Aluminous Lateritic Soil of the Republic of Haiti, W. I
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UNITED STATES DEPARTMENT OF THE INTERIOR J. A. Krug, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director Bulletin 954-C ALUMINOUS LATERITIC SOIL OF THE REPUBLIC OF HAITI, W. I. BY SAMUEL S. GOLDICH AND HARLAN R. BERGQUIST Geologic Investigations in the American Republics, 1946 (Pages 63-112) UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1948 For sale by the Superintendent of Documents, U. S. Government Printing Office, Washington 25, D. C» Price 40 cents CONTENTS Page Abstract____._.____._.___-__-___-_____-_---------__--._-___.--- 63 Introduction..--___---_-_---------------------.----.--_-_-.-- -- 63 Discovery of aluminous lateritie soil___ -___.______.____.____-_ 63 Use of term_________-__-____--___-_-_-_-----_-------__.-_--- 64 Scope and methods of investigation.________-_..-__._________.-_. 64 Acknowledgments. ___-_-_-____--_-----_-__------.._-______---- 65 Occurrence of aluminous lateritie soil .._-_---_-_-____._______.--- 66 Rochelois Plateau region.__._._______._________.______...___.___ 66 General features __---__--______-_---_-.---_-_-_______--- 66 Location, area, and accessibility-________________________ 66 Vegetation and industry..._-_--_--___--_-_._-_-.____-_- 67 Climate __-_----_-------_--__----__---_-__-----__----- 67 Topography. _______----------_-_---_---_---_-.-_----__--- 67 Ste.-Croix Valley.---.-.- _--.-.-_-._._._....... 68 Tranquille-Trahison Valley......_....__.._....._____. 68 East Extension valleys..---------------.-_-------_----- 68 Structure. ---_------------------_---------_--_.-_________. 69 Limestone..-_--_-_-_---_-----_-_-----.__-_-_-.___________ 69 Description.__________________________________________ 69 Composition. _ .____.___-.__-__.____.._._...-___...-... 70 Stratigraphic relations.. --___.- ______.._________.__ 70 Age___.-------...-_..-.--_..-.---..--................ 71 Lateritie soil deposits...____.--_..-_.__.___.________._._.__ 71 Exploratory data..----.--..___--_-.. .._-..__._.-.- 72 Isopach map..__--_-_-._----_.-__--__-_-__________.___ 73 Physical character of soil.______________________________ 73 Chemical composition._.________________________________ 74 Regional differences__._-----___-___-._.___..-... 77 Variations with depth and differences within areas...-- 78 Organic matter...__-_.________---.._.-___._______.__._ 81 Mineralogical composition._._._.-___._-___.__..__.__.__ 81 Gibbsite and boehmite____.----_-_____-___.____..._ 82 Clay minerals.- ______.______._____-___-.._...,__. 82 Hematite and goethite.__..-_--___________-.__.,-._ 83 Accessory minerals__-_-_____-_-,-___..__._.___--. 83 Reserves.____--____--___-___-_____--____-_______-________ 83 Method of computing....__.________._._.__...__._..___ 83 Reserves in drilled areas_.__.__--___.._________.___._. 84 Grade_---_-_.___.__...__...__.___.___._____.._.._.. 84 Minable tonnage._._-_____.___________-_.._._.___.____ 85 Reserves on the plateau_--_^._--__-_-__________.._.___. 85 Economic considerations_____----l._--__J_______._... 86 m IV CONTENTS Occurrence of aluminous lateritic soil Continued Page Other exploratory areas____---____________.____________________ 86 Beaumont region._________________________________________ 86 Limestone _-_-__-_---__-___-__._-__.________________- 86 Lateritic soil_-_--__--_-___________.___________________ 87 Anse d'Hainault region.___'___-_____-____ ________________ 89 Massif de la Selle region_-..._-_____-__-.--____-_-__-.__-__ 89 Pine Forest area ____________________________________ 89 Savane Zombi area.___________________________________ 90 Kenscoff area.___________-_-_---------_-______________ 90 Goyavier plateau. ____________-_--------------_------------ 91 Limestone. _ __--___-_-___-_-_-------_-__-------------- 91 Soil..- ....:... ........................ .. 91 Morne la Pierre region..________-.,-_-_-----_--__-_-----_--_ 91 General description.._-___________--__-_____-_-_------- 91 Limestone ___________-_____-_---__--_-----_-_-----_-..- 92 Soil______.___-_ __-.__________-...._..__._._-,_._ 93 Mont Puilboreau region.___________________________________ 94 Bombardopolis Plateau____-_____-____-_--__--_-______.-._ 94 He de la Tortue.___________________________ 95 Areas suggested for prospecting.___________-_____._____._ _._ 96 Origin and development of aluminous lateritic soil__-_________-___.._'___ 96 Concepts of lateritization________________.______________________ 96 Aluminous lateritic soil of Haiti._________-___---__--_-__^___.___ 99 ; Boehmite-gibbsite relationships_____________________________ 99 Clay mmerals-_-___-_--_____________..____________________ 100 : Hematite-goethite relationships____________________ ____ _ ___ 101 Genesis of the lateritic soiL__---_-___-_--__-_-________________ 101 Climatic influence.