Geology and Mineral Resources of Paraguay A Reconnaissance

110 GEOLOGY AND MINERAL RESOURCES OF PARAGUAYPageSanta Rosa well, fossils from___...________....__......._____. 74record of._____..__-_..____.__..___._...._____._ 70-71Sapucal, phonolite from ____________________________.. 37,47Schist. See Metamorphic rocks.Scoria, of Acahay caldera... --------___.._.__________..____ 38-39Seco, Arroyo, mica deposits near____________________________ 89Sedimentary rocks, of eastern Paraguay.....____._____________ 50-66Serra Geral lava, age_________..______________________ 28chemical analyses of__.._-_._..._____.______..._._.... 35description-------______...___________..__-____________ 26-27erosion of. _--.._ ...._.....______._.__...__ 28exposures..------- -... -._____.______ ._________. 28extent..--.._.--_-_-_.___________._._._._________________._. 26geomorphic character.,origin___._______.source of name ....stratigraphic relations,structure sections ...._______________.___.___._...._._._____._____. 26._-__.__________._._..._......_._______.___... 26._____________________________._.__........_.. 26.-_-_-_.________________________._....._._._.. 2828Shale, in the Caacupe series._______ _________._____.._____ 56-57of the Itacurubi series__... ...____ ____________._____ 59-61of Tubarao series.._________._______________________ 62-63weathered... ___ _ ___________ ____ _ 81Shonkinite, analyses of__._ . _____________________ 35,47,50description of samples.-. _ -__________.....___________ 45,46Siderite concretions_ _. ....________________._..... 93Silurian system, sedimentary rocks________...______________. 52-59Silver.. --._ ... . .. ._-... -................... 84Soils of Paraguay, by Pedro Tirado Sulsona.. ________._________ 101Southeastern Paraguay, igneous rocks._________________________ 15-19Precambrian rocks_.._____..._..__..____________ 13-15quartzite in ________________________ 13Spectrographic analyses, of alkalic rocks_________.____________. 50of Precambrian rocks___...........___...._....._._________. 24of Serra Geral lavas_______...._______________________ 35Stone ... . . ..... 11,16,34,92-93,96-97Structure, anticline between Rio Apa and San Juan Bautista_______________ 75faults .._.______-______________._.____....._____.__________. 63,76general relations _.. .....________.__.._._________._____ 75Gran Chaco basin. .- 76joints..___-.__- . . . 52,78,80Ypacarai depression-_----___-_----._____________________.____._________.. 76Subsurface rocks, in the Gran Ohaco__________...__________.. 69-73Sulfur...-_ 60,93Swampy lands___...____-.-.______________...___.. 8-9,62Syenitic rock, of Pao de Acucar, Brazil_________.____________ 36-37,69Tabapy. See Roque Gonzalez de Santa Cruz.Tacumbu, Cerro _- . _. 33,35,83,99Tarrant, L. N., density analyses by______....__...____________ 23,35,47Teju-cuarfi, Arroyo, fossils from._.__________________________ 67Temperature-.__ ._______________________.__... 7-8Tertiary system, sedimentary deposits..-.-____..._______________ 66-67Tillite, in rocks of Tubarao series.________________._______ 22,24,62Tin - . . -- . 94Tirado S., Pedro, Soils of Paraguay..... _. . ...........__ ... 101Tobati, clay deposits at_________________________________ 81deposits of ocher.________________________________ 56,89-90exposures of sandstone at_ - _________________ __ 55-56, 57Topography____________________________________.._._ 6Transportation.------______---_-__--_-..__.________._______.__._.___________. 9-10Tres Hermanos hills, rocks of.-..._-_____._.__._.__...____ 21-22Triassic system, igneous rocks.._...______-..._._______..._ 26-34sedimentary rocks of._______________...._________________ 65-66See also Misiones sandstone.PageTrinidad, fossils from__________________________________ 67sedimentary rocks near__________ _ ______.-.______ 65-66Trumbull, Lois D., chemical analyses by..___________________ 23,35,47Tubarao series, correlation ___ __ __ 63description-.._______.__________...________.______ 62-63exposures-...-_.____...-_. -___ .-._________. 62fossil 62tllliteln.... - . ... . 22,62Tungsten__._______-_______ __ -___ ________.__ 94Union Oil Company, well records._.________.___.---.________. 69-74Upper shale and sandstone unit of Caacupfi series ___ 56-58Vallemi cement plant._________.___________... ______ 79,87,98Vargas Pena clay pit.--_. - .- - 54-55,57,59,76,81Vargas Pena tile plant.____-----_. .. ..__ 80Vegetation..______-_____-____-_-__-__. .._______ 8-9Villa Florida, copper deposit near.._____________.____..._____ 82,90Precambrian rocks near.---- . - ___________ _ 13-15,23Villa Hayes, outcrops of red sandstone near... ___-_-___ _ ___-_-_ ______ 68-69Villarrica, mica porphyry from-----...----.---------- __________________ 37-38rocks of Tubarao series near__________._-_.___ . _________ 62Villarrica, Sierra. See Ybyturuzu, Sierra.Villeta, fossils found near _ _.. 67Volcanic rocks.. . ...- .. ._ _.-_ ________________ 12WWater resources, eastern Paraguay___________-___-_---_-_-_-_-_--.-._.______ 99in the Gran Chaeo_____. _______.____. _____ _____ _ 99-101possibilities for developing_-..._-..___..._----- . ...___ 98-99Well records, interpretation. _______ __.. .... ____________________ 74of wells in the Gran Chaco....._ ... . .__ ___ 69-74Yaguaron, granite near-..-..- -... __-_-_-___.___ ___________ _ __ 19Misiones sandstone at_-__- ___ _____ _. -___ ______ ___ . 65, 76manganese deposit_.____--__.._ _____________________________________ 88Yahape, Cerro_--_-_- ______________ ._.. _______ _ . _. 18Ybycul, early iron industry at _____ _ ________ ___________ ___.. 85Ybytymi, nepheline basalt at ...- __ __ _________ . __ 37Ybytymi, Cerro-.-----------.------------------------------------------------ 37Ybyturuzu, Sierra, olivine diabase on_-.._. _______________ _...... __ 32,35Yegros, clay deposits at_ . . . - -- 81Yhaguy, Arroyo, iron sulfide minerals near.. _ __________ __ _____ 93Yhu, clay deposits at 66,81Ypacarai, alkalic rocks near ______________ _ _ ___________ ____ 36,40-43analysis of rocks from. ____________ _.__ _. _ _________ 23arkosic sandstone near ___________________ ________________ -__ ____ 54-55Misiones sandstone near_______ ________ ___ ____ _______ ... 65paving stone from..-._________ __ _ ________________ ..____ 92tile industry at_-------- - ----- ___________ ___ 80Ypacarai, Lago.____ ___ _ ... . - 7, 53, 76Ypacarai depression.__________ __________ ______ ________________ 19, 76Ypacarai quarry._________ __________ _ ___________ ________ .. 40Ypane, fossils found near...... . ______ _ 67Ypoa, Lago.__-._. -... _ __-_____------------_ -... ._____. 7Yta-cue mine__ _ . . . - --- 86Yuty lodestone deposit._______.____- ___.__ - 86-87Zanji Moroti, analyses of rocks from ___ _ _- 23Precambrian rocks at ----- ------- - 21o