From crucible to graben in 2.3 Ma: A high-resolution geochronological study of porphyry life cycles, boyongan-bayugo copper-gold deposits, Philippines

David P. Braxton, David R. Cooke, Jim Dunlap, Marc Norman, Peter W Reiners, Holly Stein, Patrick Waters

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

The Boyongan and Bayugo porphyry copper-gold deposits are part of a belt of gold-rich copper deposits in the Surigao district of northeast Mindanao, Philippines. The detailed age relationships described in this study provide insight into the geologically short life cycles that characterize porphyry formation in dynamic arc environments. Since their late Pliocene emplacement (2.3-2.1 Ma; SHRIMP [sensitive highresolution ion microprobe] U-Pb zircon dating) at depths of 1.2-2.0 km, these deposits were exhumed, deeply weathered, and buried. Weathering of these deposits led to the development of the world's deepest known porphyry oxidation profile (600 m thick) at Boyongan, and a modest (30-70 m) oxidation profile at adjacent Bayugo. This earlymiddle Pleistocene supergene event followed a period of rapid uplift and exhumation in northeast Mindanao (2.5 km/Ma; [U-Th]/He apatite age-elevation spectrum). Subsequent rapid subsidence (≥0.34 km/Ma; radiocarbon age-elevation spectrum) and burial of these deposits are attributed to a mid-Pleistocene shift from transpressional tectonics to the present-day transtensional setting in northeast Mindanao. During this period, debris flows, volcanic material, and fluviolacustrine sediments accumulating in the actively extending Mainit graben covered the weathered deposits, preserving the supergene profiles beneath 50-500 m of cover. This detailed geochronological study documents the geologically short (<2.3 Ma) time scales over which these major intrusion-centered mineral deposits evolved from emplacement, exhumation, deep oxidation, and burial, highlighting the dynamism of tectonic processes in environments such as the Philippine Mobile Belt.

Original languageEnglish (US)
Pages (from-to)471-474
Number of pages4
JournalGeology
Volume40
Issue number5
DOIs
StatePublished - May 2012
Externally publishedYes

Fingerprint

porphyry
graben
life cycle
gold
copper
oxidation
exhumation
emplacement
Pleistocene
tectonics
mobile belt
ion microprobe
mineral deposit
debris flow
apatite
Pliocene
zircon
subsidence
weathering
uplift

ASJC Scopus subject areas

  • Geology

Cite this

From crucible to graben in 2.3 Ma : A high-resolution geochronological study of porphyry life cycles, boyongan-bayugo copper-gold deposits, Philippines. / Braxton, David P.; Cooke, David R.; Dunlap, Jim; Norman, Marc; Reiners, Peter W; Stein, Holly; Waters, Patrick.

In: Geology, Vol. 40, No. 5, 05.2012, p. 471-474.

Research output: Contribution to journalArticle

Braxton, David P. ; Cooke, David R. ; Dunlap, Jim ; Norman, Marc ; Reiners, Peter W ; Stein, Holly ; Waters, Patrick. / From crucible to graben in 2.3 Ma : A high-resolution geochronological study of porphyry life cycles, boyongan-bayugo copper-gold deposits, Philippines. In: Geology. 2012 ; Vol. 40, No. 5. pp. 471-474.
@article{53e7ed66f1db49b0b72868f541bce48e,
title = "From crucible to graben in 2.3 Ma: A high-resolution geochronological study of porphyry life cycles, boyongan-bayugo copper-gold deposits, Philippines",
abstract = "The Boyongan and Bayugo porphyry copper-gold deposits are part of a belt of gold-rich copper deposits in the Surigao district of northeast Mindanao, Philippines. The detailed age relationships described in this study provide insight into the geologically short life cycles that characterize porphyry formation in dynamic arc environments. Since their late Pliocene emplacement (2.3-2.1 Ma; SHRIMP [sensitive highresolution ion microprobe] U-Pb zircon dating) at depths of 1.2-2.0 km, these deposits were exhumed, deeply weathered, and buried. Weathering of these deposits led to the development of the world's deepest known porphyry oxidation profile (600 m thick) at Boyongan, and a modest (30-70 m) oxidation profile at adjacent Bayugo. This earlymiddle Pleistocene supergene event followed a period of rapid uplift and exhumation in northeast Mindanao (2.5 km/Ma; [U-Th]/He apatite age-elevation spectrum). Subsequent rapid subsidence (≥0.34 km/Ma; radiocarbon age-elevation spectrum) and burial of these deposits are attributed to a mid-Pleistocene shift from transpressional tectonics to the present-day transtensional setting in northeast Mindanao. During this period, debris flows, volcanic material, and fluviolacustrine sediments accumulating in the actively extending Mainit graben covered the weathered deposits, preserving the supergene profiles beneath 50-500 m of cover. This detailed geochronological study documents the geologically short (<2.3 Ma) time scales over which these major intrusion-centered mineral deposits evolved from emplacement, exhumation, deep oxidation, and burial, highlighting the dynamism of tectonic processes in environments such as the Philippine Mobile Belt.",
author = "Braxton, {David P.} and Cooke, {David R.} and Jim Dunlap and Marc Norman and Reiners, {Peter W} and Holly Stein and Patrick Waters",
year = "2012",
month = "5",
doi = "10.1130/G33125.1",
language = "English (US)",
volume = "40",
pages = "471--474",
journal = "Geology",
issn = "0091-7613",
publisher = "Geological Society of America",
number = "5",

