Coastal Morphology and Late Quaternary History, Cayman Islands, West Indies

1983 ◽  
Vol 19 (1) ◽  
pp. 64-84 ◽  
Author(s):  
C. D. Woodroffe ◽  
D. R. Stoddart ◽  
R. S. Harmon ◽  
T. Spencer
Keyword(s):  
West Indies ◽  
Late Quaternary ◽  
Cayman Islands ◽  
Present Level ◽  
Last Interglacial ◽  
Coastal Morphology ◽  
Western Atlantic ◽  
Grand Cayman ◽  
Western Caribbean ◽  
Quaternary History

AbstractInstrumental surveys of coastal profiles in the Cayman Islands, western Caribbean, reveal the presence of a horizontal erosional bench at +1.9 m on Grand Cayman and a deep horizontal notch at +6.4 m on Cayman Brac, but no raised erosional features on Little Cayman. Each island is surrounded by a horizontal constructional raised reef, usually below +2 m, here dated by U-series methods as 124,000 ± 8000 yr old, and hence broadly contemporary with other western Atlantic raised reefs of similar elevations. The different raised erosional features indicate independent vertical tectonic movement of the three islands, predating the formation of the raised reef. The accordance and horizontality of the raised reef indicates stability of the islands since the last interglacial times. An erosional notch at present sea level has formed since the sea reached its present level less than 2100 B.P., and algal benches on exposed coasts are also in equilibrium with present conditions.

scholarly journals Morphology of the Raised Shore Platforms along the Coastline between Daghmar and Dhabab, Sultanate of Oman

2017 ◽  
Vol 8 (2) ◽  
pp. 13 ◽  
Author(s):  
Salim Mubarak Al Hatrushi
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Aerial Photographs ◽  
Tectonic Activity ◽  
Present Level ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Southeastern Part ◽  
Relative Level ◽  
Shore Platforms

Raised shore platforms, are rocky surfaces formed by wave action and subaerial weathering during global high sea level stands. The present height of the raised shore platforms is attributed to several factors, mainly to eustatic sea level changes, isostatic changes in the relative level of land and sea, and vertical tectonic activities. The aim of this study is to investigate the detailed morphology of the raised shore platform along the rocky coastline between Daghmar and Dhabab, in the southeastern part of Muscat Governorate. The study also intends to establish a tentative chronology of the raised shore platforms development. The methodology is based on field observation and documentation, along with satellite and aerial photographs analysis. The results have shown that the study area has a sequence of five successive, well developed raised shore platforms and well preserved, except the platform at 10m altitude which is only found in isolated fragments. The formation of the raised shore platforms has been affected by a number of constructive factors including tectonic activity, and destructive factors such as fluvial action and subaerial weathering. No absolute dating has been reported or can be obtained from the study area, due to its erosional nature. However, dating from the shorelines adjacent to the study area, ranging in heights from 3 to 15m above sea level, revealed a narrow range of 26,400 to 29,600 years. This period coincides with the last glaciations when the sea level was at about 75m below the present level, and thus did not match with the altitudes of the platforms. This suggests that the platforms could be belong to the last interglacial high sea level, when the sea level stood at about 6m above the present level. Based on this scenario, the study concludes that the coastline of the study area has not experienced any significant uplift during the Late Quaternary. 

Genesis of terrestrial oncoids, Cayman Islands, British West Indies

1991 ◽  
Vol 28 (3) ◽  
pp. 382-397 ◽  
Author(s):  
Brian Jones
Keyword(s):  
West Indies ◽  
Active Role ◽  
British West Indies ◽  
Cayman Islands ◽  
Grand Cayman ◽  
Microbial Assemblage ◽  
Detrital Material ◽  
Different Types

Terrestrial oncoids, up to 4.3 mm long, are common in sinkholes that penetrate the dolostones of the Oligocene–Miocene Bluff Formation on Grand Cayman and Cayman Brac. The vaguely laminated terrestrial oncoids, which generally lack a nucleus, are formed of detrital material (micrite, clays, dolomite), calcified filaments and spores, and insect fragments. The abundant, diverse assay of microorganisms includes six different types of filaments and five different types of spores, which can be attributed to fungi, algae, and (or) cyanobacteria. Thin mats of mucus are commonly associated with the microorganisms. The microorganisms contribute to the formation of the terrestrial oncoids by (i) calcification of the filaments and spores, (ii) trapping and binding detrital material, and (iii) binding with their mucus detrital material to the surface of the oncoids.Identification of terrestrial oncoids relies on (i) the recognition of a microbial assemblage, (ii) the demonstration that the microorganisms played an active role in the their formation, and (iii) evidence that they formed in a terrestrial setting. If the microorganisms cannot be recognized because of diagenetic changes, identification must rely on the overall texture of the rock and its stratigraphic setting. Recognition of terrestrial oncoids is important because it provides additional evidence that a succession has been subaerially exposed. Terrestrial oncoids also indicate that the strata in which they occur are close to an unconformity.

