Citation:

dsdp.proc.79.112.1984

Name: (Figure 2) Stratigraphic distribution of Schizosphaerella in DSDP Hole 79-547B
Published: 1984
License: https://creativecommons.org/licenses/by/3.0/

Always quote citation above when using data! You can download the citation in several formats below.

RIS Citation BibTeX Citation Text Citation Facebook TwitterShow Map Google Earth

Abstract:

The Jurassic (hemi)pelagic continental margin deposits drilled at Hole 547B, off the Moroccan coast, reveal striking Tethyan affinity. Analogies concern not only types and gross vertical evolution of facies, but also composition and textures of the fine sediment and the pattern of diagenetic alteration. In this context, the occurrence of the nanno-organism Schizosphaerella Deflandre and Dangeard (sometimes as a conspicuous portion of the fine-grained carbonate fraction) is of particular interest. Schizosphaerella, an incertae sedis taxon, has been widely recorded as a sediment contributor from Tethyan Jurassic deeper-water carbonate facies exposed on land. Because of its extremely long range (Hettangian to early Kimmeridgian), the genus Schizosphaerella (two species currently described, S. punctulata Deflandre and Dangeard and S. astrea Moshkovitz) is obviously not of great biostratigraphic interest. However, it is of interest in sedimentology and petrology. Specifically, Schizosphaerella was often the only component of the initial fine-grained fraction of a sediment that was able to resist diagenetic obliteration. However, alteration of the original skeletal structure did occur to various degrees. Crystal habit and mineralogy of the fundamental skeletal elements, as well as their mode of mutual arrangement in the test wall with the implied high initial porosity of the skeleton (60-70%), appear to be responsible for this outstanding resistance. Moreover, the ability to concentrate within and, in the case of the species S. punctulata, around the skeleton, large amounts of diagenetic calcite also contributed to the resistance.

In both species of Schizosphaerella, occlusion of the original skeletal void space during diagenesis appears to have proceeded in an analogous manner, with an initial slight uniform syntaxial enlargement of the basic lamellar skeletal crystallites followed, upon mutual impingement, by uneven accretion of overgrowth cement in the remaining skeletal voids. However, distinctive fabrics are evident according to the different primary test wall architecture. In S. punctulata, intraskeletal cementation is usually followed by the growth of a radially structured crust of bladed to fibrous calcite around the valves. These crusts are interpreted as a product of aggrading neomorphism, associated with mineralogic stabilization of the original, presumably polyphase, sediment.

Data from Hole 547B, along with inferences, drawn from the fabric relationships, suggest that the crusts formed and (inferentially) mineralogic stabilization occurred at a relatively early time in the diagenetic history in the shallow burial realm. An enhanced rate of lithification at relatively shallow burial depths and thus the chance for neomorphism to significantly influence the textural evolution of the buried sediment may be related to a lower Mg/Ca concentration ratio in the oceanic system and, hence, in marine pore waters in pre-Late Jurassic times.

Project(s):

Deep Sea Drilling Project (DSDP)

Coverage:

Latitude: 33.780700 * Longitude: -9.349700

Date/Time Start: 1981-05-03T00:00:00 * Date/Time End: 1981-05-03T00:00:00

Minimum Elevation: -3938.0 m * Maximum Elevation: -3938.0 m

Event(s):

79-547B * Latitude: 33.780700 * Longitude: -9.349700 * Date/Time: 1981-05-03T00:00:00 * Elevation: -3938.0 m * Penetration: 1030 m * Recovery: 153.2 m * Location: North Atlantic/PLATEAU * Campaign: * Basis: Glomar Challenger * Method/Device: Drilling/drill rig (DRILL) * Comment: 36 cores; 305.5 m cored; 0 m drilled; 50.1 % recovery

Parameter(s):

#	Name	Short Name	Principal Investigator	Method/Device
1	Sample code/label	Sample label	Kälin, Otto	DSDP/ODP/IODP sample designation
2	Method comment	Method comm	Kälin, Otto
3	Schizosphaerella spp.	Schizosphaerella spp.	Kälin, Otto	Light microscope
4	Schizosphaerella spp.	Schizosphaerella spp.	Kälin, Otto	Light microscope
5	Schizosphaerella punctulata	S. punctulata	Kälin, Otto	Light microscope
6	Schizosphaerella punctulata	S. punctulata	Kälin, Otto	Scanning electron microscope (SEM)
7	Schizosphaerella astraea	S. astraea	Kälin, Otto	Light microscope
8	Schizosphaerella astraea	S. astraea	Kälin, Otto	Scanning electron microscope (SEM)