}

TY - JOUR

T1 - From crucible to graben in 2.3 Ma

T2 - A high-resolution geochronological study of porphyry life cycles, boyongan-bayugo copper-gold deposits, Philippines

AU - Braxton, David P.

AU - Cooke, David R.

AU - Dunlap, Jim

AU - Norman, Marc

AU - Reiners, Peter W

AU - Stein, Holly

AU - Waters, Patrick

PY - 2012/5

Y1 - 2012/5

N2 - The Boyongan and Bayugo porphyry copper-gold deposits are part of a belt of gold-rich copper deposits in the Surigao district of northeast Mindanao, Philippines. The detailed age relationships described in this study provide insight into the geologically short life cycles that characterize porphyry formation in dynamic arc environments. Since their late Pliocene emplacement (2.3-2.1 Ma; SHRIMP [sensitive highresolution ion microprobe] U-Pb zircon dating) at depths of 1.2-2.0 km, these deposits were exhumed, deeply weathered, and buried. Weathering of these deposits led to the development of the world's deepest known porphyry oxidation profile (600 m thick) at Boyongan, and a modest (30-70 m) oxidation profile at adjacent Bayugo. This earlymiddle Pleistocene supergene event followed a period of rapid uplift and exhumation in northeast Mindanao (2.5 km/Ma; [U-Th]/He apatite age-elevation spectrum). Subsequent rapid subsidence (≥0.34 km/Ma; radiocarbon age-elevation spectrum) and burial of these deposits are attributed to a mid-Pleistocene shift from transpressional tectonics to the present-day transtensional setting in northeast Mindanao. During this period, debris flows, volcanic material, and fluviolacustrine sediments accumulating in the actively extending Mainit graben covered the weathered deposits, preserving the supergene profiles beneath 50-500 m of cover. This detailed geochronological study documents the geologically short (<2.3 Ma) time scales over which these major intrusion-centered mineral deposits evolved from emplacement, exhumation, deep oxidation, and burial, highlighting the dynamism of tectonic processes in environments such as the Philippine Mobile Belt.

AB - The Boyongan and Bayugo porphyry copper-gold deposits are part of a belt of gold-rich copper deposits in the Surigao district of northeast Mindanao, Philippines. The detailed age relationships described in this study provide insight into the geologically short life cycles that characterize porphyry formation in dynamic arc environments. Since their late Pliocene emplacement (2.3-2.1 Ma; SHRIMP [sensitive highresolution ion microprobe] U-Pb zircon dating) at depths of 1.2-2.0 km, these deposits were exhumed, deeply weathered, and buried. Weathering of these deposits led to the development of the world's deepest known porphyry oxidation profile (600 m thick) at Boyongan, and a modest (30-70 m) oxidation profile at adjacent Bayugo. This earlymiddle Pleistocene supergene event followed a period of rapid uplift and exhumation in northeast Mindanao (2.5 km/Ma; [U-Th]/He apatite age-elevation spectrum). Subsequent rapid subsidence (≥0.34 km/Ma; radiocarbon age-elevation spectrum) and burial of these deposits are attributed to a mid-Pleistocene shift from transpressional tectonics to the present-day transtensional setting in northeast Mindanao. During this period, debris flows, volcanic material, and fluviolacustrine sediments accumulating in the actively extending Mainit graben covered the weathered deposits, preserving the supergene profiles beneath 50-500 m of cover. This detailed geochronological study documents the geologically short (<2.3 Ma) time scales over which these major intrusion-centered mineral deposits evolved from emplacement, exhumation, deep oxidation, and burial, highlighting the dynamism of tectonic processes in environments such as the Philippine Mobile Belt.

UR - http://www.scopus.com/inward/record.url?scp=84861375153&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84861375153&partnerID=8YFLogxK

U2 - 10.1130/G33125.1

DO - 10.1130/G33125.1

M3 - Article

AN - SCOPUS:84861375153

VL - 40

SP - 471

EP - 474

JO - Geology

JF - Geology

SN - 0091-7613

IS - 5

ER -