scholarly journals Controls on microbial and oolitic carbonate sedimentation and stratigraphic cyclicity within a mixed carbonate‐siliciclastic system: Upper Cambrian Wilberns Formation, Llano Uplift, Mason County, Texas, USA

2020 ◽  
Vol 6 (2) ◽  
pp. 276-308
Author(s):  
Daniel J. Lehrmann ◽  
André W. Droxler ◽  
Paul (Mitch) Harris ◽  
Marcello Minzoni ◽  
Dylan A. Droxler ◽  
...  
Keyword(s):  
Upper Cambrian ◽  
Carbonate Sedimentation ◽  
Llano Uplift ◽  
Mason County ◽  
Mixed Carbonate

ULTIMATE DEMISE OF LARGE UPPER CAMBRIAN MICROBIAL REEFS (MASON COUNTY, CENTRAL TEXAS)

2016 ◽  
Author(s):  
Pulkit Singh ◽  
◽  
André W. Droxler ◽  
Heath H. Hopson ◽  
Pankaj Khanna ◽  
...  
Keyword(s):  
Upper Cambrian ◽  
Central Texas ◽  
Mason County

GENETIC PORE TYPES AND A DIAGENESIS LOG FOR CARBONATES AND MICROBIALITE RESERVOIRS (UPPER CAMBRIAN MICROBIAL REEFS, MASON COUNTY, CENTRAL TEXAS)

2017 ◽  
Author(s):  
Jacob Michael Proctor ◽  
◽  
Heath Hilton Hopson ◽  
André W. Droxler ◽  
Naum Derzhi ◽  
...  
Keyword(s):  
Upper Cambrian ◽  
Central Texas ◽  
Mason County ◽  
Pore Types

scholarly journals Lithostratigraphic and allostratigraphic framework of the Cambrian–Ordovician Potsdam Group and correlations across Early Paleozoic southern Laurentia

2017 ◽  
Vol 54 (5) ◽  
pp. 550-585 ◽  
Author(s):  
David G. Lowe ◽  
R.W.C. Arnott ◽  
Godfrey S. Nowlan ◽  
A.D. McCracken
Keyword(s):  
Climate Change ◽  
Early Paleozoic ◽  
Middle Cambrian ◽  
Shallow Marine ◽  
Upper Cambrian ◽  
Subaerial Exposure ◽  
Marine Sedimentation ◽  
Lower Ordovician ◽  
Fluvial Sedimentation ◽  
Mixed Carbonate

The Potsdam Group is a Cambrian to Lower Ordovician siliciclastic unit that crops out along the southeastern margins of the Ottawa graben. From its base upward, the Potsdam consists of the Ausable, Hannawa Falls, and Keeseville formations. In addition, the Potsdam is subdivided into three allounits: allounit 1 comprises the Ausable and Hannawa Falls, and allounits 2 and 3, respectively, the lower and upper parts of the Keeseville. Allounit 1 records Early to Middle Cambrian syn-rift arkosic fluvial sedimentation (Ausable Formation) with interfingering mudstone, arkose, and dolostone of the marine Altona Member recording transgression of the easternmost part of the Ottawa graben. Rift sedimentation was followed by a Middle Cambrian climate change resulting in local quartzose aeolian sedimentation (Hannawa Falls Formation). Allounit 1 sedimentation termination coincided with latest(?) Middle Cambrian tectonic reactivation of parts of the Ottawa graben. Allounit 2 (lower Keeseville) records mainly Upper Cambrian quartzose fluvial sedimentation, with transgression of the northern Ottawa graben resulting in deposition of mixed carbonate–siliciclastic strata of the marine Rivière Aux Outardes Member. Sedimentation was then terminated by an earliest Ordovician regression and unconformity development. Allounit 3 (upper Keeseville) records diachronous transgression across the Ottawa graben that by the Arenigian culminated in mixed carbonate–siliciclastic, shallow marine sedimentation (Theresa Formation). The contact separating the Potsdam Group and Theresa Formation is conformable, except locally in parts of the northern Ottawa graben where the presence of localized islands and (or) coastal salients resulted in subaerial exposure and erosion of the uppermost Potsdam strata, and accordingly unconformity development.

Oolitized fragments of filamentous calcimicrobes and the pseudofossil affinity of Nuia Maslov from the Upper Cambrian rocks of central Texas

1998 ◽  
Vol 72 (3) ◽  
pp. 577-584 ◽  
Author(s):  
Ben R. Spincer
Keyword(s):  
Upper Cambrian ◽  
Central Texas ◽  
Llano Uplift

The origin and affinity of the problematic Nuia Maslov is reappraised from exceptionally preserved specimens in Upper Cambrian (Sunwaptan) rocks of the Llano Uplift, central Texas. Nuia is suggested to be a radial calcitic ooid that has nucleated on fragments of reworked filamentous calcimicrobes rather than a separate microorganism as has been assumed previously. Nuia is found predominantly in intrareef grainstone accumulations, as well as in interreef grainstones, invariably accompanied by other bioclastic debris showing similar radial calcite ooid overgrowths.

MICROBIAL GROWTH PROCESSES AND FABRIC DEVELOPMENT IN UPPER CAMBRIAN MICROBIAL BUILDUPS; MASON COUNTY, CENTRAL TEXAS

2017 ◽  
Author(s):  
Heath Hilton Hopson ◽  
◽  
Andre W. Droxler ◽  
Pankaj Khanna ◽  
Dan Lehrmann ◽  
...  
Keyword(s):  
Microbial Growth ◽  
Growth Processes ◽  
Upper Cambrian ◽  
Central Texas ◽  
Mason County
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