scholarly journals Biotic and sedimentologic comparison of patch reefs on the north and south shelf of Belize, Central America

1992 ◽  
Vol 6 ◽  
pp. 45-45 ◽  
Author(s):  
C. D. Burke ◽  
S. J. Mazzullo
Keyword(s):  
Central America ◽  
Sea Level ◽  
Patch Reef ◽  
Acropora Palmata ◽  
The South ◽  
Northern Shelf ◽  
Patch Reefs ◽  
The North ◽  
Species Specific ◽  
Specific Growth Rates

Holocene patch-reefs occur throughout the shallow marine platform, to the lee of the barrier reef in northern and southern Belize, Central America. Patch reefs on the northern shelf that occur within an areally extensive patch reef complex (Mexico Rocks) indicate that differences exist between reefs here and well-studied patch reefs on the southern shelf that have been used by workers as a general model for patch reef development throughout Belize. This model proposes that patch reefs on the Belizean shelf are dominated by typical Atlantic-Caribbean, biotically-zoned coral assemblages of Acropora palmata and A. cervicornis that kept up or caught up with Holocene sea level rise during the last 8000 years to form large “keep up” or in some instances “catch up” reefs.In contrast to those in the south, the northern patch reefs are not biotically zoned, are dominated by Montastrea annularis rather than Acropora spp., and are much younger (400 years old) than those in the south. In addition, northern shelf patch reefs developed predominantly by lateral growth in a milieu of static sea level and are herein called “accretion” type reefs. These differences in biotic and sedimentologic parameters between reefs on the northern and southern shelves imply fundamentally different ecologic and sea level history controls on patch reef formation from north to south. A leading contributor to the variation among the reefs along the Belizean shelf may be species-specific growth rates of the coral species that initiate each patch reef, and response to sea level fluctuation versus stasis through time.

V.—On the Cretaceous Fossils found at Moreseat, Aberdeenshire

1898 ◽  
Vol 5 (1) ◽  
pp. 21-32
Author(s):  
A. J. Jukes-Browne ◽  
John Milne
Keyword(s):  
Sea Level ◽  
The South ◽  
The North ◽  
Cretaceous Fossils

Moreseat is in the parish of Cruden, in the east of Aberdeenshire. It lies at an elevation of 300 feet above sea-level, and the surface of the ground slopes to the sea at Cruden Bay, distant five miles to the south. On the north the ground rises gradually, reaching the height of 450 feet above sea in Torhendry Ridge, which is strewn with chalk-flintsingreat abundance.

Prehistoric Roads and Tracks in Somerset, England: 2. Neolithic

1970 ◽  
Vol 36 ◽  
pp. 125-151 ◽  
Author(s):  
John M. Coles ◽  
F. Alan Hibbert ◽  
Colin F. Clements
Keyword(s):  
Sea Level ◽  
The South ◽  
The West ◽  
The Third ◽  
The North ◽  
South West ◽  
Extensive Region ◽  
Peat Deposits ◽  
Third Millennium ◽  
South West England

The Somerset Levels are the largest area of low-lying ground in south-west England, covering an extensive region between the highlands of Exmoor, the Brendon Hills and the Quantock Hills to the west, and the Cotswold and Mendip Hills to the east (Pl. XXIII, inset). The Quantock Hills and the Mendip Hills directly border the Levels themselves, and reach heights of over 250 metres above sea level. The valley between extends to 27 metres below sea level, but is filled to approximately the height of the present sea by a blue-grey clay. The Levels are bisected by the limestone hills of the Poldens, and both parts have other smaller areas of limestone and sand projecting above the peat deposits that cap the blue-grey clay filling. In this paper we are concerned with the northern part of the Levels, an area at present drained by the River Brue.The flat, peat-covered floor of the Brue Valley is some six kilometres wide and is flanked on the north by the Wedmore Ridge, and on the south by the Polden Hills (Pl. XXIII). In the centre of the valley, surrounded by the peat, is a group of islands of higher ground, Meare, Westhay, and Burtle. These islands, which would always have provided relatively dry ground in the Levels, are linked together by Neolithic trackways of the third millennium B.C. Several of these trackways formed the basis of a paper in these Proceedings in 1968 (Coles and Hibbert, 1968), which continued the work of Godwin and others (Godwin, 1960; Dewar and Godwin, 1963).