__--.______________L_____'______.'_ _______ 101 ' Distribution of low-silica aluminous lateritic soil______________ 103 ; Parent material.. -- ____________ 104 ! Limestone as source material...____._-------- --------- 105 Other possible sources..__-.------------------------- 107 Summary and conclusions_________--__-_-----_----- ------- 108 Index..T . nl ILLUSTRATIONS PLATE 20. Rochelois Plateau_---~-_^___________._________________ 72 21. Index map of the Republic of Haiti.- .____ in pocket 22] Isopach map of aluminous lateritic -soil deposits..... - - - -.-; In pocket riGTja.^ 4. Variations of the principal chemical constituents, Ste.-Croix deposit... _____----_____________ _ ______..__ 80 5. Sketch map of trenches, Lacwcotte v^eV7»~ ^;H:_^i_'_ gs 6. Belt of low-silica aluminous lateritic SOU UepOSllS in the West Indies...________ _ _____ 103 7. Proportions of Ai2o3-.Fe_o3 :Tio2 in lateritic soils and in igneous rock families. ._.- - ------_--_____ 105 CONTENTS V TABLES Page TABLE 1. Data from drilling and mapping in the Rochelois Plateau region. 72 2. Determinations of moisture, porosity, and degree of saturation of blocks of soil------------------------- ________ 74 3. Chemical analyses of composite samples representing areas in the Rochelois Plateau deposits __________________________ . 75 4. Approximate determinations of Si02 and total iron as Fe20g on samples from the Rochelois Plateau region________________ 76 5. Average chemical composition of the lateritio soil deposits of the Rochelois Plateau region.________________________________ 77 6. Chemical analyses of surface and auger-hole samples from the Ste.-Croix deposit_----.-_---___---_--------_-_-____-_-_.. 78 7. Chemical analyses of interval samples from auger hole 23, area 7, Ste.-Croix deposit.______-____--__--_---_-._________.___ 79 8. Determinations of carbon and organic matter in samples from - trench 1, Ste.-Croix deposit.__-_-_-__-_-_____.___________ 81 9. Reserves of aluminous lateritic soil in drilled areas of the Rochelois Plateau-..._____________________________ 84 10. Approximate determinations of SiO-2 and total iron as Fe20j on samples from Lachicotte Valley, Beaumont._______________ 89 11. Approximate determinations of Si02 and. total iron as Fe20s on samples from the Goyavier Plateau._____________________ 92 12. Chemical analyses of lateritic soil from the Goyavier Plateau. _ 92 13. Approximate determinations of Si02 and Fe20-3 on samples from the Morne la Pierre region__________________________ 93 14. Analyses of soil from Morne la Pierre region.___.._.________ 94 15. Approximate locations and determinations of SiO2 and Fe20s on samples from Tortue Island-_____________________________ 95 16. Chemical analyses of limestone from aluminous lateritic soil lo calities in Haiti and the Dominican Republic. _____________ 106 17. Spectrographic analyses for minor elements in limestone and lateritic soil from Haiti and the Dominican Republic.-_._- 107 ALUMINOUS LATERITIC SOIL OF THE REPUBLIC OF HAITI By SAMUEL S. GOLDICH and HARLAN R. BERGJQUIST ABSTRACT Aluminous later!tic soil containing as much as 50 percent of alumina (AbOa) Js found in several places in the Republic of Haiti. The largest deposits are on the Rochelois Plateau southwest of Miragoane on the Southern Peninsula. Mapping and drilling of the deposits indicate fifteen million long tons in place (dried basis). It is estimated that a minimum of 10 million long tons of this reserve is recoverable. The average chemical composition of this material is as follows: A1208, 46.8 percent; Si02, 3.4 percent; TiO2, 2.8 percent; Fe2Os, 21.9 percent; P2O5, 0.6 percent; MnOs, 0.5 percent; and loss on ignition, 24.1 percent. Other localities in which similar lateritic soil occurs are Beaumont in the Massif de la Hotte; the vicinity of Savane Zombi in the Massif de la Selle; and Savane Terre Rouge on the plateau northwest of Gonai'ves. In none of these regions were large deposits found. The lateritic soil is finely divided, reddish-brown, yellowish-brown, and buff- colored material. The principal minerals are gibbsite, boehmite, hematite, and goethite. Minor constituents are clay minerals and compounds of titanium, man ganese, and phosphorus. Quartz, zircon, and magnetite are accessory minerals. The lateritic soil of Haiti is similar in composition to soil deposits in the limestone valleys of the Sierra de Bahoruco in the Dominican Republic and on the limestone uplands of Jamaica. All these deposits rest on Tertiary limestone and probably are closely related in origin. Chemical analyses of the Eocene limestone bedrock from low-silica aluminous lateritic soil localities in Haiti and in the Dominican Republic show less than 0.1 percent of alumina. If this limestone is the immediate source of the lateritic soil, a large volume of limestone was weathered to