The Commonwealth of Puerto Rico can be partitioned into several subtle but distinct 'packages' of rocks as a consequence of the tectonic setting and geologic history of the Caribbean region. These packages of associated map units are treated as geologic terranes having affinities based upon lithologic rock type, depositional environment, and (or) age of deposition. Terranes are used to reconstruct and understand the large-scale geologic history of Puerto Rico. Also of use to economic geologists is the knowledge that each terrane, which hosts distinct types of mineral occurrences, requires different exploration techniques.
A total of 151 map units, identified on the geologic map of Puerto Rico, are combined into twelve associated terranes for the main island.
The geology of the islands of Mona, Culebra, and Vieques has not been reexamined in detail (1:100,000) in this study, and the terranes for these islands have been extrapolated from the 1:240,000 scale previously published maps of Cox and Briggs (1973).
Purpose:
The terrane map, which was generated by grouping geologically similar rock types, depositional environments, and (or) ages, displays twelve distinct terranes. Rocks of similar age and similar lithologic character tend to occur together. However, it must be remembered that because many of the lithologies are transitional or interfingering, they may logically be placed in more than one terrane. Terrane type was determined by the depositional environment and age of the predominant rock type for that particular map unit. Some assignments are likely ambiguous.
Ultramafic rocks in Puerto Rico are igneous rocks composed chiefly of mafic minerals, and amphibolite which is a metamorphic rock consisting mainly of amphibole and plagioclase, containing little or no quartz. These rocks have potential as hosts of podiform chromite deposits, and erode to form remnant sedimentary nickel laterite deposits.
Basalt in Puerto Rico is dark- to medium-dark, commonly extrusive, mafic igneous rock composed chiefly of calcic plagioclase and clinopyroxene in a glassy or fine-grained groundmass. Chert is found in association with basalt in Puerto Rico. Mineral occurrences observed in basalt include vein deposits of barite. The basalt has been quarried as traprock, an industrial product.
Puerto Rico's intrusive rocks have been separated into two classes; Cretaceous, and Tertiary through Cretaceous, based upon the age of intrusion. Porphyry copper deposits found in these areas are thought to be related to the younger Eocene intrusions, and the older Cretaceous rocks have associated mineral deposits such as magnetite skarns.
The Tertiary and Cretaceous intrusive terrane includes known Tertiary rocks and those rocks for which age is uncertain. Although some of these rocks have not been dated, they are included in this terrane because of their stratigraphic relationship with surrounding rocks. The age of these intrusive rocks is important, because the present potentially economic metallic mineralization of Puerto Rico has been identified with the Eocene intrusive rocks. Most important are porphyry copper systems bearing copper, molybdenum, and gold. Associated with these intrusive rocks are skarn deposits within adjacent calcareous rocks, and vein deposits in fractures and faults.
Concurrent with these two periods of intrusion was the synchronous deposition of related marine volcaniclastic rocks, which cover a substantial area of Puerto Rico.
Rocks described as alteration on the terrane map are metavolcanic rocks or hydrothermally altered rocks for which the protolith is uncertain (R. Krushensky, oral communications; 1994). Alteration is an important indicator for locating many types of mineral deposits. However, altered rocks are widespread and represent many different levels of alteration intensity throughout Puerto Rico. Only the most intensely altered rocks are identified on the 1:20,000 geologic quadrangle maps that were used to compile the 1:200,000 geologic map.
Nonvolcaniclastic terranes are composed of biogenic or clastic map units devoid of volcanic material and cover approximately 3,900 km2 or 45 percent of the surface area of Puerto Rico. An understanding of the vertical and horizontal dimensions of these terranes is important because they host intrusion-related deposits, such as skarns and vein deposits.
Pliocene through Oligocene nonvolcaniclastic terranes comprise approximately 1,500 square kilometers, or 17 percent, of the surface area and consist of limestone and calcareous clastic rock. These rocks cover older rocks present during the intrusion of metalliferous Eocene igneous rocks. This terrane is an important source for industrial minerals, including limestone and sand and gravel.
Quaternary nonvolcaniclastic terranes consist of surficial deposits of alluvium, beach and swamp deposits, identified landslide areas, artificial fill, and fault breccia. Quaternary rocks are a major source for industrial minerals.
Supplemental_Information:
The terrane map is a combination of 3 coverages (westterr, centerr, eastterr), as can be seen in the TERRANE.AML in the AML folder of the cd-rom. There is not one coverage depicting terranes for the entire island of Puerto Rico. However, there are plots of the terrane map of the island of Puerto Rico present in different formats, including PDF, EPS, and GRA. They are located in their respective folders.