Woodeaton

1917 ◽  
Vol 7 ◽  
pp. 98-119 ◽  
Author(s):  
M. V. Taylor
Keyword(s):  
Sea Level ◽  
The South ◽  
North East ◽  
The North ◽  
Dry Seasons ◽  
The Village

Woodeaton is a small Oxfordshire parish, four miles north-east of the centre of Oxford city and a little west of the wide marshy level of the ‘Plain of Otmoor.’ It stands on a low, detached and rounded hill, 315 feet above sea level, and 120 feet above Otmoor. In old days it must have been difficult of access, for Otmoor spreads away to the east of it; low pastures along the river Cherwell close it in on the north and west, while south-westwards, too, the land is low-lying and marshy. Even to the south-east a marshy hollow separates it from the wooded slopes of Beckley and Elsfield, once part of Shotover Forest. However, the well-known Roman road which connects Dorchester (Oxon.) with Alchester, and which passes along the foot of Shotover, and traverses the village of Beckley and the plain of Otmoor, runs within two miles of Woodeaton; in dry seasons it may have helped those who wished to get to the spot.

Laconia

1950 ◽  
Vol 45 ◽  
pp. 261-298 ◽  
Author(s):  
J. M. Cook ◽  
R. V. Nicholls
Keyword(s):  
Sea Level ◽  
The Other ◽  
The South ◽  
The West ◽  
Urban Settlement ◽  
West Side ◽  
The North ◽  
The Village

The village of Kalývia Sokhás lies against the base of one of the massive foothills in which Taygetus falls to the plain three or four miles to the south of Sparta (Plate 26, 1). It is bounded by two rivers which flow down in deep clefts from the mountain shelf. The hillside above rises steeply to a summit which is girt with cliffs on all but the west side and cannot be much less than four thousand feet above sea level; this von Prott believed to be the peak of Taleton. Its summit is crowned by the ruins of a mediaeval castle which was undoubtedly built as a stronghold to overlook the Spartan plain; the only dateable object found there, a sherd of elaborate incised ware, indicates occupation at the time when the Byzantines were in possession of Mystra. The location of the other sites mentioned by Pausanias in this region remains obscure, but fortunately that of the Spartan Eleusinion has not been in doubt since von Prott discovered a cache of inscriptions at the ruined church of H. Sophia in the village of Kalývia Sokhás. In 1910 Dawkins dug trenches at the foot of the slope immediately above the village and recovered a fragment of a stele relating to the cult of the goddesses and pieces of inscribed tiles from the sanctuary. The abundance of water in the southern ravine led von Prott to conclude that the old town of Bryseai with its cult of Dionysus also lay at Kalývia Sokhás; but no traces of urban settlement have come to light at the village, and the name rather suggests copious springs such as issue from the mountain foot at Kefalári a mile to the north where ancient blocks are to be seen in the fields.

scholarly journals Sedimentology and sequence stratigraphy of paralic and shallow marine Upper Jurassic sandstones in the northern Danish Central Graben

2003 ◽  
Vol 1 ◽  
pp. 367-402 ◽  
Author(s):  
Peter N. Johannessen
Keyword(s):  
Sea Level ◽  
Upper Jurassic ◽  
High Energy ◽  
Salt Dome ◽  
The South ◽  
The West ◽  
Relative Sea Level ◽  
Shallow Marine ◽  
The North ◽  
Plateau Area

Paralic and shallow marine sandstones were deposited in the Danish Central Graben during Late Jurassic rifting when half-grabens were developed and the overall eustatic sea level rose. During the Kimmeridgian, an extensive plateau area consisting of the Heno Plateau and the Gertrud Plateau was situated between two highs, the Mandal High to the north, and the combined Inge and Mads Highs to the west. These highs were land areas situated on either side of the plateaus and supplied sand to the Gertrud and Heno Plateaus. Two graben areas, the Feda and Tail End Grabens, flanked the plateau area to the west and east, respectively. The regressive–transgressive succession consists of intensely bioturbated shoreface sandstones, 25–75 m thick. Two widespread unconformities (SB1, SB2) are recognised on the plateaus, forming the base of sequence 1 and sequence 2, respectively. These unconformities were created by a fall in relative sea level during which rivers may have eroded older shoreface sands and transported sediment across the Heno and Gertrud Plateaus, resulting in the accumulation of shoreface sandstones farther out in the Feda and Tail End Grabens, on the south-east Heno Plateau and in the Salt Dome Province. During subsequent transgression, fluvial sediments were reworked by high-energy shoreface processes on the Heno and Gertrud Plateaus, leaving only a lag of granules and pebbles on the marine transgressive surfaces of erosion (MTSE1, MTSE2). The sequence boundary SB1 can be traced to the south-east Heno Plateau and the Salt Dome Province, where it is marked by sharp-based shoreface sandstones. During low sea level, erosion occurred in the southern part of the Feda Graben, which formed part of the Gertrud and Heno Plateaus, and sedimentation occurred in the Norwegian part of the Feda Graben farther to the north. During subsequent transgression, the southern part of the Feda Graben began to subside, and a succession of backstepping back-barrier and shoreface sediments, 90 m thick, was deposited. In the deep Tail End and Feda Grabens and the Salt Dome Province, sequence boundary SB2 is developed as a conformity, indicating that there was not a significant fall in relative sea level in these grabens, probably as a result of high subsidence rates. Backstepping lower shoreface sandstones overlie SB2 and show a gradual fining-upwards to offshore claystones that are referred to the Farsund Formation. On the plateaus, backstepping shoreface sandstones of sequence 2 are abruptly overlain by offshore claystones, indicating a sudden deepening and associated cessation of sand supply, probably caused by drowning of the sediment source areas on the Mandal, Inge and Mads Highs. During the Volgian, the Gertrud Plateau began to subside and became a graben. During the Late Kimmeridgian – Ryazanian, a long-term relative sea-level rise resulted in deposition of a thick succession of offshore claystones forming highstand and transgressive systems tracts on the Heno Plateau, and in the Gertrud, Feda and Tail End Grabens.

