Remarks on the cortical structure of late Paleozoic “phylloid algae”

2014 ◽  
Vol 88 (5) ◽  
pp. 1019-1030
Author(s):  
Diego Corrochano ◽  
Daniel Vachard
Keyword(s):  
Late Paleozoic ◽  
Cortical Structure ◽  
Phylloid Algae

Remarks on the Cortical Structure of Late Paleozoic “Phylloid Algae”

2014 ◽  
Vol 88 (5) ◽  
pp. 1019-1030
Author(s):  
Diego Corrochano ◽  
Daniel Vachard
Keyword(s):  
Late Paleozoic ◽  
Taxonomic Significance ◽  
Cantabrian Zone ◽  
Cortical Structure ◽  
Northwestern Spain ◽  
Phylloid Algae ◽  
Cortical System

The cortical structure of the green anchicodiacean alga Anchicodium in the Pennsylvanian Dueñas Formation of the Cantabrian Zone (northwestern Spain) is described and illustrated. Anchicodium is characterized by a broad phylloid or leaflike calcified thallus, consisting of a bilateral cortex and a poorly calcified central medulla. The organization and morphology of the cortical system have been revealed with great detail using cathodoluminescence microscopy. Anchicodium cortex is composed of up to three (four?) orders of dichotomized branched cortical siphons that are usually swollen at the center; primary siphons are bulbous and are followed by elongate cylindrical siphons. Cortical siphons are preserved as dull-bright luminescent molds filled with micrite or microsparite, and contrast sharply with the surrounding non-luminescent calcite infilling the intersiphonal spaces, originally occupied by aragonite. Anchicodium in the Dueñas Formation exhibits a variety of preservational stages. Through a compilation of the taxonomic nomenclature and morphologic re-interpretations, it is concluded that some late Paleozoic anchicodiacean algae might represent diagenetic stages of Anchicodium or Eugonophyllum without any taxonomic significance. This conclusion is suggested particularly for the taphotaxon Ivanovia.

Probable calcified metaphytes in the latest Proterozoic Nama Group, Namibia: origin, diagenesis, and implications

1991 ◽  
Vol 65 (1) ◽  
pp. 1-18 ◽  
Author(s):  
S. W. F. Grant ◽  
A. H. Knoll ◽  
G. J. B. Germs
Keyword(s):  
Red Algae ◽  
Late Paleozoic ◽  
Lateral Dimension ◽  
Geochemical Evidence ◽  
Magnesian Calcite ◽  
Primary Structures ◽  
Phylloid Algae

Samples from the Huns Limestone Member, Urusis Formation, Nama Group, at two adjacent localities in southern Namibia contain thin foliose to arched, sheet-like carbonate crusts that are 100–500 µm thick and up to 5 cm in lateral dimension. Morphologic, petrographic, and geochemical evidence supports the interpretation of these delicate crusts as biogenic, most likely the remains of calcified encrusting metaphytes. The original sediments of the fossiliferous samples contained aragonitic encrusting algae, botryoidal aragonite cements, and an aragonite mud groundmass. Spherulites within the precursor mud could represent bacterially induced mineral growths or the concretions of marine rivularian cyanobacteria. Original textures were severely disrupted during the diagenetic transition of aragonite to low-magnesian calcite, but some primary structures remain discernible as ghosts in the neomorphic mosaic. Gross morphology, original aragonite mineralogy, and hypobasal calcification indicate that the crusts are similar to late Paleozoic phylloid algae and extant peyssonnelid red algae. Structures interpreted as possible conceptacles also suggest possible affinities with the Corallinaceae.Two species of Cloudina, interpreted as the remains of a shelly metazoan, are also known from limestones in the Nama Group. It is possible, therefore, that skeletalization in metaphytes and animals arose nearly simultaneously near the end of the Proterozoic Eon.

Mass Spawning in Ancient Reef Communities: Evidence from Late Paleozoic Phylloid Algae

Palaios ◽  
2002 ◽  
Vol 17 (6) ◽  
pp. 615-621 ◽  
Author(s):  
G. T.W. FORSYTHE ◽  
R. WOOD ◽  
J.A.D. DICKSON
Keyword(s):  
Late Paleozoic ◽  
Mass Spawning ◽  
Reef Communities ◽  
Phylloid Algae

Anchicodium Johnson: branched or phylloid?

1992 ◽  
Vol 66 (4) ◽  
pp. 675-677 ◽  
Author(s):  
Andrew M. Torres ◽  
D. L. Baars
Keyword(s):  
Late Paleozoic ◽  
Thin Sections ◽  
Phylloid Algae ◽  
Collection Sites

Membranous phylloid algae of the late Paleozoic have commonly been identified as Anchicodium Johnson, whereas the genus was originally described as being cylindrical and branched, much like modern Codium. The holotypes cannot be located, but examination of one lectotype specimen and neotypic thin sections from material from several of Johnson's original collection sites indicates that the original descriptions were valid.

Late Paleozoic Phylloid Algae: A Pragmatic Review

Palaios ◽  
1991 ◽  
Vol 6 (5) ◽  
pp. 513 ◽  
Author(s):  
D. L. Baars ◽  
Andrew M. Torres
Keyword(s):  
Late Paleozoic ◽  
Phylloid Algae

Late Paleozoic foraminifera from southern Chile

10.3133/pp858 ◽  
1976 ◽  
Author(s):  
Raymond Charles Douglass ◽  
Merlynd Keith Nestell
Keyword(s):  
Late Paleozoic ◽  
Southern Chile

Subsurface stratigraphy and basin-fill architecture of the late Paleozoic eastern Taos trough, northern New Mexico, U.S.A.

2020 ◽  
Vol 57 (3) ◽  
pp. 149-176
Author(s):  
Nur Uddin Md Khaled Chowdhury ◽  
Dustin E. Sweet
Keyword(s):  
New Mexico ◽  
Sediment Accumulation ◽  
Late Paleozoic ◽  
North Central ◽  
The North ◽  
Basement Rocks ◽  
Basin Geometry ◽  
Deformation Event ◽  
Thrust System ◽  
Basin Fill

The greater Taos trough located in north-central New Mexico represents one of numerous late Paleozoic basins that formed during the Ancestral Rocky Mountains deformation event. The late Paleozoic stratigraphy and basin geometry of the eastern portion of the greater Taos trough, also called the Rainsville trough, is little known because the strata are all in the subsurface. Numerous wells drilled through the late Paleozoic strata provide a scope for investigating subsurface stratigraphy and basin-fill architecture of the Rainsville trough. Lithologic data obtained predominantly from petrophysical well logs combined with available biostratigraphic data from the greater Taos trough allows construction of a chronostratigraphic framework of the basin fill. Isopach- and structure-maps indicate that the sediment depocenter was just east of the El Oro-Rincon uplift and a westerly thickening wedge-shaped basin-fill geometry existed during the Pennsylvanian. These relationships imply that the thrust system on the east side of the Precambrian-cored El Oro-Rincon uplift was active during the Pennsylvanian and segmented the greater Taos trough into the eastern Rainsville trough and the western Taos trough. During the Permian, sediment depocenter(s) shifted more southerly and easterly and strata onlap Precambrian basement rocks of the Sierra Grande uplift to the east and Cimarron arch to the north of the Rainsville trough. Permian strata appear to demonstrate minimal influence by faults that were active during the Pennsylvanian and sediment accumulation occurred both in the basinal area as well as on previous positive-relief highlands. A general Permian decrease in eustatic sea level and cessation of local-fault-controlled subsidence indicates that regional subsidence must have affected the region in the early Permian.

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