DUKE GEOLOGICAL LABORATORY

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Friday, 12 May 2023; 6:30 PM

Orange County Mineral Society
Chester, NY
Free Admission, Refreshments

Geology and Mineralogy of the Hudson Highlands and Bear Mountain

A bridge over a river  Description automatically generated with medium confidenceDr. Merguerian’s video-enriched PowerPoint lecture will discuss the history and current understanding of the age and geological development of the Bear Mountain region including the history of bedrock studies of the metasedimentary and metaigneous rocks, the classic mineral specimens from local mines, the emphatic structural controls on the zig-zag course of the Hudson River through the Hudson Highlands and the evidence for the multi-glacial history of the region.  In addition, he will discuss his recent geotechnical work on the cable strengthening project and historic two-year (1923-24) construction of the Bear Mountain Bridge – a unique engineering feat with both above- and sub-roadbed suspension.

Map East AnchorageMerguerian’s 2003 mapping and analysis showed that the explanation for the shifting of bedrock cable ties and supports that resulted in measurable concrete bunker cracking, shifting and rupture of individual cable strands and stretching of the cables and the remedial efforts that took place to ensure safety of the anchorages, tiebacks, bridge towers and roadway.  Detailed bridge anchorage area mapping showed the presence of deeply weathered NNE-trending, steep NW dipping brittle faults that reactivate older ductile structures in the rock mass and show opening and separation within the east anchorage.  This unfavorable orientation, perpendicular to the cables, was the cause of great concern given the regional importance of this transportation connecting link and the seismic potential of the area.


Friday, 11 March 2022; 6:30 PM

Orange County Mineral Society
Chester, NY
Free Admission, Refreshments and Autographs

Gold Mining History and Geology of the Sierra Nevada Range

During the Cretaceous Era, gold-bearing fluids associated with the geological development of the Sierra Nevada range introduced gold+quartz veins into the Earth’s crust.  Erosion related to the Cenozoic uplift and tilting of the range exposed these veins to the surface and concentrated the dense gold in stream beds where a serendipitous late 1847 discovery at Sutter’s Mill in northern California led to the greatest rush of people, equipment and resources to the region ever witnessed.  There’s “gold in dem thar hills!” – an expression that spread like wildfire around the world and caught the eye of savvy investors and entrepreneurs on the East Coast who gave the thumbs up – the Gold Rush had begun.  Within five years, the terrain was dug up, overturned and searched by many different cultures using very different techniques.

Having spent four summers mapping rocks in the Sierra Nevada range and specifically in the central California gold belt the speaker (an 8-ohm speaker, btw, with no resistance to sharing his knowledge) has intimate knowledge of the geology and mining history of the region.  His Powerpoint lecture will explain the genesis of gold-bearing fluids and their injection into the roots of the Sierra and the geological processes that resulted in gold concentration in the wallrocks of the Sierra Nevada batholith.  With discussion of the geology, terrain and human migration to the area the lecture will explain the various methods of gold mining and end with images taken of the old hard-rock and placer mines and other gold venture sites and show the result of the gold miner’s efforts in the form of nugget and crystalline gold.


Friday, 09 July 2021; 6:30 PM

Orange County Mineral Society
Chester, NY
Free Admission, Refreshments and Autographs

History of Mining and Their Minerals - Western Connecticut

Tonight’s lecture will expose club members to the four types of mineralization mechanisms that have been detected in the rocks of western Connecticut.  Each with a distinctive suite of minerals, these include 1) volcanic- and shallow-level intrusive systems, 2) intermediate depth hydrothermal systems, 3) deep magmatic systems and 4) intermediate- to deep metamorphic agencies.

Through the use of maps, cross-sections, and diagrams a discussion of the bedrock geology of western Connecticut in the context of the plate tectonic assembly, will prep the stage but the lecture will be dominated by highly illustrated “visits” to many of the classic collecting localities explored during his career including specimen images from the Dukelabs.com collection.  Localities described with maps and images will include:

Bristol Copper Mine

Cobalt Mine

Hodges Nickel Mine

Lane’s Tunsten Mine

Long Hill Tungsten Mine

Newgate Prison Locality

Pegmatites (Branchville, Merryall, Harwinton, Thomaston, Southbury, Middletown District)

Roxbury Garnet Mine

Roxbury Iron Mine

Salisbury Iron District

West Redding Garnet-Epidote Locality

 


Thursday, 28 September 2017; 7:00 PM

Ulster County Community College
Stone Ridge, NY
Free Admission, Refreshments and Autographs

NYC Earthquakes: Can It Happen Here?

All geologists and seismologists agree that earthquakes produce dislocations known as faults and that preexisting faults and joints tend to localize new, recurrent earthquakes.  The bedrock beneath New York City has always considered solid and impervious to seismic activity but it is cut by a great number of NW-trending brittle faults that cut diagonally across Manhattan.  One of these, the "famous" 14th Street fault underlies a deep buried valley and controls the lower-than-average height of buildings of the New York skyline in Manhattan between 23rd and Canal streets.  The Manhattanville fault along 125th Street underlies a broad, NW-trending U-shaped valley, and the Mosholu fault in the Bronx shows similar trend, geomorphic expression and exhibits offset of surface features.  These faults underlie valleys in the region and hold the key to understanding NYC seismic risk.  

Modern seismicity along NW-trending faults in NYC is a matter of scientific record.  The epicenter of a small earthquake (~2.4 Richter) localized in NYC on 17 January 2001 plots adjacent to the trace of the 125th Street fault near 102nd Street and Park Avenue in Manhattan .  Later that year, on 27 October 2001, another similar earthquake (~2.6 Richter) struck NYC with an epicenter near 55th Street and Eighth Avenue .  Their epicenters are spatially coincident with known NW-trending faults.  North of NYC, seismicity along the NW-trending Dobbs Ferry fault in late October 1985 included two small (~4.0) tremors and many aftershocks.  More robust earthquakes in and around the vicinity of NYC were recorded in 1884 (~5.0-5.5), 1783 (~4.9), and 1737 (~5.2). More recently, the August 1884 magnitude ~5.0 NYC earthquake produced 4 m long by 3 m deep soil openings, cracked buildings and chimneys in Brooklyn . Clearly, the dynamic relationship between earthquakes and movement on reactivated faults mandates assessment of the potential seismic risk for populated urban areas underlain by deeply eroded crystalline rocks.  

Dr. Merguerian will provide evidence that the NW-trending faults of NYC should be considered “active faults”.  Unequivocal post-glacial ground rupture is difficult to demonstrate in NYC where most bedrock faults are deemed to have formed at depth and then later elevated and eroded up to the surface.  Yet, the Bronx River, which formerly flowed SSW in an open valley underlain by the Inwood Marble, shows diversion away from its "pirated" marble valley by exhibiting displacement of course across the NW-trending right-lateral Mosholu fault.  South of the fault, the river now flows in a non-glaciated south-trending V-shaped gorge through more-competent gneiss and schist of the Hartland Formation. 

Image above right shows obvious offset of orange grove planted in former straight rows across the San Andreas fault in California, the result of protracted fualt creep. (Image by John W. Shelton, Geology Illustrated, 1976.)


Tuesday, 12 April 2016; 7:00 PM

Ulster County Community College
Stone Ridge, NY
Free Admission and Refreshments

9 Million Thirsty People - Supplying NYC With Catskill Water

Most of New York City and all ofLong Island are, in fact, islands surrounded by saltwater.  So how do we get enough fresh drinking water to supply over 9 million people?  New York City relies on a system of tunnels to bring fresh water from pristine reservoirs in the Catskills (Click for high resolution 1906 Board of Water Supply map of Catskill Aqueduct).  This gravity-feed tunnel system relies on the difference in elevation between the Catskills and NYC.  It passes just south of the UCC campus, under the Rondout Creek and Shawangunk ridge southward to NYC traversing through an extremely variable geological underpinning.  The water tunnels, whose alignment and engineering intricacies were dictated by regional geology, are one of the great engineering works of the Twentieth Century.  Dr. Merguerian, who has been in almost all of the NYC tunnels during his 40+ year career as a geotechnical consultant, will explain how we get our water and take us deep (over 700') under the city inside a 23'-diameter water tunnel that was excavated beneath Queens by a 300'-long tunnel boring machine.  Digital images and allied video as seen through the eyes of a geologist will bring participants underground to see the inner workings of the tunnels and the machines and people that constructed them. Bring rubber boots, just in case of a major leak. What's that noise?


