scholarly journals Magnetostratigraphy of sediments in the Atlantic Coastal Plain and Pacific Coast of the United States as an aid for dating tectonic deformation

1981 ◽  
Author(s):  
Joseph C. Liddicoat ◽  
Neil D. Opdyke
Keyword(s):  
United States ◽  
Coastal Plain ◽  
Pacific Coast ◽  
The United States ◽  
Atlantic Coastal Plain ◽  
Tectonic Deformation ◽  
Atlantic Coastal

Petaloconchus sculpturatus alaminatus, a new Pliocene subspecies of vermetid gastropods lacking its defining generic character, with comments on vermetid systematics in general

1994 ◽  
Vol 68 (5) ◽  
pp. 1025-1036 ◽  
Author(s):  
Stephen Jay Gould
Keyword(s):  
United States ◽  
Coastal Plain ◽  
Type Species ◽  
The United States ◽  
Atlantic Coastal Plain ◽  
New Subspecies ◽  
Generic Character ◽  
Atlantic Coastal ◽  
Anecdotal Information

The systematics of vermetid gastropods is in a shambles, with few genera defined by valid autapomorphic characters. Heretofore, the genus Petaloconchus has been included among the few adequately characterized groups, thanks to possession of a double internal lamina on the middle whorls. Yet abundant anecdotal information has been available for 100 years on the absence of laminae in high percentages of individuals within samples, and in entire populations that must be placed within the genealogical nexus of Petaloconchus. I demonstrate that such a nonlaminate population exists within the very material used to define the type species of the genus, Pliocene Petaloconchus sculpturatus Lea, 1843, from the Gulf and Atlantic Coastal Plain of the United States. I use X-radiography and multivariate biometry to show that this population from the Pliocene Jackson Bluff Formation at Jackson Bluff, Florida, is fully alaminate, but otherwise indistinguishable from P. sculpturatus. After considering a range of solutions, I name this population as a new subspecies, Petaloconchus sculpturatus alaminatus. I discuss theoretical and practical issues arising from populations that lack the defining feature of their genus.

Modeling the longitudinal variation in wood specific gravity of planted loblolly pine (Pinus taeda) in the United States

2010 ◽  
Vol 40 (12) ◽  
pp. 2439-2451 ◽  
Author(s):  
F. Antony ◽  
L. R. Schimleck ◽  
R. F. Daniels ◽  
A. Clark ◽  
D. B. Hall
Keyword(s):  
United States ◽  
Specific Gravity ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Coastal Plain ◽  
The United States ◽  
Atlantic Coastal Plain ◽  
Quadratic Model ◽  
Gulf Coastal Plain ◽  
Atlantic Coastal

Loblolly pine (Pinus taeda L.) is a major plantation species grown in the southern United States, producing wood having a multitude of uses including pulp and lumber production. Specific gravity (SG) is an important property used to measure the quality of wood produced, and it varies regionally and within the tree with height and radius. SG at different height levels was measured from 407 trees representing 135 plantations across the natural range of loblolly pine. A three-segment quadratic model and a semiparametric model were proposed to explain the vertical and regional variations in SG. Both models were in agreement that a stem can be divided into three segments based on the vertical variation in SG. Based on the fitted models, the mean trend in SG of trees from the southern Atlantic Coastal Plain and Gulf Coastal Plain was observed to be higher than in other physiographical regions (Upper Coastal Plain, Hilly Coastal Plain, northern Atlantic Coastal Plain, and Piedmont). Maps showing the regional variation in disk SG at a specified height were also developed. Maps indicated that the stands in the southern Atlantic Coastal Plain and Gulf Coastal Plain have the highest SG at a given height level.

New species of freshwater diatoms from acidic localities along the Atlantic Coastal Plain of the United States

Botany ◽  
2009 ◽  
Vol 87 (4) ◽  
pp. 409-427 ◽  
Author(s):  
Peter A. Siver ◽  
Paul B. Hamilton ◽  
Jeffery Pelczar
Keyword(s):  
New Species ◽  
Coastal Plain ◽  
The United States ◽  
Atlantic Coastal Plain ◽  
Similar Species ◽  
Geographic Proximity ◽  
Freshwater Diatoms ◽  
Dissolved Humic Substances ◽  
Atlantic Coastal ◽  
A New Species

During our investigations of freshwater sites along the Atlantic Coastal Plain of North America we had the opportunity to critically study five interesting diatoms with light (LM) and scanning electron microscopy (SEM), each of which is described here as a new species. Two of the organisms are in the genus Eunotia , Eunotia lewisii Siver & Hamilton sp. nov. and Eunotia quadra Siver & Hamilton sp. nov.; two in Frustulia , Frustulia crispula Siver, Pelczar, & Hamilton sp. nov. and Frustulia inculta Siver, Pelczar, & Hamilton sp. nov.; and the last is Neidium trainori Siver & Hamilton sp. nov. All five species are reported from acidic, poorly buffered, dilute waterbodies high in dissolved humic substances. Two of the taxa are found in suites of waterbodies in close geographic proximity, two in somewhat disjunct regions, and the fifth is only known from the type locality. The relationships of each taxon to similar species are discussed.

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