Marcellus Shale

shale basin, United States

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July 20, 2026

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The Marcellus Shale is a significant shale basin located primarily under Pennsylvania, extending into New York, Ohio, and West Virginia. Shale gas is natural gas extracted from fine-grained sedimentary rocks like shale, formed from ancient organic-rich muds buried deep underground.1

Historically, gas diffused slowly from shale, making extraction difficult. However, advancements like horizontal drilling and hydraulic fracturing (fracking) have revolutionized extraction. These techniques allow for much greater gas production from shale formations. The Marcellus Shale is estimated to hold vast reserves, potentially making the region a major natural gas supplier. Shale gas has become a substantial part of the United States' natural gas production, with projections indicating its share will continue to grow.12

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fracking
Regulation
…the case than in the Marcellus Shale, a vast and rich shale gas deposit lying mainly under Pennsylvania but also extending northeast into New York and southwest into Ohio and West Virginia—a region blanketed by the scenic Allegheny Mountains and home to consumer and environmental movements that were well established…
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…the case than in the Marcellus Shale, a vast and rich shale gas deposit lying mainly under Pennsylvania but also extending northeast into New York and southwest into Ohio and West Virginia—a region blanketed by the scenic Allegheny Mountains and home to consumer and environmental movements that were well established…
Read More

natural gas
North America
Its largest gas field, the Marcellus Shale, may have up to 14 tcm (500 tcf) according to some estimates. Spanning Pennsylvania, Ohio, West Virginia, New York, and small parts of neighbouring states and producing more than 80.3 bcm (2,836 bcf) a year, this field is the largest source of natural…
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Its largest gas field, the Marcellus Shale, may have up to 14 tcm (500 tcf) according to some estimates. Spanning Pennsylvania, Ohio, West Virginia, New York, and small parts of neighbouring states and producing more than 80.3 bcm (2,836 bcf) a year, this field is the largest source of natural…
Read More

shale gas
Shale gas resources of the United States
…the United States is the Marcellus Shale, lying under most of Pennsylvania but also extending northeast into New York and southwest into Ohio and West Virginia. According to industry officials and geologists, the Marcellus has reserves so rich that it promises to turn Pennsylvania and its neighbouring states into the…
Read More
…the United States is the Marcellus Shale, lying under most of Pennsylvania but also extending northeast into New York and southwest into Ohio and West Virginia. According to industry officials and geologists, the Marcellus has reserves so rich that it promises to turn Pennsylvania and its neighbouring states into the…
Read More