License:

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

Size:

278 data points

Data

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

1 Sample label (DSDP/ODP/IODP sample designation)	2 Method comm	3 Schizosphaerella spp. (Light microscope)	4 Schizosphaerella spp. (Light microscope)	5 S. punctulata (Light microscope)	6 S. punctulata (Scanning electron microscope ...)	7 S. astraea (Light microscope)	8 S. astraea (Scanning electron microscope ...)
79-547B-6-2,97-100	light microscope	-
79-547B-6-2,148-150	light microscope, SEM	-	-
79-547B-6-3,97-97	light microscope, SEM	-	-
79-547B-6-3,136-138	light microscope	-
79-547B-6-3,139-142	light microscope	X		?
79-547B-6-4,0-3	light microscope	?
79-547B-6-4-CC	light microscope, SEM	-	-
79-547B-7-1,47-49	light microscope	X		?
79-547B-7-2,25-27	light microscope	?
79-547B-7-2,146-148	light microscope	-
79-547B-7-2,148-150	light microscope, SEM	-	?
79-547B-7-3,29-31	light microscope	?
79-547B-7-3,49-51	light microscope, SEM	X	-	?
79-547B-7-3,81-84	light microscope, SEM	X	?r
79-547B-7-3,115-118	light microscope	?
79-547B-7-4,86-88	light microscope	?
79-547B-8-1,15-17	light microscope	X	?r
79-547B-8-1,35-37	light microscope, SEM	X	?	?
79-547B-8-1,65-69	light microscope	X
79-547B-8-1,80-83	SEM		?
79-547B-8-2,0-3	light microscope	X		X
79-547B-8-2,59-62	SEM		?
79-547B-8-2,121-124	light microscope	X		?
79-547B-8-3,24-27	SEM		-
79-547B-8-3,40-43	light microscope		r	X
79-547B-8-3,54-57	light microscope, SEM	r	r
79-547B-8-3,62-65	light microscope, SEM	r	r
79-547B-8-4,43-46	light microscope	X
79-547B-9-1,119-121	light microscope, SEM	r	X
79-547B-9-2,24-28	light microscope	C
79-547B-9-2,106-109	light microscope	r
79-547B-10-1,131-132	light microscope	X
79-547B-10-3,0-3	SEM		X		?
79-547B-10-3,89-91	light microscope, SEM	X	?		?
79-547B-10-3,131-134	light microscope, SEM	X	X
79-547B-10-4,30-32	light microscope	X		?
79-547B-10-4,57-58	light microscope	X				?
79-547B-11-1,127-129	SEM		?
79-547B-11-3,66-68	SEM		?
79-547B-11-3,92-94	light microscope, SEM	X	r				?
79-547B-11-4,118-120	SEM		r		?
79-547B-12-1,7-9	light microscope, SEM	X	r
79-547B-12-2,25-28	light microscope, SEM	X	X
79-547B-12-2,46-48	light microscope, SEM	X	X			X	?
79-547B-13-1,141-143	light microscope, SEM	r	r	?		?
79-547B-14-1,144-146	light microscope, SEM	C	r		?		?
79-547B-15-1,23-25	light microscope	C		X		?
79-547B-15-1,109-111	light microscope, SEM	A	A	X	X	X	X
79-547B-15-2,71-73	light microscope, SEM	X	X		?	X	X
79-547B-16-1,67-69	light microscope, SEM	X	X			X
79-547B-16-2,16-19	light microscope, SEM	C	C		X	X	X
79-547B-16-2,126-128	light microscope, SEM	X	X		X	X	X
79-547B-17-1,79-83	light microscope, SEM	A	A	X	X	X	X
79-547B-19-1,121-123	light microscope, SEM	C	X		X	X
79-547B-20-20-CC	SEM		?
79-547B-21-1,106-108	SEM		-
79-547B-21-1,136-138	SEM		-
79-547B-22-1,119-121	light microscope, SEM	C	C	X	X	X	?
79-547B-22-2,30-34	light microscope, SEM	A	A	?	?	X	X
79-547B-22-2,74-76	light microscope, SEM	C	C	X	X	X	?
79-547B-22-2,110-113	light microscope	C		X		X
79-547B-23-2,39-41	light microscope	C	C	X	X	X	X
79-547B-23-2,57-59	SEM		-