rock; volvanics	Large slab (26 cm across x 9.0 cm thick) of banded volcanic material. Sharp contact with substrate	Hard ground		Mn crust with botryoids 0.5-2.0 cm across and 1.5-2.0 cm thick on upper surface. Botryoidal Mn crust up to 3.0 cm thick on other side.
GIK17877-1	SO84-43DS-2-M	Surface	Mn crust	1	1.0 cm thick	Rock; basalt	Highly altered volcanic material containing phenocrysts (0.3 cm) which are possibly strongly replaced by Mn	Hard ground		Botryoidal Mn crust, 1.0 cm thick on upper surfaces and sides showing sharp contact with basalt
GIK17877-1	SO84-43DS-3-M	Surface	Mn crust	1	2.0 cm thick	Rock; basalt	Highly altered, vesicular phyric lava with plag phenos (to 2.0 cm)	Hard ground		Mn crust to 2.0 cm
GIK17877-1	SO84-43DS-4-M	Surface	Mn crust	1	2.0 cm thick	Rock; basalt	Highly altered, vesicular phyric lava with plagioclase phenos (to 2.0 cm)	Hard ground		Mn crust to 2.0 cm
GIK17878-1	SO84-44DS-1-M	Surface	Mn crust	1	3.0 cm thick	Rock; basalt	Highly altered vesicular lava	Hard ground		3.0 cm Mn crust
GIK17881-1	SO84-47DS-1-M	Surface	Mn crust	1	Thick	Rock; basalt	Altered lava with plag phenos	Hard ground		Thick Mn crust
GIK17883-1	SO84-49DS-3-M	Surface	Mn crust	1	0.8-1.0 cm thick	Rock; basalt	3.0 cm thick slab consisting of palagonitized basalt (2.0 cm thick) interpenetrated by Mn oxides. Sharp contact with substrate	Hard ground		Overlain by a dense uniform layer of Mn oxide, 0.8-1.0 cm thick with subdued botryoidal features on upper surface.
GIK17887-1	SO84-53DS-1-M	Surface	Mn crust	1	0.05 cm	Rock; basalt	Altered aphyric vesicular lava,	Hard ground		0.05 cm Mn coating
GIK17887-1	SO84-53DS-2-M	Surface	Mn crust	1	1.0 cm thick	Rock; basalt	Altered vesicular lava	Hard ground		1.0 cm Mn crust
GIK17888-1	SO84-54DS-1-M	Surface	Mn crust	1	3.0 cm thick	Rock; basalt	Highly altered vesicular aphyric lava	Hard ground		3.0 cm Mn crust, filled vesicles
GIK17888-1	SO84-54DS-2-M	Surface	Mn crust	1	3.0 cm thick	Rock; basalt	Highly altered vesicular aphyric lava	Hard ground		3.0 cm Mn crust, filled vesicles
GIK17889-1	SO84-55DS-1-M	Surface	Mn crust	1	0.2 cm thick	Rock; basalt	Altered aphyric lava with dense unifor	Ooze	Foraminifera nannofossil ooze	Mn crust of 0.2 cm thick displaying sharp contact with substrate
GIK17889-1	SO84-55DS-2-M	Surface	Mn crust	1	3.0-4.0 thick	Consolidated sediment		Hard ground	Metalliferous sediment	Fe-Mn oxyhydroxide-rich crust 3.0-4.0 cm thick. Horizontal laminations (0.1 cm thick). Occasional laminations of brown glassy material (goethite?)
