PREFACE 



The present volume is the second of a series of reports dealing with the 

 systematic geology and paleontology of Maryland. The first of this series 

 was confined to the Eocene while the present volume comprises a discus- 

 sion of the next yonnger geological horizon known as the Miocene. 

 Several other reports are in preparation, two of which are already practi- 

 cally completed. The Pliocene-Pleistocene report is ready for the press, 

 and the Devonian for which the field observations are finished is largely 

 in manuscript form. It is not the intention to issue these volumes in 

 geological sequence as each forms a unit in itself. The following reports 

 are finally contemplated : 



[^ Pliocejie-Pleistocene 

 Cenozoic -| Miocene 

 I Eocene 



Mesozoic 



Paleozoic 



Jurassic-Cretaceous 

 Triassic 



Carboniferous-Permian 



Devonian 



Silurian 



Cambrian-Ordovician 



Crystalline Eocks (Archean-Silurian) 



Maryland contains a remarkably complete sequence of geological 

 formations representing nearly every horizon from the Archean to the 

 Pleistocene although the deposits vary greatly in thickness and in the 

 completeness of the faunas and floras which they contain. Two of the 

 divisions, the Crystalline Eocks and the Triassic, are nearly destitute of 

 organic remains. The other seven divisions, however, contain rich faunas 



