U.S. Department of the Interior National Park Service Natural Resource Stewardship and Science Directorate Geologic Resources Division Virgin Islands National Park GRI Ancillary Map Information Document Produced to accompany the Geologic Resources Inventory (GRI) Digital Geologic Data for Virgin Islands National Park viis_geology.pdf Version: 4/16/2019 I Virgin Islands National Park Geologic Resources Inventory Map Document for Virgin Islands National Park Table of Contents Geologic Resourc..e..s.. .I.n..v..e..n..t.o...r.y.. .M...a..p.. .D...o..c..u..m...e..n...t............................................................................ 1 About the NPS Ge..o..l.o..g..i.c... .R..e..s..o..u...r.c..e..s.. .I.n..v..e..n...t.o..r.y.. .P...r.o..g...r.a..m............................................................... 3 GRI Digital Map an...d.. .S..o..u...r.c..e.. .M...a..p.. .C...i.t.a..t.i.o...n...................................................................................... 5 Index Map .................................................................................................................................................................... 5 Map Unit List ............................................................................................................................. 6 Map Unit Descript.i.o...n..s...................................................................................................................... 8 Qs - Surficia.l. .d..e..p..o..s.i.t.s.. .(.Q...u..a..t.e..r.n..a..r.y..)................................................................................................................................ 8 Tr - Red Hoo..k. .T...o..n..a..li.t.e.. .P...o..r.p..h..y..r.y.. .(.T..e..r.t.i.a..r.y..)..................................................................................................................... 8 Te - Explosio..n.. .b..r.e..c..c..i.a.. .(.T..e..r.t.i.a..r.y..?..)................................................................................................................................... 8 Tl - Hornblen..d..e.. .l.a..m...p..r.o..p..h..y.r..e.. .(.T..e..r.t.i.a..r.y..)........................................................................................................................... 8 Tt - Biotite-h.o..r.n..b..l.e..n..d..e.. .t.o..n..a..li.t.e.. .(.l.a..t.e.. .E...o..c.e..n..e..).................................................................................................................. 8 Td - Diabase..,. .g..a..b..b..r.o..,. .a..n..d.. .d..i.o..r.i.t.e.. .(.T..e..r.t.i.a..r.y..).................................................................................................................... 9 Tutu Formati.o..n.. .(.U...p..p..e..r. .C...r.e..t.a..c..e..o..u..s..)............................................................................................................................... 9 Ktm - Tutu .F..o..r.m...a..t.i.o..n..,. .M...a..n..d..a..l. .M...e..m...b..e..r. .(.U...p..p..e..r. .C...r.e..t.a..c..e..o..u..s.)................................................................................. 9 Ktmc - Tutu Forma.t.i.o..n..,. .M...a..n..d..a..l. .M...e..m...b..e..r.,. .C..o..n..g..o.. .C...a..y.. .L..im...e..s..t.o..n..e.. .L..e..n..s.. .(.U...p..p..e..r. .C...r.e..t.a..c..e..o..u..s.)......................... 10 Ktml - Tutu Formation, Mandal Member, marble, calc-silicate rock, and marble conglomerate (Upper Cretaceous) ......................................................................................................................................... 10 Ktp - Tutu. .F..o..r.m...a..t.i.o..n..,. .P..i.c..a..r.a.. .M...e..m...b..e..r. .(..U..p..p..e..r. .C...r.e..t.a..c..e..o..u..s..)................................................................................. 10 Ktpl - Tutu Formation, Picara Member, marble conglomerate and calc-silicate-rich beds north of Maho Point (Upper Creta.c..e..o..u..s..).............................................................................................................................. 10 Ktpv - Tutu Formation, Picara Member, medium-dark-gray porphyritic meta-andesite south of Maho Point (Upper Creta.c..e..o..u..s..).............................................................................................................................. 10 Ko - Outer B...r.a..s..s.. .L..i.m...e..s.t.o..n..e.. .(..U..p..p..e..r. .C...r.e..t.a..c..e..o..u..s..)......................................................................................................... 10 Kl - Louisen..h..o..j. .F..o..r.m...a..t.i.o..n..,. .u..n..d..i.v..id..e..d.. .(..C..r.e..t.a..c..e..o..u..s..)...................................................................................................... 