Friday, 13 November 2015; 7:00 PM

Geological Society of Connecticut
Meriden, CT
Free Admission, Refreshments, and a Rub-down

Wallrocks of the Hodges Complex and Tyler Lake Granite, West Torrington, CT

This lecture focused on the bedrock stratigraphy and structure of the wallrocks and contact relationships of the mid-Ordovician (455 Ma) Hodges and younger Tyler Lake intrusives in West Torrington, CT. The lecture included the history of prospect mining, mineralogy, and research on the Hodges Nickel prospect. The related Spring 2016 field trip included many stops to best illustrate the stratigraphy and structure of the region, as mapped by the author in 1973-77 (Merguerian 1977). A link to this publication and included detailed geological maps can be found here (Plates 1 and 2 [Note: large files!]). Merguerian's other CT publications can be downloaded from: www.dukelabs.com/Publications/PubsPdf/DLPubs.html. Ample time will be spent examining and discussing separation of the subunits of the Hartland and Waramaug formations on either side of Cameron's Line, a folded Taconian plate boundary suture zone. Ductile structures and lithologies associated with Cameron's Line and contact relationships with crosscutting plutons will be examined. The trip will be an amalgam of stops from a previous NEIGC trip conducted three decades ago (Merguerian 1985d) and will include additional stops based on more recent investigations. A guidebook will be provided.


Wednesday, 14 October 2015; 8:00 PM

New York Mineralogical Club
NYC, NY
Free Admission

Geology and Mineralogy of the Second Avenue Subway, NYC, NY

The long-delayed Second Avenue Subway project in NYC has provided for a thorough three-dimensional study of the stratigraphy, structure, and metamorphism of the Hartland Formation in NYC. Site inspections and mapping over a period of 1.5 years of TBM-bored tunnels and top down ancillary station complex excavations indicate that the Hartland in this part of NYC exposes a very well-layered schistose to gneissic rock mass consisting of the assemblage muscovite-quartz-plagioclase-biotite±kyanite±staurolite±garnet with interlayers of quartz plagioclase-mica granofels, greenish amphibolite±biotite±garnet and subordinate gray quartzite±biotite±garnet. The schistose facies is lustrous and consists primarily of aligned fine- to coarse-textured muscovite and thus splits readily along the foliation and also lithologic contacts. The mica gneiss, granofels, amphibolite, and quartzite interlayers are typically massive and quite hard, contain much less mica than the schist and may not show pronounced foliation.

Superposed ductile structures are cut by brittle features including foliation joints (J1) produced parallel to the regional foliation and by steep NNE- to NE-trending (J2) joints and dip-slip faults mineralized and infilled by stilbite+calcite, by younger steep NW-trending (J3) joints and strike-slip faults (Manhattanville "125th Street" series) infilled by K-feldspar, microcrystalline epidote, quartz and pyrite, and by moderately dipping J4 joints. Gently inclined well-layered Hartland rocks in NYC cut by intersecting steep discontinuities have proven to be excellent candidates for efficient subsurface mining by TBM, traditional drill and blast techniques, and by mechanical means and methods of excavation. The Powerpoint lecture will take attendees on a virtual tour of the subsurface of NYC and show some interesting occurrences and specimens of mineral that have been discovered in the open joints and fractures.


02 May 2013; 7:00 PM

IDEAS Institute
Hofstra University, NY
Admission Free! In fact, each participant gets $5 to attend

Deep Science of Subterranean New York City

Charles Merguerian, Chair and Professor of Geology at Hofstra University for over 30 years and active consultant on subsurface geotechnical projects in New York shares his insights and investigations as he leads you through a rich video and Powerpoint lecture that will take viewers to a depth of 800 feet below the hustle and bustle and the towering heights of New York City construction. In this quiet environment produced by mechanized moles (tunnel boring machines), mechanized excavators and traditional drill and blast technology witness this exploration of the NYC tunnels and the geology exposed within them. Exposing over 1,100 million years of geological history, a subterranean landscape unfolds through the construction of utility, transportation, and water tunnels -- catapulting us forward in a very short span of the past forty years -- largely as the result of huge advances in geotechnical, metallurgical and mechanical engineering research. Experienced in all but the very first mechanized tunneling job in NYC (West-side Interceptor Tunnel in 1969), Dr. Merguerian will share his discoveries on such varied engineering constructs as the 63rd Street Subway Tunnel, the water tunnels in Brooklyn, Queens and Manhattan, the East Side Access Project, the No. 7 Line IRT tunnels and the Second Avenue Subway. Join Dr. Merguerian for this dynamic lecture and learn first-hand just how tunnels are planned and constructed for public benefit in the hard crystalline rocks of New York City and share in the unique “deep science” discoveries made during his three decades of investigations in the subterranean world of our metropolis.


Saturday, 19 May 2012; 1:30 PM

Franklin-Ogdensburg Mineral Society
Franklin Mineral Museum, Franklin, NJ
Free Admission

Mines and Minerals of Connecticut

Decades ago when minerals were still abundant and access to famous localities was if not allowed at least tolerated, travels into the wilds of Connecticut always resulted in smiles on the faces of mineral collectors and geologists. Though almost 100 known localities exist in the Nutmeg State, few are available to collectors today. Merguerian began his geological investigations in West Torrington, Connecticut during his Masters research in 1972 and continues to this very day. In an effort to better understand the geology of the crystalline highlands of western Connecticut the distribution of ore deposits can be used as a tool to better understand large-scale ancient tectonic settings as well as localized geological events. Come see and hear the details of Dr. Merguerian’s travels and investigations in Connecticut and documentation of his discoveries in the form of digital images, maps and integrated video. As always, bring ripe fruit and a limber throwing arm!


Wednesday, 09 May 2012; 6:45 PM

New York Mineralogical Club
NYC, NY
Free Admission

Geology and Mineralogy of the Inwood Marble, Northern Manhattan, NYC, NY

Field studies of the Inwood Marble in the type locality together with field data from nearby engineering construction projects have afforded fresh sampling and petrographic study of the Inwood in NYC. Consisting predominately of recrystallized dolomite and subordinate calcite marble the Inwood Marble was used for quarrying and mineral collecting yet the bland carbonate mineralogy and paucity of indicator minerals impeded the use of the Inwood Marble as a geological indicator of metamorphic conditions during tectonism in NYC. Image = Whitish tremolite pseudomorphic after diopside.

Studies of the Inwood Marble formation come from field mapping conducted on all of the natural exposures in the Inwood section of Manhattan starting in the mid-1970s, subsurface data collected during a mapping program in the East River section of NYC Water Tunnel #3 in 1985-86, and core examination combined with detailed mapping of a utility tunnel during 2009. In addition to collections made during field mapping, samples were studied from Isham Park, Inwood Hill Park and from other natural exposures in northern Manhattan and The Bronx. Interestingly, Inwood metacarbonate rocks of northern Manhattan contain minerals that are consistent with metamorphic facies estimates from the kyanite-staurolite-garnet-bearing pelitic rocks surrounding the marble of NYC. Late tremolite pseudomorphic after diopside (shown below) suggests that retrograde metamorphism has affected the rock mass in the replacement of diopside, a higher grade phase. As this is a work in progress, we continue our efforts to better refine this preliminary study. Come see and hear the details of Dr. Merguerian’s investigations and documentation of his new discoveries in the form of digital images, maps and integrated video. As always, bring ripe fruit and a limber throwing arm!


