Fractures, Fluids and Veins: Utica Shale, Hydrothermal Dolomite and Basement Faults, Central New York Mohawk Valley, NY Bruce Selleck Department of Geology Colgate University Thanks: Kristen Meisner, Jason Fredrick, Matt Loewenstein and Nicole McDonald Colgate Brian Slater, Rich Nyahay, Taury Smith NYS Museum Res. Char. Group Bob Jacobi - SUNY Buffalo and Norse John Martin – NYSERDA Gary Lash – SUNY Fredonia

Questions: Is there anything left to be learned about hydrothermal dolomite (HTD) systems than could guide further exploration in the northern Appalachian Basin?

Can outcrop data from natural fractures in the Utica Shale help with exploration and development strategies? How do Utica Shale fracture systems compare with the Marcellus and other Devonian shale targets?

Part I • Temperature and fluid composition (salinity) of basement- and Utica Shale-hosted veins •basement-hosted – high-salinity, evolved fluids •shale-hosted – low-salinity, compaction and clay dehyration

• Timing of hydrothermal fluid flow in basal sand aquifer •U-Pb ages of authigenic monazite and xenotime - ~450 million years

•Fluid sources for hydrothermal dolomite (HTD) systems •HTD systems localized by faults that extend to basement •seismic pumping preferred mechanism for hydrothermal fluid flow •mixing of basement brines and shale-derived fluids

Part II •Natural fracture systems in the Utica Shale •Mode 2 (strike-slip) vs. Mode 1(extension) fractures •Mineralized vs. non-mineralized fractures •Regional patterns •Natural fracture sidewall cementation

Adirondack Massif

Utica outcrop 74NY-8 Core

Approximate western limit of Taconic overthrust Marcellus outcrop

Matejka Core

684’

CORE - 74NY-8

678’

Fe-dolomite in Potsdam Sandstone

660’

Fe-chlorite and Fe-illite alteration of basement

Basementhosted calcite vein

faulting in Potsdam Sandstone

Alteration of basement rock by Paleozoic fluids adds salinity to fluid through hydration reactions between fluid and anhydrous minerals in basement

vapor bubble

-118.0 C

+20.1 C

50 mm

50 mm

+85 C

-88 C

50 mm

Basement-hosted vein Core 74NY-8

-33 C

Th= 141oC Tm=-29oC ‘warm, highly saline’ heating 50 mm

50 mm

warming cooling

+110 C

50 mm

Th = +141 C

-29 C =Tm ice

50 mm 50 mm

Basement-hosted veins document high-salinity fluid circulation

W

Western Mohawk Valley

Tug Hill Plateau, NY

Eastern Mohawk Valley

Central Mohawk Valley

Edenian

pre-middle Silurian erosion

Steuben Fm. Dolgeville Mbr.

Sugar River Fm

Trenton Group

Chattfieldian

Denley Fm.

Flat Creek Mbr.

Glens Falls Fm.

Kings Falls Fm Napanee Fm

Selby Fm Lowville Fm

Pamelia Fm.

Balmville Fm.

Black River Group

Watertown Fm.

Turonian

Late Ordovician

Rust Fm.

Utica Shale Fm.

hiatus

(after Goldman, et al 2004)

E

S. Chuctanunda Creek – Utica Fm.

Crystalline illite

BSE Calcite-cemented silty mudstone.

E-W calcite veins in Flat Creek Member of Utica Shale, South Chuctanunda Creek, Montgomery Co. Veins occupy Mode 2 (strike-slip) fractures surfaced by sub-horizontal slickenlines.

bitumen

Thickest sections of veins occupy dilatational jogs in E-W Mode 2 fractures. Multiple episodes of faulting and calcite precipitation are recorded. Bitumen and methane inclusions are common. Bitumen coats terminated calcite crystals in latest(?) growth zones.

BSE

BSE

volcanic clasts

N-S sand injectite and calcite veins, Utica Shale. Injectite are capped by coarsely crystalline calcite. Veins occupy Mode 1 (tensile) fractures. Fine sand injectite is internally derived from Utica Shale during compaction. Sand was separated from mud by vertical flow of fluid in vein during E-W extension and compaction/dewatering of mud. Sand grains include volcanic clasts - not derived from underlying Cambrian sandstone.