10 Kla - Louis..e..n..h..o..j. .F..o..r.m...a..t.i.o..n..,. .p..o..r.p..h..y..r.i.t.i.c.. .l.o..c.a..l.l.y.. .v..e..s.i.c..u..l.a..r. .a..n..d..e..s..i.t.e.. .la..v..a.. .(.C...r.e..t.a..c..e..o..u..s..)......................................... 11 Klb - Louis..e..n..h..o..j. .F..o..r.m...a..t.i.o..n..,. .p..o..r.p..h..y..r.i.t.i.c.. .l.o..c.a..l.l.y.. .a..m...y.g..d..a..l.o..i.d..a..l. .b..a..s..a..l.t. .a..n..d.. .p..il.l.o..w... .b..a..s.a..l.t. .(.C...r.e..t.a..c..e..o..u..s..).................. 11 Klm - Lame.s..h..u..r. .V...o..l.c.a..n..i.c..-.I.n..t.r.u..s..i.v..e.. .C..o..m...p..l.e..x..,. .u..n..d..i.v..id..e..d.. .(..L..o..w..e..r. .C...r.e..t.a..c..e..o..u..s..).............................................................. 11 Lameshur. .V...o..lc..a..n..i.c..-.I.n..t.r.u..s..i.v..e.. .C..o..m...p..l.e..x..,. .C..a..r..e..e..n.. .H..i.l.l. .I.n..t.r.u..s..iv..e.. .S...u..it.e...................................................................... 11 Kct - Lameshur Volcanic-Intrusive Complex, Careen Hill Intrusive Suite, trondhjemite (Early Cretaceous) ......................................................................................................................................... 12 Kcc - Lameshur Volcanic-Intrusive Complex, Careen Hill Intrusive Suite, coarsely porphyritic keratophyre (Early .C...r.e..t.a..c..e..o..u..s..)..................................................................................................................... 12 Kcp - Lameshur Volcanic-Intrusive Complex, Careen Hill Intrusive Suite, porphyritic keratophyre (Early Cretaceous) ......................................................................................................................................... 12 Kca - Lameshur Volcanic-Intrusive Complex, Careen Hill Intrusive Suite, phenocryst-poor keratophyre (Early Cretaceous)......................................................................................................................................... 12 Kcf - Lameshur Volcanic-Intrusive Complex, Careen Hill Intrusive Suite, plagioclase-phyric keratophyre (Early Cretaceous)......................................................................................................................................... 13 Kcm - Lameshur V.o..l.c.a..n..i.c..-.I.n..t.r.u..s..i.v..e.. .C..o..m...p..l.e..x..,. .C...a..r.e..e..n.. .H..i.l.l. .I.n..t.r.u..s..i.v.e.. .S...u..i.t.e..,. .g..a..b..b..r.o.. .(.E..a..r..ly.. .C...r.e..t.a..c..e..o..u..s..)........ 13 Kcsd - Lameshur Volcanic-Intrusive Complex, Careen Hill Intrusive Suite, sheeted dike complex (Early Cretaceous) ......................................................................................................................................... 13 Lameshur. .V...o..lc..a..n..i.c..-.I.n..t.r.u..s..i.v..e.. .C..o..m...p..l.e..x..,. .W...a..t.e..r. .I.s..l.a..n..d.. .F..o..r.m...a..t.i.o..n.......................................................................... 13 Kwp - Lameshur Volcanic-Intrusive Complex, Water Island Formation, porphyritic keratophyre (Lower Cretaceous) ......................................................................................................................................... 13 Kwa - Lameshur Volcanic-Intrusive Complex, Water Island Formation, phenocryst-poor keratophyre (Lower Cretaceous.)........................................................................................................................................ 13 Kwf - Lameshur Volcanic-Intrusive Complex, Water Island Formation, plagioclase-phyric keratophyre (Lower Cretaceous.)........................................................................................................................................ 14 2019 NPS Geologic Resources Inventory Program II Kws - Lameshur Volcanic-Intrusive Complex, Water Island Formation, basalt and basaltic andesite (Lower Cretaceous.)........................................................................................................................................ 14 Kww - Lameshur Volcanic-Intrusive Complex, Water Island Formation, volcanic wacke and bedded tuff (Lower Cretaceous.)........................................................................................................................................ 14 Kwr - Lameshur Volcanic-Intrusive Complex, Water Island Formation, radiolarian chert (Lower Cretaceous) ......................................................................................................................................... 14 Geologic Cross S...e..c..t.i.o..n...s............................................................................................................... 15 Cross Sect.io..n.. .A...-.A..'.......................................................................................................................................................