Tuesday, 21 February 2012; 7:30 PM

Dirt Talk
Sycamore Bar and Flower Shop Brooklyn, NY
Admission Fee

Geology and Soils of New York City

Geological discoveries in the fields of hardrock and glacialgeology have been made during the past four decades of research, the result of continuous mapping and laboratory research on collected samples from New York City. Indeed, access to surface and subsurface exposures has produced a treasure trove of geological information that alters our view of the Paleozoic tectonic development of this portion of the Appalachian mountain chain as well as the Pleistocene glacial history of New York City and vicinity. Holocene (post-glacial) alteration of the in-situ and transported glacial regolith has produced our modern soils. With ample overview of the regional geology, the talk will zero in on the geology and soils of Brooklyn. Come see and hear the details of Dr. Merguerian’s investigations and documentation of his new discoveries in the form of digital images, maps and integrated video.


Saturday, 21 May 2011; 2:30 PM

Franklin Mineral Society
Franklin, NJ
Free Admission and Refreshments
Bring Ripe Fruit for Throwing!

Geological Wonders of the World Trade Center Site

Join Charles Merguerian of Hofstra’s Geology Department and Duke Geological Laboratory (shown here on-site with field assistant H. Manne) for a lecture on the unique geological discoveries made during excavation for the World Trade Center site in southern Manhattan.  Visits to the site during blasting and construction and study of the mapping and collected samples has allowed a new interpretation to emerge concerning the bedrock geological development of NYC.  In addition, new insights into the timing and effects of glaciation including the development of giant plunge pools within the top of rock have been discovered.  Come see and hear how the new construction effort in Manhattan has offered a treasure trove of new geological information that has changed the way we interpret the geology of New York City and vicinity.


23 November 2010

American Society of Civil Engineers

20th Annual Mueser Rutledge Technical Lecture

CUNY Graduate Center

NYC, NY

Geological Constraints on TBM Penetration on Hard Rock Tunneling, NYC

Principal Charles Merguerian of Duke Geological Laboratory and Professor of Hofstra’s Geology Department offered a lecture detailing the intrinsic and episodic geological features that constrain TBM penetration and utilization in hard rock crystalline terrains as found in New York City.  Drawing from his personal involvement and using case histories from the NYC area including the 63rd Street Tunnel, Brooklyn Tunnel, Queens Tunnel, Con Edison Steam Tunnel,Manhattan Water Tunnel, Croton Tunnel, No 7 Line Extension Tunnel, and East Side Access, Merguerian explained how the combined effects of lithology, metamorphism, and geological structure have controlled efficient tunneling.  Simple geological investigations during the pre-bid stage are the most cost-effective means to mitigate losses encountered during TBM tunneling. Promotions offering free admission and refreshments filled the audience.

https://www.ascemetsection.org/news-events/event-calendar/eventdetail/393/-/20th-mueser-rutledge-technical-lecture

https://www.ascemetsection.org/news-events/section-news/g-i-chapter/520-20th-annual-mueser-rutledge-technical-lecture


12 May 2010

New York Mineralogical Club

People's Center - American Museum of Natural History

NYC, NY

The World Trade Center Site: New Perspectives on New York City Geology

Milking the lecture circuit big-time, Dukelabs own Dr. Charles Merguerian of Hofstra University’s Geology Department presented a lecture on the unique geological discoveries made since 2004 and during recent excavations at the World Trade Center site. Visits to the site during blasting and construction combined with the study of the mapped and collected samples have afforded a new interpretation to emerge concerning the bedrock geological development of Manhattan. In addition, new insights into the timing and effects of glaciation including the development of giant 100' deep plunge pools within the top of rock have been discovered. Participants who stayed awake and alert (thanks Mom) heard how the new construction effort in Manhattan offered a treasure trove of new geological information that changed the way we interpret the bedrock development and glacial geology of New York City and vicinity. Follow this link to Merguerian's 2008 History Channel appearance on Super City: New York.


17 April 2010

Garvies Point Museum

Glen Cove, NY

Geology of Subsurface Mega-Construction Projects, New York City, NY

Constructing new and the repair of existing water tunnels, subway tunnels and buildings all involve digging into what lies beneath New York City (NYC). Having spent many years specializing in investigating the surface and subsurface geology of NYC, Dr. Merguerian’s popular and oft-repeated lecture concentrated on the geologic controls on the utilization of tunnel-boring machines. His research has paved the way for more efficient tunneling in crystalline terrains and has opened the field for municipal mega-construction projects, including water, utility and transportation tunnels. His lecture focused on exciting new tunneling contracts in NYC including the Third NYC Water Tunnel, the Second Avenue Subway, the East Side Access project, and the #7 Line IRT Extension project.


15 March 2010

Geological Society of America, NE Section

Baltimore, MD

Tectonics Implications of Bedrock Studies at the World Trade Center Site, New York City

Dr. Merguerian presented the distinctions he has found between disparate metamorphic rock formations at the World Trade Center site that have afforded new interpretations on the tectonic history and former depth of formation of NYC bedrock. A packed house in Baltimore was treated to full exposure to the field occurrence and petrographic differences between the Walloomsac, Hartland, and Manhattan formations which were formerly lumped together as the Manhattan Schist. Investigations at the WTC site have indicated that an equilibrium metamorphic mineral assemblage (kyanite-garnet-staurolite) indicates a minimum depth of burial of 24 km (~14 miles) below the earth's present surface.


19 November 2009; 6:00 PM

IDEAS Institute

Hofstra University, NY

The World Trade Center Site: New Perspectives on New York City Geology

Charles Merguerian of Hofstra’s Geology Department presented an IDEAS lecture on the unique geological discoveries made during recent excavations of the World Trade Center site. His visits to the site since 2004 during blasting and construction as well as the study of the mapped and collected samples have allowed a new interpretation to emerge concerning the bedrock geological development of Manhattan. In addition, new insights into the timing and effects of glaciation including the development of giant 100' deep plunge pools within the top of rock have been discovered. Participants who for some strange reason managed to stay interested heard how the construction effort in southern Manhattan has offered a treasure trove of new geological information that has changed the way we interpret the bedrock development and glacial geologic sculpting of New York City and vicinity. Follow this link to Merguerian's 2008 National Geographic appearance on Naked Science - Birth of America.


16 November 2009

Suffolk Gem and Mineral Club

Bayshore Library, NY

Geology of the World Trade Center Site

Rising out of the ashes of the devastation at the World Trade Center site in Manhattan, geologist Charles Merguerian presented a lecture to the enthusiastic Suffolk Gem and Mineral Club on new interpretations of the bedrock geology of NYC based on mineralogical discoveries in rocks at the WTC site. In addition to the textural evidence for shearing and folding of two rock formations (the Hartland and Walloomsac formations) the petrographic data indicates an assemblage kyanite-staurolite-garnet that has fixed a minimum depth of metamorphic recrystallization of the exposed bedrock at 24 km (~14 miles) below the earth's present surface. Follow this link to Merguerian's 2008 National Geographic appearance on Naked Science - Birth of America.


02 June 2009

W.T. Clarke High School Science Fair

Westbury, NY

Mega-Construction Projects in Subsurface New York City

Intrepid Hofstra University Professor and Dukelabs geologist Charles Merguerian spoke to junior and senior-level high school science students on the scope of his research concerning the utilization of tunnel-boring machines in the subsurface of NYC. The talk included information about the third NYC Water Tunnel, the Second Avenue Subway, the East Side Access project, and the #7 Line IRT Extension project.


17 April 2009

Natural Science Research Symposium

Hofstra University, NY

The Southern Termination of the Yonkers Gneiss in Van Cortlandt Park, New York City, NY

Learning early how to milk the presentations, Dukelabs geologist J. Mickey Merguerian presented the work he had conducted with Dr.Charles Merguerian at the 2009 Hofstra University Natural Science Research Symposium. His Powerpoint talk provided a new interpretation of the Mosholu fault and the distribution of the Yonkers and Fordham gneisses near Van Cortlandt Park in NYC. This work has changed the New York State geological map by allowing for an extension of the Yonkers Gneiss southward from its previous mapped termination in The Bronx (see map and joint paper link below).