GIK17889-1	SO84-55DS-3-M	Surface	Mn crust	1		Rock; basalt	Altered, vesicular aphyric lava, hydrothermal?	Ooze	Foraminifera nannofossil ooze	Mn crust, veins with hydrothermal, material
GIK17889-1	SO84-55DS-4-M	Surface	Mn crust	1		Rock; basalt	Altered, vesicular aphyric lava, hydrothermal?	Ooze	Foraminifera nannofossil ooze	Mn crust, veins with hydrothermal, material
GIK17893-1	SO84-59DS-1-M	Surface	Mn crust	1	0.25 cm	Rock; basalt	Highly vesicular altered basalt	Ooze	Nannofossil foraminifera ooze	0.25 cm Mn crust, hydrothermal veins
GIK17893-1	SO84-59DS-2-M	Surface	Mn crust	1	0.1 cm	Rock; basalt	Highly altered vesicular basalt	Ooze	Nannofossil foraminifera ooze	Granular Mn crust, 0.1 cm thick
GIK17893-1	SO84-59DS-3-M	Surface	Mn crust	1	5.0 cm	Rock; basalt	Highly altered vesicular aphyric lava	Ooze	Nannofossil foraminifera ooze	Mn crust up to 5.0 cm, glass+ hydrothermal material+Mn crust up to 2.0 cm, sediment in cracks
GIK17893-1	SO84-59DS-4-M	Surface	Mn crust	1	0.1 cm	Rock; basalt	Highly altered vesicular basalt	Ooze	Nannofossil foraminifera ooze	Granular Mn crust, 0.1 cm thick, alteraion zoning
GIK17894-1	SO84-60DS-1-M	Surface	Mn coating	1	Thin	Rock; basalt	Moderately vesicular and altered basalt, microphenos of plagioclase	Hard ground		Thin Mn coating
GIK17894-1	SO84-60DS-2-M	Surface	Mn crust	1	0.2 cm thick	Rock; basalt	Highly altered vesicular basalt with possible evidence of hydrothermal alteration	Hard ground		Compact Mn crust on upper surface (0.2 cm thick)
GIK17894-1	SO84-60DS-3-M	Surface	Mn coating	1	Thin	Rock; basalt	Moderately vesicular and altered basalt, microphenos of plagioclase	Hard ground		Thin Mn coating
GIK17894-1	SO84-60DS-4-M	Surface	Mn coating	1	Thin	Rock; basalt	Moderately vesicular and altered basalt, microphenos of plagioclase	Hard ground		Thin Mn coating
GIK17897-1	SO84-63DS-1-M	Surface	Mn crust	1	Up to 1.0 cm thick	Rock; basalt	Altered pillow basalt with palagonite?. Sharp contact with substrate	Ooze	Foraminifera nannofossil ooze	Granular to botryoidal Mn crust up to 1.0 cm thick overlying somewhat Flecks of light brown Fe-rich material on surface of the crust.
GIK17897-1	SO84-63DS-2-M	Surface	Mn crust	1	Up to 1.0 cm thick	Rock; basalt	Altered pillow basalt with palagonite?. Sharp contact with substrate	Ooze	Foraminifera nannofossil ooze	Granular to botryoidal Mn crust up to 1.0 cm thick overlying somewhat Flecks of light brown Fe-rich material on surface of the crust.
GIK17897-1	SO84-63DS-3-M	Surface	Mn crust	1	Up to 1.0 cm thick	Rock; basalt	Altered pillow basalt with palagonite?. Sharp contact with substrate	Ooze	Foraminifera nannofossil ooze	Granular to botryoidal Mn crust up to 1.0 cm thick overlying somewhat Flecks of light brown Fe-rich material on surface of the crust.
GIK17897-1	SO84-63DS-4-M	Surface	Mn crust	1	Up to 1.0 cm thick	Rock; basalt	Altered pillow basalt with palagonite?. Sharp contact with substrate	Ooze	Foraminifera nannofossil ooze	Granular to botryoidal Mn crust up to 1.0 cm thick overlying somewhat Flecks of light brown Fe-rich material on surface of the crust.
