Geology of Long Island, Bahamas: a Field Trip Guide
Total Page:16
File Type:pdf, Size:1020Kb
Smith ScholarWorks Geosciences: Faculty Publications Geosciences 2004 Geology of Long Island, Bahamas: A Field Trip Guide H. Allen Curran Smith College, [email protected] John E. Mylroie Mississippi State University Douglas W. Gamble University of North Carolina - Wilmington Mark A. Wilson The College of Wooster R. Laurence Davis University of New Haven See next page for additional authors Follow this and additional works at: https://scholarworks.smith.edu/geo_facpubs Part of the Geology Commons Recommended Citation Curran, H. Allen; Mylroie, John E.; Gamble, Douglas W.; Wilson, Mark A.; Davis, R. Laurence; Sealey, Neil E.; and Voegeli, Vincent J., "Geology of Long Island, Bahamas: A Field Trip Guide" (2004). Geosciences: Faculty Publications, Smith College, Northampton, MA. https://scholarworks.smith.edu/geo_facpubs/137 This Conference Proceeding has been accepted for inclusion in Geosciences: Faculty Publications by an authorized administrator of Smith ScholarWorks. For more information, please contact [email protected] Authors H. Allen Curran, John E. Mylroie, Douglas W. Gamble, Mark A. Wilson, R. Laurence Davis, Neil E. Sealey, and Vincent J. Voegeli This conference proceeding is available at Smith ScholarWorks: https://scholarworks.smith.edu/geo_facpubs/137 Geology of Long Island, Bahamas: A Field Trip Guide by H. Allen Curran, John E. Mylroie, Douglas W. Gamble, Mark A. Wilson, R. Laurence Davis, Neil E. Sealey, and Vincent J. Voegeli 12th Symposium on the Geologyof the Bahamas and Other Carbonate Regions Gerace Research Center San Salvador, Bahamas 2004 COVER PHOTO: The Holocene/ late Pleistocene contact is sharp and well exposed at many places along the rocky windward (east) coast of Long Island. These cliffs are located immediately south of Coral Gardens (Stop 5). Here transgressive-phase carbonate eolianite beds of the North Point Member of the Rice Bay Formation overlie regressive-phase eolianite beds of the Cockburn Town Member of the Grotto Beach Formation. View is looking north toward Coral Gardens. Photo by Al Curran. 12th Symposium on the Geology of the Bahamas and Other Carbonate Regions Geology of Long Island Bahamas: A Field Trip Guide by H. Allen Curran John E. Mylroie Douglas W. Gamble Dept. of Geology Dept. of Geosciences Dept. of Earth Sciences Smith College Mississippi State University UNC at Wilmington Northampton, MA O 1063 Mississippi State, MS 39762 Wilmington, NC 28403 Mark A. Wilson R. Laurence Davis Neil E. Sealey Dept. of Geology Dept. of Biology & Environ. Sciences Media Enterprises Ltd. The College of Wooster University of New Haven P.O. Box N-9240 Wooster, OH 44691 West Haven, CT 06516 Nassau, Bahamas Vincent J. Voegeli Gerace Research Center San Salvador, Bahamas Production Editor: Anna M. Dustira Smith College Copyright 2004 by the Gerace Research Center, San Salvador, Bahamas All Rights Reserved No part of this publication may be reproduced or transmitted in any formor by any means, electronic or mechanical, including photocopy, recording, or any informationand retrieval system, without permission in written form. ISBN 0-935909-74-5 Printed in USA ' I I 7,4•Jtl'W • •• , .