28 March 2009

Long Island Geologists

Stony Brook, NY

Redefining the southern terminus of the intrusive contact between the Yonkers and Fordham gneiss in Van Cortlandt Park, New York City, NY

Dr. Merguerian coauthored a joint paper along with Daniel Vellone, Doug Isler, and J. Mickey Merguerian at the Long Island Geologists conference focusing on their work in the Croton water tunnel - a part of the NYC aqueduct system. The Merguerians' study of the structure, lithology, and petrography of the Proterozoic rocks exposed in the tunnel along with the detailed mapping done by Vellone and Isler has helped provide a new interpretation of the Mosholu fault and the distribution of the Yonkers and Fordham gneisses near Van Cortlandt Park in NYC. This work has changed the New York State geological map by allowing for an extension of the Yonkers gneiss southward from its previous mapped termination in The Bronx.


07 March 2009

New York Mineralogical Club Show

Holiday Inn at 57th Street

NYC, NY

Geologic Controls on Mega-Construction Projects in Subsurface New York City

Undaunted Dukelabs geologist Charles Merguerian was guest speaker at the biannual mineral show of the New York Mineralogical Club. He spoke on conditions of anonymity about the utilization of tunnel-boring machines in the subsurface of NYC. His lecture focused on exciting new construction contracts in NYC including the South Ferry Terminal, the Third NYC Water Tunnel, the Second Avenue Subway, the East Side Access project, and the #7 Line IRT Extension project.


17 October 2008

Geological Association of New Jersey

Montclair, NJ

Geological Controls on Means and Methods of Hard Rock Excavation, New York City, NY

Dr. Merguerian was the invited keynote speaker at the GANJ conference held at Montclair State University. By explaining the differences in rock types and their inherent mechanical strengths, Dr. Merguerian discussed the various choices available to contractors (TBM vs. mechanical means) for efficient rock excavation in NYC. An accompanying conference paper can be found here.


12 September 2008

Deep Foundations Institute

Berlin, CT

Bedrock and Glacial Geology of New York City

Dr. Merguerian was an invited lecturer at the DFI conference this year which was devoted to better understanding the underpinnings of NYC geology. His lecture focused on the constitution of the various soil types and bedrock of New York City in an effort to allow designers and contractors to better understand their excavation and support choices in the in-situ and transported regolith and bedrock units that constitute the region. Follow this link to Merguerian's 2008 National Geographic appearance on Naked Science - Birth of America.


08 May 2008

ASCE Met Section Geotechnical Group - Manhattan on the Rocks Seminar

New York City, NY

Evaluating Geological Controls on Hard Rock Excavation, New York City, NY

Please join the ASCE Met Section Geotechnical Group and others from the national geotechnical community at this one-day Specialty Seminar on engineering geology, rock engineering, and construction. Invited speakers will include Professor Charles Merguerian (Hofstra University), Chris Snee (SneeGeoconsult), Vincent Tirolo (Slattery Skanska), Duncan Wyllie (Wyllie and Norrish), David Winslow (GZA GeoEnvironmental), and Roy E. Hunt (Consultant).

https://www.ascemetsection.org/news-events/event-calendar/eventdetail/114/-/manhattan-on-the-rocks-quot-one-day-seminar


08 April 2008

American Society of Civil Engineers

NYC, NY

Evaluating Geological Controls on Hard Rock Excavation, New York City, NY

Dr. Merguerian was an invited lecturer at the Manhattan On-The-Rocks conference of the ASCE Metropolitan Section where he discussed the means and methods of hard rock excavation in the city of New York. His one-hour discussion focused on the geological evolution of New York City and how careful study of published books and maps by professional geologists and engineers can lay the foundation for cost-saving pre-bid investigations. Such academic studies are best backed up by the geotechnical study of borings (fractures, rock types, rock fabrics) as well as density studies and petrographic analysis. Such allied investigations better predict the subsurface conditions that allow contractors and designers to plan for cost-effective excavation endeavors. A related published paper can be found here.


12 March 2008

Geology Department

Brooklyn College, NY

Mega-Construction Projects in Subsurface New York City

Dr. Merguerian’s academic lecture concentrated on the history of tunnel boring machines and the geologic controls on machine excavation in the subsurface of NYC. His lecture focused on exciting new tunneling contracts in NYC including the Queens Water Tunnel, the Con Edison Steam Tunnel, the Manhattan Water Tunnel, the East Side Access project, the Second Avenue Subway, the IRT #7 Line Extension, the South Ferry Terminal project, and the proposed LI Cross Sound Link Tunnel. Click here for an ear-pleasing, hum-filled video of a 2007 Hofstra University IDEAS lecture on this topic.


25 February 2008

Suffolk Gem and Mineral Club

East Islip Library, NY

Geologic Controls on Mega-Construction Projects in Subsurface New York City

Constructing new and the repair of existing water tunnels, subway tunnels and buildings all involve digging into what lies beneath New York City (NYC). Having spent many years specializing in investigating the surface and subsurface geology of NYC, Dr. Merguerian’s lecture concentrated on geologic controls on the utilization of tunnel-boring machines in the subsurface of NYC.


16 November 2007

Natural Science Research Symposium

Hofstra University, NY

Geology and Tectonics of the World Trade Center

Dr. Merguerian presented the preliminary results of his new research on the structural geology of the World Trade Center site in southern Manhattan at the 4th Annual Division of Natural Sciences Research Day at Hofstra University. Speaking in front of a packed house of students, faculty, and staff, his Powerpoint lecture described the techniques of gathering geological information in an active construction zone, showed images of rock outcrops exposed at that time in the west bathtub area of the site and presented some important new ideas concerning the distribution and structure of the various rock types of the Walloomsac and Hartland formations.


08 November 2007

IDEAS Institute

Hofstra University, NY

Geologic Controls on Mega-Construction Projects in Subsurface New York City

Constructing new and the repair of existing water tunnels, subway tunnels and buildings all involve digging into what lies beneath New York City (NYC). Having spent many years specializing in investigating the surface and subsurface geology of NYC, Dr. Merguerian’s lecture concentrated on geologic controls on the utilization of tunnel-boring machines in the subsurface of NYC. His research has paved the way for more efficient tunneling in crystalline terrains and has opened the field for municipal mega-construction projects, including water, utility and transportation tunnels. His lecture focused on exciting new tunneling contracts in NYC including the third NYC Water Tunnel, the Second Avenue Subway, the East Side Access project, and the #7 Line IRT Extension project. Click here for an ear-pleasing, hum-filled video of this 2007 Hofstra University IDEAS lecture.


10 October 2007

New York Mineralogical Club

People's Center - American Museum of Natural History

NYC, NY

Geological Wonders of Yellowstone National Park, Wyoming

Our courageous Dukelabs geologist Charles Merguerian spoke to the New York Mineralogical Club on the brewing danger of a volcanic eruption at Yellowstone National Park - home of Yogi Bear and BooBoo! His video-enhanced lecture embraced the regional geology of the area including the Grand Teton range, the 1925 Gros Ventre rock slide, hot spot tracks of the American west and the natural thermal beauty of Yellowstone. Three eruptive events were discussed in the context of modern studies of the Yellowstone caldera. These include the 640 Ka – Lava Creek Caldera, the 1.3 Ma – Mesa Falls Caldera, and the 2.1 Ma – Huckleberry Ridge Caldera. Do the math! Cleary, we are overdue for a major eruption at this important landmark. The lecture was based on a Hofstra University field course conducted in 2006 for which an online guide is available for download.


