BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA STRATIGRAPHY, STRUCTURE, AND PETROLOGY OF THE MT. CUBE AREA, NEW HAMPSHIRE BY JARVIS B. HADLEY CONTENTS Page Abstract.................................................................................................................................. 115 Introduction.......................................................................................................................... 115 Acknowledgments................................................................................................................. 117 Stratified rocks....................................................................................................................... 117 General statement........................................................................................................ 117 Orfordville formation................................................................................................... 119 General statement................................................................................................ 119 Post Pond volcanic member............................................................................... 119 Black schist............................................................................................................ 121 Hardy Hill qu&rtzite............................................................................................ 122 Sunday Mountain volcanic member................................................................. 123 Low-grade rocks of the Orfordville formation................................................. 123 Thickness............................................................................................................... 123 Age.......................................................................................................................... 124 Albee formation............................................................................................................ 124 General statement................................................................................................ 124 Lithology and petrography................................................................................. 124 Piermont member................................................................................................ 126 Thickness............................................................................................................... 126 Age.......................................................................................................................... 127 Ammonoosuc volcanics................................................................................................ 127 Correlation............................................................................................................. 127 Lithology and petrography................................................................................. 127 Thickness............................................................................................................... 128 Age......................................................................................................................... 128 Clough formation.......................................................................................................... 129 Correlation............................................................................................................. 129 Lithology................................................................................................................ 129 Thickness............................................................................................................... 129 Age.......................................................................................................................... 130 Fitch formation............................................................................................................. 130 Correlation............................................................................................................. 130 Lithology................................................................................................................ 131 Thickness............................................................................................................... 131 Age.......................................................................................................................... 132 Littleton formation...................................................................................................... 132 Correlation............................................................................................................. 132 Lithology................................................................................................................ 133 Thickness............................................................................................................... 134 Age...................................................................................................................... 134 (113) Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/53/1/113/3431124/BUL53_1-0113.pdf by guest on 01 October 2021 114 J. B. HADLEY----MT. CUBE AREA, NEW HAMPSHIRE Page Plutonic and hypabyssal igneous rocks............................................................................ 134 General statement........................................................................................................ 134 Fairlee quartz monzonite............................................................................................ 136 Oliverian magma series................................................................................................ 136 General statement................................................................................................ 136 Baker Pond gneiss................................................................................................ 137 Smarts Mountain granodiorite........................................................................... 137 Mascoma group.................................................................................................... 137 Age of the Oliverian magma series.................................................................... 143 New Hampshire magma series................................................................................... 143 General statement................................................................................................ 143 Bethlehem gneiss.................................................................................................. 143 Haverhill granodiorite......................................................................................... 148 Pegmatite dikes and sills.................................................................................... 148 Metabasalt dikes and sills older than the metamorphism.................................... 149 General statement................................................................................................ 149 Lithology and petrography................................................................................. 149 Age.......................................................................................................................... 151 Femic dikes younger than the metamorphism....................................................... 151 Structure................................................................................................................................ 152 General statement........................................................................................................ 152 Piermont anticline........................................................................................................ 154 Ammonoosuc thrust..................................................................................................... 154 Salmon Hole Brook syncline...................................................................................... 156 General features................................................................................................... 156 Subsidiary folds.................................................................................................... 157 Schistosity and cleavage...................................................................................... 157 Stocks of Haverhill granodiorite........................................................................ 158 Northey Hill thrust...................................................................................................... 158 Bronson Hill anticline.................................................................................................. 159 General statement................................................................................................ 159 Domes associated with Oliverian magma series............................................. 159 Mode of intrusion of Oliverian magma series................................................. 162 Subsidiary folds and thrust faults..................................................................... 164 Indian Pond and Mt. Clough plutons............................................................. 164 Metamorphism...................................................................................................................... 166 General statement.......................................................................................................