Photos of Broad Peak

Calcarenitic eolianites over calcrete paleosol over calcarenitic eolianites (Grotto Beach Formation by James St. John

Calcrete paleosol (orangish-brown horizon) separating two Pleistocene-aged calcarenitic eolianite limestones at Watling’s Quarry, southwestern San Salvador Island, eastern Bahamas.

The dominant paleosol type on San Salvador Island (& other Bahamian islands) consists of hard, reddish-brown to orangish-brown colored, irregularly-sculpted crusts. These are referred to as calcretes or caliches or terra rosas. Calcrete paleosols cap all of the Pleistocene-aged stratigraphic units, except where removed by erosion. The Holocene-aged units (Hanna Bay Member & North Point Member of the Rice Bay Formation) haven’t been around long enough to develop calcrete paleosols atop their outcrops.

Stratigraphy: The upper unit (= most of the cliff face) is the French Bay Member of the Grotto Beach Formation (lower Upper Pleistocene). The unit below the orangish-brown calcrete paleosol is the Owl's Hole Formation (Middle Pleistocene).
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The surface bedrock geology of San Salvador consists entirely of Pleistocene and Holocene limestones. Thick and relatively unforgiving vegetation covers most of the island’s interior (apart from inland lakes). Because of this, the most easily-accessible rock outcrops are along the island’s shorelines.
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Stratigraphic Succession in the Bahamas:

Rice Bay Formation (Holocene, <10 ka), subdivided into two members (Hanna Bay Member over North Point Member)
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Grotto Beach Formation (lower Upper Pleistocene, 119-131 ka), subdivided into two members (Cockburn Town Member over French Bay Member)
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Owl's Hole Formation (Middle Pleistocene, ~215-220 ka & ~327-333 ka & ~398-410 ka & older)
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San Salvador’s surface bedrock can be divided into two broad lithologic categories:
1) LIMESTONES
2) PALEOSOLS

The limestones were deposited during sea level highstands (actually, only during the highest of the highstands). During such highstands (for example, right now), the San Salvador carbonate platform is partly flooded by ocean water. At such times, the “carbonate factory” is on, and abundant carbonate sediment grains are generated by shallow-water organisms living on the platform. The abundance of carbonate sediment means there will be abundant carbonate sedimentary rock formed after burial and cementation (diagenesis). These sea level highstands correspond with the climatically warm interglacials during the Pleistocene Ice Age.

Based on geochronologic dating on various Bahamas islands, and based on a modern understanding of the history of Pleistocene-Holocene global sea level changes, surficial limestones in the Bahamas are known to have been deposited at the following times (expressed in terms of marine isotope stages, “MIS” - these are the glacial-interglacial climatic cycles determined from δ18O analysis):

1) MIS 1 - the Holocene, <10 k.y. This is the current sea level highstand.

2) MIS 5e - during the Sangamonian Interglacial, in the early Late Pleistocene, from 119 to 131 k.y. (sea level peaked at ~125 k.y.)

3) MIS 7 - ~215 to 220 k.y. - late Middle Pleistocene

4) MIS 9 - ~327-333 k.y. - late Middle Pleistocene

5) MIS 11 - ~398-410 k.y. - late Middle Pleistocene

Bahamian limestones deposited during MIS 1 are called the Rice Bay Formation. Limestones deposited during MIS 5e are called the Grotto Beach Formation. Limestones deposited during MIS 7, 9, 11, and perhaps as old as MIS 13 and 15, are called the Owl’s Hole Formation. These stratigraphic units were first established on San Salvador Island (the type sections are there), but geologic work elsewhere has shown that the same stratigraphic succession also applies to the rest of the Bahamas.

During times of lowstands (= times of climatically cold glacial intervals of the Pleistocene Ice Age), weathering and pedogenesis results in the development of soils. With burial and diagenesis, these soils become paleosols. The most common paleosol type in the Bahamas is calcrete (a.k.a. caliche; a.k.a. terra rosa). Calcrete horizons cap all Pleistocene-aged stratigraphic units in the Bahamas, except where erosion has removed them. Calcretes separate all major stratigraphic units. Sometimes, calcrete-looking horizons are encountered in the field that are not true paleosols.
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Subsurface Stratigraphy of San Salvador Island:

The island’s stratigraphy below the Owl’s Hole Formation was revealed by a core drilled down ~168 meters (~550-feet) below the surface (for details, see Supko, 1977). The well site was at 3 meters above sea level near Graham’s Harbour beach, between Line Hole Settlement and Singer Bar Point (northern margin of San Salvador Island). The first 37 meters were limestones. Below that, dolostones dominate, alternating with some mixed dolostone-limestone intervals. Reddish-brown calcretes separate major units. Supko (1977) infers that the lowest rocks in the core are Upper Miocene to Lower Pliocene, based on known Bahamas Platform subsidence rates.