14 April 2007

Long Island Geologists

Stony Brook, NY

Newly Discovered Serpentinite Bodies Associated with the St. Nicholas Thrust Zone in Northern Manhattan

Merguerian spoke at the Long Island Geologists conference on the tectonic significance of slivers of serpentinite found with coauthor Cheryl Moss at a building excavation at 165th Street and Amsterdam Avenue in NYC. His powerpoint lecture shared images and thin sections of the core samples used in their study. Their joint paper is available here. An oblique regional view of the distribution of all serpentinites known in NYC and vicinity has helped outline the Taconian suture zone in NYC. Dr. Merguerian coauthored two other papers (dubbed the Merguerian Power Hour by accomplice Daniel Vellone) at the same conference.


12 April 2007

Jones Beach Conservation Society

Jones Beach, NY

New York City Earthquakes - Fact or Fiction

Dr. Merguerian spoke at a packed house (five people showed up - but only two paid!) at the Jones Beach Conservation Society in New York on the possibility of a damaging earthquake striking NYC. Merguerian's research has provided the first evidence for surface deformation in response to faulting in NYC suggesting that ground-breaking rupture and seismic activity can not and certainly should not be ruled out for this region. This new data identifies a potential failure surface along which earthquake energy could be released - important because large magnitude earthquakes struck NYC in 1737, 1783, and 1884. Do the math - we're about due!


03 March 2007

New York Mineralogical Club Show

Holiday Inn at 57th Street

NYC, NY

Geological Wonders of Yellowstone National Park, Wyoming

Fearless Dukelabs geologist Charles Merguerian was the guest speaker at the biannual mineral show of the New York Mineralogical Club on the brewing danger of a volcanic eruption at Yellowstone National Park - home of Yogi Bear and BooBoo. His video-enhanced lecture embraced the regional geology of the area including the Grand Teton range, the 1925 Gros Ventre rock slide, hot spot tracks of the American west and the beauty of Yellowstone. Three eruptive events were discussed in the context of modern studies of the Yellowstone caldera. These include the 640 Ka – Lava Creek Caldera, the 1.3 Ma – Mesa Falls Caldera, and the 2.1 Ma – Huckleberry Ridge Caldera. Cleary, we are overdue for a major eruption at this important landmark. The lecture was based on a Hofstra University field course conducted in 2006 for which an online guide is available.


02 March 2007

Asian American/Asian Research Institute

NYC, NY

New York City Earthquakes - Fact or Fiction

Dr. Merguerian spoke at the Asian American/Asian Research Institute in New York City on the possibility of a damaging earthquake striking NYC. Merguerian's research provides the first evidence for surface deformation in response to faulting in NYC suggesting that ground-breaking rupture and seismic activity can not and certainly should not be ruled out for this region. Because large magnitude earthquakes have struck NYC in 1737, 1783, and 1884, this new data identifies a potential failure surface along which earthquake energy could be released. Given the population, cultural development, infrastructure, and financial investment concentrated in New York City, the specter of a massive earthquake must be considered in revising existing building code designs and emergency preparedness procedures. Unfortunately, despite the scientific community’s pleas for action, severely limited emergency planning exists at the present time. Clearly, this should be changed as pre-emptive urban seismic planning is an absolute necessity in New York City. His AAARI Powerpoint lecture is available online at this link.


27 October 2006

Natural Science Research Symposium

Hofstra University, NY

New Geological Discoveries in Southern Manhattan

Dr. Merguerian spoke on his field work and analysis of southern New York City. Drill core examined from over two dozen separate locations south of Canal Street in Manhattan over the past three years have been fruitful in affording surface mapping from areas of natural exposures north of 59th Street. In this southern area of rare surface exposure, drill core and other forms of subsurface information prevail. They indicate that the region is underlain by internally sheared units of the Walloomsac, Manhattan, and Hartland formations together with sheared slivers of serpentinite and foliated granitoid rock.

This work supports the contention that the venerable Manhattan Schist formation actually consists of three schistose units, now mapped as the Hartland, Manhattan, and Walloomsac formations. These coeval lithostratigraphic units have different paleogeographic origins. In addition, a newly discovered belt of schistose and calcareous rocks appears south of Canal Street in NYC in two separate along strike areas near the World Trade Center site and also reappears across town near the Brooklyn Bridge. Exposed as a result of new construction efforts, the duplication of hitherto unrecognized Walloomsac rocks on either side of southern Manhattan suggests repetition by folding and/or faulting.

A paper on ths topic presented at the 13th Annual Meeting of the Long Island Geologists is available for download here.


26 September 2006

Department of Earth and Planetary Sciences

American Museum of Natural History, NY

New Insights into the Structural Geology of NYC

A luncheon presentation at the Mineral Sciences Department of the American Museum of Natural History by Dr. Charles Merguerian focused on new discoveries from construction sites in NYC. Recent work indicates that in southern Manhattan duplication of a continuous belt of sheared Hartland schist and granofels and Walloomsac graphitic schist and calc-silicate rocks occurs in a tract where aluminous rocks of the Manhattan formation were expected. Based on new data concerning the distribution of serpentinites and a wealth of existing data from historic construction efforts, new insights and interpretations of the structural geology and tectonics of the region were discussed. A highly spirited question and answer period delighted all attendees and resulted in tar and feathering of the featured speaker. A 1994 summary paper on the structural geology of NYC can be found here.


09 May 2006

Stamford Mineral Society

Stamford, CT

Mega-Construction Projects in New York City

Dr. Merguerian presented an animated lecture at the annual dinner of the Stamford Mineralogical Society - animated by people exiting hastily from the onset. His talk described new tunneling contracts in the City of New York including elements of the Third NYC Water Tunnel, the Second Avenue Subway, the East Side Access project, and the #7 Line Extension. He discussed new discoveries in deep tunnels that have changed our views of the geology of New York City and show examples of minerals found during mapping of the Queens Tunnel. In the past decade, Merguerian's research has strayed to include geologic mapping and analysis of tunnels bored by tunnel boring machines (TBMs). This work has verified geological relationships established by surface mapping and has provided new insights into the relationships between TBM penetration rates, geological structure, and rock type in the New York City area. Geotechnical research, along with engineering, have evolved efficient methods in constructing water, utility, and transportation tunnels in urban areas.


22 April 2006

Long Island Geologists

Stony Brook, NY

Structural Implications of Walloomsac and Hartland Rocks Displayed by Borings in Southern Manhattan

A joint paper presented by Charles Merguerian (speaker) and Cheryl Moss of Mueser-Rutledge Consulting Engineers focused on a new discovery of a continuous belt of Walloomsac graphitic schist and calc-silicate rocks in an area of Manhattan where aluminous rocks of the Hartland formation were expected. Always on the look-out for the unusual, Merguerian and coauthor Moss have spent countless afternoons examining drill core and construction excavations and have found the presence of unusual calcareous and graphitic rocks based on their investigations. This paper was presented at the 13th Annual Meeting of the Long Island Geologists and is available for download here.


22 April 2006

Long Island Geologists

Stony Brook, NY

Evidence for Multiple Glacial Advances and Ice Loading From a Buried Valley in Southern Manhattan

Cheryl Moss (speaker) and Charles Merguerian also presented a paper on a newly discovered NW-trending buried valley in southern Manhattan that holds evidence for multiple glaciations. Always on the look-out for the unusual, Cheryl Moss of Mueser-Rutledge Consulting Engineers and coauthor Charles Merguerian of Hofstra University have found serpentine-pebble basal till overlain by additional glacial drift units. They will report on their findings and the support for the multi-glacier hypothesis for New York and vicinity. Their joint paper can be found here.


22 April 2006

Long Island Geologists

Stony Brook, NY

Orchard Beach Ultramafic Erratics – Where Are They From?

Drs. Nehru E. Cherukupalli (Speaker) and Charles Merguerian (Listener) presented the preliminary results of their petrographic and geochemical analysis of three separate and seemingly unique ultramafic erratics found on striated bedrock at Orchard Beach, NY. Their joint paper is available here.