The terrane coverages (westterr, centerr, eastterr) were created by using the ARC DISSOLVE command on each of the respective geologic coverages. The DISSOLVE command eliminates arcs between adjoining polygons with the same attribute; in this case the same terrane type.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 1999
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None Planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -66.87565987
East_Bounding_Coordinate: -66.12332654
North_Bounding_Coordinate: 18.49706269
South_Bounding_Coordinate: 17.92821608
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword:
Geology
Terrane
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: Puerto Rico
Access_Constraints: None
Use_Constraints:
Anyone who uses these data must cite US Geological Survey.
These data are not to be used at scales showing more detail than 1:100,000.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Bawiec, Walter J.
Contact_Organization: U.S. Geological Survey
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing address
Address:
954 National Center
12201 Sunrise Valley Drive
City: Reston
State_or_Province: Virginia
Postal_Code: 20192
Country: United States
Contact_Voice_Telephone: (703)648-6148
Contact_Facsimile_Telephone: (703)648-6383
Contact_Electronic_Mail_Address: wbawiec@usgs.gov
Data_Set_Credit: The terrane map was created by transducing 151 map units, as described by Richard D. Krushensky, into 12 geologic terranes, deemed useful in understanding the mineral resources of Puerto Rico.
Native_Data_Set_Environment:
Windows_NT, 4.0, Intel
ARC/INFO version 7.1.1
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report: The terrane map, which was generated by grouping geologically similar rock types, depositional environments, and (or) ages, displays twelve distinct terranes. Rocks of similar age and similar lithologic character tend to occur together. However, it must be remembered that because many of the lithologies are transitional or interfingering, they may logically be placed in more than one terrane. Terrane type was determined by the depositional environment and age of the predominant rock type for that particular map unit. Some assignments are likely ambiguous.
Logical_Consistency_Report:
Polygon and chain-node topology present.
All polygons have a label, and all polygons are closed.
Completeness_Report:
There are TWELVE GEOLOGIC TERRANES OF PUERTO RICO, which are listed below:
NONVOLCANICLASTIC TERRANES
Quaternary:
Pliocene through Oligocene:
Eocene through Cretaceous:
INTRUSIVE TERRANES
Tertiary through Cretaceous:
Cretaceous:
VOLCANICLASTIC TERRANES
SUBAERIAL:
MARINE:
Tertiary
Tertiary and Cretaceous:
Cretaceous:
ALTERATION TERRANE
SUBMARINE BASALT AND CHERT TERRANE
ULTRAMAFIC ROCK AND AMPHIBOLITE TERRANE
Map Units Contained in Each Geologic Terrane
[Stratigraphic units listed alphabetically within terrane]
NONVOLCANICLASTIC TERRANES
Quaternary:
Qa Alluvium
Qb Beach deposits
QTs Blanket sand deposits
Ql Landslide deposits
Qs Swamp deposits
af Artificial fill
Pliocene through Oligocene:
Tcbga Almirante Sur Sand Lentil of Cibao Formation
Ta Aguada Limestone
Tay Aymamon Limestone
Tcm Camuy Formation
Tcb Cibao Formation
Tcbg Guajataca Member of Cibao Formation
Tgua Guanajibo Formation
Tjd Juana Diaz Formation
Tla Lares Limestone
Tcbmi Miranda Sand Member of Cibao Formation
Tcbm Montebello Limestone Member of Cibao Formation
Tmu Mucarabones Sand
Tpo Ponce Limestone
Tcbq Quebrada Arenas Limstone Member of Cibao Formation
Tcbr Rio Indio Limstone Member of Cibao Fomation
Ts San Sebastian Formation
Tfb Fault breccia
Eocene through Cretaceous:
Tco Corozal Limestone
Kcot Cotui Limestone
Tc Cuevas Limstone
Tg Guayo Formation
Klm La Muda Formation
Kp Parguera Limestone
Kpe Penones Limestone
INTRUSIVE TERRANES
Tertiary through Cretaceous:
TKas Alkali syenite
TKap Augite andesite porphyry
TKahp Augite-hornblende porphyry