·• _/ ....• ·••·• ··•••·l ._ ., 0o._• • ,-� ...... ' • .. THE · .. ...... .. �\ LIT rt.�IJ-1,. ;;_"" ;.;;_ •. .. BAHAMA . baco \ • 1$. ,' . - - -: E I ISLANDS . r FLORIDA [ \�;�.• -�, I ..... GrancfBahama Is. !/ ·:- -t,o 0 100mi. 8 �> : • ·· · J . ··:rt·i .: -s, 1 .-" '· ·• . , ...••·• .,: ! I I .,.. .. ... • I , ._. •• / p ••.,100n ••• •• •••• • •• '• ✓ 100km . • • • I .._-- 0 Mia 0... -. �-.. , "9'.,.i. ;�Bimini ,: �:-.�·"•;_ 11 in fathoms . Berrt•0\ \ . Eleuthera "S' Bathymetric contours ·.� Ids Ids. � l ,' ( .. .. ,, { ··�:-, ls :.i-..,.. \\ .-.,"If-• r I j A \ ' . \ . �'- ...... __ , ,' ,.. r \' "c."I \ / • -_.. .•· · = Andros . .. \ \ ·�=·,/l / ts : 1 ·;1 {,") . .:. 'i:Q.r�'o (�fiiew • ... :1 / 'l:i� · ' 0 �.·· 'r:- :n :·• ,. � , ·, Providel")C'e- :. --1000 ...\ 0 'o \ m �'·· .. \ .. ''·H .l§> ! .. ••u••····•::: ... ··· : . -:: :;,,,. ··.. , -..::, ..... .:. 1:.. .... -t--�� '< , . , ·• ....... .... �,i.. .."'- � ,... .,,. •• ·, • • (<': .,... ....� · .. ,oil>•···· o� cat Is I/ l " •· '.• ' •:.� ,;,. •� f : +,:. •••._ •,-. I \o1 . \ I � •• ' I \ � •;,. •· •• .' \ •.. •···· ,j,�"!J ,, � �'c, '· • •• �..,.. ..\ • '\I ., ' c-:,'-<;. · � \ ','J) · . ·, •��\ ... / '\��h � {..�· ·,; \ /�-:'- SAN SALVADOR �·oo'N _.-•··•. '.I � . · ·· �'· .• · · rong. uc ot ... �.:..,. .... ,� ....., IS. _ . · ·-..• · ............. � � '··� �---�,• ,, -',, r.. •. ......,., , ", _ (!!!; -:, . - · . � �,..,• �\ • 11,e-..... ocean, ,·�'·•. ... ... .,· .�. ..-..._ \' ' , 1 i Qay Sal \ . · ·�-, \ "'· ,._ .... ./ \, 'RtJm' , � \ Bank ··• ... \\ o,. .: Great •· · .,_ \ Cay ,., . • ...... •◄, •····•.. .r-. ' ······• 4JY Exuma 100. ..• '/4. ·· . · •\ .,,.... .•• I samana Cay ·· _, �.} <S) •• •• � �• I ,..,,.,a. ..... !i�;."' , .......... ·•• Y-i, . ·"' · _ -·-·· •••• ··· ··- LONG IS. It:'; · '\� ·•, \\ Crooke ... � · + • . d � ..... ··,1;o .fS",/ ··, -..;, .,· �· s •• 0_ �•{ / ,_/ :.:P!Jtr!�C��'S --·� . • . ·•.. · g.: •,1:r;-.., ..', _ . ... l ,- .,,,.'A·r .\1�- .. .... - , . .. .. ,., •�'iO � ... , \ ; .,, '\ 1 ·· ··· Mayaguana Is. ·:.:·-: ,,�.-::,,,._.,:· ·,-:·�·•:·, ..,,,·',•::::,-. �-. ...... .... .. .. ·• ...... , .·•·... ·. l !.:�1· � . · . -� . .. ... · .. ...J�;;;,•.,) \.,- .. , ,.,,/,, ··, .·,; ,··�cklinsls. '-� ·,, ., ., .. ,--:-- . · ·�\i - . ..... .... ,, •. .. ....... · ., ·, ! , "!) o. .. , . � ....t . ......-... 1' 1{::·N. !.,.' .,,·.·•�':.- -\'"'¥'/:•: .. ' ·· ."'·• . •.: I ,.. .... .,. ,.., �!.··n.�":t. .. q -� ... .._ •• ' • • • •·. - 1··� -.. ;;i,�� · ... •··· (• , ... • , � 1 . iil'i,., • = I .., • ._., as:.,\ · ,:-_, .,., • .,..... -- . ✓..... �-. - -........ ,/ ··!. Carcos . .:, ,-·-·····- ·· · · A··· ,.... ., ... _,, '/ ,•· .. ,,,. .. -:-,- ... ,·'\ I · · " ',. ' - , ' ,- I�--/. , "> B k ' 1 - ,- ' . I '" > ,' t,/;;:./ IS _., . -, , , ., , '_, --? ' - ,--J an I t •... "',_,.., '-'. ;:-,,�u;�i."-� · · ·. ' .... ... - -, · '(),,. "" '"" ..,.,.) �:.·-�· , ,.,,.,reat ' ......... ' ,...,. ,- \ ..,.:�·-· :·· •• -�.�:, , 4."1:filJ/Xi:;llilJl�il_l ·: • • • •""-.1:S:9.!o� I I ,1 ..-- /, • G '•• • • . ' .,_, ' , ·.. / • •,-:;-, ,. , ! 'lnagua Is. "'· . , ;; .. ...--- -- ·- - ,--' . ··.. - ......... ......... ' , ' ,--: . cu BA -----. ---- ' ..... / .