16 April 2005

Long Island Geologists

Stony Brook, NY

Newly Discovered Ophiolite Scrap in the Hartland Formation of Midtown Manhattan

Dr. Charles Merguerian delivered yet another joint paper at the Twelfth Annual Meeting of the Long Island Geologists on a new discovery of a mass of sheared serpentinite in midtown Manhattan. Always on the look-out for the unusual, Merguerian and coauthor Cheryl Moss of Mueser-Rutledge Consulting Engineers spent four afternoons examining the geology and contact relationships of a small, highly deformed and elongated serpentinite body that has been uncovered in a deep building construction site at 43rd Street and Sixth Avenue in midtown Manhattan.

Serpentinites are black to greenish-black, fine-textured rocks containing serpentine group minerals including chrysotile, lizardite, and antigorite together with amphiboles, chlorite, brucite, magnesite, talc, calcite, and relict chromite, magnetite, olivine and pyroxene. Similar to the famous Staten Island and Hoboken NJ serpentinites, many scattered bodies of serpentine rock have been encountered in the subsurface of NYC over the years as a result of construction.

In addition to the legendary mass known from Manhattan between 54th and 62nd Streets along the shore and 10th Avenue (Cozzens 1843; Gratacap 1887), a few bodies were penetrated by borings in the geotechnical investigation stages of the #7 Line extension in Manhattan and in transit tunnels excavated beneath the Hudson River. Their joint paper makes a bold comparison between Appalachian serpentinites and those of the Coast Ranges of California, suggesting that they originated in a similar tectonic setting.


16 April 2005

Long Island Geologists

Stony Brook, NY

Loading Patterns in Varved Pleistocene Sediment in the NYC area

Another joint paper with Merguerian, this one presented by Cheryl Moss of Mueser-Rutledge Consulting Engineers highlighted their work on the loading of Pleistocene lake strata. The data shows a systematic geographical distribution pattern that may indicate where younger glacial ice once over-rode pre-deposited lake strata. Although preliminary at the present time, such data may prove beneficial in establishing the thickness, scope, and extent of the Woodfordian glacier and help to support the multi-glacier hypothesis of Sanders and Merguerian (1998).

Their joint paper on loading patterns in NYC can be found here.


16 April 2005

Long Island Geologists

Stony Brook, NY

Post-Alleghenian Deformation of the Shawangunk Ridge in NY and NJ

Based on a research trip with Hofstra University structural geology students led late last year (2004), new field data supports the idea that deformation of the Shawangunk ridge in NY and NJ may be of Mesozoic age. At High Point State Park in NJ, the Shawangunk strata is overturned and changes in strike away from typical non-Appalachian trends. The geometry of the structures forces the conclusion that deformation was the result of right lateral shear, perhaps resulting from an early stage of opening of the Atlantic ocean basin. In a joint paper at the Twelfth Annual Meeting of the Long Island Geologists, Hofstra University students Jeff Wills, John Bigolski, and Charles Merguerian share some new ideas on the age and style of Appalachian deformation saw the light of day in poster form. Their joint paper can be found here.


08 April 2005

Colonial Academic Conference

Hofstra University, NY

Applications of Geology to Mega-Construction Projects in New York City

Merguerian delivered a keynote after-dinner candle-lit talk to research students attending the Colonial Academic Conference at Hofstra University in April 2005. His lecture was based on research which has concentrated on geologic mapping of tunnels bored by tunnel boring machines (TBMs) which has verified geological relationships established by surface mapping and has provided important new insights into the relationships between TBM penetration rates, geological structure, and rock type in the New York City area.


05 March 2005

New York Mineralogical Club Show

People's Center, American Museum of Natural History

NYC, NY

Geology of the Painted Desert and Petrified Forest, AZ

Awed by a visit to the region in July 2004 with his assistant Mickey, the elder Merguerian spoke at the New York Mineralogical Club Mineral Show about the landscape formation and geology of the Painted Desert and Petrified Forest region of northeastern Arizona. In the 1800s, U.S. Army map makers and surveyors described the "Painted Desert" and its trees turned to stone. Here, the geologic history of the region peaks during Mesozoic time - an era when dinosaurs ruled the earth. After growing to great height and thickness, the tall trees fell and were washed by swollen streams into a broad floodplain. There they were covered by silt, mud, and volcanic ash, and this blanket of deposits cut off oxygen and slowed the logs decay. Gradually, silica-bearing ground waters seeped through the logs and encased the original woody tissue with silica. Slowly the process continued, the silica crystallized into quartz, and the logs were preserved as dense, multi-hued petrified wood. Images of these magnificent petrified logs and video clips of the region adorned the Powerpoint presentation on this unique area. A 2010 geological field guide to northern Arizona can be found here.


05 November 2004

New York Academy of Sciences

NYC, NY

Inquiry Teaching of Geology in New York City Parks

Dr. Merguerian spoke to the Education Section of the New York Academy of Sciences to end the 2004 lecture circuit on the subject of utilizing New York City parks to teach inquiry based geological education. His lecture focused on the bedrock and glacial features exposed in Central, Inwood, and Riverside parks in Manhattan, the New York Botanical Garden, and some smaller parks in The Bronx that best illustrate the inquiry method of teaching geology in New York City. Participants, many of whom were tired from teaching at their day job, brought ripe fruits and vegetables and limber throwing arms for some big-time lecture fun.


21 October 2004

IDEAS Institute

Hofstra University, NY

12 Million Thirsty People:  Supplying New York City and Long Island with Fresh Water

Most of New York City and all of Long Island are, in fact, islands surrounded by salt water. So how do we get enough fresh drinking water to supply 12 million thirsty people and their dehydrated pets? Speaking for the IDEAS Institute Lectures Series at Hofstra University, Dr. Merguerian diagrammed how Long Island sits above trillions of gallons of fresh groundwater that is pumped to the surface for drinking water and how, by contrast, New York City relies on a system of gravity-feed pressure tunnels to bring fresh water from reservoirs over a hundred miles away in the Catskills. These huge water tunnels and their distribution systems constitute the greatest engineering work of our twentieth century (and let's face it - what a century it was!). Participants (thanks Mabel, for showing up) were treated to a video-laced Powerpoint presentation that took them deep under the city inside a huge water tunnel constructed beneath Queens, Brooklyn and now in Manhattan. Follow this link to a supplementary handout on the History and Construction of the NYC Water Supply.


15 October 2004

Natural Science Research Symposium

Hofstra University, NY

The Narrows Flood - A Catastrophic Glacial Meltwater Breach of the Narrows Channel, NYC

Geotechnical investigations specific to the Narrows have provided the tantalizing interpretation that an episodic breach took place through the Harbor Hill moraine which drained northern meltwater lakes and eroded the Narrows channel. Subsurface information compiled from multiple sources indicates that two tills, outwash fans, and varved lake strata form a continuous blanket of regolith in the NY Harbor area and support a multi-glacier hypothesis for the region. Varved lake clays provide evidence that the Harbor Hill moraine acted as a dam, impounding glacial lakes in the Hudson Valley. In a brief cameo appearance (10 minutes), Professor Merguerian spoke at the Divisional Natural Sciences Research Day at Hofstra University to explain, to a small but obviously stunned audience, how such an event could have redirected the flow of the ancestral Hudson River across the Upper New York Bay into its modern course. Follow this link to a 2003 paper on this subject.


08 September 2004

New York Mineralogical Club

People's Center, American Museum of Natural History

NYC, NY

Geology of California and the Mother Lode Gold Belt

Dr. Charles Merguerian of Hofstra University of Duke Geological Laboratories spoke to the New York Mineralogical Club at the Museum of Natural History. Based on his experience mapping in the foothills gold belt of the Sierra Nevada, Merguerian described a west to east transect view of the geology of the state and then focused on the geology and history of the Mother Lode gold belt. With first-hand knowledge and an extensive line of bull as a composite resource, his video-enhanced Powerpoint lecture featured images of many crystalline gold specimens found in the area of the Mother Lode. A field guide to the region can be found here.