TKat Augite trachybasalt
Td Porphyritic dacite
TKda Amygdaloidal dacite
TKg Diabasic gabbro
Tga Gabbro
TKgm Granodiorite quartz monzonite
TKhda Hornblende dacite
TKh Porphyry Hornblende quartz-diorite
Thp Hornblende quartz diorite porphyry
TKdi Diorite
TKqd Quartz diorite-granodiorite
TKk Quartz keratophyre
Trhp Rhyodacite porphyry
Cretaceous:
Kdi Diorite
Kdh Diorite-hornblende gabbro
Kcag Granodiorite of the Caguas pluton
Kmc Granodiorite of Morovis and Ciales stocks
Kpgq Quartz diorite - plutonic complex of Punta
Guayanes
Kpsg Granodiorite of the plutonic complex of Punta Guayanes
and the granodiorite of San Lorenzo batholith, undivided
Ksl Granodiorite-quartz diorite of San Lorenzo batholith
Ku Granodiorite-quartz diorite of the Utuado batholith
Kib Intrusive breccia of the Daguao Formation
Kslg Mixed granodiorite-diorite of the San Lorenzo batholith
Kpgg Granodiorite of plutonic complex of Punta Guayanes
Kpsq Quartz diorite of plutonic complex of Punta Guayanes
and of the Granodiorite of San Lorenzo batholith
Kslq Quartz diorite facies of Granodiorite of San Lorenzo
batholith and diorite-hornblende gabbro
Kpgqm Quartz monzonite of plutonic complex of Punta
Guayanes
Kpob Two pyroxene olivine basalt
VOLCANICLASTIC TERRANES
SUBAERIAL:
Kcb Cambalache Formation
Kpo Pozas Formation
MARINE:
Tertiary
Tca Carreras Siltstone
Tj Jicara Formation
Tjo Jobos Formation
Tl Los Puertos Formation
Tm Monserrate Formation
Tor Ortiz Formation
Tpa Palmarejo Formation
Tra Raspaldo Formation
Tr Rio Culebrinas Formation
Trd Rio Descalabrado Formation
Trp Rio Piedras Siltstone
Ty Yunes Formation
Tertiary and Cretaceous:
TKa Anon Formation
TKamo Anon-Monserrate Formations, undivided
TKay Anon and Yauco Formations, undivided
TKam Anon and Maricao Formations, undivided
TKci Cibuco Formation
TKgu Guaracanal Formation
TKl Lago Garzas Formation
TKaym Anon, Yauco, and Maricao Formations, undivided
TKlam Lago Garzas, Anon, and Maricao Formations, undivided
TKly Lago Garzas and Yauco Formations, undivided
TKal Anon Formations and Lago Garzas, undivided
TKm Maricao Formation
TKmy Maricao and Yauco Formations, undivided
TKmly Maricao, Lago Garzas, and Yauco Formations, undivided
TKn Naranjito Formation
TKy Yauco Formation
Cretaceous:
Kac Achiote Conglomerate
Kal Alonso Formation
Kba Barrazas Formation
Kcam Camarones Sandstone
Kcn Canovanas Formation
Kca Cariblanco Formation
Kcan Cancel Breccia
Kcar Carraizo Breccia
Kcoa Coamo Formation
Keo El Ocho Formation
Kfa Fajardo Formation
Kfr Frailes Formation
Kg Guaynabo Formation
Kh Hato Puerco Formation
Kja Jayuya Tuff
Kln Los Negros Formation
Kma Magueyes Formation
Kmal Malo Breccia
Kman Manicaboa Formation
Kmar Maravillas Formation
Kmag Martin Gonzalez Lava
Km Melones Limestone
Kmo Monacillo Formation
Kpa Pajaros Tuff
Kpi Pitahaya Formation
Kra Rio Abajo Formation
Krp Rio de la Plata Sandstone
Kr Robles Formation
Ks Sabana Grande Formation
Kta Tabonuco Formation
Kte Tetuan Formation
Kt Torrecilla Breccia
Kto Tortuga Andesite
Kv Vista Alegre Formation
ALTERATION TERRANE
TKmv Metavolcanic rock
TKha Hydrothermally altered rock
SUBMARINE BASALT AND CHERT TERRANE
Kabcj Formations A, B, C, & J
Kav Avispa Formation
Kap Avispa and Perchas Formations, undivided
Kbo Bqueron Basalt
KJc Cajul Basalt
Kce Celada Formation
Kcg Cerro Gordo Lava
Kco Concepcion Formation
Kctt Cotorra Tuff
Kd Daguao Formation
Ke El Rayo Formation
Kf Figuera Lava
Kfd Figuera and Daguao Formations, undivided
Ki Infierno Formation
Kl Lajas Formation
Klo Lomas Formation
Kmam Mameyes Formation
KJm Mariquita Chert
Kper Perchas Formation
Kso Santa Olaya Lava
ULTRAMAFIC ROCK AND AMPHIBOLITE TERRANE
KJa Amphibolite
KJas Amphibolite-Serpentinite
KJs Serpentinite
KJb Spillitized Basalt
