Great Hill State Forest No. 1 Mica Quarry

Past Producer in Middlesex county in Connecticut, United States with commodity Mica

Sections on this page

Identification information
Geographic coordinates
Site location context
Geographic areas
Commodities
Materials information
Mineral occurrence model information
Host and associated rocks
Nearby scientific data
Economic information about the deposit and operations
Mining district
Ownership information
Workings at the site
Links to other databases
Bibliographic references
General comments
Reporter information

Geologic information

Identification information

Deposit ID	10067613
MRDS ID	W000406
Record type	Site
Current site name	Great Hill State Forest No. 1 Mica Quarry
Related records	10119248

Geographic coordinates

Geographic coordinates:	-72.54052, 41.59599 (WGS84)

Site location context

Political divisions (FIPS codes)

Middlesex(county)

Connecticut(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Middle Haddam(quadrangle 1:24,000 scale)

Hartford(quadrangle 1:100,000 scale)

Hartford(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Outlet Connecticut River(hydrologic unit)

Lower Connecticut(hydrologic accounting unit)

Connecticut(hydrologic subregion)

New England(hydrologic region)

Geographic areas

Country	State	County
United States	Connecticut	Middlesex

Commodities

Commodity	Importance
Mica	Primary

Comments on the commodity information

Workings Consist Of, Open Cut 90 Feet Long, 40 Feet Wide, 15 Feet Deep. Quarried By New Haven Trap Rock Company 1942; By Worth Spar Co. Inc. 1943. Strike of Dike Probably N.N.E.-Neither Mining Attempts Successful. Known As Great Hill Mica Quarry Or St
WORKINGS CONSIST OF, OPEN CUT 90 FEET LONG, 40 FEET WIDE, 15 FEET DEEP. QUARRIED BY NEW HAVEN TRAP ROCK COMPANY 1942; BY WORTH SPAR CO. INC. 1943. STRIKE OF DIKE PROBABLY N.N.E.-NEITHER MINING ATTEMPTS SUCCESSFUL. KNOWN AS GREAT HILL MICA QUARRY OR STATE FOREST NO. 1 MICA QUARRY. MINED FOR ONLY MICA.

Materials information

Materials	Type of material
Perthite	Ore
Beryl	Ore
Plagioclase	Ore
Quartz	Ore
Muscovite	Ore
Tourmaline	Gangue
Garnet	Gangue

Mineral occurrence model information

Model code	33
USGS model code	13a
Deposit model name	Be-Li pegmatites

Host and associated rocks

Host or associated Associated

Rock type Plutonic Rock > Pegmatite

Stratigraphic age (youngest) Late Permian
Host or associated Host

Rock type Metamorphic Rock > Schist
Host or associated Host

Rock type Plutonic Rock

Host or associated	Host
Rock type	Metamorphic Rock > Schist

Host or associated	Host
Rock type	Plutonic Rock

Nearby scientific data

(1)	-72.54052, 41.59599	ListMap

Economic information

Comments on the geologic information

Geol.Desc: Pegmatite Body Irregularly Cross Cuts Schists-Irregular Distribution of Pods-Mica Books 2 To 15 Inches In Dia.,-3/4 To 4 Inches Thick. Beryl Crystals 1 To 8 Inches Long, One Half Inch To 5 Inches Thick.
GEOL.DESC: PEGMATITE BODY IRREGULARLY CROSS CUTS SCHISTS-IRREGULAR DISTRIBUTION OF PODS-MICA BOOKS 2 TO 15 INCHES IN DIA.,-3/4 TO 4 INCHES THICK. BERYL CRYSTALS 1 TO 8 INCHES LONG, ONE HALF INCH TO 5 INCHES THICK.

Economic information about the deposit and operations

Development status	Past Producer
Commodity type	Non-metallic
Significant	No
Production years	1942, 1943

Mining district

District name	East Hampton

Ownership information

Type Operator

Owner New Haven Trap Rock Co.. Worth Spar Co. Inc..

First year 1943

Type	Operator
Owner	New Haven Trap Rock Co.. Worth Spar Co. Inc..
First year	1943

Comments on the production information

MINING UNSUCCESSFUL BECAUSE OF LOW GRADE. ONLY SMALL PRODUCTION. ESTIMATE BERYL AS MINOR. PRODUCED MICA CONCENTRATES.

Comments on the reserve resource information

FIGURES LACKING, ACTUAL SIZE OF PEGMATITE UNKNOWN BUT PROBABLY MODERATE QUANTITES OF FELDSPAR AVAILABLE.

Workings at the site

Type of workings Surface

Overall length 27.43M

Overall width 12.19M

Type of workings	Surface
Overall length	27.43M
Overall width	12.19M

Comments on development

TOTAL$: US

Reference information

Links to other databases

Agency	Database name	Acronym	Record ID	Notes
USGS	Mineral Resources Data System	MRDS	W000406

Bibliographic references

Deposit

BROOKINS, D.G., 1970, "CONTRI. TO GEOCHRON. IN CONN.," CONN. GEOLOGICAL SURVEY, R.I. NO. 5, PG. 12, 1
Production

CAMERON, 1954
Deposit

Cameron, E. N., And Others, 1954, Pegmatite Investigations 1942-45 New England: USGS Professional Paper 255, P. 21Cameron, E. N., And Others, 1954, Pegmatite Investigations 1942-45 New England: USGS Professional Paper 255, P. 21

General comments

Subject category	Comment text
Deposit	USGS TOPO, 1961, "MIDDLE HADDAM", AT 1:24000, LOCATES QUARRY BY SYMBOL. BROOKINS GIVES GEOCHRON. DATES OF ABOUT 260 M.Y. FOR SIMILAR PEGMATITES. REPORT IN USGS FILES. ; INFO.SRC : 1 PUB LIT

Reporter information

Type	Date	Name	Affiliation	Comment
Reporter	01-APR-1972	Windolph, John F.	U.S. Geological Survey
Updater	21-AUG-1997	Mchone, Nancy	Connecticut Geological and Natural History Survey	Added Model_Num And Model

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.