This link will bring you to guidebooks and papers on the geology of California.


17 April 2004

Long Island Geologists

Stony Brook, NY

Geology of Central Park - From Rocks to Ice

Charles Merguerian spoke about the joint research project in Central Park conducted with Dukelabs advance scout Mickey in late 2003. New lithologic mapping has redefined the extent of aluminous rocks mapped as Hartland formation throughout Central Park. Their field guide covers the south part of the park - the area most visited by travelers and tourists. They also conducted a trip on 26 June 2004 for the Long Island Geologists. Their fully extended abstract and field guide can be found here.


25 March 2004

Geological Society of America, NE Section

Tysons Corner, VA

Brittle Fault Chronology of New York City

Hofstra University Professor and Dukelabs director Charles Merguerian discussed the chronology of the brittle faults of New York City, pointing to evidence of neotectonic activity along NNW and NW-trending faults and their bearing on the potential for intraplate earthquakes in NYC. Follow this link to a 1994 ABC World of Discovery documentary on NYC faults and earthquakes.


21 February 2004

New York State Museum

Albany, NY

Minerals of the Queens Tunnel

Our geologist and talkative lecturer Charles Merguerian hoofed it to Albany with able assistant Mickey Merguerian to speak on one of his favorite topics - "The Minerals of the Queens Tunnel". Along NNE and NNW trending faults in New York City, pulses of low-temperature mineralization left their trace in the form of beautifully grown zeolites, calcite, quartz, and pyrite. Participants ooohed and aaahed at the many crystal specimens shown. This link brings you face to face with a gallery of many of the specimens found during his mapping.

This link will bring you to some cool images of Queens Tunnel Thin Sections.


29 December 2003

Department of Earth and Planetary Sciences

American Museum of Natural History, NY

Geology of the NYC Water Tunnel System

Dukelabs geologist and Hofstra University Professor Charles Merguerian discussed the geology of the NYC aqueduct system paying particular attention to the distribution tunnels beneath NYC. His Powerpoint talk focused on the results of over 25 years of research in the water tunnel system showing many subsurface views. The subsurface data has helped verify Merguerian's surface mapping and points to the presence of hitherto unknown rock units, ductile- and brittle faults, and volcanic rocks, never before found in NYC. A handout on the history of the NYC aqueduct system can be found here.


08 October 2003

New York Mineralogical Club

People's Center, American Museum of Natural History

NYC, NY

Geology and Scenery of the Bear Mountain Region

Dukelabs geologist and Hofstra University Professor Charles Merguerian discussed the geologic control on the scenery of the Hudson Highlands in the vicinity of Bear Mountain at the October meeting of the New York Mineralogical Club. The talk explained both the bedrock and glacial geology of the region and explained causes for mineral formation.With the direct help of Mike Hawkins and Erik Rutnik of the New York State Museum, images of minerals from classic localities were shown.

Ancient rock of over a billion year vintage decorate the Hudson Highlands in this tract of New England. The Hudson River course is emphatically controlled by the structural geology with bends in the river conforming to major cross faults. The erosive effects of glacial ice flow from two major contrasting directions (NW to SE and NE to SW) was superimposed on the prevailing geologic structure, resulting in truly spectacular scenery. Many brought vegetables in the event Merguerian screwed up. This link will bring you more about the construction of the Bear Mountain bridge.


22 June 2003

Rapid Excavation and Tunneling Conference

New Orleans, LA

Rock Mass Properties and Hard Rock TBM Penetration Rate Investigations, Queens Tunnel Complex, NYC Water Tunnel #3, Stage 2

Enduring great hardship, Merguerian traveled to New Orleans and spoke at the Rapid Excavation and Tunneling Conference in mid-June. Between visits to Bourbon Street and a local clinic, he presented a coauthored paper (Merguerian and Ozdemir, 2003) on penetration rate studies for the Queens Water Tunnel.


17 April 2003

Long Island Geologists

Stony Brook, NY

The Narrows Flood – Post-Woodfordian Meltwater Breach of the Narrows Channel, NYC

Merguerian spoke at the 10th Annual meeting of the Long Island Geologists. Showing tremendous diversity and an unfathomable ability to concoct bizarre conclusions from weak data spanning divergent branches of geology, he spoke on the subject of the Narrows Meltwater Breach and coauthored a paper on Quicktime Virtual Reality.

His Narrows Flood contribution can be found here.


01 March 2003

New York Mineralogical Club Show

Holiday Inn - 57th Street

NYC, NY

The Classic Minerals of New York City

Dukelabs geologist and Hofstra University professor Charles Merguerian spoke at the NY Mineral Club Show on the subject the Minerals of NYC. Long the focus of thorough geologic investigation and multi-level excavation, over the past 150 years NYC has yielded many spectacular mineral specimens. These specimens are sought after by collectors because such specimens are rare in crystalline terranes such as found in NYC. Much of the rock floor of NYC is covered by younger strata. Luckily, surface and subsurface rock removal as a prelude to construction of buildings and municipal systems have allowed for the preservation of minerals, typically found along faults and in pegmatite veins.

Dr. Merguerian, who has studied the geology of this region throughout his career and still promises one day to get it right, discussed the geological background for NYC mineralization, the formation of minerals from various geological environments, and described the joys of urban mineral collecting. His talk was highlighted by views of classic and new NYC mineral specimens, some of which come from the NY Mineralogical Club's collection. This link will bring you to NYC mineral heaven.


20 November 2002

Sigma Xi Lecture

C.W. Post University, NY

Geological Wonders of the Queens Tunnel

Thrilled with the prospect of being chosen to speak to Sigma Xi, Merguerian spoke on his experiences mapping the structural geology of the Queens Tunnel. His lecture focused on an absolutely thrilling three-year long research project mapping the structural geology of the Third New York City Water Tunnel in western Queens. Varying in depth from 690’ to 760’ below the surface and extending in a curved path from Maspeth northeastward to Woodside thence westward to Long Island City, the tunnel has been excavated by a 300’ long tunnel boring machine or TBM. Beginning in October 1996, the TBM bored a cylindrical 23’ diameter transect through metamorphic rocks of the Appalachian mountain chain. The five-mile long tunnel afforded a magnificent continuous exposure of the subsurface geology of western Queens, a region not touted in the Michelin travel brochures for it's natural surface exposures.

This link will bring you to some cool images of Queens Tunnel Minerals.

This link will bring you to some cooler images of Queens Tunnel Thin Sections.


17 April 2002

Long Island Geologists

Stony Brook, NY

Brittle Faults of the Queens Tunnel Complex, NYC Water Tunnel #3

Extending his streak of non-compensated appearances, Charles Merguerian spoke at the Ninth Annual Long Island Geologists Conference at Stony Brook on Saturday, 20 April 2002. His topic was on the brittle faults of the Queens Tunnel. Superimposed on the granulite facies gneisses of the Queens Tunnel Complex, are a sequence of brittle faults. Each with its unique character, orientation, and relative age, the youngest episode of brittle faulting trends NW-SE with steep dip and show predominately strike-slip offset. Correlative with the famous "125th Street fault" of New York City and parallel to many faults in the NYC area, the faults define a set of fractures along which a recent (2001) earthquake has been localized.

Hosted by our long-time friend and colleague, Dr. Gil Hanson, the conference is a mainstay for geologists and students to meet and present the results of their research on the Geology of the New York Metropolitan region. Click on the link above for past conference publications and the other fine programs organized by the LIG. An extended abstract can be found here.