GIK17898-1	SO84-64DS-1-M	Surface	Mn staining	1	Thin	Rock; carbonate	4 lithified carbonate blocks	Ooze	Nannofossil foraminifera ooze	Slight Mn staining
GIK17899-1	SO84-65DS-1-M	Surface	Mn crust	1	1.0-3.0 cm thick	Rock; basalt	Highly altered vesicular basalt (light brown)	Hard ground		Granular Mn crust (1.0-3.0 cm thick) on upper surface
GIK17899-1	SO84-65DS-2-M	Surface	Mn crust	1		Rock; carbonate	Carbonate	Hard ground		Mn crust
GIK17899-1	SO84-65DS-3-M	Surface	Mn crust	1		Rock; carbonate	Carbonate	Hard ground		Mn crust
GIK17899-1	SO84-65DS-4-M	Surface	Mn crust	1		Rock; carbonate	Carbonate	Hard ground		Mn crust
GIK17902-1	SO84-68DS-1-M	Surface	Mn crust	1	0.5-1.5 cm thick	Rock; basalt	Vesicular basalt. Sharp contact with substrate	Ooze	Foraminifera nannofossil ooze	Granular compact Mn crust 0.5-1.5 cm thick
GIK17902-1	SO84-68DS-3-M	Surface	Mn coating	1		Rock; basalt	Dense fresh lava with rare plagioclase phenos taken from conglomerate	Ooze	Foraminifera nannofossil ooze	Mn coating
GIK17902-1	SO84-68DS-6-M	Surface	Mn coating	1		Rock; basalt	Altered, vesicular and phyric lava with large plagioclase phenos (to 1.0 cm)	Ooze	Foraminifera nannofossil ooze	Mn coating
GIK17902-1	SO84-68DS-8-M	Surface	Mn coating	1	0.2 cm thick	Rock; basalt	Altered lava with some large plagioclase phenos (to 1.0 cm)	Ooze	Foraminifera nannofossil ooze	Mn crust of 0.2 cm (imbedded in conglomerate)
GIK17903-1	SO84-69DS-2-M	Surface	Mn crust	1	0.5-0.9 cm thick	Rock; basalt	Slightly altered (palagonitized) basalt. Sharp contact with substrate	Hard ground		Granular compact Mn crust 0.5-0.9 cm thick on the upper surface and sides
GIK17903-1	SO84-69DS-3-M	Surface	Mn crust	1	1.0 cm thick	Rock; basalt	Lava piece	Hard ground		1.0 cm Mn crust
GIK17905-1	SO84-71DS-1-M	Surface	Fe-Mn staining	1		Rock; basalt	Slabs of vesicular basalt 5.0 cm thick with ripple marks on the undersurface. Upper 0.8 cm of basalt darker colour reflecting possible interpenetration by Mn oxides	Ooze	Foraminifera nannofossil ooze	Light brown Fe staining on upper surface. Mn staining (0.1 cmm) on upper and lower surfaces. Mn crust (1.2 cm) on sides of slab
GIK17905-1	SO84-71DS-8-M	Surface	Mn coating	1		Breccia; volcavnics	Fine grained breccia	Ooze	Foraminifera nannofossil ooze	Mn coating
GIK17906-1	SO84-72DS-1-M	Surface	Mn crust	1	2.0 cm thick	Rock; basalt	Altered, vesicular and phyric pillow lava with plagioclase phenos (to 1.0 cm) and glass rim	Hard ground		Mn crust of 2.0 cm thick
GIK17906-1	SO84-72DS-1-M	Surface	Mn crust	1	2.0 cm thick	Rock; basalt	Severely altered, vesicular and phyric pillow lava with plagioclase phenos (to 1.0 cm) and glass rim	Hard ground		Mn crust of 2.0 cm thick
GIK17906-1	SO84-72DS-3-M	Surface	Mn crust	1	2.0 cm thick	Rock; basalt	Altered, vesicular and phyric pillow lava with plagioclase phenos (to 1.0 cm) and glass rim	Hard ground		Mn crust of 2.0 cm thick
GIK17908-1	SO84-74DS-1-M	Surface	Mn crust	1	2.0 cm thick	Rock; basalt	Altered, vesicular and phyric lava with plagiioclase phenos (to 1.0 cm)	Hard ground		Mn crust of 0.2 cm
GIK17908-1	SO84-74DS-2-M	Surface	Mn crust	1	2.0-3.0 cm thick	Rock; basalt	Thin brownish (Fe-rich) substrate of altered basalt	Hard ground		Botryoidal, very compact Mn crust 2.0-3.0 cm thick
GIK17917-1	SO84-83DS-1-M	Surface	Mn staining	1	<0.1 cm	Breccia; volcavnics	Breccia containing pieces of aphyric lava	Hard ground		Thin (<0.1m cm) patchy Mn staining.