In light of the successful island-to-island correlations of Middle Pleistocene, Upper Pleistocene, and Holocene units throughout the Bahamas (see the Bahamas geologic literature list below), it seems reasonable to conclude that San Salvador’s subsurface dolostones may correlate well with sub-Pleistocene dolostone units exposed in the far-southeastern portions of the Bahamas Platform.

Recent field work on Mayaguana Island has resulted in the identification of Miocene, Pliocene, and Lower Pleistocene surface outcrops (see: <a href="http://www2.newark.ohio-state.edu/facultystaff/personal/jstjohn/Documents/Geology-talks/Kindler-talk.htm" rel="nofollow">www2.newark.ohio-state.edu/facultystaff/personal/jstjohn/...</a>). On Mayaguana, the worked-out stratigraphy is:
- Rice Bay Formation (Holocene)
- Grotto Beach Formation (Upper Pleistocene)
- Owl’s Hole Formation (Middle Pleistocene)
- Misery Point Formation (Lower Pleistocene)
- Timber Bay Formation (Pliocene)
- Little Bay Formation (Upper Miocene)
- Mayaguana Formation (Lower Miocene)

The Timber Bay Fm. and Little Bay Fm. are completely dolomitized. The Mayaguana Fm. is ~5% dolomitized. The Misery Point Fm. is nondolomitized, but the original aragonite mineralogy is absent.
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The stratigraphic information presented here is synthesized from the Bahamian geologic literature.
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Supko, P.R. 1977. Subsurface dolomites, San Salvador, Bahamas. Journal of Sedimentary Petrology 47: 1063-1077.

Bowman, P.A. &amp; J.W. Teeter. 1982. The distribution of living and fossil Foraminifera and their use in the interpretation of the post-Pleistocene history of Little Lake, San Salvador, Bahamas. San Salvador Field Station Occasional Papers 1982(2). 21 pp.

Sanger, D.B. &amp; J.W. Teeter. 1982. The distribution of living and fossil Ostracoda and their use in the interpretation of the post-Pleistocene history of Little Lake, San Salvador Island, Bahamas. San Salvador Field Station Occasional Papers 1982(1). 26 pp.

Gerace, D.T., R.W. Adams, J.E. Mylroie, R. Titus, E.E. Hinman, H.A. Curran &amp; J.L. Carew. 1983. Field Guide to the Geology of San Salvador (Third Edition). 172 pp.

Curran, H.A. 1984. Ichnology of Pleistocene carbonates on San Salvador, Bahamas. Journal of Paleontology 58: 312-321.

Anderson, C.B. &amp; M.R. Boardman. 1987. Sedimentary gradients in a high-energy carbonate lagoon, Snow Bay, San Salvador, Bahamas. CCFL Bahamian Field Station Occasional Paper 1987(2). (31) pp.

1988. Bahamas Project. pp. 21-48 in First Keck Research Symposium in Geology (Abstracts Volume), Beloit College, Beloit, Wisconsin, 14-17 April 1988.

1989. Proceedings of the Fourth Symposium on the Geology of the Bahamas, June 17-22, 1988. 381 pp.

1989. Pleistocene and Holocene carbonate systems, Bahamas. pp. 18-51 in Second Keck Research Symposium in Geology (Abstracts Volume), Colorado College, Colorado Springs, Colorado, 14-16 April 1989.

Curran, H.A., J.L. Carew, J.E. Mylroie, B. White, R.J. Bain &amp; J.W. Teeter. 1989. Pleistocene and Holocene carbonate environments on San Salvador Island, Bahamas. 28th International Geological Congress Field Trip Guidebook T175. 46 pp.

1990. The 5th Symposium on the Geology of the Bahamas, June 15-19, 1990, Abstracts and Programs. 29 pp.

1991. Proceedings of the Fifth Symposium on the Geology of the Bahamas. 247 pp.

1992. The 6th Symposium on the Geology of the Bahamas, June 11-15, 1992, Abstracts and Program. 26 pp.

1992. Proceedings of the 4th Symposium on the Natural History of the Bahamas, June 7-11, 1991. 123 pp.

Boardman, M.R., C. Carney, B. White, H.A. Curran &amp; D.T. Gerace. 1992. The geology of Columbus' landfall: a field guide to the Holcoene geology of San Salvador, Bahamas, Field trip 3 for the annual meeting of the Geological Society of America, Cincinnati, Ohio, October 26-29, 1992. Ohio Division of Geological Survey Miscellaneous Report 2. 49 pp.

Carew, J.L., J.E. Mylroie, N.E. Sealey, M. Boardman, C. Carney, B. White, H.A. Curran &amp; D.T. Gerace. 1992. The 6th Symposium on the Geology of the Bahamas, June 11-15, 1992, Field Trip Guidebook. 56 pp.

1993. Proceedings of the 6th Symposium on the Geology of the Bahamas, June 11-15, 1992. 222 pp.

Lawson, B.M. 1993. Shelling San Sal, an Illustrated Guide to Common Shells of San Salvador Island, Bahamas. San Salvador, Bahamas. Bahamian Field Station. 63 pp.