+32˚C

-38˚C

50 µm

50 µm

+45˚C

-13˚C

50 µm

-7˚C

Utica Shale E-W Vein Th= 109oC Tm=-1.3oC ‘warm, near freshwater salinity’

Cooling Warming Heating

50 µm

+100˚C

50 µm

Th = +109.2˚C

=Tm ice -1.3˚C

50 µm

50 µm

-1.3˚C

50 µm

-2˚C

+37˚C

50 µm

-25˚C

50 µm

+61˚C

-18˚C

50 µm

-10˚C

Utica Shale N-S Vein Th= 106oC Tm=-4.0oC ‘warm, near seawater salinity’

Cooling Warming Heating

50 µm

50 µm

-4˚C

+100˚C

50 µm

Th = +106.1˚C

50 µm

=Tm ice -4.0˚C

Matejka Core

Matejka Core – Chemung County – hydrothermal dolomite development in Trenton-Black River (Smith, 2005) Utica Shale calcite veins – early, pre-stylolite Mode 1 (tensile) fractures with fibrous calcite

Fluid inclusions – ‘warm, near freshwater salinity’

Utica Shale and Basement-hosted Veins Fluid Inclusions Freshwater

TH

% Salt

0

TM

5 Seawater

10 15 20

NaCl saturated brine

30 Na – Ca – Mg Cl brine

Basement core veins – high salinity brine N-S veins - compaction water near seawater salinity E-W and Matejka veins - clay dehydration water salinity less than seawater

40

Bruce W.D. Yardley 2009 The role of water in the evolution of the continental crust Journal of the Geological Society; v. 166; p. 585-600

High-grade metamorphic basement consumes water to hydration reactions. The Grenville basement beneath the Appalachian Basin is a highly dehydrated granulite facies terrane. Sedimentary basins are overpressured at depth as mud compacts to shale. Fluids are low in dissolved solids due to fresh water added from clay mineral transformation reactions.

Fluids that interact with basement rock equilibrate to highly saline, isotopically evolved waters (A, B). Lateral flow is limited by low hydraulic conductivity; vertical flow along fractures and faults, facilitated by seismic pumping.

Overpressure of compacting mud and sand limits lateral flow of fluids. Fluids from early compaction dewatering are near sea water salinity (C) . Fluids released during later clay mineral transformation are ‘pre metamorphic’ and may be essentially fresh water (E). Later fluids are isotopically evolved due to equilibrationwith host sediments.

Lim, Kidd and Howe, 2005 Fluids in tectonic veins – Taconic Orogen. Vein fluids in western portion of orogen have seawater or lower salinity

T melting of ice oC

Seawater Freshwater Fluid inclusion homogenization T

oC

% Salt

0 5 Shale-derived fluids

10 15

HTD fluids**

20 NaCl saturated brine

Most evaporite brines

30 *Taconic fluids from Lim, Kidd and Howe, 2005 **HTD from Smith, 2005

Na – Ca – Mg Cl brine

***Basement fluids from Selleck, et al 2005

Basement-hosted fluids from Adirondacks***

40

Adirondack Massif

Utica outcrop

Approximate western limit of Taconic overthrust Marcellus outcrop

Matejka Core

Schematic cross-section hydraulic head is underpressured

Shale and sandstone

hydraulic head is overpressured

Mud compaction and clay dewatering add water to fluid, lowering salt content

Shale

Carbonate Sandstone

Basement

Basement hydration reactions remove water from circulating fluid; cations and chloride are added to fluid raising salt content

Mixing of shale-derived and basement-derived fluids - a source for dolomitizing fluids?

Shale and sandstone

Shale

Carbonate Sandstone

Basement Faults provide hydraulic connections between fluid reservoirs

High salinity (Mg-bearing) basement-derived brine Low salinity shale-derived water

Seismic Pumping – flow rates of 100’s of meters/day; 106 -107 m3 per event

lo-K basinal shale or carbonate

hi-K sand aquifer low-K basement

fluids heated at depth are pumped upward from compressional zones

cool fluids are ‘pulled’ into dilatent zones

5 km

fault 10 kilometers

Utica Shale and Basement-hosted Veins Stable Isotopes

d18OPDB

d13C

Anomalous carbon isotope values likely related to microbial fermentation of bitumen later in E-W vein development

NY HTD

‘evolved’

freshwater

d18OSMOW (water) (calculated) shale-derived waters

?

seawater

Tm

most HTD fluids

basement-derived waters

Calculated oxygen isotope values of waters

Authigenic overgrowths – monazite – Potsdam Sandstone – Late Ordovician - Taconic

448 +-16

Detrital core – “Grenville” basement

Dating hydrothermal fluid flow using authigenic monazite

http://www.uky.edu/KGS/emsweb/trenton/gloadesxsection.gif

Summary - Part 1 – Mohawk Valley Veins/Fractures

• Basement-hosted calcite vein fluids - highly saline, evolved • E-W Utica Shale veins – low salinity, evolved, anomalous carbon values • N-S Utica Shale veins associated with sand injectites – near normal seawater, evolved

• Fluids from Taconic deformation zone are evolved, low salinity • ‘Evolved’ fluids have equilibrated with rock reservoirs with regard to major elements, trace elements and isotopic (including Sr) systems • Hydrothermal dolomite fluids may represent mixing of basement-derived and shale-derived fluids

• Fluid flow in basal sand aquifer dated by authigenic monazite – 455-442 ma – ” Taconic”

W

Western Mohawk Valley

Tug Hill Plateau, NY

Eastern Mohawk Valley

Central Mohawk Valley

Edenian

pre-Silurian erosion

Steuben Fm. Dolgeville Mbr.

