MARYLAND GEOLOGICAL SURVEY 
U S.GHOLOGICGAL SURVEY 
WM BULLOCK CLARK, STATE GHOLOGIST 
CHARLES D WALCOTT. DIREGTOR 
Yas ¢ 
He HOR LES 
| 3 
/ clase . 
INTERSECTION 
“STONE 
F \redines 
LEGEND 
With descriptions of the 
geological formations 
PLEISTOCENE 
Clayey loam, ocaupying wpper 
portion of Jormation, carrying 
Pot gravel layers and. scatlered 
c boulders; lower half composed 
of clay, sand, gravel and 
boulders. 
Clay loam, occupying upper 
part of formation, carrying 
ravel layers and scattered 
joulders ; Noiuer half composed. 
usually of clay, sand, gravel 
and boulders. 
COLUMBIA GROUP. 
Loam and sand predominant 
in the upper portion, sand and. 
gravel in the lower part of for- 
mation. 
Sunderland 
NEOCENE 
rth Reddish and yellowish sands 
i l | and gravel, locally indurated 
AINIONIE 
to sandstone and conglomerate. 
li 
a) 
Lafayette 
1 
EOCENE 
Greensand, sand, and indu- 
rated sand; foxsilifercus. 
Greensand and. xand, locally 
indurated. 
COLUNNAR SECTION 
Showingaverage thicknesses 4 
FORMATIO! MATERIAL 
Greenish-black sandy clay, . 
containing green cimoretions Talbot 
and lignite. 45 feel. 
Clow Tenses, loam, sand, grav 
= mypienburna heulure peal, 
i} 
in 
i ¢ ; : ey tH 
: 38 N ~ Lk a= scorer Pow | _ ay Y BNI 
wicomt ce aa ; cs (eee a | Mi ieee) Nh 
Fake 
i \ 
i 
Interbetided savid, sandy clay 
and clay ; sands at times Ido 
r 
Suuderlant Loar, sand, pravel. 
ra > 
c 
oO ] 
Interbedded clay and sand, the 
o) ‘ormer predominating » sand 
= | loeatly indurated, Sand, gravel, conglomerate, 
9 Patapsco 
2) 
o 
JURASSIC 2 
Interbedded sand, gravel and 
clay - arcose, bed of clay near 
buve, ocewpying a quarter of 
the total thickness of formation: 
thin sand bed at base locally 
indurated. 
Siu 
RELVCIN LO: Re 
Patuxent 
TRIASSIC 
Clay, sand. 
Usually in rusty brown round= 
ed boulders or narrow dikes, 
29) 
3 Diabase 
SILURIAN-CAMBRIAN 
or 
PRE-CAMBRIAN 
In light colored dikes composed 
of quartz, feldspar and mica, 
Pegmatite 
Dark compact rocks ocourring 
in narrow bands. 
Basic Dikes 
HFISHING BATTERY 
Tnterbedded olay and sand, 
indurated. sand. 
Compact ai'eenish-qray rock 
| with inconspicuous quarl= and 
Seldspar phenocrysts. Horn- 
| blende and epidote abundant 
tn weathered specimens. 
Meta-Rhyolite 
Bir 
Nose 
Clay, sand, indurated sand. 
hd, f or reddish 
ae ta y qe ctaraotetiNe 
broken outcrops. 
Serpentine 
Peridotite 
Pyroxenite 
ae 
Dark, hard rock with white 
‘eldspur and bronzy pyroxenes, 
Nigger head.’ 
Hypersthene Gabbro 
Norite 
S| Dark, hard, sometimes coarse 
i ‘ained rock weathering in 
Lh a ded boulders. “Ni per 
ae) cd: 
Gabbro 
Meta-gabbro 
Clay, sand, indurated sand, 
i. Quartz-hornblende gabbro gravel, arcose. ‘ 
. ht granitic rock with folic. o) 
a Re i ee ee 
Granite-gneiss 
f d Micaceous hornblendie and. 
ii i f| 
| Light granitic rock, often cf ‘ chloritic gneisses and schists 
banded, strongly micaceous 
and cecasionally conglomeritic. 
Mica-gneiss 
4 ort 
\ 
\ 
fcenumnenaeest 
: ; ; , 5 “ | Galena 
Foi Colemaar \ 
20 
MARYLAND GEOLO 
W™ BULLOCK CLARK 
\, STATE GEOLOGIST CONVENTIONAL SIGNS 
“IN CO-OPERATION WITH MINES AND QUARRIES MINES AND QUARRIES VERTICAL SECTION ON LINE A-B 
IN OPERATION NOT WORKING 
U. S. G EO LO G | C L S U R VEY *® --_______Bullding Stone No a a Building Stone Sea. Level. 
CHARLES D.WALC Lhe eee Se Ee Clay and Kaolin ee ee Clay and Kaolin 
0 
, L , DIRECTOR nd bak dy Gan aT Flint and Spar e.daee er em Flint and Spar Stsqchanna River 
1902 
; 
np Seale Woo 
4 zy o a é i 3 4 Miles, — ; 
i i —— —. + ———— = hi SEES TT AA A A A PSS ELE IEE ——— ; Ze 
| oe th, 4 a a ae 5 Kilometers EUh iver Sassafras River 
} Contour interval 20 feet. Northeast Iver 
Datumis mean sea level, 
15 a | L | { 
{0 Fs 76: 5! 7600" 55. 50 
Geology of the Crystalline Rocks by F. Bascom 
Geology of the Coastal Plain Formations by G. B. Shattuck, 
A, Bibbins, B. L. Miller and F. B. Wright : 
Surveyed in 1899,1900 and 1901 
UTH BY AHOENS CO BALTIMORE MD. 