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report: The Centerr coverage is a derivitive coverage of Central coverage which has a Root Mean Square (RMS) error of 38.848 meters, which means locations shown on the digital coverages are within 38.848 meters of their location on the ground. This error was computed during the transformation of coordinates from scanning units (inches) to polyconic meters.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: Richard D. Krushensky
Publication_Date: 1999
Title: COVERAGE CENTRAL -- Geology of the Island of Puerto Rico between 66 7' 30" and 66 52' 30" West Longitude at a Scale of 1:100,000
Geospatial_Data_Presentation_Form: Map
Series_Information:
Series_Name: U.S. Geological Survey Open-File Report
Issue_Identification: USGS OFR 98-38
Publication_Information:
Publication_Place: Reston, Virginia
Publisher: U.S. Geological Survey
Source_Scale_Denominator: 200,000
Type_of_Source_Media: Mylar
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 1999
Source_Citation_Abbreviation: USGS OFR 98-38
Source_Contribution: Each geologic map unit is assigned to a geologic terrane. The arcs from the digital geologic map were dissolved, by terrane code, into the terrane map. This resulted in a map having much fewer polygons.
Process_Step:
Process_Description: Each polygon is assigned a geologic map unit mnemonic, which represents a specific geologic unit. Each map unit mnemonic is assigned to one of twelve geologic terranes, based upon its' depositional environment, lithology and/or age. The ARC command DISSOLVE is used to remove common arcs from adjoining polygons having the same terrane attribute. This results in a terrane map having fewer polygons and being much simplier than the original geologic map.
Process_Date: 1999
Process_Step:
Process_Description:
First draft of metadata created by wbawiec using
FGDCMETA.AML ver. 1.2 05/14/98 on ARC/INFO data set
g:\resdgs2\adorrzapf\puerto\centralterr
Process_Date: 19991027
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Point
Point_and_Vector_Object_Count: 1553
SDTS_Point_and_Vector_Object_Type: String
Point_and_Vector_Object_Count: 2726
SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains
Horizontal_Datum_Name: North American Datum of 1927
Ellipsoid_Name: Clarke 1866
Semi-major_Axis: 6378206.4
Denominator_of_Flattening_Ratio: 294.98
Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
The purpose of this coverage is to provide the arcs necessary to draw outlines around colored terranes. Terranes are colored by linking formation names (FMATN) of the EAST, CENTRAL, and WEST coverages to a lookup table called PRPROV.LUT. Look at TERRANES.AML in the AML folder to see how this coverage is used.
Items listed below are found in the INFO files associated with the polygon attribute table (*.PAT) and arc attribute table (*.AAT).
The first four items (AREA, PERIMETER, CENTRALTERR#, CENTRALTERR-ID) are Arc/Info generated and should never be altered. The last item, PROV, was used in the early development of this coverage, but is no longer current.
The first seven items of *.AAT (FNODE#, TNODE#, LPOLY#, RPOLY#, LENGTH, CENTRALTERR#, CENTRALTERR-ID) are Arc/Info generated and should not be altered. The last item, NOPLOT, has a value of either '0' or '1'. Arcs with a value of NOPLOT = '1' are located on the east and/or west sides of coverages that adjoin another coverage. When these arcs are not plotted, the join between adjacent coverages becomes transparent when plotting more than one coverage.
>
>CENTRALTERR.PAT:
>
>COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME
> 1 AREA 4 12 F 3
> 5 PERIMETER 4 12 F 3
> 9 CENTRALTERR# 4 5 B -
> 13 CENTRALTERR-ID 4 5 B -
> 17 PROV 4 4 F 0
>
>
>CENTRALTERR.AAT:
>
>COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME
> 1 FNODE# 4 5 B -
> 5 TNODE# 4 5 B -
> 9 LPOLY# 4 5 B -
> 13 RPOLY# 4 5 B -
> 17 LENGTH 4 12 F 3
> 21 CENTRALTERR# 4 5 B -
> 25 CENTRALTERR-ID 4 5 B -
> 29 NOPLOT 4 4 F 0
>
>
Entity_and_Attribute_Detail_Citation: none
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey Information Services