Sugar River Fm

Trenton Group

Chattfieldian

Denley Fm.

Flat Creek Mbr.

Glens Falls Fm.

Kings Falls Fm Napanee Fm

Selby Fm Lowville Fm

Pamelia Fm.

Balmville Fm.

Black River Group

Watertown Fm.

Turonian

Late Ordovician

Rust Fm.

Utica Shale Fm.

hiatus

(after Goldman, et al 2004)

E

Rodman Whetstone Gulf

Preliminary fracture study - localities

Pixley Falls

Delta Res. Tn. of Minden

S. Chuct. Ck.

Foreland Little Falls

Hinterland Fultonville

Ross 1

N5W Mode 1 (J1a) tensile fractures filled with sand (right) and calcite (left)

~E-W Mode 2 (J1) fractures with sense of motion indicators

Mode 2 (strike-slip) fracture with sense of motion indicator

Mineralized E-W fracture

Little Falls

J1 fracture with sidewall cementation

Delta Res.

Fibrous calcite vein in tensile J1 fracture

NW (J1) and NE (J2) Mode 1 fractures

Whetstone Gulf

J2 fractures abut J1 – Whetstone Gulf

NW Mode 1 (J1) fractures – Whetstone Gulf

J1 = ~E-W, Mode 2

Preliminary fracture analysis - Utica Shale

Fractures in Utica Shale in central Mohawk Valley – note strong E-W modes

Fractures in Silurian and Devonian strata, central Mohawk Valley – note strong NE modes

Jacobi, Cruz and Billman, 2000

Engelder, et al 2009 – Marcellus

Eastern and Central Mohawk Valley

Tug Hill and Western Mohawk Valley

Summary: Part II – Utica Shale Preliminary Fracture Study •Central and eastern Mohawk Valley – E-W Mode 2 fractures, N-S Mode 1 fractures form J1 and J1a. Mineralized, sand injectites. NE Mode 1 form J2 fracture set. Less commonly mineralized. •Central Mohawk Valley - E-W Mode 2 fractures (J1a) exhibit fracture sidewall cementation. •Eastern Mohawk Valley and Tug Hill Plateau – NW Mode 1 fractures form J1. NE Mode 1 fractures form J2 and J3. Mineralization rare. Sidewall cementation uncommon. •Joint patterns in Utica Shale differ from those in Silurian and Devonian strata in nearby northern Appalachian Plateau outcrop. •Jointing in Utica in Mohawk Valley occurred prior to early Silurian erosion of Upper Ordovician strata. Oneida and Herkimer Formations rest unconformably on already jointed (J1 +J1a) Utica Shale.

References: Lim, C., Kidd, W. and Howe, S., 2005, Late shortening and extensional structures and veins in the western margin of the Taconic Orogen (New York to Vermont), Journal of Goeloyg, v. 113, pl. 419-438 ENGELDER, T., LASH, G., AND UZCATEGUI, R., (2009) Joints that enhance production from the Middle and Upper Devonian Gas Shales of the Appalachian Basin; AAPG Bulletin, vol. 93, # 7, p. 857-889 Goldstein, A., Selleck, B. and Valley, J. (2005) Pressure, temperature, and composition history of syntectonic fluids in a low-grade metamorphic terrane; Geology, v.33, p. 421-424 Jacobi, R., Smith, G., Cruz, K., and Billman, D., 2000, Geologic investigation of the gas potential in the Otsego County region, eastern New York State; NYSERDA #4863L-ERTER-ER-99 MARTIN, JOHN P., HILL, DAVID, and LOMBARDI, TRACY, 2004, Fractured Shale Gas Potential in New York, Northeastern Geology and Environmental Science, vol. 26, no. 1 & 2, pp. 57-78. NYAHAY, RICHARD E. and MARTIN, JOHN P., 2008, Delineating the Utica Formation From Outcrop to Subsurface, Geological Society of America Northeastern Section - 43rd Annual Meeting, 27-29 March Selleck, B.W. (2005) Exploring the root zone of an ancient fault-driven hydrothermal system in the Adirondack Lowlands, New York; NYSGA Fieldtrip Guidebook, 77th annual meeting, pp. 12-31 Selleck, B.W., Williams, M., and Jercinovic, M. (2008) In situ U-Th-Pb microprobe dating of authigenic monazite and xenotime in the Potsdam Sandstone, eastern New York: A new approach to dating hydrothermal fluid flow and dolomitization: Eastern Section AAPG Abstracts, October, 2008 Smith, L. 2006, Origin and reservoir characteristics of Upper Ordovician Trenton-Black River hydrothermal dolomite reservoirs in New York, AAPG Bulletin, v. 90, p. 1691-1718 Yardley , B., 2009, The role of water in the evolution of the continental crust, Journal of the Geological Society; v. 166; p. 585-600