Eleven new species of snakes of the genus Typhlops (Serpentes: Typhlopidae) from Hispaniola and Cuba

Zootaxa ◽  
2007 ◽  
Vol 1400 (1) ◽  
pp. 1-26 ◽  
Author(s):  
RICHARD THOMAS ◽  
S. BLAIR HEDGES
Keyword(s):  
New Species ◽  
West Indies ◽  
West Indian ◽  
Indian Species ◽  
Cayman Islands ◽  
The West ◽  
Related Pair ◽  
Western Caribbean ◽  
Species Groups ◽  
Morphological Differences

Here we describe 11 new species of blindsnakes of the genus Typhlops from the West Indies. Four of the new species are from southern Hispaniola and were previously confused with T. hectus Thomas. Seven other species are described from Cuba and are related to T. biminiensis Richmond. Diagnostic morphological differences distinguish all of these species, and at least three pairs are known to be sympatric. With these new taxa, 40 species of Typhlops are now recognized from the West Indies, all of which are endemic to the region. Nearly all species are found on single islands or island banks. We classify West Indian Typhlops into nine species groups, most of which exhibit geographic patterns. The West Indian species form two clades: the T. biminiensis Group with its 12 species is centered in the western Caribbean (Bahamas, Cayman Islands, Cuba) and the remaining species, grouped into eight species groups, form a large clade (Major Antillean Radiation) centered in Hispaniola, but with a closely related pair of lineages in the Puerto Rico region (7 sp.) and northern Lesser Antilles (5 sp.).

scholarly journals Late Quaternary Fossil Mammals from the Cayman Islands, West Indies

2019 ◽  
Vol 2019 (428) ◽  
pp. 1 ◽  
Author(s):  
Gary S. Morgan ◽  
Ross D.E. Macphee ◽  
Roseina Woods ◽  
Samuel T. Turvey
Keyword(s):  
West Indies ◽  
Late Quaternary ◽  
Cayman Islands ◽  
Fossil Mammals

Tardigrada of Grand Cayman, West Indies, with descriptions of two new species of eutardigrade, Doryphoribius tessellatus (Hypsibiidae) and Macrobiotus caymanensis (Macrobiotidae)

Zootaxa ◽  
2011 ◽  
Vol 2812 (1) ◽  
pp. 28 ◽  
Author(s):  
HARRY A. MEYER
Keyword(s):  
New Species ◽  
Costa Rica ◽  
Leaf Litter ◽  
West Indies ◽  
Caribbean Sea ◽  
Cayman Islands ◽  
Insertion Point ◽  
Grand Cayman ◽  
Two New Species ◽  
The Caribbean

Terrestrial tardigrades were collected from moss, lichen and leaf litter from Grand Cayman in the Cayman Islands, West Indies. Six species were found. Milnesium tardigradum Doyère, 1840, Minibiotus intermedius (Plate, 1889), Paramacrobiotus areolatus (Murray, 1907) and P. richtersi (Murray, 1911) have been reported previously from other islands in the Caribbean Sea. Two species on Grand Cayman were new to science. Doryphoribius tessellatus sp. n. belongs to the ‘eveli- nae-group’, with two macroplacoids and cuticular gibbosities. In having two pairs of posterior gibbosities and cuticular depressions forming a reticular design, it is most similar to Doryphoribius quadrituberculatus Kaczmarek & Michalczyk, 2004 from Costa Rica. It differs from D. quadrituberculatus in its gibbosity sequence (III:4:2:2), the number of teeth, size of macroplacoids and details of the reticular design on the dorsal cuticle. Macrobiotus caymanensis sp. n. belongs to the ‘polyopus-group’ of species. It differs from other species of the group in having a shorter buccal tube, a more posterior stylet support insertion point and fewer, larger egg processes.

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