4
- Ordovician system-Continued page
- Alsate shale 31
- General features 31
- Local features 31
- Marathon anticlinorium 31
- Dagger Flat anticlinorium 31
- Relation of Marathon and Dagger Flat areas 31
- Microscopic character 31
- Fossils and age 32
- Stratigraphic relations 32
- Fort Peña formation 32
- General features 32
- Local features 32
- Marathon anticlinorium 32
- Dagger Flat anticlinorium 33
- Jones ranch area 33
- Microscopic character 33
- Fossils and age 33
- Stratigraphic relations 34
- Woods Hollow shale 34
- General features 34
- Local features 34
- Woods Hollow Mountains 34
- Simpson Springs and East Bourland Mountains 35
- Other localities 35
- Microscopic character 35
- Fossils and age 35
- Stratigraphic relations 36
- Maravillas chert 36
- General features 36
- Local features 37
- Marathon anticlinorium 37
- Monument Spring and Rock House Gap 38
- Dagger Flat anticlinorium 39
- Southeastern exposures 39
- Microscopic and chemical character 39
- Fossils and age 41
- Stratigraphic relations 42
- General problems of Ordovician stratigraphy 42
- Correlations and regional relations 42
- General correlations 42
- Correlations in trans-Pecos Texas 43
- Correlations with central Texas 43
- Correlations with Oklahoma and Arkansas 43
- Conditions of deposition 43
- Faunal facies of the Marathon Ordovician 43
- Source of the sediments 44
- Depth of water during deposition 45
- Origin of the chert beds 46
- Origin of the boulder beds 46
- Correlations and regional relations 42
- Alsate shale 31
- Devonian (?) system 47
- Caballos novaculite 47
- General features 47
- Local features 48
- Northwestern exposures (facies 1) 48
- Marathon anticlinorium (facies 2) 49
- Dagger Flat anticlinorium (facies 3 and 4) 50
- Southeastern exposures 51
- Microscopic and chemical character 51
- Novaculite 51
- Banded chert 51
- Sandstone 52
- Fossils and age 52
- Stratigraphic relations 52
- Caballos novaculite 47