-··· -'.:•\·_.l; "',.. ••· .•1 ,,0- ~-, • . , · · ™1�����·.... .._ t • ........... ' f \ . · . --00 ' ', .. ' . , ............ .,.. / ,__ '· "-- .·- ...:·• .. , . ', --�,\ .. ' �-. - ... ' ' ---·-···· '.t -- '�·, ' ·�i..c��ll'!,!ft,:� ......__.._ ,.',._ �..\�· '• .• '• • .· "'l:i!:o.!.lt:il!PO.Ci:i;:;;,,•\:•.. •• ,_ •... !,:;,.•·· and White, 1995). and San Salvador (modifiedfrom Curran Archipelago and locations of Long Island Figure 1. Index map forthe Bahama GEOLOGY OF LONG ISLAND, BAHAMAS: A FIELD TRIP GUIDE INTRODUCTION The purpose of this field guide is to Columbus Monument describe and illustrate some of the well exposed LONG ISLAND and most interesting geological sites on the north THEBAHAMAS end of Long Island, Bahamas. Long Island is one of the Bahamian "Family Islands" or "Out Islands," and it has a population of about 4,000 inhabitants. The north end of the island lies ATLANTICOCEAN about 270 km southeast Nassau, the capital city of The Bahamas, located on New Providence Island (Figure 1 ). Life on scenic Long Island is tranquil and community oriented. The island has a past history of salt production by the now defunct Diamond Salt Company. Sponging still operates on a small scale, and tourism and its related activities is growing. Originally named Fernandina by Christopher Columbus, in honor of his Spanish king mentor, the island takes its present name O kllom eters 20 from its geographic form. It truly is a long island, extending for about 120 km in length, but with a width of no more than 7 km at the widest Figure 2. Overview map of Long Island. The Tropic point (Figure 2). The late Quaternary, all of Cancer crosses the island just south of Stella carbonates geology of Long Island is varied and Maris. Cartography by Doug Gamble. spectacular. This field trip is restricted to the north end of Long Island, given that only part of presented in the text. We are guests on Long one day is available for our geologic Island, and all field trip participants are urged to reconnaissance. We hope that this field guide treat the areas we visit with the utmost respect. and trip will pique interest in the geology of It is illegal to undertake scientific research in Long Island and serve as a catalyst for future The Bahamas without a research permit. geologic investigations over the greater extent of the island. Many of the sites we will visit are on PLEASE DO NOT MAKE SAMPLE private or restricted landsand special permission COLLECTIONS AT ANY STOP WITHOUT is necessary for entry to some of these areas. For ASKING THE FIELD TRIP LEADERS IN these reasons, it may not be possible for ADVANCE. WE REQUEST THE SAME someone who is using a copy of this fieldguide RESPECT FOR PRESERVATION OF at a later date to follow precisely in our THESE GEOLOGIC SITES FROM ALL footsteps. Last-minute changes owing to SUBSEQUENT USERS OF THIS weather conditions or time constraints may result GUIDEBOOK. in our field trip taking alternate routes and visiting a slightly differentselection of sites than 1 REGIONAL SETTING Masaferro (1997), and Manfrino and Ginsberg (200 I) has demonstrated that the Bahama banks The Bahama Islands comprise a 1,000 are undergoing both depositional progradation km long portion of