22 March 2002

Geological Society of America

Springfield, MA

Rhyodacite Dikes of the Queens Tunnel Complex, NYC Water Tunnel #3

On the road again, Merguerian spoke at the 37th Annual meeting of the NE Section of the Geological Society of America on the subject of rhyodacite dikes. He discussed the scientifically startling and unforeseen discovery made during excavation of the Queens Tunnel. Exposed ~800' beneath Woodside, Queens, a suite of at least five sub-parallel red-colored rhyodacite dikes display pristine igneous textures. Although the tunnel boring machine (TBM) may have removed dikes no longer visible in the tunnel walls, the exposed dike rocks underlie a minimum of 667' between stations 109+20 and 152+40 and compose 15.4% of the tunnel perimeter rocks within that 4,320' tunnel reach. They occur as tabular, discordant bodies roughly oriented N53°W and average just under 10' in thickness.

The rhyodacites are highly porphyritic. Suspended in the red, siliceous groundmass are phenocrysts of hornblende, clinopyroxene, biotite, plagioclase, and subordinate K-feldspar. The groundmass is enriched in quartz and K-feldspar and dusted with fibrous aggregates of iron oxide - the probable result of quenching and devitrification of initial felsitic volcanic glass. Cracked and partly replaced hornblende phenocryst suspended in hyalocrystalline groundmass rich in iron oxides.

The dikes crosscut folded Proterozoic Y granulite facies rocks of the Queens Tunnel Complex with which they are genetically and temporally unrelated. The dikes are cut by a generation of steep, NNE-trending brittle faults that are cut by younger, steep NW-trending faults. The injection of a suite of rhyodacite dikes that are chemically, texturally, and temporally unrelated to their bedrock hosts, mark an anomalous geological formation that adds a new chapter to the evolution of the New York City area. The GSA abstract and a related paper can be found here.

This link will bring you to some cooler images of Queens Tunnel Thin Sections.


13 February 2002

New York Mineralogical Club

People's Center, American Museum of Natural History

NYC, NY

The Petrographic Microscope - The Field Geologist's Second Best Friend

Dukelabs Geologist Charles Merguerian spoke at a meeting of the New York Mineralogical Club. Accompanied by his field assistant, J. Mickey Merguerian, his digital talk was entitled: "The Petrographic Microscope - The Field Geologist's Second Best Friend". If carefully handled, rocks can be sliced so thin that most minerals in them become transparent to visible light. Viewed under a polarizing (petrographic) microscope, with light penetrating them from beneath, such thin sections reveal the identity and composition of minerals by exhibiting their unique optical properties. By viewing their textures and spatial relationships, the mineral paragenesis (sequence of formation) can be learned in this way. Field geology is enhanced tremendously using petrographic techniques to peer into the invisible world of internal mineral relationships.

His talk was in digital format using the most modern technology available that morning. He explained the art of thin section preparation from field collecting, to rock chip preparation, to final production of the thin section – basically a rock and glass sandwich (hold the lettuce and mayo – add the epoxy!). Rock textures unique to the igneous, metamorphic, and sedimentary rock types were examined next as an introduction to the secrets of interpreting geologic history through the magic and natural beauty of the petrographic microscope. Follow this link to the Dukelabs petrographic gallery.


12 November 2001

Geological Society of America

Boston, MA

The Queens Tunnel Complex - a Granulite Facies Orthogneiss Terrane Exposed in NYC Water Tunnel #3

Having spent the better part of three years working on the geologic mapping and analysis of the Queens Tunnel, our very own Dr. Merguerian of Hofstra University has coauthored a paper with Drs. Pamela and Patrick Brock from Queens College about the anomalous bedrock formation found in the tunnel. Based on detailed mapping by CM and joint analysis with the Brocks, they have recognized that the tunnel exposes predominately complexly deformed crystalline rocks of great age, hardness, and high metamorphic grade. Twice the age of the Hartland bedrock series that was anticipated in the subsurface of western Queens as based on existing maps, surface mapping in adjacent areas, and projections from exposed rock in the vicinity, granulite facies Fordham Gneiss is now recognized in the subsurface of western Queens. Their joint paper entitled "The Queens Tunnel Complex - a granulite facies orthogneiss terrane exposed in NYC Water Tunnel #3" was presented by Charles Merguerian at a special theme session at the 2001 Annual Meeting of the Geological Society of America. Their abstract can be found here.


21 April 2001

Long Island Geologists

Stony Brook, NY

Young Rhyodacite Dikes Found in the Queens Tunnel, beneath Woodside, Queens

Charles Merguerian and Pamela Chase Brock spoke at the Eighth Annual Long Island Geologists Conference at Stony Brook University. Hosted by our long-time friend and colleague, Dr. Gil Hanson, the conference is a mainstay for geologists to meet and present the results of their research on the Geology of the New York Metropolitan region.

Pamela Brock spoke about the petrographic, geochemical, and geochronologic data that have together proven that the rocks of the Queens Tunnel are Grenvillian in age (Brock, Brock, and Merguerian, 2001).

Merguerian spoke about mapping of the raw tunnel excavation exposed by the Queens Tunnel TBM (tunnel boring machine) and an anomalous suite of red-colored volcanic dike rocks ~700’ beneath Woodside, Queens (Merguerian, 2001). Chemical- and petrographic studies indicate that the rocks are rhyodacitic in composition (chemically between rhyolite and dacite) and exhibit textures and other characteristics typical of shallow-level (hypabyssal) volcanic rocks. Because they are now found adjacent to the high grade (granulite facies) bedrock series exhumed from depths of roughly 40 km, their presence in a depth position close to where they were initially injected forces a new view of the developmental geology of the NYC region. Rocks of this composition and structural setting have never before been reported from the New England Appalachians.


27 September 2000

Distinguished Faculty Lecture

Hofstra University, NY

Tunnel Vision - Subterranean Paradise or Name That Quake

Dr. Merguerian was chosen as the 2000 Distinguished Faculty Lecturer at Hofstra University where he explained his facscinating experiences mapping the Queens Tunnel from 1997-2000. Be sure to download an unsigned copy of his lecture text here (great for wrapping fish, blocking sunlight, shimming tables, and soaking up oil spills). A byproduct of this effort was a supplementary handout on the History and Construction of the NYC Water Supply.


19 June 2000

Queens Mineralogical Society

Flushing, NY

Geology of the Queens Tunnel

In June 2000 Merguerian spoke at the Annual Meeting of the Queens Mineralogical Society on the topic of "are there or are there not, flying saucers?" Oops, sorry Jimi. The topic was the Geology of the Queens Tunnel. In the audience at the time were Drs. Patrick and Pamela Brock whose interest and experience in granulite-grade rocks of New England led to new enlightenment and collaborative research with Dr. Merguerian on the Queens Tunnel Complex.

This link will bring you to some cool images of Queens Tunnel Minerals.

This link will bring you to some cooler images of Queens Tunnel Thin Sections.


11 June 2000

Nassau Mineralogical Club

Mineola, NY

Geology, Mines, and Minerals of Connecticut

Geologist Charles Merguerian spoke to the Nassau Mineralogical Club in early May 2000 on the topic "Geology, Mines, and Minerals of Connecticut". Having spent over twenty five years mapping the bedrock geology of western Connecticut and having developed and promoted more outlandish, baseless hypotheses per square mile than any living geologist, CM was uniquely qualified to lead this discussion. He shared tales of geology, "locality lore", mining history, obscure package store localities, and many other useful tidbits of information. Some of the kodachromes of the region's mineral specimens in his collection are shown above. This link will bring you to guidebooks on mineral collecting in Connecticut.

This link will delight you with a Connecticut Mines and Minerals slideshow.


10 March 2000

Nassau Mineralogical Club

Mineola, NY

California Gold and Gold Mining

Dukelabs geologist Charles Merguerian spoke to the Nassau Mineralogical Club meeting on the subject of California Gold and Gold Mining. Using 35mm slides he explained the bedrock geology of the California gold belt and brought images of the mines and mining techniques (both old and new) used to extract gold. The lecture was highlighted by images of actual gold specimens from the gold terrains of California that he visited while conducting field research from 1978-1981. This link will bring you to guidebooks and papers on the geology of California.

This link will delight you with a California Gold slideshow.


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