scholarly journals Incipient Glacier Development within Katmai Caldera, Alaska

1957 ◽  
Vol 3 (21) ◽  
pp. 13-17
Author(s):  
E. H. Muller ◽  
H. W. Coulter
Keyword(s):  
Sea Level ◽  
Wall Rock ◽  
Crater Wall ◽  
The South ◽  
The Past ◽  
The North ◽  
South West ◽  
Direction Of Movement ◽  
North And South

AbstractAn unusual opportunity for the study of glaciers in the process of development is afforded in Katmaicaldera in south-western Alaska. A violent eruption in 1912 destroyed the summit of glacier-clad Mount Katmai, creating a caldera 4 km. wide and 800 m. deep. Ice cliffs produced by beheading of the glaciers have since thinned and shrunk away from the rim of the caldera, except in the south-west. There, local reversal of direction of movement has resulted in an ice fall which descends part way down the crater wall. In the past thirty years two small glaciers have formed, near 1525 m. above sea level, within the caldera on large masses of slumped wall-rock below the north and south rims respectively. Elsewhere the sheer walls of the crater descend so steeply to the level of the caldera lake that permanent snowbanks cannot accumulate. The lake, which continues to rise at a rate of more than five meters per year, is at present the primary deterring factor in glacier development in the caldera.

IV.—The Carrara, Massa, and Versilia Marble District

1915 ◽  
Vol 2 (12) ◽  
pp. 554-565
Author(s):  
C. S. Du Riche Preller
Keyword(s):  
Sea Level ◽  
Coarse Grained ◽  
Maximum Height ◽  
The South ◽  
The North ◽  
The Mediterranean ◽  
Apuan Alps ◽  
Marble Industry

The range of the Apuan Alps, commonly called the Carrara Mountains, is an offshoot of the Apennines, trending N.N.W. to S.S.E., parallel to the Mediterranean littoral, from which it rises within a distance of barely four miles to a maximum height of 6,000 feet above sea-level. Exclusive of the outer belt of the more recent strata, the Triassic formation, within which the saccharoidal marble beds are situated, covers about 25 by 13 kilometres or about 130 square miles, of which the marble zone proper represents 64 square miles or about half. The range is bounded on the north by the Aullela valley in the Lunigiana district; on the east by the Serchio valley in the Garfagnana district; and on the south by the Serchio valley in the Province of Lucca. The marble district, whose western part faces the Mediterranean, comprises the three divisions of Carrara, Massa, and the Versilia in the corresponding parallel valleys of the Carrione, Frigido, and Serravezza Rivers. The Versilia division, which forms part of the Province of Lucca, is composed of the Seravezza, Stazzema, and Arni subdivisions, of which the last-named lies on the eastern watershed of the Apuan range. The Versilia division also includes Pietrasanta, Camajore, Massarosa, and the wellknown watering-place of Viareggio, near the last-named of which are situated extensive subaqueous deposits of a peculiarly coarse-grained, sharp macigno sand. These deposits, formed as a delta in a lacustrine expanse by the River Serchio, constitute an important and indispensable adjunct of the marble industry as grinding material for the numerous marble saw-mills in the three parallel valleys already referred to.

IV.—Low-tide Causeways

1897 ◽  
Vol 4 (8) ◽  
pp. 361-362 ◽  
Author(s):  
Edwin Hill
Keyword(s):  
Sea Level ◽  
The South ◽  
The West ◽  
The North ◽  
Four Corners

I Suppose that most of us are familiar with the processes by which necks of land are cut down, by which promontories are turned into peninsulas, and the peninsulas into islands, while the islands in their turn become rocks. I have elsewhere called attention to all stages of the process as shown in the four corners of Sark. On the south there is the Coupee causeway, an isthmus 200 feet above sea-level, with a crest only some six feet in width; on the north, an isthmus yet lower, and parts beyond already being separated by the sea; on the west, an island, Breqhou; on the east, rocks, the Burons. There are to be seen all stages of the process, but does that process always proceed through all those stages to the end?

Sign in / Sign up

Export Citation Format

Share Document