1994. The 7th Symposium on the Geology of the Bahamas, June 16-20, 1994, Abstracts and Program. 26 pp.

1994. Proceedings of the 5th Symposium on the Natural History of the Bahamas, June 11-14, 1993. 107 pp.

Carew, J.L. &amp; J.E. Mylroie. 1994. Geology and Karst of San Salvador Island, Bahamas: a Field Trip Guidebook. 32 pp.

Godfrey, P.J., R.L. Davis, R.R. Smtih &amp; J.A. Wells. 1994. Natural History of Northeastern San Salvador Island: a &quot;New World&quot; Where the New World Began, Bahamian Field Station Trail Guide. 28 pp.

Hinman, G. 1994. A Teacher's Guide to the Depositional Environments on San Salvador Island, Bahamas. 64 pp.

Mylroie, J.E. &amp; J.L. Carew. 1994. A Field Trip Guide Book of Lighthouse Cave, San Salvador Island, Bahamas. 10 pp.

1995. Proceedings of the Seventh Symposium on the Geology of the Bahamas, June 16-20, 1994. 134 pp.

1995. Terrestrial and shallow marine geology of the Bahamas and Bermuda. Geological Society of America Special Paper 300.

1996. The 8th Symposium on the Geology of the Bahamas, May 30-June 3, 1996, Abstracts and Program. 21 pp.

1996. Proceedings of the 6th Symposium on the Natural History of the Bahamas, June 9-13, 1995. 165 pp.

1997. Proceedings of the 8th Symposium on the Geology of the Bahamas and Other Carbonate Regions, May 30-June 3, 1996. 213 pp.

Curran, H.A., B. White &amp; M.A. Wilson. 1997. Guide to Bahamian Ichnology: Pleistocene, Holocene, and Modern Environments. San Salvador, Bahamas. Bahamian Field Station. 61 pp.

1998. The 9th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 4-June 8, 1998, Abstracts and Program. 25 pp.

Wilson, M.A., H.A. Curran &amp; B. White. 1998. Paleontological evidence of a brief global sea-level event during the last interglacial. Lethaia 31: 241-250.

1999. Proceedings of the 9th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 4-8, 1998. 142 pp.

2000. The 10th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 8-June 12, 2000, Abstracts and Program. 29+(1) pp.

2001. Proceedings of the 10th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 8-12, 2000. 200 pp.

Bishop, D. &amp; B.J. Greenstein. 2001. The effects of Hurricane Floyd on the fidelity of coral life and death assemblages in San Salvador, Bahamas: does a hurricane leave a signature in the fossil record? Geological Society of America Abstracts with Programs 33(4): 51.

Gamble, V.C., S.J. Carpenter &amp; L.A. Gonzalez. 2001. Using carbon and oxygen isotopic values from acroporid corals to interpret temperature fluctuations around an unconformable surface on San Salvador Island, Bahamas. Geological Society of America Abstracts with Programs 33(4): 52.

Gardiner, L. 2001. Stability of Late Pleistocene reef mollusks from San Salvador Island, Bahamas. Palaios 16: 372-386.

Ogarek, S.A., C.K. Carney &amp; M.R. Boardman. 2001. Paleoenvironmental analysis of the Holocene sediments of Pigeon Creek, San Salvador, Bahamas. Geological Society of America Abstracts with Programs 33(4): 17.

Schmidt, D.A., C.K. Carney &amp; M.R. Boardman. 2001. Pleistocene reef facies diagenesis within two shallowing-upward sequences at Cockburntown, San Salvador, Bahamas. Geological Society of America Abstracts with Programs 33(4): 42.

2002. The 11th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 6th-June 10, 2002, Abstracts and Program. 29 pp.

2004. The 12th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 3-June 7, 2004, Abstracts and Program. 33 pp.

2004. Proceedings of the 11th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 6-10, 2002. 240 pp.

Martin, A.J. 2006. Trace Fossils of San Salvador. 80 pp.

2006. Proceedings of the 12th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 3-7, 2004. 249 pp.

2006. The 13th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 8-June 12, 2006, Abstracts and Program. 27 pp.

Mylroie, J.E. &amp; J.L. Carew. 2008. Field Guide to the Geology and Karst Geomorphology of San Salvador Island. 88 pp.

2008. Proceedings of the 13th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 8-12, 2006. 223 pp.

2008. The 14th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 12-June 16, 2006, Abstracts and Program. 26 pp.

2010. Proceedings of the 14th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 12-16, 2008. 249 pp.

2010. The 15th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 17-June 21, 2010, Abstracts and Program. 36 pp.

2012. Proceedings of the 15th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 17-21, 2010. 183 pp.

2012. The 16th Symposium on the Geology of the Bahamas and Other Carbonate Regions, June 14-June 18, 2012, Abstracts with Program. 45 pp.
Broad Peak ò Falchen Kangri (8 051 m) es una montanha d'Imalaia situada lòng de la frontiera entre Paquistan e China. Es la dotzena cima pus auta dau mond. Read further
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